Is 70,000 barrels a day a possibility for the oil spill?
Posted by Gail the Actuary on May 14, 2010 - 10:15am
NPR is now reporting that the oil spill could be 70,000 barrels of oil a day, which is considerably greater than the estimate of 5,000 barrels per day currently being reported. What is the view of Oil Drum readers regarding the likelihood of the higher estimate being accurate? According to the story:
The analysis was conducted by Steve Werely, an associate professor at Purdue University, using a technique called particle image velocimetry. Harris tells Michele Norris that the method is accurate to a degree of plus or minus 20 percent. That means the flow could range between 56,000 barrels a day and 84,000 barrels a day.
Another analysis by Eugene Chiang, a professor of astrophysics at the University of California, Berkeley, calculated the rate of flow to be between 20,000 barrels a day and 100,000 barrels a day.
We also know that the oil tends to mix with water to produce a "chocolate mousse" mixture. The controlled flow rates of wells drilled by BP's at its Thunder Horse platform (another deep water platform) seemed to produce oil of 40,000 to 50,000 barrels a day, when the wells were in maximum production based on the graphs below from this post:
Natural gas production is in addition to the oil production shown on these graphs, bringing the barrel of oil equivalents up somewhat (10% - 15%) from this level. This Deepwater Horizon well is different, so this may not have particular relevance.
What are readers views on the likelihood of higher oil spill estimate being correct?
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When I saw the first images of the leak I remember thinking, "That looks a lot bigger than the quarter-inch hole posited at The Oil Drum."
I know it's in this thread -- but can someone please remind me -- what is the inside diameter of the pipe from which all this oil is escaping -- I've read 6 3/4 inches -- one rig worker in an mp3 interview said 12 3/4 inches -- an NPR story yesterday reportedly implied the pipe was actually 6 feet across -- yikes !!
Video images are tough to scale. Can the worlds oceans actually be destroyed through a 6 3/4 inch pipe?
As posted downthread, I was listening to NPR this morning (Friday) and heard someone say that the riser pictured is only the casing, and that the actual oil/gas flow runs through a 9" pipe inside the riser.
Have been seeing consistent reports that the interior of the yellow riser from which the oil is flowing is 20 inches. http://www.npr.org/templates/story/story.php?storyId=126809525&ps=cprs
or 53 cm. O.D. http://www.cbc.ca/world/story/2010/05/14/gulf-of-mexico-spill-0514.html
Even with a 9" drill pipe coming out of it that would leave ample room for inserting a 15cm. (6 in.) pipe-in-a-pipe diversion attempt.
The end of that inside drill pipe had been capped earlier leaving the 2 leaks of oil, one out of the riser casing outside the drill pipe (video) and the other at the BOP.
the 20 " looks about right if you look at the halliburton wellbore diagram posted yesterday.
It may be (although no one has said AFAIK) that the leak is flowing through the valve (BOP) at the wellhead within a 7" drill pipe. This pipe runs on out through the larger 21" riser pipe and out some distance beyond it's broken end. Most of the flow is out the broken end of the riser as can be observed in the videos now posted online. Early on the drill pipe was cut off and capped to prevent oil from leaking there. It is a pretty good bet that the drill pipe is badly cracked or broken off within the riser near or at the BOP where the riser has a pretty dramatic kink - thus the flow we see is traveling mostly through the riser until it exits at the broken end.
Seeing what happens to an annular in a very similar kind of situation, and given the internal BOP X-ray pressure readings estimate of 8,000-9,000 given by TinFoilHatGuy it seems if that was converted to total static pressure those annulars would have been hard pressed to hold.
After they were opened I'm figuring they were well on their way to begining to look like the pic I linked above from gcaptain and Undertow. So the well has to be leaking from both the inner drill pipe and the riser housing from how I understand the setup, b/c if the shear had closed successfully AFAIK all would be moot, and since a lot of that cutting and shredding is outer of the string some of the leak begins in the outer riser portion of the BOP.
This leaves us with the question you (and I and all lot of others) have been wondering; Is this drill string broken, eroded, split just within or somewhere after the BOP inside the riser where it cannot be seen? Perhaps the X-ray pressure drop estimate within the BOP given by TinFoilHatGuy is of value here. 8-9k underneath 450psi above seawater outside.
Tempting to say that almost all of the restriction exists from the BOP to the outer riser, that the flowrate was diminished a bunch when the cap was placed on leak #1 due to sealing the drillstring, and that the junk shot basically has to plug the shear ram area or to simply plug the annulus scoured out by the opening of the annular and disintegration caused by the blowout.
Tempting except for the fact that BP was quoted repeatedly as saying they didn't expect capping leak #1 to significantly diminish the overall output by much. So far that call seems spot on.
Source please
Don't have a cite, can't remember where I saw it (may have been a blog, don't think it was NPR), but I did read a story or a post that said the pipe was 5 (as I recall--not 6) feet wide.
No leak.
1,000 barrels
5,000 barrels
might be 100,000 barrels
70,000 barrels
If I have a pipe of given size and I know the flow pressure and the specific gravity and temperature of the outflow. Should I not be able to calculate a flow rate? What am I missing?
I watched a video of the purported failed casing spewing petroleum and methane gas -- and wondered of the same.
This? It's not the one the calculation is based upon.
http://www.youtube.com/watch?v=2JTM2QyAfCI
But *do* you know the pressure?
Yes. Where the video is taken the pressure is 2240 PSI.
We're not talking pressure upstream of the blowout preventer here, we're talking pressure after it's gone through the pressure drop at the leak in the BOP.
The video permits us to guesstimate volumetric flow by (1) seeing the velocity at which it's expelled from the drill pipe, (2) knowing the interior diameter of the drill pipe that the flow is coming from and (3) assuming that it's high-Re (turbulent) rather than laminar flow in the drill pipe.
Q [m^3/s]] = v [m/s] * π (D/2)^2 [m^2]
where Q is volumetric flow, v is velocity, and D is the pipe interior diameter.
I should have said pressure *gradient*. Tinfoilhatguy seems to be suggesting that one could calculate the flow rate from first principles based on the forces acting on it. To do that, you need the pressure upstream of the BOP ... or whatever choke point is controlling the flow rate.
The calculation you're proposing is the same as what the scientists in the NPR article did, and which I have done elsewhere in this thread.
The pressure upstream of the BOP is at least 8,200 PSI above the 2240 PSI at the seabed, and probably higher due to what Rockman calls "geopressure." That pressure is dropped across an orifice of unknown area formed by damage or blockage within the BOP. Once you calculate the flow based on the flow velocity from the video, you can guesstimate what the area of the orifice is. Increasing flow(remember, the flow was thought to be near zero for the first few days after the disaster began) means that that orifice is being eroded and is increasing in area.
GOR
In an earlier thread I did a poor man's particle imaging velocimetry by eyeballing the video frame-by-frame, and came up with about 16,000 BPD, give or take a factor of 2.
After reading a little more, I realize I underestimated the diameter of the riser pipe, which would bring my calculation up to 30,000 BPD or so -- again, give or take a factor of two.
This is lower than NPR's scientists' estimates, but every calculation I've seen agrees that the true flow rate is much more than 5000 bpd.
One way to look at it: for a flow rate of 5000 bpd, the oil would have to be coming out of the riser at about 25 cm/sec, roughly the speed of a tortoise in a hurry. Look at this video. Does that look like 25 cm/sec to you?
So the report of telemetry link to a ROV was not accurate?
Where's the math on the fluid flow and what are you assuming for the GOR?
Math details:
Pipe diameter is roughly 16 inches (0.4 meters), estimated using this photo with 12-inch wrench for scale.
From video, looking at motion of black stuff (oil) *only* and ignoring the much faster white stuff (gas), black stuff goes 1 pipe diameter in about 0.4 seconds, giving a speed of about 1 m/s.
Notice flow out of pipe is separated: gas in the top half, oil in the lower half. To get oil volume, multiply area of lower half of pipe times oil velocity:
0.5 * pi * (.2 m)^2 * 1 m/s = 0.06 m^3/s = 30,000 barrels/day
Possible errors of 50% or so in oil velocity, cross-sectional area of oil flow, and in the assumption that the black stuff is 100% oil, for a cumulative factor of 2 uncertainty.
0.06 m^3/s translates into 5184 bbls/day according to the conversion I have
1 m3 = 6.2898105697751 bbl
Edit: missed the conversion, however given the 2 phase flow occuring I don't believe your equation is enough.
how 'bout using the garden hose method ?
how many garden hoses does this look like ?
multiply garden hose result x 171 bpd to 342 x bpd, corresponding to 5 gpm for inner city garden hoses to 10 gpm for suburban garden hoses, respectively(i'm not making this up, i have actually measured these rates). of course, size matters in all aspects of hoses.
0.06 m3/s
60*60*24=86400 s in a day
thus 0.06*86400=5184 m3/day
And thus 5184*6.29=32607 barrels a day.
Ouch!
i don't have a definitive link, but every resource i've checked listed the riser's diameter as 21". don't know if that is inside or outside diameter. shouldn't you run your calcs based on the actual size of the riser as opposed to a guesstimate using a monkey wrench as a guide?
Most pipe is sized in approximate OD for that large diameter, but I would say that it is nominal 22" pipe but measures 21" on the ID (0.500" wall). Not likely to have large pipe sized in odd numbered OD's.
One photo showed a 12" wrench near pipe and someone guessed pipe to be 16", but 12" wrench is usually a little longer than 12", plus end of pipe may be slightly deformed to look smaller.
My guess on flow out of riser unobstruted is 16,000 bbl per day or about one cubic foot per second. If pipe is 21" ID and half of pipe is ejecting oil (balance of volume is gas) then cross sectional area of oil is 173 in*2, and 144 in*2 for each cubic foot, as oil looks to be moving at 1.00 ft per second or 0.33 meters per second.
Note that at 5000' depth if half the volume out of pipe is gas, then at surface of the GOM the gas would have 340 times the volume of the oil, or about 1909 cu ft of gas for each barrel of oil. BP is losing $150,000 per day in escaping gas, $1,200,000 in escaping oil, or about $500 million per year in total lost energy after they kill the well.
my hopelessly out of date halliburton cementing tables lists 20" o.d. k-55 133 lb/ft casing with an i.d. of 18.73" but only has a collapse resistance of 1500 psi. totally inadequate for 2350 static pressure at 5000' sea water depth. not much help.
someone more ambitious than i can probably find a current version of halliburton cementing tables online and free. sometimes refered to as the "little red book".
Looking at the video, I see a big decrease in gas flow over the duration of the video clip. A lot of gas at beginning and almost none at the end. The flow is not steady over the elapsed time of the video. I wonder how representative the clip is of the average of an hour or so. Also flow does not seem to be uniform across the outlet of the pipe. More flow from top. Almost none from bottom. It might even be water lying still along bottom. What one uses for the cross sectional area of the flow is surely less than the area of the pipe. But it is very hard to pick a number that one can believe in. 50% errors are a good guess, IMHO.
Answer to Gail's question about how accurate it is: Not very accurate, but a damn site closer to the truth than 5000 bpd.
It looks to me like the flow is coming out of a small hole constriction several pipe diameters upstream of the field of view. It is spreading out from that hole and also rising within the pipe due to bouyancy.
It is hard to get accuracy, but one can draw some very valuable conclusions even from a very inacurate measurement. This is not good. And it doesn't need to be exagerated at all to make a case for serious reconsideration of BAU.
ThunderHorse reports the managed flow output from five (5) wells, I think. This is one well, but unrestricted flow. It could be more, or less, than ThunderHorse.
I had been thinking that if the flow had increased from 1000 to 5000 bpd in first week, it was very puzzling why it stopped increasing and stayed at 5000. Now I don't have to worry about explaining that.
Is this the only source of the leak? I thought there were at least three places where the oil was leaking from. Am I remembering wrong?
There are two points now leaking. There were 3, but one has been capped.
Using your method on the first part of the video where the stratified flow occurs and eyeballing the velocity I got about 33,000 bpd. And the annular flow that follows it is likely to be an even higher flowrate. For sure that flow is nowhere near 5,000 bpd.
And BP obviously has known this from day one.
Are you accounting for a change in gas solution from say 2,500 scf per barrel to say 1,000 scf per barrel in your analysis?? And the velocity component that adds to the effluent?
And a formation volume factor at discharge of 1.73 Reservoir barrels per stock tank barrel.
FF
From the video the only thing you can determine is the rough flow of oil at the ocean pressure at that depth. Say about 2500 psi. That flow would be almost all oil, which is why I used the stratified flow part of the video. 33,000 bpd would be a conservative number for that. How much gas would evolve in the oil from 2500 psi to atmospheric you'd probably know better than me.
That flow would be almost all oil
What is your basis for this statement?? Do you know the bubble point of the reservoir. Tengiz is about at this depth and it is around 3,660 psi. With the high GOR, I would expect a high bubble point.
Still there is a significant "explosion" of gas being liberated from this oil on "flash vaporization" from the pressure inside to outside the pipe. This energy is not due to Bernoulli's equation or nozzle flow and I want to know how it is being accounted for in the calculations.
Edit for Tengiz bubble point
FF
Here is Standing's Correlation for the Solution Gas Oil Ratio versus pressure from 15 to 13015 psi for a 3,000 GOR bubble point oil at 250 degrees Fahrenheit reservoir temperature. It comes from my reservoir simulator. The calculated bubble point is 7,556 psia.
You guys are likely brilliant but way out of your expertise area.
http://img199.imageshack.us/img199/6496/standingscorrelation300.jpg
FF
FF - my one PVT class was a LOOONNNGGG time ago! Bubble point is the pressure where the soluble gas comes out of solution?
Is the implication here that a lot of the volume is solution gas coming out of solution and not 'flow from reservoir' per se?
Toller-
You are correct on all counts. The thermal (temperature) changes make this a 3 dimensional problem--- that curve needs to be a surface.
If you have every written reservoir simulation software to track through the bubble point, you never forget the mathematical difficulties/instabilities it creates.
and that is only for a black oil model, a compositional model, aside from being nearly worthless without a history match, would be more complex.
Was listening to NPR this morning and heard someone say that the riser pictured is only the casing, and that the actual oil/gas flow runs through a 9" pipe inside the riser.
Skytruth did a similar analysis based on coast guard observation of the slick. They came to 25 000 barrels a day. (http://blog.skytruth.org/). It is expected that half of light crude will evaporate after on day. This gave an estimate of the leak at the bottom at 50 000 barrels a day.
I'd bet my salary this leak wasn't north of 20,000 bbls/day. An unfrac'ed well with restricted flow through a partially closed BOP into open ocean when the Gulf's best frac'ed controlled wells can barely managed 50,000 bbls/day.
70,000 bbls/day are just laughable.
Some people just want this disaster to be worse than it already is to fuel their agenda.
I should not even worry about it. In the path, but what shows up, shows up.
"best frac'ed and controlled" means that they are presumably maintaining pressure control on the reservoir, and thus limiting flow.
Presumably, the particle velocity analysis data is reproduceable... I know some of the methods they are using, and they are pretty simple, solid stuff.
If you know the size of the cross section of the pipe, and the velocity of material coming out of the pipe, you can measure flux. Period, full stop.
The errors in the analysis are introduced via the following factors: losing track of a particle and over-estimating its velocity; turbulent flow increasing apparent velocity; and mis-measurement of distance from the flow itself, which will cause the velocity measurements to be improperly scaled.
How much is your salary? Because I would take that bet... that well is pumping out more than 20k bbl/day, easy. 20 thousand barrels a day is 580 gallons a minute... that's well within a reasonably good fire hose capacity, and looking at that video, that's what I see.
1000 gpm (water) can be forced through 2,500 feet of 5" fire hose with a pressure of 150 psi... I think the pressure is a bit higher in the reservoir, and the well bore is minimum 7 inches (probably more at this point).
Over estimating velocity - maybe
overestimating the amount of oil in the flow - definitely (most of the flow will be gas that disperses the oil making the oil look like a higher percentage)
I'm gonna maintain my upper limit.
The non industry people also need to google "oil formation volume factor" or Bo. It is the relative volume of oil at pressure divided by its volume after shrinkage (at atmospheric conditions). For a 3,000 GOR oil, it could be pushing 2.00. So all your at pressured flow estimates will be cut in half as gas continues to evolve at surface.
FF
I‘m not an oil guy but I doubt a factor of 2 here.
From the last kink/obstruction in the riser onward, the oil pressure will be pretty much equal to the water pressure. Plus any pressure differential necessary to push the fluid through the pipe. This differential should be rather small, compared to formation pressure at least.
Eyeballing the diagram you posted above, at 2500 psi, the gas remaining in solution is ~800 ft³/b. At least that‘s how I think the diagram should be interpreted.
I do not know what remaining "shrinkage factor" this would result in (1.2-1.3 maybe).
Of course temperature will be different (probably much lower than 250F, maybe even close to water temperature), and the time the gas has to separate might play a role too.
Assuming that 2200 ft³/b (under atmospheric pressure) has separated, and that the gas is compressed 160 fold, and a shrinkage factor as above, I get a gas to oil volumetric ratio of 2 to 1 (volume to volume, not ft³/b).
Consistent with what we see in the video.
Rainer
You got part the oil part of it but since the differential across the pipe leak is small then the bottomhole pressure is likely below the bubble point as is the near wellbore area.... so gas is being liberated continously from the bottom of the well to the top and in the near wellbore region of the reservoir.
Gas is breaking out in the near wellbore region due to this pressure reduction and the gas saturation exceeds the critical gas saturation so the relative permeability to gas is nonzero and free gas is flowing from the reservoir as well as the dissolved gas you are accounting for. The free gas will likely be a larger contributor. Muskat's Method is an ordinary differential equation solved by a fourth order Runge Kutta method to calculate gas saturation versus pressure in such a reservoir.
Good Luck.
FF
You still betting your salary on it?
Because I want to fix my roof and rewire the basement.
;p
While I'm dying to know what the real number is and hope BP can get a flow meter in the pipe they're inserting, I doubt we'll ever really know the real number.
But sure, my salary that will never be able to be claimed by anyone on the internet is hereby bet.
It's a bet!
You're unclaimable virtual salary vs my anonymous and unimpeachable credibility!
Sure thing.
But, more seriously:
The estimate of total fluid flow through the end of that pipe are probably close to accurate.
70 K is probably high, but 20 K is probably low.
Your point about percentage of oil vs gas is quite well taken.
What's the percentage, by volume, of gas vs oil in a freely flowing, newly produced reservoir? That's not even close to my area of knowledgeable discussion, but I am guessing that since a) it's (obviously) a gassy reservoir, and b) the gas is continuously expanding as it rises through the well and depressurizes, and c) gas in the oil is released as the oil rises in the well, that the percentage of gas is high.
What's a good guesstimate? 50%? 75%?
Say it's 75% gas, 25% oil by volume. If the total fluid flow is 50k barrels per day, and 75% of that fluid flow is actually gas, we're still talking 12,500 barrels of oil per day.
The question is, assuming your salary is higher than mine, are we betting my salary vs your salary, or are we betting your salary, full stop. Because I can't afford that, and I really do need to fix my roof.
All these big numbers are a little hard to picture. If the flow is 75% NG, and the flow is 10,000 barrels/day...uhhh..quick math, lots of assumptions...we're just shy of 1000 standard cubic feet per second of gas at the surface. Would that be detectable? Or does it get spread over many acres and then get lost in the chop?
is your upper limit for the total of both leaks? or just the one we've seen video of?
I would be betting on the total flow rate from the well.
over at latoc there is a poster who spent the last week out in the gom with the recovery effort. his information seems to confirm a minimum of 26,000 bbls/day, much more likely:
"I was out in it. Ten 300T vessels skimming AT the incident site - not further away - could not keep up with the oil release despite skimming 2-4000 bpd EACH! We weren't even close."
http://www.doomers.us/forum2/index.php/topic,67590.msg1037142.html#msg10...
on the permitting, bp said max flow was 160,000bpd, are you factoring in that information?
The barrels they are skimming are probably barrels of oil-water mixture--and the substantial majority of this mixture is probably water--so the amount of oil they are removing from the ocean is much lower than you are thinking.
he discusses that in another thread - "OK, good question, once the mix/or slurry comes into the holding tanks it's decanted, a procedure where they pump off the water just underneath the oil to get a higher concentration. We were getting somewhere around 85 to 95% product before pumping it to the barge."
I'm not hearing much about the toxic volatiles in the air. As these blow ashore, how can they not render the Gulf Coast uninhabitable?
EPA is monitoring volatiles, particulate matter, and H2S at several stations in Placquemines and St. Bernard parishes. They say that when wind is right, VOC (total volatile organic compounds) is high enough for some people to smell, but still safe. If someone wants to put the data into graphical form, here it is:
http://www.epa.gov/bpspill/air.html
The wind has been out of the south and southeast for several days here in New Orleans; I can't smell it, but several friends say that the air smells a lot like weak diesel fumes.
The supercritical pressure for methane is 673 psi, so above that pressure (and I estimate that at 5000 feet, the pressure exceeds 2000 psi - which is way above the critical pressure), methane is acting as a liquid, not a gas. So I would not place your bet based on that assumed factor.
Retsel
So the outflow density or temperature does not matter. I thought maybe if there was a gas component to it, but school was so long ago. Why can't they just telescope a hand held meter into the stream via ROV?
Any time BP felt like it they could use an ROV to stick a pitot tube into the oil jet and get a velocity profile. That would get them a within 5-10% of the flow rate.
Any time BP felt like it, they could release all sorts of info that would help independent analysis of this thing, even just longer film clips of the outflow. Instead, they prefer to claim that there is no way to determine the flow rate.
I am guessing that, if the flow rate is variable, they chose a clip that minimizes the flow rate.
BP themselves have admitted that the flow rate could be 60,000bbl/day, so I'm guessing that it is much higher than that.
It seems to me that if you want to make a calculation based on visual observation, you need the diameter of the pipe from which the flow emmanates. That it was constricted earlier should not matter. So, you look at the 21" pipe, measure velocity, and use the oil stream you have to get a BPD estimate.
I am not sufficiently mathey/graphey to extrapolate from this, but the comment earlier about it is only 9" and it went through the BOP seems irrelevant to me. Wat matters, again, is flow where it can be measured, from pipe that can be measured.
Many weeks ago (far too many, IMO) a figure of 52,000 BPD was bandied about, with no one denying. I would therefore place the actual flow at not less than 52,000.
Craig
I'll bet with Greq on this one.
You know the Bernoulli Detective Agency is really good if they can differentiate the fluid flow inside that pipe from the thermodynamic expansion of that gas crude oil mixture possibly going through the bubble point and a 150 degree temperature drop at the exit.
What component of the velocity is flow and what component is expansion and gas liberation??
FF
Is it possible because of the large temperature drop from (presumably)the BOP to the end of the pipe that some gasses are actually condensing back to liquid at depth?
Yes it is a mess
I'm sure you meant "fuel" as a pun, right?
Just curious, who are those people and what exactly would their agenda be?
As for the disaster, I was listening to some journalist on NPR yesterday, quite convincingly argue (not that I bought his arguments) that this spill really wasn't all that bad and that the Gulf would easily absorb the oil and nature would take its course and everything will be just fine and dandy.
For the record, your worst case scenario of 20,000 bbls/day, sounds pretty damn dire to me.
And while I'm not much of an expert, I do think that 70,000 bbls/day is probably a gross exaggeration, However I also think that neither the 20 or 70 thousand bbls/day means very much to the public at large.
Maybe the MSM should put this mess into perspective by just telling J6pk in terms they can relate to. How about, "The Sh!t has really hit the fan this time, folks, and while the turds aren't quite as big as they might have been, they stink about as bad as any we've ever smelled and if your livelihood depended of the Gulf waters you better get yourself a bigger paddle because the one you lost when you were just up sh!t's creek, probably wouldn't have cut it anyway! So, you might want to consider reassessing your agendas...
Good luck!
Good call.
I suppose there is the disturbing "scientific agenda" that should also concern us.
Isn't that all about finding out the truth? Scary prospect that.
http://suchabastard.files.wordpress.com/2008/08/shitcreek.jpg
Those are *BIG* paddles but have you seen the creek?!
That's why you need more than one!
A high pressure reservoir is normally "throttled" back in production quite a bit for several reasons, including stability of the reservoir rock (supposedly a major problem at Thunderhorse), potential water coning, economic processing equipment (don't size for a short lived maximum production) and more.
With continuing sand erosion for almost a month, there is every reason to believe that this well is producing more oil than it ever would as a BP production well.
Alan
Where in the f is the oil??
All the flow rates increase increase increase But I haven't seen a picture yet of a solid oil slick...
It reminds me of the difference between production and reserves in a deepwater discovery.
An article this morning says all the recovery efforts after separation have yeilded a whopping 1000 barrels.
FF
It was supposed to have hit the beach in Florida 3 weeks ago.
http://www.aolnews.com/nation/article/wheres-all-the-oil-and-wheres-it-g...
I suppose I could write an article about the general idea of dispersion?
Or could we have a discussion on this?
I get a feeling that people have all sorts of problems with this concept. For example, for all the carbon emissions that occur, people still complain about where it all goes, pointing to that the level in the atmosphere is only around 400 parts per million. By gOD, you can't even see that! That is what dispersion and diffusion and drift causes, an effect that results in a rise in the overall background, but not necessarily anything you can immediately see.
This in fact may also be the one physical law that will save the day. If material disperses enough and natural processes break down the oil and byproucts, we could eventually dodge a bullet.
An article would probably work, but it should be not too long, and include as much a possible in terms of practical implications. There is a danger in going over everyone's head. People do like an article on a topic as a backdrop for their discussions.
One thing people get in their heads is that somehow complexity plays a role in how material disperses.
Scientists can come up with all these sophisticated models with detailed finite element grids (going over peoples heads) when in reality all these models converge to the same thing and one can use fundamental entropic arguments to arrive at the same result.
A case in point is the path of a tracer solute through a porous material. This paper documented a case where they could change the simulation parameters wildly and come up with pretty much the same result:
Biogeochemical Models in the Environmental Sciences
I think it all boils down to the concept of entropy. I tried my hand at coming up with a fit to the same empirical curve they provided for soil water movement; and with a single maximum entropy-based equation got just as good agreement (see the blue curve).
The point is that all the complex calculations in the world are often pointless when you are dealing with a situation with a high degree of disorder. The situation simplifies enough that one can use universal approaches to describe the result.
I don't understand this idea of going over people's heads. Apparently lots of people are very impressed by linking to some study by scientists who use supercomputers and days of compute cycles to arrive at some conclusion, yet remain wary of someone else that comes up with the same result with minimal effort.
I will likely submit something but not dumb it down. Fearing that ideas will go over people's heads are what got us into these situations in the first place. Ignorance is a dangerous concept.
Another case in point is the entire atmospheric CO2 debate. We always genuflect to the climate scientists who wield either huge supercomputer runs or detailed theoretical math to justify their conclusions. Yet in the end, one can simply use logic and some probability concepts to arrive at the same conclusion. This is what I wrote about here:
http://mobjectivist.blogspot.com/2010/05/how-shock-model-analysis-relate...
I would like to put something together along these lines. I will decide whether to post it on my blog or on TOD when I finish. In my experience TOD has this huge wait time (often two weeks) on publishing posts by people not in the inner circle of TOD editors. I will get a day turnaround if I post it myself and then just place a link here.
Wait times vary. HIgh technical articles that have a lot of HTML issues can be delayed because of the HTML issues. Right now, we are running a lot of oil spill articles fairly quickly.
Oil can also spread so thinly on the surface of water to be barely visible. But people tend to believe that their eyeballs are high quality scientific instruments that can detect anything that is significant.
http://en.wikipedia.org/wiki/Oil_spill
Even a slick this thin would be damaging to the ecology of life on the surface.
Given BP have come out and said the GOM is so big that this slick won't harm it, it's not surprising some people actually accept such bullshit reasoning. It is after all, far more amazing to see a volcano erupt and conclude it emits more GHGs than it is to consider all those seemingly clean airliners flying daily.
here it is:
http://www.boston.com/bigpicture/2010/05/disaster_unfolds_slowly_in_the....
I have already seen those pictures. I don't see anything in there that is not 99% water... maybe the ones right at the rig.
You have obviously never cleaned a one barrel oil spill out of a creek. I unfortunately have.
FF
I agree with your thinking; if that much oil was actually being released, then the Gulf should be covered with it. It seems that there are three reasons of why the Gulf is not covered with oil (assuming that a lot more than 5000 bbl/day is being released).
One reason is that a large portion of the oil is probably not making it to the surface (per a marine biologist). It may be stuck in the thermocline boundaries somwhere down in the Gulf.
The second reason why much of the oil is not observable from the surface is because of the oil dispersants that are being used, both down at the well head and at the surface. What is happening is that much of the oil is affecting sea life deep down in the Gulf, not just at the surface.
The third reason is that the oil is lighter in gravity than most crude oil and the Gulf is warm, so somewhere between 20 to 30 percent of the oil is likely vaporized at the surface of the Gulf.
Of course, some of the oil is being burned or skimmed off the surface of the Gulf.
Retsel
Maybe because there are no private planes and helicopters allowed over the spill area? Maybe because there are no private boats allowed near the spill area? Maybe because the fishing boats involved in the cleanup/containment operations all needed to sign a contract to shutup? Government and BP are doing a good job in keeping the nasty pictures out of the press...
The lower picture shows what sand cut can do to a malfunctioning BOP
It seems that at least 1 restriction exists, that the restriction(s) are subject to sand cut and that the trend in estimates has been continually upward.
Of course we are not looking at a full on flow of the 53 cm. or 21 in. riser diameter. But it should be noted that we are looking at video of flow rate that is 4 days old and is subject to ,mostly upward, change so far.
There is one other trend ,which is perhaps somewhat subjective, but may signal an accelerating flow rate. There is continual slippage in the design and effectiveness of operational fixes. My emergency response red flags go up a bit when mitigation efforts seem to be constantly behind the curve.
72K BPD going vertical...Wild Mary Sudik..Oklahoma City, 1930
http://en.wikipedia.org/wiki/Oil_gusher#cite_note-12
Hey, driller guys... Do you still use the Hughes bit?
Thanks
Will this help?
YouTube video of these 2 boys from Alabama who have an idea about tackling the oil spill.
http://www.youtube.com/watch?v=k5SxX2EntEo
Donald Long
Pensacola
Engineering is all about the scale...
So they used 1/4lb of hay for a small cup of oil. That's about 20,000 tons of hay required per day for 5,000 barrels. Then they have to deploy it over the slick, let it agitate for several hours maybe? Then scoop up 40,000 tons of hay/oil mix and dispose of it somewhere.
That's a lot of hay.
--- Hay Hay Hay ---
A lot of Hungry cows this winter &
more imported beef
They could offset coal in the steam plants. Take
the Bio fuel credits - to offset FF consumption.
wait - Tar bails? Sorry ...
Probably quickly consume all the hay on the continent
That video is making its rounds as if it's a novel discovery. Straw was used in the 1969 Santa Barbara spill.
'Some people just want this disaster to be worse...'
And some people (namely BP) go out of their way to obfuscate.
How come it took weeks for the public to see this video?
How come no-one seems to know the diameter of this pipe?
How come no-one seems to know what type of calculations BP uses to arrive at 5000 bpd?
This is a very public disaster, and I assume that BP will be quite happy to have thousands of volunteers enlist to clean up beaches and limit the damage. But somehow everything that is going on down there needs to be shrouded in secrecy.
"How come it took weeks for the public to see this video?"
I'm not sure it did... the version I looked at on Youtube has the date on the film and although blurry it looks like it wasn't filmed until 5/12, and I think it went public the next day.
BP may have known earlier that it was flowing at that rate (whatever it may be) indicated on the video, but maybe not.
Or maybe they released a May 12 video to make it appear they just found out.
"This is a very public disaster" - yes but not public enough. BP doens't want to release certain information, claiming some kind of proprietary rights, I think; but it seems to me this emergency is too important to allow that and they should make much fuller disclosure to the government and public. Also, maybe it should be declared a national emergency, not just a group of state emergencies.
Minimizing the oil amount as they have done (if purposeful) is sort of like the kind of "honesty" of admitting to stealing $5 from someone while at the same time not telling them about the $75 you also took from them, which you have in your other pocket. That's even worse than normal dishonesty. Should be criminal to do that.
If its that high I'd like to see an aerial of it "breaking the surface".
Does anyone have a link to video of leak surfacing?
It should burn.
FF
I found this intriguing but I would not call it breaking the surface.
http://blog.al.com/live/2010/05/gulf_oil_spill_news_links_alab.html
why would it need to 'break the surface'? the outflow appears to be horizontal, yes? the currents are pretty strong in 5,000ft of water, too.
Any references or links to what the currents are on location - and on surface vs subsurface?
I don't know maybe gravity.
The currents are pretty slow at that depth at least to 3200 ft. We have RT data from Shell Ram- Powell platform at 29N, 88W down to 3200 Ft:
http://www.ndbc.noaa.gov/station_page.php?station=42364
Though an interesting side note: The Pelican research vessel http://blogs.nature.com/news/thegreatbeyond/2010/05/oil_spill_science_ma... found some possible oil stratifying in the water column with gaseous evidence of high microbial activity at 3,000 feet. Implying that microbes are feasting on oil. Likely the comparisons to Alaska are moot, since the gulf ecosystem is much more dynamic at its latitude, as long as the oil remains off shore.
Look what I found. A video from BP that I haven't seen linked on this forum or elsewhere, showing the failed deployment of the 100-ton dome.
http://bp.concerts.com/gom/cofferdam_video.htm
Shows a view of the outflow from a new angle, and a whole lot of puffy black clouds going up the side of the dome rather than inside.
Until I watched that my comprehension of the flow was nonexistent. Now I can feel another wave of doom engulfing me.
I'm amazed and still trying to get my head around it.
For 70,000 bbl/day =2000 gal/min the velocity out the 16" pipe would be 500 in/sec. The oil flow doesn't look nearly that fast. The white gas stream is definitely faster. If so, it would be coming out as a jet straight out the pipe - not so, it is coming out at an angle.
Consider this 16" pipe as same area and flow as about heavy duty 500 garden hoses flowing 4 GPM /hose. Stick a hose with that flow rate in a bucket and you will get alot more mixing turbulence than shown in the picture.
I SWAG 20,000 bbl/day ratioing the flow coming out to my experience sticking flowing pipes into tanks.
Doublecheck your math, I think you may be off by a factor of 10 somewhere.
And dang, am I the only guy in the room who likes the metric system?
Oops, divided by dia instead of area. I get your 1 m/sec.
What are you, French or something?
Exactly, regarding metric. In metric, I could do the calculations involved here in my head. Maybe that should be the first improvement to the field of engineering in the US that should be applied. Consider it a safety issue.
Nothing annoys me more about US science and engineering than the persistent use of that retarded system we invented over here that is Imperial.
"My car gets forty rods to the hogshead and that's the way I likes it."
On April 1st I sent some water use estimates (via eMail) in the US standard unit "Acre-feet/day" instead of m3/sec.
Reykjavik was not amused.
Alan
I couldn't agree more!
I guess I was lucky enough to have been brought up in a metric world, to me anything else just doesn't make sense :-)
Since I'm a scuba diver I'll give this practical example of how metric really helps keep it simple stupid! When I first started diving we didn't even have an underwater air pressure gauge we had a J valve reserve which you opened with a lever once you started to feel it getting hard to breathe. We only knew our fill pressure at the compressor. Dive computer? Fuggedaboutit!
Now try this calculation in your head when you are already under the influence of a little nitrogen narcosis...
Here's the calculation in metric:
Lets say I have a pair of 10 liter Cressi scuba tanks filled to 200 atm pressure which equals about 4000 cubic liters of breathing gas. I want to know for aproximately how long I will have air at a depth of 20 meters.
If my Surface air consumption is about 20 L/min and knowing that every 10 meters of depth equals 1 atm of pressure, I have 3 atm of pressure at that depth so my consumption is 3 times surface consumption or 60 L/min.
Say I know I want to leave about 1000 cubic meters for decompression and ascent so I now divide the remaining 3000 liters by 60 L/min and have a rough idea that I'll have about 50 minutes of availabe air for bottom time.
Now here is the same calculation without the benefit of metric.
I have a pair of 610.2 cubic inch scuba tanks filled to 2844.7 psi of pressure which equals about 244,095 cubic inches of breathing gas. I want to know for aproximately how long I will have air at a depth of 65.6 feet.
If my Surface air consumption is about 1,220.5 cubic inch/min and knowing that every 33 ft of sea water equals 14.2 psi of pressure, I have 42.6 psi of pressure at that depth so my consumption is 3 times surface consumption or 3661.5 cubic inch/min.
If I want to leave about 61023.75 cubic inches of air for decompression and ascent so I now divide the renmaining 183071.25 liters by 3661.5 cubic inch/min. and have a rough idea that I'll have about 49.9 minutes of availabe air for bottom time.
So which calculation would you rather be doing if your life depended on it? ;-)
Your second calculation is a great example of carrying a silly number of digits and not rounding properly like you did in the first one. What on earth does the measurement system have to do with the fact that you used nice round numbers for everything in the "metric" calculation? Multiply any SI unit by PI and then use it in your head.
Ok, I admit I was putting the second calculation in a less than flattering light by doing that. However even if you round to the next significant number the point remains that doing the calculation in metric is much more intuitive and much less susceptible for making gross errors. I don't know about you but I have ten fingers and can easily do multiplication and division by tens in my head.
There is a reason science generally uses the metric system.
Of course, the true strength of the metric system for mental arithmetic is that all the conversion factors are powers of 10.
But in addition, it so happens that many common measurements are nice round numbers in the metric system. Some of these are deliberate (the density of water, its freezing and boiling point, the size of a human), and some are accidental (sea-level pressure, the acceleration of gravity), but it's true nevertheless.
This is indeed a huge advance on acre-feet, etc. However the truer strength of the metric system is the relationship between length, area, volume (capacity), and weight (mass). So one litre of water weights one kilogram, and occupies 1000 cubic centimetres; one cubic metre weighs one tonne, etc. Very elegant.
The downside of metric is the lack of ancient and very useful names for shorter measures. A kilometre easily replaces a mile, one metre easily replaces a yard, kilos for pounds, litres for gallons - but we lack handy names like "foot", "inch", "ounce", "cup", etc. "He missed the putt by 15cm." is just not quite as smooth. The persistence of acres in real estate indicates that hectares have not been a success so far.
The traditional units are handy for rough use. In timber at least the informally defined "metric inch" and "metric foot" are used, being 25mm and 300mm respectively. So what was 8 feet of 2x4 is now labelled a nominal 2400x50x100mm.
Unfortunately I was brought up when schools taught metric but in the real world mostly imperial units were used, so now I have trouble visualising metric sizes, but am equally uncertain over how many ounces are in a pound for example. And don't ask me about chains and rods ;)
Except that the standard U.S. 8 foot 2x4 stud is actually 92.625 inches long by 1.5 inches deep by 3.5 inches wide.
This makes it 2343 x 38 x 89 mm.
The traditional systems of measurement are just full of little traps for the unwary like this.
Let's say you go to an oil cleaning plant and drive a truck load of oil across a scale. It weights 44,000 pounds. You drop off a sample at the office, and dump your load into the tanks. Then you drive back across the scale and your truck nows weighs 11,000 pounds. The girl at the office tells you the oil was 35 degrees API. QUICK! How many barrels of oil are you going to bill them for?
You are under a lot of time pressure because you only have a pencil, a piece of paper, and the trucks behind you are starting to honk at you. There's one truck a minute driving across the scales and they know that time is money.
Alternatively, you drive the same truck across the scale and it is 25,000 kilograms. You drop off a sample, and dump your load. When you come back, your truck weights 5,000 kilograms and the girl tells you the density of the oil was 850 kilograms per cubic metre. How many cubic metres of oil did you just deliver?
You have a pencil, paper, and the same honking trucks. Which scenario would you prefer?
This is something of a real-world example, because we did this kind of thing in the Canadian oil industry. The American Petroleum Institute had an incredibly complicated procedure for gauging oil tanks and calculating the volume, correcting several times for temperature in the process, whereas we just used to weigh the trucks.
I know this isn't your point, but why on earth would this plant do its billing by volume rather than by mass?
Driver's note to self: postpone all oil deliveries until late afternoon; schedule truck maintenance and vacation time for February.
In general, you ship oil by mass and sell it by volume. However, if you have the density you can translate between mass and volume with a simple, 4-function calculator (in the metric system). If you have the density and either the volume or the mass, you have (almost) everything you need to determine the price.
Company's note to driver: The plant operates 24 hours per day, 365 days per year. You will drive whenever we tell you to drive and take your vacation whenever we tell you to take your vacation.
The interesting thing about these guys is that you can call them up at 3:00 AM on a Sunday morning, and not only will they answer the phone, they will be *cheerful* when they answer. The reason is that if you call them at 3:00 AM they know that they are going to make a lot of money that day.
Because we all know everything that uses metric units always comes out in neat round numbers, right? Let's say the truck weighed 24, 973.8 kg, and after you dump it it weighs 5,278 kg, and the oil density was 847.3 kg/m3. Quick, whip out that pencil. The SI system is great, but it does not magically make all numbers come out even.
You will note that I rounded both the metric and Imperial measurements in the interests of keeping things simple. With a little more study, you could determine that the metric and Imperial measurements were more or less the same. However, it's not totally obvious to the layman that 35 degree API oil has a density of 850 kilograms per cubic metre.
You wouldn't measure truck weights to 0.1 kg nor oil densities to 0.1 kg/m3. The equipment is not that accurate. However, you would normally use one or two decimal places in calculating oil volume in m3.
For instance, in the example you gave, the truck would contain 19,695 kg of oil, which if you divide it by the density of 847 kg/m3 would give you 23.25 m3 of oil. Anybody who can do long division could figure that out. If you converted it to imperial by multiplying by 6.29, that would be 146 barrels.
However, if I said the truck contained 43,419 pounds of oil, and the API gravity was 35.5 degrees API, what would you do? (Hint: the answer is 146 barrels)
If you were shipping water to the water disposal plant, it would be even simpler: 19,695 kg of water would be 19.7 m3 of water. And the driver would find it useful to know that 19.7 m3 of water weighed 19.7 tonnes.
Ever since I heard about peak oil I've thought one of the good things about sliding down the back side of Hubbert's Peak might be that we (in the U.S. and any place else that lags behind) finally convert to the metric system once and for all. That, and more cuddling. Definitely more cuddling.
Yes, there will definitely be more cudgeling.
Remember, GH, that there are two places you need to check on to estimate total flow. If both are about the same (and, the laws of physics say they should be pretty close), then you need to doublt what you see in one flow.
Craig
Unfortunately I cant see the video....Is the cofferdam down? E.g. are the black clouds oil or possibly sludge from the bottom being disturbed?
tt, from what I see in the video oil appears to be coming out from under the cofferdam, and flowing up the side. Almost like a black mold. It appears to be fairly thick, and clings to the sides of the cofferdam. It does not appear that there is any disturbing of the bottom sediment.
I know nothing about all this, but I started thinking about how one might calculate it and this led to some (possibly stupid) questions for those that do:
1. Does all the oil come to the surface, and how quickly?
2. If it comes fairly quickly, days or even weeks, couldn't one take samples at the surface throughout the spill zone to come up with a total of how much has reached the surface?
3. Knowing the delay to reach surface, could one then make an estimate of the total so far, and therefore the average rate?
4. Has this been done?
Question 1: No, it does not. I heard a story today from a research vessel in the Gulf - oil down at 1,300m. Although I haven't seen anything current in the press I believe BP is injecting dispersants at depth into the flow and this may be a contributing factor. This means that surface estimates are going to have significant error - underestimating the volume of the leak. Consequences for the environment - unknown. There are bacteria at depth that make a living from oil seeps and support communities of other organisms - bonus time for them... hopefully the dispersants aren't toxic to these organisms.
Question 2: Because of reasons above, no, you can't calculate the spill volume - however it is probably handy to know how much is reaching and floating on the surface for other reasons. I believe people are making such measurements.
Question 3: No, for reasons stated above.
Question 4: See above.
How much of the oil is reporting to the surface, vs flowing subsurface?
See the vertical profiles in slides 11, 12 of:
"Deepwater Blowouts: Modeling for oil spill contingency, planning, monitoring, and response." Mark Reed et al.
These seem to show most hydrocarbons in the middle between floor and surface.
Are there any published reports of the oil density for Deepwater Horizon blowout? Or estimates of gas/oil fractions?
thank you for signaling this.
Following the paper, the main part of hydrocarbons are still trapped between 300 and 700m , and this is scaring.
The oil spill moedels I've seen are used to evaluate spilling on the surface (mostly from tankers).
A few days after the blowout (using satellite pictures) a 20.000 to 30.000 flow was evaluated from oil spill models, ad now I'm wondering if they was using a version of this OSCAR model (which is able to model seafloor spilling) or another.
Bottom line: the flow is more than 5000, for sure. How much more, is directly linked to the political and economical convenience of the responsible.
Thanks, David.
BTW... as to the dispersants... don't they just 'dissolve' the oil? I mean, it doesn't go away. It just goes into solution, and mixes with the sea water. Right?
And, if that is true, all you are really doing is makinmg it less visible. The oil is still there. And, if it is damaging to marine life, that might even make matters worse.
I mean, imagine a shellfish that makes its living filtering sea water. Suddenly, there is oil in the water - small blobs, to be sure, but oil. And it coats your gills. That would be bad, right?
It seems to me that they are being quite cavalier about this.
Craig
Craig
"It just goes into solution, and mixes with the sea water. Right?"
Dispersants are a fancy name for SOAP or Surfactants
They help the oil breakup into smaller droplets so they "disperse".
The oil is still there - just not as obvious.
ITOPF Dispersants See figures etc.
Microbacteria eventually feed on it.
Nature Fighting Back Against Gulf Oil Spill
Re "don't they just 'dissolve' the oil?"
Oxygenated fuels such as Ethanol, methanol do dissolve in water.
David
The New York Times is also finally reporting on the question of the size of the spill. It's taken an awfully long time (given that this issue has been reported on since day 1 here on TOD) but it's good to see that the MSM is finally catching on.
Size of Gulf Oil Spill Underestimated, Scientists Say
5000 or 50000 thousand does not really change the urgency or the approaches to stop or mitigate does it? It makes for good press for the people predicting the end of the world as we know it.
I would think ,given the amount of gas, that the range predicted by the profs in the article would be much wider.
it doesn't make a difference in terms of the mitigation effort.
it does make a difference to the people of the gulf coast, their lives, their plans, their future.
and, it's just 1 of 2 leaks, we don't have a flow calculation on the second leak.
I believe that's the BP party line. That it doesn't really matter. Why? Because it best suits their PR angle which is all they seem to be worrying about when it comes to public information. But I think it does matter a great deal when trying to evaluate the impact.
Low-balling assumes they fix the leak(s).
It's hitting the coast, they can't dink around with low-balling it much longer.
I have a question. Wide varying estimates are being made. Fair enough. Much of the volume coming out of the pipe is gas which significantly complicates estimations.
My question, is all that gas from a separate pocket the well is in? Or is it gas that was trapped in the oil under great pressure (22,000 feet below sea level) and is now released because the oil is only 5,000' bsw?
If that's true, then wouldn't the oil (black flow) still contain a statistically significant amount of gas that will get realeased as the oil makes its way to the surface?
And if that's true, then wouldn't the actual amount of oil in the black flow be less than it appears at this depth? Wouldn't that skew calculations as well? In other words instead of half the pipe flowing oil as it appears, maybe only a quarter (or 1/3 or ...) of the pipe is actually oil?
"Statistically significant" is the operative phrase as that is all we have going for us. If you look at it from the perspective of 70,000 barrels per day and this goes on for 2 weeks, it will put the volume at 1 million barrels. This will essentially place the size of the reservoir at the 50 percentile rank of all reservoir sizes in the USA. I don't have statistics for the GOM by itself. So then we can look at a place like the North Sea, and a comparable outflow of this rate for about a year would place it at a 50% rank for that set of fields.
As I said elsewhere in this thread, take a look at the rank histograms of oil reservoir sizes and you might get a upper limit gauge on potential outflow.
The point is that the initial investment in offshore areas is much larger so that has at least something to do with the expected size. Someone will set up a stripper well in their backyard and be happy to get a barrel per day, but that will never happen offshore.
Size of Oil Spill in Gulf Underestimated, Scientists Say
That put's it at the 95th percentile of all USA fields and bigger than average in comparison to a North Sea field. This may give something of a limit to think about.
The oil has gas in it, sort of like soda water. When the pressure is released, the gas bubbles out. There is a release from the reservoir as it enters the pipe; another release as it leaves the riser; and, finally, yes, the pressure at 5,000 ft would keep some of the gas in the oil. It would not make a big difference. If you doubt that, open a clear bottle of club soda, and let it go flat. Then measure the difference in volume. Not that much.
The main factor as it goes up from the reservoir is that it does become a gas, and displaces some of the oil, so that it acts to reduce total flow of liquid to the extent of that volume. As the bubbles come out of solution on the way up through 5,000 ft of water, there is nothing to minimize the total voluem of the oil, though, since it is not in a restricted area.
Right now it sounds to me that it is rising part way, and it is being hit with reagents to break it up and allow the oil to dissolve. That way, the sea water becomes an oily mess, sort of like your dishwater in the kitchen sink does after you have done a load of greasy dishes. There is no oil floating on the surface, and yet you would not want to drink the stuff in the sink.
Craig
The particle image velocimetry appears to provide the best quantitative estimate of velocity of the flow out the pipe. One major uncertainty is the oil fraction.
Particle Image Velocimetry See Steve Wereley's home page.
See Wereley's book: "Particle Imaging Velocimetry
However, here the velocimetry appears to be inferred from the video which probably degrades the accuracy.
Size of Oil Spill in Gulf Underestimated, Scientists Say"
Note missing data and description of BP's feeding a pipe in to draw off the oil flow:
Missing data causing rig reconstruction mystery
That last article, if accurate, is hugely, devastatingly damning.
I am having trouble understanding the supposed events here. Are we to believe BP and Transocean shut Halliburton out of the room while they discussed the cement? Meanwhile Halliburton went off in a huff and ran their own test which showed everything was "OK". Inside the closed room BP and Transocean then hallucinated their own test which was also presumably "OK" but had no knowledge that Halliburton were doing things behind their backs without telling BP or Transocean? I just don't get it.
In order, yes, we can believe that. It happens a lot that the rig operator and overall overseer of drilling and HSE (Transocean) and the leaseholder and overall responsible party (BP) would, in fact get together on their own without a subcontractor to discuss the results of a given set of tests... that's pretty normal. To then apparently throw out the results of those tests based on some "other tests" that noone has seen and no one will admit to conducting or analyzing.... that's not normal.
Halliburton didn't run off in a huff according to this account, nor did they conduct any more tests according to this account - they had already conducted their tests, showing that the well was not sealed properly - according to this article, they waited for BP and TransOcean to let them know what the plan for proceeding was.
Inside the closed room is where, if this account is truthful and accurate, the big, big trouble happened, and where the people who made that decision probably ruined their careers and their lives... IF the article is accurate. That's where, apparently, the results of the Halliburton pressure tests of the cement job were deemed not relevant, the "results" of some "other" test, so far not in evidence in any reports or data... were used to justify displacing the drill mud with sea water and running the cement plug in the top hole.
Ok, on re-reading the lawyer's statement it can be read that way (no Halliburton second test) but my first reading of it was that he claimed Halliburton had conducted their own second test unlike BP/Transocean who conducted a claimed "phantom test".
Tow -- I’ve sat in a company man’s office more than once and observed very similar “conversations”. And I’ve seen service company hands (including myself) ordered to leave a meeting so the remainder of the conversation would be private. I’ve been there when the company man got some onshore managers on the speaker phone and closed his door so no one could listen. Having a service company do some sort of CYA procedure is also not uncommon. As I mentioned earlier I’ll usually follow up with an email to document my position. There are some very territorial aspects of life on an offshore rig that could make many folks a little uncomfortable. Ego is a very strong component in these situations. You don’t find many non-Alphas who take to the life style/stress you’ll find in offshore operations. Thus conflicting opinions are not uncommon.
Some may have even noticed my monumental efforts to check my ego at times.
RM, I hadn't noticed - I'll be sure to be on watch now that you've given the heads up :)
The line between confidence and hubris can be thin at times. Confidence and decisiveness are a requirement for success when the going gets tough - and that includes the confidence to back off when appropriate - and the confidence to tell the higher-ups to lump it when its appropriate. Batting 100% is not a human characteristic either.
Obviously all reservoirs are different.
My opinion is that no one ever gave a damn about trying to understand the statistical distribution of oil reservoirs. Millions and billions of dollars go into the industry and all that comes out are useless heuristics, with no fundamental understanding behind the numbers. But of course, how else could it be -- oil companies run the show and they have to protect their own proprietary information.
That said, this is the best estimate of a rank histogram of reservoir sizes in the USA:
There are well over 10,000 defined reservoirs/fields in the USA with anywhere from 10,000 barrels to almost 10,000 million barrels.
The solid black line is a model fit using entropic dispersion that I outlined here:
http://www.theoildrum.com/node/6255
Of course this doesn't tell you anything more than what we can expect as a typical reservoir size. So what would I guess for this particular reservoir? Heck if I know. It doesn't really matter in the greater scheme of things, as far as peak oil is concerned. But now that this spew has the potential to wreak havoc, we just have to know!
Isn't that weird how things work out?
Seriously, all the historical oil production information should be made public knowledge, pronto. All we have to emulate is the procedure tha the UK and Norway do, and place all the information on the internet.
So this is what the size distribution looks like for the North Sea:
http://mobjectivist.blogspot.com/2008/10/estimating-urr-from-dispersive-...
Like I said, I can do a pretty good job of understanding the size distribution from a statistical point of view, but to try to guess the size of a single reservoir, you have to do careful monitoring of reserve growth over time.
http://www.theoildrum.com/node/4311
Jean Laherrere has conducted numerous fractal analyses. e.g.
Estimates of Oil Reserves 2001
Laherrere does a pretty good job of empirical curve fitting but this "Fractal analysis" is pretty lame heuristics in my opinion. Most of that kind of math comes put of the Mandelbrot/Taleb fractal school where they just talk and nothing ever fundamental, as far as a derivation from first principles is concerned, comes out of it.
Fractal analysis = heuristics.
Got anything better than Laherrere?
Sure. See the links for a model based on rate dispersion and the maximum entropy principle.
This is arguably better than Laherrere because it actually uses ideas from probability and physics. I say "better" reservedly of course because you can't really argue against heuristics, as a heuristic by definition actually has no basis to argue against. All masters of the heuristic do is represent the data as a curve.
Sounds like one of those pitches you hear, from shills trying to sell a "scientific" system for picking horse races, or even lotto.
WHT:
I have worked with rank/abundance data before getting interested in peak oil. It occurs in ecology in the study of biodiversity, and in looking at statistical data about the population sizes of nations, etc.
In my work I followed the biodiversity literature and plotted the data on a semi-log paper, log for y axis, and linear for x axis.
Could I get your data so that I can replot it that way? Or could you do a special replot? As I write this, I have the wild idea that
the individual reservoirs might correspond to the rise and fall to extinction of individual species of micro-biota. Have you thought of that as a possible cause for the distribution?
You might want to look at the first link I put in my comment. I already made the analogy to biodiversity and have it worked out reasonably well. I also talk about city distributions.
Likely that the distribution oil has at least something to do with the cycles of biota. My model assumes a uniform distribution of these waves through history. (The biodiversity analogy is between metacommunities and local communities) Otherwise the distribution follows from a maximum entropy distribution of reservoir aggregation rates. I welcome any additional help on these topics because it's pretty interesting and I don't think anyone has worked it out quite so simply.
Web,
Your "cycles of biota" idea is interesting but there are some big problems there.
The fossil record doesn't uniformly preserve the record of biota. There are large variations in depositional environments which leave some very significant gaps. A particularly frustrating one for paleontology is, "Romer's Gap", as an example. That one "happened" at the beginning of the Mississippian Period. We must presume that things were happening at that time, but we don't have much record of it to examine. Same problem throughout much of the Jurassic Period; not enough deposition going on. Deposition in the marine environment (where oil is formed) is strongly affected by erosional factors in the terrestrial environment, which will vary widely over time for any number of reasons. There is also significant variability over time in the creation of anoxic, shallow sea bed environments which are a necessary pre-condition for the preservation of the biotic sediments which ultimately will become "oil".
There obviously is a pattern between biotic environments and oil formation, but the geological record only provides the coarsest imaginable resolution.
Thanks for the feedback.
Impulse response functions sufficiently smear out any variations over time so that only the overall power-law behavior remains. Any smearing or disorder that occurs in nature is appropriately modeled in terms of entropy. And entropy is defined as a probability which won't necessarily show much structure.
So you have to account for the lack of structure in the power-law curve before you can start ascribing effects due to fine details in the biological record.
The math is straightforward but fairly novel. I have applied it to much more than just this topic. A few days ago, I posted an updated application to the characterization of the impulse photoresponse of amorphous silicon.
http://mobjectivist.blogspot.com/2010/05/characterizing-mobility-in-diso...
This shows some structure in the power law in the form of extra inflection but only because the geometry of the detector is clearly defined. That is what dispersion due to entropy and disorder results in, and makes it difficult to weed out the causal and deterministic factors. And we are talking on the scale of microseconds here (not eons)!
Same goes for the atmospheric CO2 impulse response. Even though carbon emissions have only recently occurred in the historical record, we are seeing the results as rising CO2 levels in which one can make out the inflections, but they already have started to smear.
Compare this against processes that have been evolving over millions of years.
One of the huge challenges in anyone trying to deny the ideas behind the theory of entropic disorder is that they will essentially have to disprove it over all the different application domains. Entropy exists in all sorts of natural behaviors and certain artificial ones and it happens to show much universality. It is the great leveler of deterministic theories.
Does anybody have any guesses about the GAS flow rate?
From what I've seen of the flow out the end of the broken riser, and doing some back-of-the-envelope calculations, it appears to me that ANY attempts to collect the entire flow are doomed to failure.
Based on some numbers I found in another TOD thread, it sounds like the gas-to-oil ratio may be as high as 3000 cu ft/bbl. If that's the case, even if the oil is only flowing at 5000 bbl/day, that's one HELL of a lot of gas!
If they can't put any back pressure on it (for fear of rupturing whatever connection they can make into the end of the riser) they're going to get some pretty spectacular velocities when this gas expands to near STP at the surface.
I'm convinced that, unless they separate out the gas AT DEPTH (where it's volumetrically handleable) they're not going to be able to do ANYTHING with the flow once it gets to the surface.
I keep hoping that I've missed something and that I'm just wrong, but nobody's corrected me yet.
I don't think you are wrong. Without some median stage, they can't do it. If hydrates don't get them, the velocity will.
I think the "junk shot" is the only chance of stopping this thing short of a successful relief well.
The real solution is the relief well. Anything else is just twiddling thumbs while they wait for that. This side activity creates the impression that they are doing "all they can" to fix it quickly, and there's a small chance it might actually work.
I guess it also helps if people get involved to think they are doing something, rather than just watch the oil creep up to the coast.
Tinhat posted a link above to an AP story saying that at the spill site, "At times, the fumes have become so intense it has caused a burning sensation in the nostrils and nausea. Workers have been wearing respirators while on deck." Another AP story yesterday or the day before mentioned the need for respirators at the spill site (can't find that one right now).
http://blog.al.com/live/2010/05/underwater_chemical_spraying_o.html
Yesterday I tried to convert 5k bbl/day into something I could get a better handle on, and came up with two and a half 40-foot shipping containers per hour. In the evening I walked my dogs about a mile from my truck and looked back, trying to imagine that volume per hour traveling a mile up through open ocean and resulting in conditions so bad that respirators would be needed.
Maybe some industry people who've been on-site at blow-outs could comment on whether the conditions reported by AP correspond better to 5k bbl/day, or 50k. I realize that gas is mixed with the oil, and I imagine that could greatly influence surface conditions.
If the military can remotely operate "predator drones" why are there not special craft the purpose of which would be to scoop up a certain amount of oil and then carry it back for unloading to a "mother ship" parked some distance away in a safe location for its crew?
Big Oil appears to be way behind the military in its technology.
You learn when things go wrong. N. T. Obot
HOG:
(Did you chose your handle so that it could be shortened in this way?)
I think I see your point. To drive it home a bit, I ask:
Remind me, please. When was the last time the military turned a profit and declared a dividend?
Well of course the military only returns its dividends to its owners, who are not us common folk. As for "when", well, certainly in feudal times when the purpose of a military was to protect a baron's landholding from costly raiders. Also to the British in defending the Suez canal last century. 'Course it seems to me quite obvious that defence is no longer the purpose of a military, so then the computation becomes very complex. But then, defence was clearly never the purpose of the British military controlling India for 250 years either.
Ok, here we are arguing, figuring, and betting salaries and all that - good sport! BUT - BP has submersibles down there 24/7 with video and lots of fancy equipment. They CLEARLY have the capability to produce high quality video of BOTH leaks AND to sample the stream to analyze/estimate gas content. They UNDOUBTEDLY have video taken since the spill started that could shed light on whether the rate is increasing or not and if so then by how much.
I am willing to wager they RIGHT NOW have pretty reasonable estimates of the flow - and if they don't then it is ONLY because they DON'T want to know for fear someone else will find out.
Anyone want to make a wager on why this information has not been shared to date?
Here they release a bit of video and we have estimates within 24 hours making it to the press - a really hard task isn't it? By releasing video from which it is possible to make estimates but about which good, intelligent people can disagree what purpose is served?
Prove me wrong BP - do a little homework and take some responsibility for this mess.
Remember this 5k bbl/day estimate (I think it was upped because the slick had gotten so large so quickly and the 1k estimate was no longer credible) has been floating around in the press for many days now and the figure is just a back-of-the-envelope calculation based on rather poor data - why has no one bothered to provide a more accurate estimate?
IP, You are likely right and for those exact reasons. The USA oil industry has gotten away for years with keeping discovery/reserve/production numbers close to the vest. It is all IP and trade secrets, IP. Somewhere our government got it in their heads that this would improve the competitive marketplace.
So BP has work going on in the North Sea and they are forced to report everything they do, but not in the USA, And the USGS or MMS doesn't do anything to help the situation.
BP is not in the business of disclosing intelligence, it's in the business of making money. Better to direct these questions to NOAA and MMS who are paid by US taxpayers to act in our interest.
Exactly
" (I think it was upped because the slick had gotten so large so quickly and the 1k estimate was no longer credible) "
I recall that first reports were actually that the BOP had worked, and there was no oil leak, whatsoever.
I am torn between three views:
I want to treat reports from fellow members of my species as true. This seems to be an attitude that comes pre-wired in most of us.
And:
I know that members of my species often misinterpret what their senses tell them and report in a way that is misleading.
And:
Some members of my species have developed an ability to make misleading statements, this ability is adaptive in the sense used in the theory of evolution.
This morning I heard a statement from BP spokes person that it was not possible to measure the flow rate accurately.
This is surely intended to mislead because of the final word 'accurately'. There is surely a level of accuracy that makes this statement unargueably true. But do we really need that level of accuracy to go forward? I think not. And I think he realized that before he made the statement, and nevertheless stopped before entering into a discussion of how much accuracy is needed. If someone had thought to question him, he would have said he didn't want to confuse the public, the poor suffering public, with confusing details.
Was there really no leak when the first reports were made? I don't know.
About BP proving you wrong. They won't take that approach. They will come up with another carefully crafted misleading statement, and perhaps a different spokes person, if they perceive that this one has lost credibility.
No it wasn't but I am not surprised that's how you remember it. The first report by Admiral Landry after the rig sank was "We are not saying nothing is coming out, we are saying we can't see it." (Reported by Houston Chronicle from the press conference CNN webcasted without the sound). The next morning Landry's words were "we have no evidence of a leak" (which actually means the same thing but sounds different). That was reported as a definitive "no leak" by the press. Likely it took time to complete a full ROV inspection along the riser.
It is also likely that there was a initial leak, probably under 1,000 bpd, and it took a number of hours for that leak to fill several thousand feet of 20 dia pipe until the oil started leaking out the broken end.
When you look at the riser end leak shown when the large containment dome was tried and compare it to the recent leak video take a few days later two things stand out.
1 - the leak has substantially increased in size, which supports the projection that the restriction area is eroding , and;
2 - there is much more gas in the flow.
As both shots only show a few second of a variable flow it does not give a good picture.
For those trying to calculate particle velocity remember that the optical properties of water are different than air and that almost all ROV video lenses (except those for close up macro inspection) are very wide angle.
Welcome back to the mud pit.
Glad to have you back.
Me, too, Shelburn. I've been awaiting your return.
We've been branding and then moving cattle. No chance to even see what was on the net.
In that case, welcome back, but sorry about the smell in here. You'll get used to it after a while. ^_^
How can this smaller tube procedure be effective:
WASHINGTON -- BP officials said Thursday they would thread a small tube into a jagged pipe on the seafloor to suck oil to the surface before it can spew into the Gulf and add to a disaster apparently set in motion by a long list of equipment failures.
Engineers will have to make sure the 6-inch-wide tube is inserted deep enough into the 21-inch-wide pipe so gas and seawater don't mix, which can form crystals that could clog the tube. They'll also have to thread the tube into the pipe without hitting debris around the riser.
The smaller tube will be surrounded by a stopper to keep oil from leaking into the sea. The tube will then siphon the crude to a tanker at the surface, though BP declined to estimate how much oil the tube will be able to collect.
http://blog.al.com/live/2010/05/bp_will_try_smaller_tube_to_st.html
"How can this smaller tube procedure be effective?"
effectiveness in collecting oil? perhaps 10k bbls/day? if lucky, 1/7th of the total. (better than nothing, sure)
effectiveness in giving bp something to wave in front of cnn? aha, now i think we understand what is going on here.
it is theatre, nothing more. remember, there's a second leak behind this one, even if they manage to get the stopper in place, the oil will just flow out of the leak above the bop.
it is long past time to take this out of bp's hands.
Here's how this might work--imagine a 7" lab cork with two holes, one large, say 3" hole from where the gas escapes, and a second 2" hole with a tube, from where liquid is extracted. The 2" hole is on the bottom when inserted into the horizontal pipe.
The 2" pipe or tube extracting the liquid empties into the standard, 7" drill string for transport to the surface through an "airtight" reducer (expander) fitting.
If some liquid is allowed to escape with the gas, very little gas should enter the 2" pipe on the bottom. The horizontal pipe on the floor is acting as a G/L "separator" albeit with very little margin to cleanly separate the phases. You get a "dirty" separation which excludes water, but which at least vacuums up some of the oil at its source, making it easier for the skimmers up top.
Oops, just became aware that the riser in horizontal position is 21". You could have a cork (stopper) that has a (secant) removed at the top to allow the gas to easily get by, instead of having two holes.
The stopper would be ~ 18" one. Should be plenty of room left at the top for the gas to escape by, while scooping up liquid through a 6" tube transecting the stopper near the center-bottom of the riser lying in horizontal position.
The six-inch tube extracting liquids would be connected to the 7" D, drill string to surface. No contact between Hydrocarbons an water except near the outlet of riser. No guarantee plugging would not occur at this location. But the worse that could happen is all the gas would just be forced through the 6" tube.
The other problem with your "stopper" analogy is the drill pipe that's still sticking out of the end of the riser. It's gonna be DAMN tough to get a seal around that.
HOG: ;-)
In WSJ this morning, on pg. A5, there is a graphic that shows three different drawings of the open end of the riser. In two of them, there is drill pipe sticking out of the open end of the riser. But in the one where they show the bent end of the vacuum pipe
that makes it possible to insert into the riser --- in that picture, the drill pipe is moved out of the riser and is lying by itself on the ocean floor.
The information that you are working with is incoherent and irrational. If it is deliberately incoherent and irrational, and you succeed in making sense of it, it is because you have gone mad trying. Don't go there, friend. Don't go there.
Note: I can't find the graphic in WSJ on the web. If anyone knows the URL, please post it. I think it tells a lot about where we stand in the information chain. If Rupert Murdock's people are misinformed, what chance do we have?
Thanks you two for the suggestion--it appears I'm not helping in this, just driving myself and other innocents crazy.
My solution doesn't require knowing exactly from where the oil is coming out or how big the pipe is.
It involves confining the rising oil and gas column by creating a sea water vortex (virtual wall) around the lighter hydrocarbon phases. Then, even if dispersant is used, much of it could be recovered by collecting the "foam" which will collect at the center of the vortex on the surface. See comments below.
This would not be that difficult to do, and it would work regardless of how much oil is coming out, as long as they vacuum it up as fast as it reaches the surface.
HOG, Another thing to consider is the difference in specific gravity between the oil/gas mixture and the water. This will pump oil/gas up the pipe with several hundred pounds pressure. A throttling valve at the bottom end could be adjusted to make sure 99% of the oil/gas flow goes up the pipe and no water. At the surface a normal gas oil separator could be used.
If 16,000 barrels of oil is flowing through the smaller 6" pipe (tube) then the velocity in that tube will be 5.4 ft/sec. at 5000' depth. But at the surface that velocity becomes about 1800 ft/sec as the gas tries to expand and that is unlikely as the speed of sound is 1050 ft/sec.
The container that catches the oil and gas will have to hold some back pressure or the pipe throttled back to retain some pressure. The inserted pipe will not "suck" anything and will likely have to withstand some reasonable amount of back pressure, meaning that seal between the 21" riser and the 6" draw pipe (tube) will need super integrity. I estimate force on the seal will be at least three thousand pounds or 10 psi back pressure x (area of 21" pipe - area of 6" pipe).
Any back pressure on the riser adds to the leakage at the two other points and less oil likely to be captured by this new "inserted" pipe method. I also think this "junk shot" idea will not work. I have seen as little as 3000 psi force teflon seals out of their gland and grind them to bits, and BP thinks golf balls and rubber will stop this 8000 psi (at BOP) oil flow? Stupid!
Here is what I would do to stop most of this oil leaking:
1. Find a fairly straight point in the riser that was not deformed, in a horizontal section of the pipe. Cut off the riser and drill pipe square.
2. Attach a new slightly larger vertical pipe to the riser with an elbow and seal that can hold a couple thousand pounds force. This new pipe should have a large chamber of about 4 or 5' diameter and 10 feet long connected to it maybe 100 to 200 feet from the riser. The chamber will have a 3" pipe coming out the top and extending maybe 50 to 100', besides having a 6" pipe starting 2 or 3 feet from the bottom and exiting out the top. This 6" pipe goes to the recovery vessel or tank up top.
3. The chamber could be slightly heated but should not have methane hydrates form since it will have no water inside. Gas will exit the 3" pipe after expanding due to the rise from the ocean floor. Oil hopefully pools up to about 2 or 3 feet then goes up the pipe to the recovery ship.
This plan could be tried in less time than the containment dome required.
Your idea sounds similar to the "Hot Tap" idea that they are considering, eg:
http://blog.newsweek.com/blogs/thehumancondition/archive/2010/05/10/bp-s...
I think by now it's pretty obvious that BP is just throwing spaghetti against the wall and hoping something sticks.
Let's hope they have a prolific pasta chef.
Just a basic knowledge question, about the gas coming out not oil. As the gas comes up the water colum (I know it expands) does it disolve into solution witht the seawater, or does it break the surface and just sit on top of the ocean (and need to be somehow collected as well)? I am assuming it's heavier than air since wasn't it the same gas mix that enveloped the platform or would that have changed after the initial event?
we're screwed if that gas is forming some acid that's "stable" (unlike carbonic acid)
5000 feet of water provide a lot of mixing space
maybe some algal bloom will take care of that oil, but as far as i know, that would suck the oxygen from the water, killing pretty much everything that breathes
I'm still no expert in the field, but as far as I've been able to determine, I think MOST of the gas is methane, which is lighter than air, so it SHOULD just float away.
I don't believe the claims that the original gas out of the pipe onto the deck of the Horizon were "heavier than air". That original blast of gas came up the pipe with a few thousand barrels of mud and water. I suspect what happened was that the mud and water, as it fell back through the plume of gas, stirred things and carried enough of the methane down with it to set things off.
More non-expert questions:
1. What is the "footprint" of the oil when it first reaches the sea surface? If there were no currents, the oil would form a spreading circle at the surface. But the currents at all depths will deform that circle. Can we predict the shape of the footprint; and focus recovering the spill there, before it gets spread all over the GOM and elsewhere?
2. How long does it take the oil to reach the surface?
Even in a "still" column of water, the oil and gas would not break the surface continuously at a "fixed" location, because of the random breaking up of the stream into various "bubble trains" which carry various packets of oil in different directions. Thus you have multiple locations on the surface where the oil is coming out, and even these rapidly change positions, making life difficult for surface collectors of oil.
My feeling is that if you "could" get it all to come out (and remain) at a single, unmoving location on the surface, the job of collecting it would become a whole lot easier.
One way of "confining" the rising gas and oil to a single bubble train, might be to induce rotation in the column of sea water surrounding the leak so the sea water would act as a "virtual wall", using centrifugal forces created by the difference in gravity, to continually force the lighter stuff toward the center, discouraging it from breaking up into multiple trains heading off in different directions.
Would it work for a 5000' column--can't say for sure, but the method should be studied as a means to control future spills that are not so deep underwater.
If the gas is mostly methane, it should continue to rise after breaking the surface. If it has relatively small amounts of methane, but a lot of propane, maybe not. It should not be difficult to measure and report what the methane/propane ratio is at the surface. Even after separation of the methane initially, the oil remaining on the surface will continue to outgas light hydrocarbons which would hug the surface when there is no "lift" in the atmosphere.
Awesome HOG.
That is the kind of thinking I was alluding to in my Solution web-site.
Move seawater like the sea moves water. Move air like the atmosphere moves air.
Think like Viktor Schauberger not like I sack NewTON!
As the gas comes out it forms bubbles, at 5000' below surface. Bubbles rise. On the way up they expand and break up into smaller bubbles. And also some bubbles collapse as the gas in them goes into solution in ocean water. The bubbles that reach the surface pop and release gas into atmosphere. These popping bubbles are far too small to be seen in the midst of the visual clutter of wind drive white caps.
Also smaller bubbles rise much slower than larger bubbles, so a lot of gas gets 'left behind' in the ocean.
Oil blobs also break up on the way up to the surface, but on a much different time scale than gas bubbles, and, obviously, have much less solubility in seawater.
And, "spreading oil on troubled waters" doesn't always work at reducing the trouble. Look at some picture of booms placed to stop the oil around islands. The oil is on the troubled side.
As an engineer, who has experience of pipe related accidents and analysis, i am extremely concerned about the condition of the BOP, the Riser and the whole "Drill string?" in general. From the video's i've seen BP are tip-toeing around the riser, and i'd be as nervous as well. The damage to the pipewall at the BOP looks serious, and with the 2-phase flow, erosion and damaged (Yielded) pipe at the BOP, I think BP believe the drill string is hanging on by a thread. A dynamic event such as a gas kick going back up the pipe would have placed tremendous stress and strain on the pipewall as well. I think BP want to leave the well alone, and just cap it off subsea. I think all the domes etc are are sideshow, else BP could have mechanically crimped the pipe by now, however, restricting the flow, is again, going to place stress back in to the pipe wall.
Looking at the video of the pipe leak, one can easily visualise it filling a barrel every second or so. allowing for 50% gas, its still in the region of 25-30000 barrels p/d.
In all of this though, the reaction of the US public is amazing to me. I guess the colour of Britney spears knickers is more important........
Best of luck all those involved.
That is very good point. Remember, they fixed that one leak. Maybe that caused already a lot of stress to the rest of the pipes because of sudden pressure/flow changes? All BP is now doing is try to GENTLY gather oil OUTSIDE, not to restrict it IN THE PIPE!
They may not even need sand for erosion. High gas velocities will eventually do the same thing. Assuming the vibrations don't fatigue it first.
Flow rate that high are pretty unusual. Wikki reports on a number of gushers at around the 100,000 BPD mark, but they are mostly associated with giant fields. As far as I am aware Kirkuk in Iraq holds the record for the single most (controlled) productive oil well. I've seen reports and daily stats claiming peak controlled flow at just over 100,000 BPD for one of its wells - recorded back in the 60s. But this coming from one huge field.
Here's an idea. Quit messing around with these little "top hats" and 2- and 6-inch diameter pipes. This job calls for the mother of all Shop Vacs.
Drop a 5000 foot length of plain old drilling riser, the stuff they typically use to run from seafloor to drilling platform, down to the leak, so its inlet is a few feet away from the broken pipe. Use the biggest diameter riser pipe you have on hand, 21 inch diameter I believe is typical.
On the deck of the drilling platform, run the riser into a big tank. It doesn't have to hold much pressure, it just has to be really big, and isolate its contents from the atmosphere.
Now, get the highest-volume pump you can find, and suck on the top of the riser pipe as hard as you can for a few minutes. A mix of water, oil, and gas will get slurped into the pipe. The oil will provide buoyancy. Clathrates will provide buoyancy. And the gas will provide a hell of a lot of buoyancy.
Once the pipe is primed with the oil/water/gas mix, switch off the pump: you don't need it any more. The buoyancy of the mix in the pipe will provide suction to slurp more water/oil/gas from the bottom. The buoyant fluid mix will rise up the pipe, slowly at first, then probably at ridiculous speeds near the top as the gas expands.
The tank at the top is a phase separator. The oil/water/gas mix rushes into the tank, and you allow the gas to rise to the top of the tank. Run a pipe away from the tank, and burn off the gas. Run the oil/water mix to another settling tank to separate out the oil.
The biggest danger here is the fluid mix coming out of the pipe. It's going to be a high-speed turbulent foam of oil, water, and lots and lots of gas. Separating off the gas safely is the big challenge.
Don't need a pump because hydrates will clog the unheated, untreated riser immediately.
Not if it's a *big* pipe.
Assume gas-to-oil ratio of about 3000 cubic feet per barrel (a common number thrown around here), and a flow rate of 50,000 barrels a day of oil.
Using the ideal gas law, I make it 1.8 x 10^8 moles of gas a day. Typical clathrates contain 46 molecules of water per molecule of guest molecule, so that's about 8.2 x 10^9 moles of clathrate a day. Which is...
1700 kilograms/second of clathrate. (For comparison, the mass flow of the oil itself would be just 80 kg/s in this case) This is a lot of mass, no wonder the big dome with its wimpy little pipe clogged up immediately, but a good high-volume pump should have no trouble keeping a few tons/sec of slurry moving through a 21" pipe at a brisk pace.
"a brisk pace" is somewhat inappropriate wording. If you run ANYWHERE CLOSE to that amount of gas to the surface through a pipe that size, it'll be coming out the top at velocities high enough that they won't be able to do anything with it.
I've said it before and I'll hope again that somebody can prove me wrong. They've GOT to separate the gas from the oil AT DEPTH. Let the gas go - it's (relatively) harmless unless and until you constrain the expansion to a pipe.
Any idea how to do that? Below about 300 meters depth, the methane will be in clathrate form, not a gas. Above 300 meters depth, the volume of gas is going to be large. Though now that I think about it, not nearly as large as at the surface... at 300 meters depth, the gas volume is 30x less than at the surface.
You could try putting a gas separator a few hundred meters below the surface, with a riser pipe leading from there down to the leak... but now we're not exactly talking about off-the-shelf components.
Look at the money, is it feasible to extract only 5000 barells at that depth?
I guesstimate the number 70,000 is the correct one!
BP does *NOT* want to measure flow rate
That last sentence is pure BS !!
The Explorer ship that is going to supposedly capture and process the oil from the "coffer dam", "top hat" or "smaller pipe", can only process 15,000 b/day of liquids.
If BP is polluting the water with, say, 50,000 b/day, then BP needs to know this. And have three more comparable ships under charter and underway RIGHT NOW !
(Unless BP knows that none of the strategies except the relief well will work and the attempts are just PR window dressing).
And why is BP not drilling FOUR relief wells but only two ? Any one well has significant risks of delay due to a variety of problems (see Rockman and others). The chances are significant that if only two relief wells are drilled, both will be delayed.
Best Hopes for a $50 billion cap (or unlimited) on consequential damages paid by BP,
That might motivate them to get serious.
Alan
http://www.washingtonpost.com/wp-dyn/content/article/2010/05/13/AR201005...
I can understand your outrage Alan, however I hardly think BOP's response isn't serious:
Right from the outset, chairman accepted that BP would be responsible for 100% of the cleanup costs (yes I know that's federally mandated). He never even tried to wriggle out of responsibility for collateral costs (loss of fishing and tourism business etc) even when these were limited to $75M by statute (a cap which is about to be lifted, it seems)
There have been multiple responses (coffer dam, "Top Hat", relief wells, other schemes in the, er, pipeline) - which seem to reflect a very nearly "money no object" willingness to confront the leak and deal with it. The efforts that aren't relief wells aren't window dressing, they are attempts to deal with the situation, which is very difficult to do at 5000ft. BP don't know they will fail, but can't be sure they will succeed, either.
I don't think David Nicholas' statement is BS at all - it reflects the fact that BP are trying desperately to deal with a very very bad situation, regardless of how many bpd it is.
The company may deserve to be roundly condemned for letting this happen, but it's hardly been sitting on its hands. IMHO BP is super-serious about a situation that's already cost them 15% of their market cap - how could they be anything else?
Regards Chris
BP is hiring people at $10/hour to work in swamps, in coveralls with the heat and humidity and mosquitoes to clean up the oil spill.
One can get a "crew" for the cameras paying that princely sum. One cannot get an effective crew that can get the job done for that.
Exxon paid more than that three decades ago for EV.
BP is not serious about stopping this well ASAP or cleaning it up properly. They are looking for the least cost option instead.
Best Hopes for a 50+% loss in market Value by BP, they deserve it !
Alan
"Least cost" option is drill two relief wells (one creates too much risk exposure).
"ASAP" option is to drill four relief wells. Analysis should show that the the average time to completion is days or even weeks less, but the average cost is higher.
BP is apparently going to drill two relief wells.
Alan
Alan do you seriously think the question of drilling more wells hasn't been thought of by all parties concerned? We don't know why they are not drilling 4 wells but I'll bet it isn't cost. Or due you think BP just told the US government "we won't do that because it is more expensive" and they replied "that's fine then".
BP is still in charge. And it still has influence at MMS I suspect.
Non-industry professionals (such as the Coast Guard) may not be aware of the high risk of delay for any single well. Not their field.
Add a little smoke from BP ...
Alan
Alan, I'd bet real money this entire key post plus every other forum discussing this is being fed into a big database where it's being poured over by god knows who. I am astonished that posters on TOD continually think we are more aware of the situation than "they" are.
Now you (and I for that matter) may not like the actions but we are intentionally and frustratingly not in the loop.
Sending another two rigs would seem good PR (if there's such a thing at this stage) as well. Somewhere there will be a risk/benefit analysis.
Do you think BP will say "we won't do that because it is more expensive" even if that is the reason ?
4 wells being drilled independently move faster? Really? What dynamics allow that to happen?
""ASAP" option is to drill four relief wells. Analysis should show that the the average time to completion is days or even weeks less, but the average cost is higher."
1) read
2) think
3) then post.
"4 wells being drilled independently move faster? Really? What dynamics allow that to happen?"
if well #1 fails we only have #2 in progress. more wells means faster (possible) time to completion. the only valid reason (aside from cost) not to drill more relief wells is safety.
Ah, so its the risk of failure that they mitigate by drilling additional relief wells, it doesn't actually speed up the time per well. Assuming they do not believe there is a high risk of failure in the first well, maybe their reasonably confident they don't need 4 wells.
So only if both relief wells fail to hit the target does it demonstrate they should have had more spudding. I thought there was something wrong with Alan's argument.
Hypothetical Risk Profile for each well (as an illustration)
- 80% chance of one week delay
- 50% chance of one month delay
- 20% chance of two month delay
- 5% chance of three month delay.
With two relief wells, 64% chance of both wells being delayed one week. With four wells, only a 41% chance that all 4 will be delayed a week.
With two relief wells, 25% chance of both wells being delayed one month. With four wells, only a 6% chance that all 4 will be delayed a month.
With two relief wells, 4% chance of both wells being delayed two months. With four wells, only a 0.16% chance that all 4 will be delayed two months.
With two relief wells, 0.25% chance of both wells being delayed three months. With four wells, almost no chance that all 4 will be delayed three months.
Reality is more complex, but the principle is the same.
Alan
I think there could also be a safety issue in bringing in more drilling rigs. Its getting pretty crowded around the sell head with 3 DP drilling rigs including the Discoverer Enterprise, at least 3 DP ROV support vessels, and a couple other vessels like the Q4000 and the Viking Poseidon.
Besides the obvious risk of collision, DP (dynamically positioned) can not operate too close to each other as the thruster wash impacts on the other vessels and could cause the DP computers a lot of headache trying to compensate for the various forces involved.
Relief well #1 will spud a half mile away from the wild well. Equal spacing would give 0.7 miles between each of four relief wells.
And RW #3 and #4 could move a few hundred yards further out if that is not adequate.
Alan
Good point.
Yea too bad it wasn't AIG or Fannie Freddie that spilled it, then we could feel sorry for them.
Better look closely at those Union Pension Fund Holdings at the SEIU or NEA before you wish to much of a loss for BP though.
How in the Hell can BP stop a leak if they don't know everything about it? They have measured it, believe me. Saying they haven't is disingenuous at best, fraudulent at worst.
The fact is the don't want anyone to KNOW how much oil is leaking, how much dispersal agent they are using, at what depths, and what sort of agent(s), or anything else that might be useful in determining the extent of the problem, the cost of mediation, and so forth.
They have no intention of paying anywhere near the total cost of damage done. They have legions of lawyers (nice alliteration, eh?) leaping about to muddy the already oily waters. In the end, they will be declared too big to fail, the taxpayers will bail them out and foot the bill, and you can make book on that.
Of course, that is my opinion. Someone talk me down.
Craig
If you want to know why there is no better official estimate then I suggest you ask the US authorities not BP. The party line is currently "it is not possible to estimate accurately" and hasn't been 5000 BPD for a long time - or as Admiral Landry put it "Don't get hung up on that 5000 BPD figure." Also note that at no time did BP or Transocean ever state officially that the leak was sealed at any point. That was based on a Coast Guard statement and even then they tried to tell the truth initially: "We are not saying nothing is coming out. We are saying we can't see it." (only reported by the Houston Chronicle) which by the next morning had been transformed into "We have no evidence of a leak." which everyone (other than the Chronicle) dutifully reported as definitively "no leak".
As long as there is no empirical evidence of numbers more then 5000 bpd you can always deny them. Plausible deniability is useful in court to be able to say: "not by our estimates, and there is no proof...blahblah". So, yes, it doesn't surprise me one bit that BP doesn't have an interest in the real numbers.
""I don't think an estimate of the flow rate would change either the direction or the scale of our response to it," Nicholas said."
The statement is pure PR, though badly done.
Yes, none of us are in the loop. But how does this loop function? Let's speculate. No doubt BP has established a crisis response team. Imagine yourself in charge of this team. Everyday you and other senior executives meet with senior engineers, spill clean up contractors/advisors, lawyers, and political and public relations advisors/consultants.
With regard to the spill numbers, BP's engineers probably do have an estimated spill range with supportable numbers at both ends, and this range may be changing. They are also providing a variety of engineering options to stop the spills based on these numbers. The engineering responses are based on an understanding of this range, which is not to say that solutions other than drilling a relief well can or do deal with the upper numbers.
BP's spill response professionals continue to roll out BP's clean up efforts. They report on all they are doing to obtain and deploy resources. They are likely focused on what they can do with the resources at hand and that can be obtained in the near term. With regard to a spill of this size, the size of the spill is almost not relevant to them because they will continue to do their immediate jobs with the resources they actually have, even if it seems they are bailing an ocean of oil with a teaspoon.
BP's lawyers probably advise it to admit to as little as possible without making false statements to government entities, and so probably advise that if numbers are used in public statements at all that BP choose the bottom end of the spill rate range as long as it is defensible. They understand that if BP provides a range or suggest a variety of numbers that these statements will be fodder in later legal claims, particularly with regard to deposing and cross examining engineers and senior executives. They will also need to provide evidence in court that BP responded proactively and aggressively and so encourage an aggressive response, whatever it is.
BP's PR and political advisors/consultants likely view this situation from a global perspective. They understand that a minority of people in the US and around the world will be personally impacted by this spill, and that the majority will judge BP by vague impressions of (1) how badly it screwed up in causing the spill together with (2) how it responds. BP can do little with regard to the former other than attempt to control when and where information is released to the public and also point fingers at others. BP largely controls the latter and can attempt to focus public attention on its spill control and clean up responses. They see that the best outcome to this situation is that most people around the world come to the conclusion that BP is "working hard" to address the spill, that spills happen, and that what is more important is how a company responds. They likely recommend that BP frame this situation by accentuating the positive, that is, the actions BP is taking to respond. Where near term control of a spill is difficult and unlikely, whether or not a near term response is likely to work is not as important from a PR perspective as that BP's responses are seen as being aggressive and positive.
Taking all this advice into account, the message coming out of BP related to the spill size could be expected to (1) focus media attention away from spill numbers and on to BP's spill response efforts, and (2) if they are used at all, select numbers from the low end of the range that are technically defensible so as to minimize liability. While the logic behind this approach is that spill numbers are not relevant to response, stating this in public should be seen as a PR mistake because it describes the message frame instead of actually working the frame.
I would expect BP to answer questions about spill size by first changing the subject back to their response efforts and if pressed stating that it is difficult to estimate the actual spill rate, but that BPs has the best engineers working on this and there are hundreds of vessels and thousands of people working, blah, blah, blah.
Thus, what BP says in public does not mean that BP doesn't have internal estimates of the spill rate or that their engineering fixes are not developed in light of knowledge of actual spill rates. The question is whether BP's engineers have faith in anything other than drilling a relief well, whether they look at the high end spill numbers and despair of near term solutions but soldier ahead anyway. BP's engineers may be taking near term actions to stop the spill with great internal doubt about their efficacy, but doing so in part because BP's lawyers and PR people insist that BP must be seen as being proactive and aggressive.
Cynically, the responses by engineers and spill clean up contractors can be used to paint a PR picture in a false light, and engineers and spill response contractors may support efforts with dubious benefits but that have politically useful results. It is always possible to respond positively even if such responses are unlikely to work or have substantial benefits. Most people react positively to efforts to clean up one's own mess and forget details about the power dynamics, structural problems, hubris, and mistakes that created the mess in the first place.
Going forward, if only the only entities involved in and capable of engaging meaningfully in offshore oil safety regulation are the oil companies and government, nothing will change. Best wishes for establishing a technically proficient independent watchdog organization that will fight the fundamental corruption in our country that limits safety advances, pre-positioned response capability, and liability.
So, two observations or actually questions:
1. If the figure is indeed actually closer to 70,000 bbls a day, does that mean that it's possible that the BOP didn't work at all? Rather than MOSTLY doing its job as has been reported?
2. The video we're seeing is only 30 seconds long. Given that BP probably has hours and hours of this particular leak recorded, is it possible that what we're seeing is the least-case scenario in all that footage? Can the oil be spewing any faster than what we're seeing in the video excerpt? Could BP have cherry-picked the video excerpt to give us a least-worse view of the leak?
I'll bet BP does not have final say on what is released. Do you honestly think all relevant parties don't have access to the video? Do you think the US government asks BP for permission to release footage? NASA spilled the beans first when they published the first spill pick. Shortly after their near real time public feeds of new incoming images experienced "hardware problems" and went offline for days. I suspect they annoyed some other government agency.
The video we've seen was released by BP. For all their "full access to BP's command center", the feds haven't released a single bit of info from below the waterline.
To be precise I believe it was released by the "Deepwater Horizon Unified Command/Joint Information Center" and not BP.
http://www.deepwaterhorizonresponse.com/go/site/2931/
http://www.youtube.com/user/DeepwaterHorizonJIC
Perhaps they don't ask "permission", because they know full well that they do not need permission, but a corporatist government such as that inhabiting Washington, is never going to kick its corporate BAU clients in the guts if it doesn't have to. They look after their own as well as they can (and as well as they can get away with). Is this news to you? I expect it is VERY likely that the very limited footage released so far is highly selective indeed.
I am not a conspiracist by any means, but the very notion that BP is not intrested in the leak rate is very very very very very alarming.
The leak rate is everything. It tells you the problems (engineering) upstream and the problems (environment) downstream.
Without it, all engineering is compromised.
I'm stunned...
Good grief has everyone taken leave of their senses? I suggest you send your post off to the MMS, Coast Guard, FEMA etc. as they obviously haven't considered that having the best possible knowledge of what's going on is important to them and they'll be glad to have this fact pointed out.
In this situation without a great deal of knowledge, the internet will start making up its own information to fill the void and conspiracies and accusations of bad faith are common when people don't understand what's going on. Some of us believe BP is acting in good faith and with their best efforts and others feel that BP is trying its best to make a bad situation worse. Neither of us can prove our assumptions, so no argument really can win at this point.
We have the public statement by an official BP spokesperson that measuring the flow is not important.
We have a statement from Woods Hole that they have the equipment required to directly measure velocity and that they have talked extensively with BP. Implied is that they would be willing to share their equipment and expertise with BP ("the entire world is willing to help").
Engineering judgment (mine) is that:
- one of the ROVs could be loaded up with the Woods Hole equipment and is likely to give (after several measurements over time) a good estimate of the flow from the pipe. Further measurements (going back several weeks when they were first technically possible and going forward in time) could provide additional useful information.
- said use of one ROV will not materially slow down or interfere with other efforts to contain the spill.
- a good estimate of flow is required to properly prepare for any of the capture options (coffer dam, top hat, small pipe plug, hot tap) and would be useful for "junk shot" and the relief wells as well as surface containment efforts.
For the capture options, BP would need to know how much production and entrained water they would need to process (the ship on site is limited to 15,000 b/day).
The last point is contradicted by the BP statement.
With the contradiction, I do not doubt my engineering judgment that knowing (within a few %) the flow rate would be either quite useful or essential (depending upon the mitigation option).
Therefore I doubt the BP statements below.
which leads, quite logically, to questions of BP motives, veracity, mendacity, integrity and much else.
Alan
Alot of things have to come together to deploy equipment. How many ROV's does BP have. Can they spare the hours of visual data lost to bring an ROV to surface to then attach the equipment. Is there a port on the ROV that can accept the data input? Once attached to the ROV and put in place, what is the error range of the flow? Is it somewhere along the same lines as what BP engineers have for a range (5k-60k bbls/d). Does BP even have any available resources to process greater than the 15k bbls/d from another ship? Does the liquid need to be processed in any case or simply pumped from one tank to another (maybe just venting methane rather than compressing and storing it). If it need not be processed, then what is the storage capacity (as that is all that matters now). So I would say its not quite as simple as you think and so you can either choose to believe BP is acting in good faith or bad faith.
How many ROV's does BP have ?
BP can get just about any ROV in the world that it wants (if it is willing to pay). Thus if ANY ROV can handle the equipment, BP can get it. This also solves any problems with a shortage of ROV time.
Does BP even have any available resources to process greater than the 15k bbls/d from another ship?
According to press reports, not on site.
Alan
Your excuses are a bit weak. All available resources have been made available to this effort including the resources of the US govt/DOD/govt labs. Simple logic suggests that knowing the leak rate and composition is important information for mitigation efforts. They were able to get a gamma ray scanner fitted for work at depth and hooked up to an ROV. I am sure the team working on this has pretty good estimates and answers to most of the questions being debated here.
As this came under the umbrella of homeland security pretty early on the reasons for failure to inform the public and release data may have run into some additional complications...
I would hardly think there is anything simple about what they're doing. I am merely elaborating on possible sources of logisitical issue, which are irrespective of "bulk resources" provided by the government. Many projects have failed because the mentality of "throw resources and manpower at the problem" doesn't account for actual usefulness of those resources and manpower.
Maybe every ROV in the world could come rushing to the gulf, but if it would take a week, what use would it be to a solution tomorrow?
I will reiterate (probably unnecessary) that your excuses are weak.
It has been three and a half weeks.
Just about every ROV in the world could be in New Orleans (or Venice or Port Fourchon) by now, and any ROV could be deployed as needed.
Shortage of ROVs is not an excuse.
Alan
There is a limit to the number of ROVs that can be deployed. At the moment my guess is there are at least 10 to 12 ROVs on site and it is doubtful more can be safely deployed because there is no more room for ROV support vessels.
Each ROV dive to 5,000 feet is planned very carefully and has to be coordinated with any other ROV working in the same area. The last thing you need is a 2 ton ROV out of control or tangled up further complicating an already confused situation.
"First do no harm".
hey, that's a lot of nice information about rov's.
the question alan asked is, can one of the 10 or 12 be outfitted with the woods hole equipment and give us a useable number for the size of the leak?
why do you always seem to obfuscate?
'first do no harm'
is there a risk of increasing the flow by measuring it? who does it harm? bp?
The point I was making had to do with why they weren't deploying more ROVs. They do have more standing by.
"First do no harm" - any collision between vessels or problems with ROVs getting tangled up could set the work back by hours or days and could even damage the riser or BOP and increase the flow further. Safety is paramount.
As for measuring the flow speed at the outflow there is a standard piece of ROV deployable equipment is used to measure current speeds up to several knots, probably 10 ft/sec or more. There is probably one or more units already onboard the ROV support vessels, or could be flown out anytime, they aren't large. I'm sure they could be inserted into the outflow.
Or the Woods Hole equipment could be used assuming it is suitable for the depth (almost certainly) and is either stand alone or capable of interfacing with the ROV data system.
Why haven't they done it?
1 - They may have more important tasks. But it isn't a large project to install the offshore measuring equipment, (I'm not sure about the Woods Hole equipment) when you are on deck to fit some other tools package That excuse seems weak.
2 - There might be a safety concern about getting the ROV into the flow where it might be damaged. If this was around the BOP I wouldn't let them do it as an ROV is like a 200 HP car, same power and same weight. If it gets out of control it could damage piping and control systems on the BOP. But this leak is hundreds of feet away from the BOP and there doesn't seem to be anything close by to hurt except the ROV itself, and they are tough little beasties.
3 - Maybe they have already made that measurement and are just not releasing the information. If they have measured it then the MMS and the USCG have the information as they are observing everything going on.
4 - Maybe BP has their own reasons not to make the measurement.
McClatchy reporter in Houston says there are 7 ROVs on blowout site in operation, + one more not presently working (blank screen). Reporter describes the command HQ scene.
And again I'll bet that what was really meant was "not an important outstanding issue" (because they already have the best information available internally at "Unified Command").
Further I am certain, in my own mind, if someone came up with a plan guaranteed to shut off the flow today safely, but it would cost 5 billion dollars, then it would be authorised immediately.
By the way Kent Well's exact words were: "I think what we've been very clear about is we dont know what it is. There's just no way to measure it."
That is the agreed current party line from "Unified Command".
I question "motives, veracity, mendacity, integrity and much else" of just about everyone in positions of power but I strongly suggest to you that there are agencies involved here that should equally have questions directed at them who are quite happy to spin against BP on decisions they themselves pretty much made. That's how the system works.
My experience dealing with oil company safety is that the "system" is set up in reaction to crises, that oil company lobbyists jack the laws so pols can take credit for doing something without actually changing the balance of power, that oil company regulatory staff jack the regs to neuter the laws to the extent possible, that oil companies have tremendous political power that is used to constantly pressure and intimidate government agencies, and that the oil companies work hard to limit meaningful citizen participation in critical judgments about oil development safety and risks, and that no one except for the oil companies and government have the resources to pay any attention to the all-important details of oil development safety, with the result that the government get captured.
Saying that the government pretty much makes decisions itself, while perhaps technically true in a abstract legal sense, is a gross oversimplification of the governance reality that produced this catastrophe. The oil companies have far more power than the bureaucrats or politicians. Go ahead and whip the bureaucrats for a while -- it's politically useful especially with the anti-government crowd -- even if it helps collapse civil society.
Regardless, this entire disaster is a product of oil company action and the industry deserves to be tarred with its own mess so that everyone remembers that this is their failure. As I've said before, the oil companies and their conservative allies will use the government as a whipping boy -- that seems to be its primary utility to them. Not that government staff doesn't deserve to be replaced for failing to protect citizens, but even if every bureaucrat is replaced, the couragous and principled in the next round of regulators will be driven out by the oil companies and the complacent and obedient rewarded, if citizens fail to demand that the government do better. In general, it's specious and lazy to attack government for its failures without working to make it function properly.
If the industry feels no pain as whole, and perhaps more importantly if industry leaders pay no individual costs (in substantial amounts of lost cash or jail time), there will be no fundamental change. Wanna bet BP execs get big delayed or hidden bonuses for dealing with this crisis?
Everything about the mad dash for deep GoM production is to do with Peak Oil and that "can't" be explained to the public. I am disgusted by all in positions of power whether they be oil companies, banks, media, politicians, Kings or whatever. Those that think they are doing the right thing are deluding themselves at best and being actively misled by a few at worst. I am sure they disagree.
Ever seen the BBC Peak Oil Drama Burn Up where a fictionalised head of a fictionalised BP was persuaded to release unequivocal audited data on Saudi Arabia to the press as the "right thing" to do. Then the CIA stepped in and started killing everyone in desperation to retrieve the situation. Lucky it is fiction. I won't give the end away.
I think that there's a distinction to be made about what BP is saying publicly here, and what their engineering staff, responsible for the engineering solution, are assuming.
BP is a multi-billion dollar brand, subject to intensive brand management in the normal way for such entities. The brand managers will be desperate to minimise the damage to their baby, and have every reason to low-ball the numbers. It's their job to do that, even if involves being "ecomnomical with the truth".
There's no reason, however, to think that the crisis-engineering team ever listened to the brand message. Why should they - they have a far clearer understanding of the leakage extent than the marketeers. They're well-positioned to make their own estimates, so they'll do that - then dream up their (hopefully) solutions. And they know far better than anyone writing on this board about whether there;s a spare ROV for a few days.
I'm not particularly convinced that the costs of getting accurate numbers are worth the benefits - and accurate numbers shouldn't be confused with the expected brand management activities we've been seeing in the media.
Regards Chris
Your argument is internally inconsistent. You believe that BP has more accurate estimates. How expensive can a Congressional Subpoena be?
No, I don't think so ... and I think you are avoiding the point of the various posts on this. The BP PR flack says this stuff (the flow rate isn't that relevant, etc), and they expect their comments to be taken on board, and it seems that they have been. I agree with the poster(s) - down-playing the rate "Shucks guys, we don't have no time to measure the goddam rate, we're busting our ass trying to stop the sucker ...", etc, is totally ingenuous at best, but more likely pure spin.
I think posters have every reason to express a little outrage at such insouciance, frankly. BP might fear plaintiff lawyers long-term (a little), but they don't fear the gubmint and its agencies ... why on earth would they?
Centrifugals will not pump a gas and they are not particularly fond of oil. The casing will air lock. Of course you could draw a vacuum on the casing and get rid of the gas. BP would need very large centrifugals and very large power supply to drive the pumps.
Reciprocating pumps I don’t think will get the volume.
moved post
idontno
Please verify pronouncement first.
Centrifugal compressors work just fine on gas when designed for that.
I have a hard time understanding BP's claim that they can't get a good fix on the flow rate of the escaping oil/gas.
It is fundamentally a fairly simply determination: if you know the upstream pressure (which I think they have a pretty good handle on), and the approximate area of the irregular 'orifice(s)' formed by the openings in the pipe, then a few simple calculations should provide a reasonably decent estimate of the flow rate.
While the area of the openings can't be measured directly, the visual footage of the leaks should enable one to make a fairly good approximation of the area. One doesn't need anything more than a good still photo and a ruler to do that.
Of course, having two-phase flow complicates the matter, but I would imagine that one can make two approximations: one for 100% gas, and the other for 100% oil, and that should give the boundaries. There are also somewhat more elaborate means of calculating two-phase flow, which I am sure the oil industry is quite expert in.
70,000 bbl/day day at first sounds like a huge flow to be coming out of a small opening, but it amounts to 2,040 gal/min or 4.5 cubic feet/sec. With all that pressure behind it, it is quite possible that the oil squirting out of the openings could easily have a velocity in excess of 100 ft/sec. In which case, all you would need is a bit less than 7 square inches of opening, which would be equivalent to a 3-inch diameter pipe. So I think when put in those terms, it is not out of the realm of possibility that the leak could be as large as 70,000 bbl/day.
Of course the important measure is flow multiplied by time. It could be a smaller flow rate but if this goes on for twice as long as projected, it would be equivalent to having twice the flow rate in a shorter time.
So we have the uncertainty principle at work here. They can't say how fast it is flowing and they don't know how long it will last.
WebHubbleTelescope -
True, the flow will eventually vary over time (hopefully deceasing, but maybe not, if erosion makes the openings larger). But in the relatively short time frame of several weeks, it shouldn't be all that great a factor. Of course, if (shudder) it is still flowing months from now, then one might see an attenuation of flow. One can have several flow numbers for different chunks of time and then integrate it all to come up with an estimate of the total release.
Again, we are just trying to get some ballpark estimates to see if some of the initially released flow numbers pass the reasonableness test. (And I am beginning to doubt that they do.) There is absolutely no need to estimate this with pinpoint accuracy.
when the well is brought under control we could have an answer as to how much has leaked from the reservoir by the majic of material balance and volumetric calculations. in reality, a reservoir simulation would be needed,but knowing the pressure loss, ooip and pvt properties of the oil, water and gas, and an estimate of water influx, if any, into the reservoir, the amount lost can be estimated. lots of room for errors in this analysis, but i would wager that the total spew can be estimated a lot more accurately than all the current guestimates. not to take away from all the thought and analysis that has taken place here. but npr ??? not real credible, imo.
and unfortunately, bp may be the one doing the calculations.
No we don't - the Uncertainty Principle is something completely different ... all we have here are one, two, or more unknown pieces of information that are needed to calculate the flow rate per day. No need to over-blow it.
That flow is extremely easy to calculate. It's 100,000's of bpd. The assumption is that the BOP (or something else) is restricting the flow so you do not have an open 20" pipe connected to a 10,000 psi reservoir.
Would you like to share your "extremely easy" calculations with us???
Way too many variables for me:
1. What is the oil/gas/water/sand ratio of the mix exiting the pipe?
2. What is the effect of the pressure at depth on this substance? Is this mix compressable? Is the measure of velocity/volume at depth a good estimate of the same at the surface?
3. At what point in the water column do the various components of this substance begin to separate? What percentage of crude oil components separate into solid/semi-solid "tarballs", and at what depth do these components reach near neutral bouyancy? It occurs to me that the water column is, in effect a refinery, separating the different components.
4. How much emulsification of the lighter components of the crude occurs, and what effect does this have on the volume reaching the surface? Do the more volatile components actually evaporate immediately when reaching the surface?
5. Are the videos of the mix exiting the pipes representative of this process over time? Does the flow fluctuate? How consistant is the composition of the mix over time? Has/will the ratio of oil to gas increase over time?
Many more questions/variables will make any postulated estimate useless. There is only one good answer to the question of how much:
Too much.
Ghung -
While I agree that any amount is too much, I don't think it all has to be that complicated to make a rough estimate.
One can first start by assuming the leak is 100% oil. That eliminates factors such as compressibility. I would then just do a simple orifice calculation with an opening area estimated by visual examination of the photos and an assumed pressure drop based on what we know about the pressure on the downstream side of the BOP. We can also allow for some pressure losses due to typical pipe friction loss factors.
Once the leak has escaped the opening and is now in open water, for the purposes of our estimation it doesn't matter a wit what the stuff does: it's already out. What happens once the stuff hits the ocean surface is another question that has nothing to do with estimating how much oil is coming out of the pipe. I would agree with you, though, that it is a far more difficult task to determine how the various components of the leak 'partition' once they are out in the environment.
This should represent a worst case, as we are not concerned (too much) about the natural gas phase, as that will rapidly dissipate into the atmosphere once it hits the surface.
We can then start playing around with various ratios of oil to gas to back away from the worst case example. This should allow for a ballpark estimate that is useful in showing whether the original 5,000 bbl/day is reasonable or a deliberate low-ball. Remember, we don't have to know the flow within three decimal places.
Caught a thread last night regarding the registration of the rig. Out on a well so I couldn’t respond at the time. But here’s the short answer. I can see how folks could be confused especially since most of us have serious doubts about BP’s integrity. But we don’t need to develop false issues. There already appears to be enough sins by the parties involve to justify a lynching.
A little clarification on the requirements for drilling in the US OCS offshore areas. It does not matter what flag a vessel flies: Liberian or the planet Venus. No drilling rig can operate in US water unless it meets all the standards required by the MMS. As pointed out, many rig fly a foreign flag for tax reasons. But that has no bearing of safety equipment or procedures used on the rig. No one has the RIGHT to drill a well in our OCS. It is a privilege granted only after the rig proves it complies with all MMS standards. The regs that deal with these issues not some short memo. It covers thousands of pages of requirements and regs. Comply satisfactory or you don’t get a drill permit. Simple as that.
OTOH, are the MMS regs and enforcement satisfactory? I think most have come to the correct conclusion that the system is very lacking. I’ve seen a rig fined by an MMS inspector because he found too many burned out light bulbs. Rules are rules, right? In the oil patch it’s called “getting ink” from the feds. Too much ink and you get a big fine. Way too much ink and they’ll shut down the operations. Way, way too much ink and they’ll cancel your operator’s license. I suspect by the time the blow out investigation is concluded they’ll discover the standards are more than adequate for the little stuff but grossly lacking for the big stuff: the stuff that burns down rigs, kills hands and destroys a big chunk of the environment. Just MHO.
There already appears to be enough sins by the parties involve to justify a lynching.
*eyebrows raised* Care to summarize the sins we are 100% sure about that justify a lynching. I was under the impression that we still lack a great deal of vital information.
Greg -- I agree about reserving judgment until we hear documented facts. But from what I've seen as well as some bits I've gotten from private sources BP made what would be considered (by everyone in the oil patch IMHO) a very poor and dangerous operational decision. I’ve seen company men fired and careers destroyed for less serious bad decisions. But we do need to wait for the final investigation before we toss that rope over the tree limb. But it doesn’t hurt to wax that rope up while we wait.
I assume we're talking about the failed negative pressure tests followed by the decision to displace the mud with seawater. I am very concerned about why that decision was made, but there's so much confusion and several different accounts that. I'm not a downhole guy by any means, but I've heard alot of arguments between downhole guys on what is "usually done" given these circumstances, so until some concensus is given, I'm going to hold off judgement.
Greg -- way beyond that. I apologize because I’m about to give you the Mother of all teases but I promised the source not to repeat it until there’s very sure confirmation. Even had I not promised to not repeat the story I don’t think I would until I saw official confirmation. It’s that condemning and inflamatory. This new story is either one of the biggest intentional lies or the truth. Nothing vague about the implications. Not a story that grew and altered as it got repeated multiple times. And the ultimate confirmation will come from an independent third party that hasn’t even been mentioned in the event. Like I said: a very bad tease that would certainly beg for details but I won’t expand. Sorry.
And I fully agree about withholding judgment. Fair speculation is another matter IMHO.
Then I guess I'll just say that I hope the truth prevails.
I assume you do not use the word "condemning" lightly, and I know you just said you promised not to spill the beans but are you implying criminal negligence or just massive incompetence?
If the story, whatever it is, is true, are we going to see the responsible parties do hard time?
Anything that serious without credibility behind it could be very damaging to many people and I approve of Rockman keeping silent until allegation turns to fact.
Mother of all teases
Rockman, can you say whether this is something that will inevitably come out eventually and be officially confirmed, or is there a chance it'll be successfully suppressed?
FOR ALL
As usual I start with the big IF. IF the story is true I can promise you the lawyers of the company these potential witnesses work for already have their sworn statements in the can. And, IF those statements exist they will become a part of the official public record. Absolutely no chance of suppression. These potential witnesses, IF they really exist, don’t have a dog in the fight. Credibility will be very high.
My definition of a secret: something only one person knows. Anymore than it’s only limited knowledge. IF the story is true it will start leaking from the sources soon IMHO. If we don’t see that happening in the next week or so I’ll become more suspicious of its validity.
Criminal vs. negligent: all in the eye of the beholder IMHO.
ROCKMAN -
Wow! That sounds rather murky (so to speak).
Just be careful not to have an 'accident' before this comes to light. These days, a little paranoia is a healthy thing.
Hmmm. Now that you mention it one of the hands almost backed into me with his pickup on this well site about an hour ago. Was that an old BP sticker on his hard hat?
I’m far removed from the facts so I‘m not a threat to anyone. Why I won’t repeat the details. But I’ll remind folks that they keep hearing about BP, Transworld and Halliburton. But there may been have a dozen or more different service companies on the rig. And there is constant interaction between these different hands. Lots of eyes out there. Lots of cross chatter. Very few secrets.
Rock,
Do you think it likely that there is an existing recording of that meeting (with participants on-shore as well?) recorded off-site? I would assume yes but if not surely there should be.
Coincidentally just as I write this NASA has decided to remove a launch-constraint and proceed with Atlantis countdown despite having found a "ball-bearing" where it shouldn't have been and not being certain where it came from. However every part of that decision sequence has been recorded.
Tow - probably no recordings but emails dominate the oil patch these days. Many times I’ve followed up conversations with an email (I always copy to my flash drive just in case there’s a “server problem” and the message ends up missing. Your basic CYA move. But in the end there will be a lot of witnesses and such folks with strong tech backgrounds will add much detail to the story. We won't hear from those folks right now IMHO. They'll say what the have to say but that won't happen until they're under oath. Out of court you can get sued for your opinions. In court you're required to offer them.
I think that it is interesting that BP, according to a reporter that emailed me, flat out refused to discuss actual Thunder Horse production numbers. Their only on the record comment regarding Thunder Horse was that 2010 2Q maintenance would affect 2010 production.
I think that is is somewhat revealing about their corporate culture that they are trying to stonewall reporters--when the actual production numbers are reported to the MMS. I suppose BP thinks that if they don't acknowledge the collapse in production from the main structure, they think that reporters and trade journals won't "break" the story. So far, they have been right.
I still haven't seen it.
The seal assembly in the wellhead was tested to 10,000.
Prior to displacing the riser, a positive pressure test held.
The negative pressure test showed 1,400 psi on the drillpipe and 0 psi on the choke and kill lines. If the drillpipe contained seawater and the choke and kill lines contained mud prior to displacing the riser than this is exactly what the pressure should read.
In the last 120 seconds something let go and the standpipe pressure went from 1,500 psi to 5,800 psi. I can't imagine what the men on the rig floor were going through then.
FF
Rockman, you are talking about a legal hanging.
I just returned home from time with my father in Kentucky (Mother's Day) and the mood here is much less concerned with legal niceties.
Best Hopes for Punitive Damages and Jail Time,
Alan
"everyone in oil patch" would include those making the decision. So you have heard that someone/group knowingly made a "very poor and dangerous operational decision". Now this may turn out to be true or not but if it is, given the outcome, I would suggest that they should by now be either under arrest or under compulsory psychiatric detention.
That's what would happen to me if I knowingly decided to drive my car with no brakes and killed eleven people at a bus stop.
Actually, vehicular homicide is about the safest possible crime to commit#. RARELY prosecuted.
A sore point with bicyclists.
Alan
# If memory serves, Laura Bush ran a stop sign and killed someone. No charges. I did not follow that closely.
Running a stop sign is different from knowingly driving without brakes (perhaps it shouldn't be). In the UK I would expect a fixed fine for the first offence assuming no other parties involved (if anything at all) and a prosecution for the latter even if no other parties involved (police stop and check discovered no brakes perhaps as the reason I ran the stop sign). But that's in the UK and maybe my expectations of what would happen aren't absolutely accurate.
I see the Laura Bush incident was in 1963 when she had only just turned 17 and she killed a friend.
I thought about felony discharging without a permit under CWA. Easy to prove, I would think, but I am no lawyer.
Simply not good enough Rocker ... we expect immediate and totally considered responses 24/7, even if you have a monkey wrench in one hand, and the other capped over a drill pipe stopping an awkward flow. Lift yer game!
The well is at say 32000 ft. To do a flow calculation you need to know the friction head in the well. Then, you need to know the friction head of the BOP. Then you need to know the friction head of the riser. This will limit the flow. A good example of this in the summer I water my lawn with a soaker hose made from recycled tires. When the hose is pressured, many bubbles form at the beginning of the hose and decrease as the end of the hose is approached. If you remove the cap at the furthest end, water does not squirt out. The friction head of hose is too great. No matter what the pressure is in the well the friction head will limit the flow.
I not sure where you will find a way to calculate the friction head in the well bore.
You need all that to predict the flow but not to measure the flow. There is a velocity exiting either a 16" casing or a 9" drill string. Velocity and area combine to define volume flow. Another way to look at it would be to work out the velocity exiting the pipe at 5000 a day through a 16" or 9" pipe and then look at the video. What does your gut tell you about BPs estimate? I think it's way low. IMHO
Settinglake
Yes, Q=VA one of the simplest formulas for measuring flow rate. And here are two reason for why it is important to know.
1) If you are going to capture the oil you need to know how much to adequately size the collection and treatment system. Off by a factor of 10 and someone is going to be very embarrassed when they bring it to the surface and then most of it overflows back into the ocean.
2) From the little I've heard and seen, all of this flow is coming up through a 9 inch dia. pipe within the 21 inch pipe which have been partially blocked by the BOP. I'll let someone else compute the needed pressure to drive this much flow through such a small area with a high friction loss at the BOP. The pressure information is needed so the appropriate design and operational changes can be made to ensure it doesn't happen again.
This reservoir may have had one of the highest if not the highest internal pressures encountered (just my guess). The following question will be, is this a singular anomaly or are their other reservoirs out there with even higher internal pressures, and how do you know before you stick your straw into it?
I'm sure BP knows this.
A co-worker in the next cube was just watching some talking heads on CNN "debating" this new flow figure (as reported by NPR). The idiots were freely interchanging "barrels" with "gallons" when talking about the two figures (5000bbl/day vs. 70,000bbl/day). 5000 gallons, 5000 barrels, 70,000 gallons, 70,000 barrels. They were saying "gallons" a lot more than "barrels."
Took me a couple of minutes to convince co-worker the correct unit is barrels. Then he really realized the magnitude of this disaster.
Where's the oil? Model suggests much may be gone
http://news.yahoo.com/s/ap/us_gulf_spill_where_s_the_oil;_ylt=Am5LmPxt4w...
I agree MMS does have much to say about the rig but the USCG has even more to say. Subchapter F details the requirements for design of the rig and ocean going vessels. If the vessel is American flagged, it is obligated to comply with the USCG regulations. The USCG issues the Certificate of Seaworthiness. This certificate must be posted on the vessel or MODU before it can go to sea. USCG is tasked with ensuring safety at sea. This also includes Solas requirements. The USCG was given this responsibility after the Titanic. It hasn’t changed since. The only thing that has changed is once the USCG was under the jurisdiction of Treasury whereas now they are under the jurisdiction of Homeland Security. The MMS takes over where the USCG leaves off. For example the USCG does not have much to say about safety relief systems but the MMS has a interest. There are overlaps and this is the reason that designing one of these complicated rigs so difficult-trying to comply with all the regulations. These regulations can be found in the CFR’s
Another issue that has not been addressed is who classified the rig-probably the American Bureau of Shipping (ABS). The ABS has their own set of specifications for the rig. The insurance companies rely heavily on the ABS for issuance of insurance. So there are three parties involved in the design and construction of an offshore platform-USCG, MMS, and the classification society. They all have their own little important niche.
Lately, because of lack of personnel in the USCG, the USCG has given the ABS the authority to make shop inspections for new equipment under the jurisdiction of the USCG.
The USCG determines how many licensed personnel must be on board a ship or MODU and this is normally shown on the Certificate of Seaworthiness.
D-Day. The junk shot will go down today and if successful will be followed by an attempt to kill the well.
Speculation based on available evidence: Time is of the essence as the leak rate has been steadily increasing and there is a fear that remaining constraints on the flow are deteriorating. Attempts to capture the flow from the riser have run afoul of the velocity of the flow and the entrained gas content and have been abandoned. We should wish them luck with this.
IP: I heard the same thing. If I remember correctly in a BP review they had stated they had been working on all the technical equipment related to setting up the junk shot witha staged shot sequence (I believe they said at least ten separated shots staggered one behind the other). They seemed to show genuine interest in moving up this approach as soon as they determined the internals on the BOP using the equipment from Sandia. They said all along they wanted to insure the internal integrity and have some of the pressures before they went into the lines to start the kill and then be prepared to pump mud. If the flow is really as high as some have suggested then I wonder if the junk shot does not work they will immediately try to remove the riser and put the new BOP stack on . Any of you top engineers have thoughts?
I WISH I could summon a little more enthusiasm for the junk shot, but I'm afraid it's the BEST shot remaining. I hope the erosion in the BOP hasn't yet smoothed out the flow path enough to let everything get through.
Houston to the trigger man: "Don't worry, if you fail, only about 30 million people are going to suffer. No pressure, no pressure at all, man" :)
I have asked this question before...
If one assumes that the main avenue (only?) for the leak through the BOP is the drill pipe, and this pipe extends some thousands of feet down into the well then how is junk injected at the wellhead going to plug the leak?
I assume that no information regarding the exact path of the flow through the BOP has been made public, so I can hope that perhaps the rams succeeded in at least partially shearing the DP and/or some significant portion of the flow is coming outside the pipe through damaged shears and annular preventer...
The choke and kill lines they are working on enter the well at the bottom of the BOP stack below the rams so they have direct access to the well bore and inside the casing - assuming something isn't really messed just up below the BOP.
As I understand it they can blow something that is near neutrally buoyant, hard and pliable at the same time - like golf balls and pieces of tire rubber - and the flow will take it up and hopefully enough will jam in the leaks to slow or stop the flow.
If the flow is slowed enough they can pump in drilling mud and kill the well.
The kill and choke lines were severely damaged when the rig sank and the riser bent over. The ROV crews have been working to clear the debris and cut off the damaged portions of the piping. At the same time onshore teams have been designing and manufacturing fittings that the ROV can clamp onto the pipes that will handle at least 20,000 psi.
Understood - my question regards the path of the oil feeding the leak - is it coming up a few thousand feet of drill pipe and through the BOP within that pipe (maybe a little restricted due to partially activated shear rams) and out past the annular preventer to the kink and then exiting the broken drill pipe into the riser at that point? OR is it also flowing around the DP within the BOP and past a damaged annular preventer and into the riser?
If the former, how is the junk shot going to reach the entrance to the drill pipe?
The junk shot pretty much assumes the flow is coming up the well bore - hence my comment "assuming something isn't really messed just up below the BOP."
I'm not familiar enough with BOP plumbing to know if there is an alternate path through the choke and kill lines to inject something into the annular. Or if there is another set of lines that can be tapped into the annular.
When this was being discussed by BP officials they said they were going to try to reconfigure the BOP to enable this operation. Tapping in below the valve sounds reasonably straight forward. Perhaps they also intend something like you suggest. They did scan the interior so I assume they have a reasonable idea of the leak path.
Some of the piping on the outside of the BOP was severely damaged either when the rig was pulling on the riser and BOP after it lost power or when it sank.
The choke and kill lines were part of what was damaged. The ROVs have been working to clear those lines and have cut them off so specially designed and manufactured fittings can be attached. Those fittings have to be able to handle 15,000 psi or more.
I believe this is what BP was referring to when they were talking about reconfiguring the BOP. Its being "reconfigured" so the ROVs can hook up a surface line (coiled tubing unit?) to the lines.
Here's hoping this bit of sphagetti sticks!
Like I said, the engineers were waaaay to cagey over the riser.
D-day indeed....
IP, can you elaborate on that "junk-shot" for today.....Settles is talking about a pipe insertion on CNN.
Sorry, I can't. We should know by tomorrow what went down - barring some disaster or great success that can't wait.
I_P, andyimages
Located this BP explanation of the junk shot from Environmental News Service
A more detailed blow by blow in there as well. Seems they brought up the mis-wired control panel.
Thanks, but that only explains how they intend to hook up the plumbing and control the flow - it doesn't answer the question of how the 'junk' will get to the leak entrance if that happens to be a drill pipe hanging a few thousand feet down the well... Here's hoping the leak is actually through the innards of the BOP and not through an intact drill pipe.
Yes but it sounds as if they have more hopes for it.
Hmmm and I wonder with a refurbished control pod if they'd be trying those shear rams again too? Probably not unless the junk does not 'plug immediately' (the BOP side) or at all.
What causes this mud to stay down and not be caught in the rising oil/gas column? Perhaps they are thinking the huge pumping facilities will be able to put enough mud weight into the oil column fast enough to get ahead of it. Seems like a lot of volume for choke and kill ports, but maybe they hope to have something to hit the restriction ahead of it, anyone?
The whole point of the junk shot is that if it works, there won't *be* a rising oil/gas column.
If the kink in the drill pipe near the main leak is a leak source, then it would seem the mud has to go down the well casing and all the way up to that point. There was oil coming from the end of the drill string previously so with that capped it sounds good unless the drill string is open beyond the BOP.
I am sure they are talking about this well - they want to kill it and shut it in ASAP. They will have to overcome well pressure with their mud column - but must have the flow through the BOP stopped first so the mud goes down instead of up...
That's how I understand it as well. Hook on, get the ports open with the rebuilt panel, junk the BOP and then push mud down to overcome well pressure.
If all that happens and the drill string is intact from the BOP upward probably going to be a good day. Don't know how well that pipe bends double w/o leaking.
Best hopes for some spaghetti with some serious meatballs in it this time.
So the mud would go into the casing/drill pipe via one of the ports on the BOP if the junk fill works? (as opposed to from the top of BOP?)
Yes. (also see shelburn explanation above) One source said control ports but in this article choke and kill. Perhaps one of the oilpatch guys will help us out. I am interested in what pipe I.D we are talking here?
"According to Transocean's fleet inventory, the BOP is a Hydril 18¾ inch 15,000 psi, six-ram system with a Cameron 15,000 psi wellhead connector." http://www.upstreamonline.com/live/article214534.ece
A generic diagram of a BOP, choke and kill down low.
http://www.glossary.oilfield.slb.com/DisplayImage.cfm?ID=300
Man, that's some impressive hydraulic specs. The BOP's rams need, on the backside of the drive cylinders, sufficient pressure to balance the operating pressure (15,000 psi or 100 MPa) plus sufficient excess to actually shear the heavy pipes (probably at least 5,000 psi or 33 MPa). How does one provide a guaranteed reservoir of drive fluid at 133 MPa under 1.5 km of seawater? Ouch.
"plus sufficient excess to actually shear the heavy pipes (probably at least 5,000 psi or 33 MPa)..... "
Heavy wall pipe of 6-5/8" diameter (about 0.43") when flattened would have a cross sectional area of 19.5". If the pipe is alloy steel like ASTM A387 gr-2 then the yield point is 45ksi and tensile is 75ksi. Minimum force to shear would be 60% of tensile so that is about 878,000 lbs. plus the force to overcome internal pressure (maybe 15,000 psi) adds another 273,000 lbs. for a total theoretical force of 1,151,000 lbs. At 6000psi working pressure of ram, the diameter of the BOP cylinder must be at least 16 inches.
IIRC other posts have mentioned air motors that charge an accumulator to provide this pressure to the rams and air pressure is maintained by battery operated pumps. Congressional hearings revealed battery had low voltage in DW Horizon's test of BOP.
You err by adding gross lb-force for cutting required to lb-force/unit area to counteract internal pressure. 878,000 lb force to cut the pipe could be generated with 5,000 psi driving fluid pushing a 175 sq inch (15 inch diameter) piston, or as you propose, 6,000 psi driving fluid pushing a 146 sq inch (13 inch diameter) piston. Add then the lb-force/sq in (pressure) required to overcome max internal pressure, eg. 15,000 psi.
Of course it occurs to me than a lot of the problems could be overcome by allowing internal pressure to act on both the fromt and the back of the drive pistons using a second sealed cylinder ..... some fancy seals required then, but it should all be containable within to BOP chamber.
IP, can you elaborate on that "junk-shot" for today.....Settles is talking about a pipe insertion on CNN.
President Obama live right now
http://www.cnn.com/video/flashLive/live.html?stream=stream1&hpt=T1
He doesn't sound very happy and is going so far as to say that even the US government is responsible...
Last Atlantis shuttle launch now at that link above. But Obama clip at http://news.blogs.cnn.com/2010/05/14/obama-blasts-oil-executives-for-gul...
He also acknowledged that the Federal Government shares a portion of the blame.
This sounds like the beginning of 'let BP off the hook." And, furthermore, it sounds like the fix is in!
Craig
I am curious about the net barrels of oil spilling, meaning:
Oil leaking - evaporation/bio-degrading - skimming - burning - dispersants.
Now assuming the oil leak is a constant volume, and evaporation/bio-degrading removes a certain fixed percentage of the oil spill each day, at some point we hit an equilibrium - i.e. things stop getting worse even though the oil is still leaking.
I have no clue how to calculate or estimate this, but I think it's more relevant than the gross oil spilled. Any ideas? The oil spill maps seem to show the spill at a constant size, but I don't have an idea whether that's just a function of wind patterns or if the spill already has reached some type of equilibrium.
See documents
Transcript House Oil Spill Hearings
Transocean - Major Accident Hazard Risk Analysis Deepwater Horizon, August, 2004
At Hearing on "Inquiry into the Deepwater Horizon Gulf Coast Oil Spill"
Scientists find oil plume below Gulf's surface
This is consistent with what I am hearing from local shrimpers who have been out there.....oil moving under the surface, to the west, and under the booms. Enormous quantities of dispersants are being released from the Air Force planes...
Maybe Rockman or some expert can confirm this. A friend was telling me that the Deepwater Horizon operation involved drilling one vertical hole, and then deep under the ocean floor, sending the drill bit horizontally to try to hit oil deposits.....is this accurate? He was saying that the horizontal holes would spider out from the one main hole. Is that correct?
Andy -- As far as I know the blow out was a straight hole. But offshore wells are often drilled at an angle from the vertical so they reach distant targets (the relief well is such a directional hole) from the platform. And in some cases they actually turn the well bore horizontal. Done offshore but much more common onshore. You find most "multiple laterals" (your spider) onshore
RM - This whole thing has baffled me. If they were going to drill some laterals later, wouldn't they have set the pipe above the zone by some considerable distance? And, if so, unless they are far luckier than me, when they went to run cement, with open hole below, a lot of that cement would have gone down and not up. They might not have noticed if they were geting returns all the while, so it is not unreasonable to think they might not have known that they had a well flowing while running cement. Also, if that were the case and the cement was lighter than the mud by any considerable amount, that cement could well have been getting diluted by the flow. I have never worked offshore, so I don't know how things work on these TA'd wells out there, but I have found two onshore where casing was run well above TD which had no cement behind the pipe when I went to plug them - we pulled all pipe which was run ( I bought the leases they were on, and no CBL's were run.) These were, obviously, shallow wells but the same principles would hold true. And not even HOWCO always get perfect cement jobs, else there wouldn't ever be any need for subsequent squeezes.
woody -- Not sure where the lateral chat came from but there was no possibility for any lateral to be drilled from this well bore. Perhaps BP brought up drilling laterals during the development drilling phase.
Too bad there isn't a mobile emergency blowout preventer unit that can be lowered and attached to the blowout preventer stack and make sure the shear jaws drive through the pipe.
The insertion pipe is mildly ingenious because it uses the riser as the Top Hat encasement in order to exclude sea water. How much oil it can remove is the question however.
If 70,000 barrels is accurate are we at a rate where moves on the blowout preventer stack have nothing to lose?
Sorry, but the insertion pipe is a pipe dream. Unless they figure out - AND CONSTRUCT - some way to separate the gas from the oil AT DEPTH so they collect just the oil and let the gas go, any recovery effort is doomed to an abrupt failure.
Indications are that there's something on the order of 15 million cubic feet/day of gas escaping (assuming 3000 cuft/barrel and 5000 barrels/day) I did some back-of the-envelope calculations assuming a pipe with a 12" bore and came up with a velocity of about 150 miles per hour if the gas goes up the pipe.
I keep HOPING that I've made an enormous blunder in my calculations, but so far nobody's corrected me.
Most of the gas will remain in solution with the oil at the subsea pressures of +/-2100 psi. Even free gas will be compressed by a factor around 145 times at these pressures. The fluids that we see exiting the riser into the sea water is likely being forced through a relatively small orifice.
I'm an unknowledgeable member of the public who found this site through another link and don't really belong here. However, at the risk of being banned, I'd have to answer, respectfully, and I think I speak for the public, that that would be your problem at this point. The oil has to be gotten to the surface controlled and contained where it won't do any further environmental harm or be stopped at the well. Frankly, from what I've seen, if I had the power I would order military marshall law and take over the accident. I'd impose measures where results were gotten or heads would roll. And the decision would be made mostly due to the contradictions I've seen expressed here by insider people who see themselves as experts...
Jetblast--Anyone and everyone belongs here; this is not some exclusive club-type of website. Rather, it is meant to be a font of information that the public can use about the issue of Peak Oil and all it might touch. So welcome, and don't be afraid to ask elementry questions; that's what this site is here for.
Story circulating in New Orleans
With appropriate caveats:
Alan
If this is true they need to put that guy on suicide watch. Greed wins out over good sense all too often. Actually, not just greed but ego/hubris.
Suicide watch would be appropriate. I’ve known of two company men who killed themselves after a loss of life accident/serious accident. One I was working with in Wyoming. Almost killed the driller while testing the BOP. He also had a near miss fatality on a previous well. Went home to Idaho on his days off, sat on the couch with the TV on and put a bullet in his brain. No suicide note. Guess he didn’t feel he needed to explain anything.
Every oil company I've ever worked for cement is allowed to cure for 48 hours prior to CBL. It has to develop adequate compressive strength for accurate acoustic impedence (density*acoustic velocity).
It is run first step in completion prior to perforating but ....it very well could be different in the deepwater offshore.
The Transocean daily rig report from 8:00-11:00 AM that morning reports the "Well Static".
So either the CBL was planned and the well starting kicking between 11:00 AM and 4:00 PM, the Transocean driller/pusher is part of the conspiracy, or Schlumberger can get out on location offshore one helluva lot faster than they move onshore. Or "Well Static" might not mean what I think it means.
They are very good though.
Wait time for CBL
http://www.onepetro.org/mslib/servlet/onepetropreview?id=00014200&soc=SPE
I note that two of the dead (Blair Manuel and Gordon Jones) were employees of Schlumberger subsidiary MI-SWACO.
However if your story is true then it is horrendous and BP employees (and anyone else that signed off on proceeding) are criminals in my mind (strange the Schlumberger concern didn't extend to employees of their subsidiary though). If it is not then whoever started the false story is a criminal.
I am sure we will find out.
It's one thing for a supervisor to man up and take his crew off the rig. But a crew supervisor's authority doesn't extend beyond the bounds of subsidiary companies. In the case that this story is factual, our alleged SLB man has my respect for doing what he thought was right (at the right time), at a non-zero amount of risk to his livelihood. That, and I reckon that in retrospect, our alleged SLB man wishes he HAD sounded the horn to EVERYONE, given the outcome.
Are we supposed to assume that all this went on without the knowledge of Rig Manager, Jimmy Wayne Harrell, as well? He wouldn't notice that all Schlumberger personnel, who were supposed to be running a CBL test, just got up and ran for their lives? No other Transocean personnel noticed that either and/or bothered to inform him or query it?
Or he did notice it and just thought "Hey it's the oil patch - that sort of thing goes on all the time and BP says it fine even though I furiously disagree as well so what the hell, I'll just press on even though the test was not performed and the contractors ran screaming for their lives."
Or the entire story is fictional.
Yeah, It is probably fictional. I can't find an independent corroboration anywhere. And I do think someone from SLB would have spilled those beans by now. But hey, I wasn't on the rig. And at the time it may not have looked as though they were running for their lives, but maybe just wimping out. It's probably just a case of us wanting a bad guy to blame it all on.
I wonder if this is what Rockman was referring to up the thread. . .
In any case, the more evidence there was that the well was kicking, the more irresponsible it was to reduce the hydrostatic pressure by displacing the heavy mud with seawater.
One wonders if the BP guy's primary motivation was to stay close to the budgeted cost.
How often does an exploratory well get converted for production? I've gotta think that BP thought this was going to be a lucrative operation - but why the rush to completion? Need to prove new production capacity for the market?
They were reportedly in the process of temporarily abandoning the well, which involves cementing the casing and setting cement plugs. A production platform would be moved in later.
This was going to be a tieback well to ThunderHorse from what I understand, but was being abandoned temporarily until the tieback was built.
IP -- If you drill an exploration well with no plans to produce it you classify it as “expendable”. This is normally done on the shelf where you’ll later set a platform and drill your development wells from it. If you’re lucky you might be able to set it over one of your exploration wells and saave it. In Deep Water you have a different option. Since the wells are completed subsea with the well head on the bottom and the flow lines laid to some distant gathering facility you have more opportunities to save an exploration well that might have cost $200 million to drill. It wasn't a rush since it might be 3 or more years before they could produce this particular well. It was to save the cost of the well.
Thanks! So the conversion is not technically difficult? In the story as I understand it there seems to have been some hurry to finish up the process of sealing the well and moving off - was that just a 'time is money' issue or was there some other urgency? I suppose if the argument was whether the well was safe to produce from or not then that is a different matter - but cutting corners on the cement curing time seems ...what can I say?
Approx $600 per minutes gives new meaning to the phrase "Time is Money"
So with loads of BP bigwigs on board celebrating the rigs excellent safety history someone decided that this was exactly the right time to put money before safety just as teams of contractors were allegedly fleeing the rig fearing it was about to explode?
That's certainly what's being suggested.
What else do company people do? It's all about money... bottom line... this week, this quarter. Pump up the company stock, the boss needs to cash in those options!
Craig
Yes I see just how much money this "Company Man" has saved BP. And he had a go at killing some of his bosses while he was at it - what a day! Suicide Watch? He should be under enforced lock and (throw) key (away) if this is true. I do sincerely hope it is true because, if not, TOD posters I respect have allowed themselves to be used unwittingly as a conduit for a most despicable lie.
My head genuinely hurts right now.
With appropriate caveats and labeled "Story circulating in New Orleans".
I got this story. I can either sit on it or post it with caveats.
Given the PR lies, lack of effort, and lack of transparency by BP (all known) I chose not to hide this story.
And one cannot defame BP. Their reputation is now worthless.
Alan
As I said up the thread, IMO it tells us something about the BP corporate culture when they reportedly won't even confirm the accuracy of the Thunder Horse production data that they provided to the MMS.
Worth noting that this story appeared nowhere else at all on the Internet prior to your posting (as far as I can see with search engines). If it's true then I commend you for posting it. Personally if I'd heard the story I'd have posted to TOD along the lines of "Does anyone know if there were Schlumberger employees on the rig?" as a first step and see what the response was.
We will know soon enough but it's either a huge, huge story and congratulations for posting it or just a "Big Lie" that people often believe because "why would anyone make such a thing up?"
Tell me about it. Sounds like amateur hour out on the rig if this was the case as read. If a contracter is willing to walk off a rig and give up good pay because they felt endangered, maybe someone should have stopped what they were doing.
Good god man.
I’ll never tell WT.
If the story is true I’m not surprised the SWACO hands weren’t pulled out. Though a sub of SLB they function separately from the wire line loggers. The manager of one sub might not have even known the name of the other sub’s manager and might have not even known there were SWCO hands out there.
I think it's bullshit. Purely because it sets off my internal bullshit detector. However given what the outcome was it is quite possible that the true story would set off my bullshit detector. So who knows...
I do though imagine the US Congress will go ballistic and probably start demanding death penalties having just held hearings where nobody mentioned this and thus no Schlumberger witnesses present before them. I'd imagine they will be just as angry at Schlumberger for not telling them. If it's true of course.
It does seem that news of a Schlumberger evacuation of their personnel would have leaked before now, but on the other hand it seems bizarre that someone would put together and circulate a false story like this.
In any case, as you said, if it is more or less true the stuff is really going to hit the fan.
I emailed a reporter I know who is covering the oil spill story and I asked him he knows anything that would confirm or refute the Schlumberger evacuation story.
Update: The reporter I contacted said he is definitely going to investigate (this was the first time he had heard rumors of a pre-explosion Schlumberger evacuation).
Maybe he can check with local airports for flight plans. I expect Homeland Security and DEA would frown on helicopter flights that leave the shore, go over the horizon, then come back after just enough time to pick up a load of drugs (or worse).
Bollocks! Helicopters come and go all of the time out there.
If this story turns out to be true, I would imagine that those Schlumberger employees have already been subpoenaed and will probably be called to testify in the upcoming criminal investigation and trial. So my guess is that they couldn't have just shown up of their own volition at the congressional hearings and simply told what they knew.
As for the BP people not mentioning this episode, well it's going to be interesting to find out who knew what and when they knew it.
All I can say is that this whole story makes me very sad, angry and depressed on so many levels, what a complete clusterfuck!
Makes me wonder if the anger in Obama's voice at his press conference about the spill this afternoon had more than a little something to do with his personal knowledge of what actually transpired.
Na,he was mad because he didn't make as much as he thought he would at last nights fund raiser in New York. BTW, the other day he got up and said he was going to send his experts to make sure those guys at BP knew what they were doing. Some of those experts were standing next to him and if they had really dazzled the oil guys with new workable solutions we would have heard about it. Note, he basically said verbatim what everyone else has said for the last several days. Any president wants to show they are in charge.Unfortunately he and most others know this can take a long time. Of course it is silly to think it is not in BP's interest to throw everything at this.
Bets on whether ROCKMAN heard this too?
I'm confused. Why would SLB order the company man to kill the well and shut-in? Wasn't mud still in the well (effectively killing the well at the time) when SLB would have been there or had they displaced the riser of mud at that point and SLB wanted the riser full? Hmmm, more questions arise.
A "kill pill" uses very heavy mud, heavier than production mud.
Alan
So SLB could have demanded that. What would have been the followup action after killing the well and shutting it in? Reevaluation of the cement job, bring HB back on to do a squeeze job. Wait for more curing time? Abandon the well?
The “ordered the company man” is the one part that doesn’t fit at all. No matter the disagreement a subcontractor will never order a coman to do anything. He might refuse an order or he might tell the coman to go screw himself. I seen and done both. But never gave one an order. Perhaps it was a misinterpretation. Perhaps the SLB gave the coman an ultimatum. That I’ve seen first hand a number of times.
But soon we’ll be able to judge the validity of this story. Now that the MSM has the smell of blood we should be seeing SLB in the spot light very soon. They’ll have to respond in some form. Any form of confirmation will be solid gold proof IMHO. An absolute and clear denial would offer the same. SLB would never cover-up such an event. NEVER for a variety of reasons. A “no comment” will be subject to interpretation but could make me assume some level of truth to the story
As I responded to another TODer I consider the story 100% true or an absolute lie. No room for anything in between IMHO.
Rock,
In my company's safety culture, anyone has the authority to stop work if they recognize a clearly unsafe condition. That doesn't mean that they can pull rank on a client (that's oxymoronic, eh?), but they are authorized to at least make noise and walk away with their crew from a bad situation. I'm guessing, if this story is true, that that kind of situation happened - the SLBjack saw what was happening, got the s**t scared out of him, and piped up - giving the company man an offer of fix this now or we walk. Not an order, but like you said an ultimatum. I think it just got garbled in the retelling, IF this is a true story.
Thanks for your insight - D
Dumb question: How did Schlumberger get out to the rig? Did BP pick them up in its own helo, then refuse to take them back when it could easily have done so?
BP would have flown them out. No company owns their own choppers for the most part. They are contracted from commercial companies like PHI and AirLog. The coman has absolute say over who flies and when if BP is picking up the $10,000 or so price tag. But SLB is free to contract their own flights.
My jaw wasn't in any condition to pick up after reading this. I truly hope some people had too many recreational pharmaceuticals and made this up. OTOH it DOES sound like one of those things that would be hard to make up .....
You know the difference between an oilfield story and a fairy tale don't you??
A fairy tale starts "Once upon a time " and an oilpatch story starts "This ain't no shi**"
FF
This story did come from within the industry. I agreed to keep the source(s) confidential.
Alan
Another dumb question: Was there no one, no official--Coast Guard?--Schlumberger could have notified of the perceived danger? Could, would the Coast Guard have ordered BP to stop what they were doing?
Oh, there will be. There will be.
why would schlumberger be called in ?
halliburton had the contract for: it seems - everything on this well.
halliburton has their own logging services, having acquired welex in the way back of long ago. i believe welex invented the cbl
Elwood: an operator might bundle many of the services together with one vendor like Halliburton to get a better discount. As a general rule I don’t: each division has to earn the bid independently. I get competitive bids from each division.
Wow, source of this info?
from within the offshore community in New Orleans. *NOT* first or second hand, but not some internet scam from Peoria or Nigeria either. That is why I called it "circulating".
Apparently, never published on the internet before my post.
Unlike others, I am not in a professional position where the long arm of BP can reach out and damage my career.
Alan
As a lay person, I’ve been thinking about how to understand this situation using everyday experiences. It involves capture of a mixed liquid and gas stream underwater. The only jets of mixed liquids and gases most of experience are opening beers and sodas that have been shaken up. Perhaps such everyday experience can serve as a simple model.
This is not to make light of this situation. It is heartbreaking in many ways. But, most of us don't have experience with mixed pressurized liquids and gases, except for beer and soda.
Imagine you have an ice-cold (just above freezing point) beer bottle with a built-in 1/4" straw that passes through the cap. The straw is sealed in two places: (1) just where it passes through the cap and (2) at the end of the straw. Shake the beer. Then gouge two holes in the straw some distance from each other big enough to allow a substantial amount of beer to spill out. A mix of beer, gas, and ice will blast out of the two holes.
Your goal is to either stop the beer from flowing out or collect the beer in your glass. But there are a number of conditions: (1) the beer bottle and all your tools are at the bottom of your pool; (2) you and your beer glass are floating in a pool chair and you are manipulating things at the bottom of the pool with very long chopsticks and exacto knives; (3) the built in straw is loose, so there is a risk of it popping out if it is manhandled, allowing much more beer to blast into the pool; and (4) all of the things you use to accomplish these tasks are cold enough to allow beer to freeze on them.
First idea: Collect the fizzing and jetting beer with a funnel and transport it through a straw to your glass. In theory, the rising bubbles will carry the beer to the top of the pool and into your glass. If one puts a metal funnel that narrows to 1/4" over the underwater beer jet, the fizzing gas, water turbulence, and/or formation of ice in the funnel will mean that the leak will likely back up in the funnel and flow over the edge of the funnel and into the pool. Very little beer will pass through the funnel and ice will ultimately block the funnel. Is this roughly what happened with the BP dome? If memory serves, the dome had roughly the same size outlet as the diameter of the ruptured drill pipe and is even smaller than the riser pipe. Do the same thing with a bigger funnel with a 1/2" outlet and more beer will be captured, but it will be watered down. Seems like the way to make this work is to have an outlet pipe big enough to capture the turbulent flow and expanding gas while at the same time warming the dome and expecting to separate beer from water. I have no idea if existing offshore piping is big enough or strong enough to do this job.
Second idea: Collect the fizzing and jetting beer with a smaller funnel. Less ice formation and perhaps less water gets sucked up, but I don't see how this deals with turbulence so the beer would nonetheless back up in the funnel. I understand this to be analogous to the top hat idea.
Third idea: pump chunks of stuff (lime rind) to the bottom of the pool and inject it into the broken seal at the beer cap to try to clog it up so beer doesn't flow into the straw. Whether this works would seem to depend on the force of the jetting beer, the nature of the clogging stuff, and whether there is sufficient purchase in the broken seal for the clog to stick.
Fourth idea: Cut the straw off evenly upstream of the hole and stick a cap over it. Whether this works would seem to depend on whether the cap can be forced over the straw and be made to stay in place. The jetting beer would seem to make placement of the cap difficult. Ever tried to attach a sprinkler on a flowing garden hose? Also, what about the second leak? Do you cut the straw upstream of both the leaks? Does this cutting risk having the straw pop out? Is the straw strong enough to take the pressure or might it rupture somewhere else?
Seems like BP faces a situation where it may be able to stop the spill in the near term only if it first cuts the riser off entirely upstream of both leaks, but this would increase flows for awhile and may risk creation of a new leak closer to the BOP or catastrophic failure. BP may be avoiding such action because if it doesn't work, it's liability could increase substantially. But if it doesn’t slow flows until the relief well is drilled, it liability may be astronomical anyway. It's hard to see how the spill is stopped in the near term without making a clean purchase for a cap of some sort either on the riser or BOP. If the cut is in the weakened riser, then the cap may need to be connected to an outlet pipe to let the oil flow out to keep pressures lower so the riser does not burst. If the riser is cut away from the BOP so a valve can be attached to the top of the BOP, the issue becomes one of whether it is possible to use existing bolts or whether the BOP would need to be encased in something to which a valve can be attached. Success would seem to depend on the extent of damage to the BOP and whether the restriction in flow comes primarily from the BOP or crimps in the riser. In any case, a new valve could be kept open until it is firmly secured.
BP may be in a position where it must take greater risks than it is currently willing to assume to avoid ever increasing liability.
Your analogy is excellent. A few refinements will explain some of your technical questions:
There are multiple leaks in the straw: one of them is right at the bottlecap, so there's no way to cut back behind it.
The key here is that there's *another* straw going into the beer cap, this one with no holes and a good valve. You jam the lime rind in through here, so you don't have to fight the flow of beer out the leaking straw.
Masses of info, ideas and theories in the comments.
in the meantime what is the situation with oil containment on the beaches?
Is the oil reaching the beaches in large quantities or is it sinking beforehand?
To stop some of the oil reaching the beaches, why not spray it with sand before it reaches the beaches.
The sand will sink taking some of the oil down with it.
The quantities of sand available are enough to make one weep, so it's supply will never run out.
Wouldn't this be better, environment-wise, than chemicals, and cheaper?
So, where's the oil?
From what I'm reading, deepwater oil leaking from the seabottom is poorly understood and likely to be quite different than shallow water spills - gas bubbles coated with hydrates, methane solution into seawater, complex mixtures with different oil drop sizes, deep currents. In particular, apparently hydrates are only very slightly less dense than seawater.
OK, if the oil leak rate is larger (my guess is 20-25 KBOPD) and the surface analysis suggests much less, and the reports upthread about oil deep in the water column are correct, shouldn't NOAA, USN, and private research groups be putting together a survey effort to find the damn oil?
My question, what technologies could be used to do that?
1) Direct sampling, hopefully with onboard analysis, e.g. flourescence. Presumably a ship could lower a tool with many chambers, and collect samples from a range of depths rather quickly. Still this would be slow way to make a 3-D model of the plume(s).
2) Some kind of logging - how about resistivity tool quick run down and up the water column? Other ideas? Ballast at the end of a wireline? Quicker
3) Remote sensing - acoustics, resistivity, something else high tech from a navy sub with our without surface vessel to reciprocate signal. Possibly could cover large areas more rapidly
Any ideas? Am I nuts? (wait, don't answer that last one).
Geonola: As with everything they have stated they are taking samples. They are sampling during the underwater dispersant program and after,and everywhere else. Fortunately, they are testing tar balls to see if they are from this spill as there are many other sources in addition to the estimated 1,000,000 barrels per year or more that seep into the Gulf each year. Fortunately, they test every dead animal too. It is amazing how many animals die in normal times but now they must all be due to BP(according to the public). Wait to see how many folks who have been unemployed or sick will come clamoring to put the blame on BP.
As others have pointed out there were questions around what happened to all the oil in the Bay of Campeche blowout in 1979 that occurred in relatively shallow water at estimated rates of up to 50,000 barrels of oil per day for a total of of something like 240,000,0000 gallons over the total spill time (sorry to change units in one sentence).
Again as other have stated, water temp, oil gravity and makeup, current, etc. can determine how much actually makes it to shore. Despite the volume that headed toward South Teaxs the amount that actually made it to the beaches was much smaller than anticipated. In fact unlike what is happening in Florida where the press and politicians have played a role in scaring away tourists from yet affected beaches the South Texas tourism apparently was not hurt.
Ironically much of the effort now by workers is to clean up debris from many beaches before oil washes up to make it easier to clean up if/when it does. I wonder how much junk they have found while cleaning up some of these spots that is unrelated to any spills.
I have always been amazed at the ability of the sea to not only deal with the natural seepage worldwide but to somehow seem to recover, albeit it slowly, from catastrophic inputs i.e something like 24 tankers were sunk of the East Coast during WWII.
BTW I am not trying rationalize anything BP did. They are big but are probably wishing they had Apple's or Cisco's cash and debt position (or even Exxon's). I believe that had just paid top dollar($7 billion) for Devon's deep water stuff worldwide. They are going to take a massive long term hit even if they avoid some serious negligence costs (At least their guys were probably not drunk like the Valdez captain)
I just remember when all of Asia was not going to have a summer due to the Kuwait fires and how all the experts insisted it would take years to extinguish the fire. But they got after it and improvised and the worst predictions did not come true. News media and individual agendas being what they are insure that the "this could be" this "might be " are used for the story. It just is not interesting if somebody cannot make the most dire predictions. Just go back and look at some of what was said three weeks ago about where we would be now. Not saying it could still not get really ugly.
Now on the prediction of what all this global debt might do to the economy well...........
"As others have pointed out there were questions around what happened to all the oil in the Bay of Campeche blowout in 1979 that occurred in relatively shallow water at estimated rates of up to 50,000 barrels of oil per day for a total of of something like 240,000,0000 gallons over the total spill time (sorry to change units in one sentence)"
What spill exactly are you talking about that was 240 million gallons? That would be the second worst spill ever and I have never heard of it. I believe this list is pretty much correct in rankings.
http://envirowonk.com/content/view/68/1/
It is the #2 spill on your list -
"Mexico - 1980 - 100 million gallons - An accident in an oil well caused an explosion which then caused the well to collapse. The well remained open, spilling 30,000 gallons a day into the ocean for a full year."
I'm not sure where they got their information but they got some of the facts wrong. It was a blowout that started in 1979 in the Gulf of Mexico and it was almost 10 months (not a year) until a relief well killed it.
It blew at a rate of 10,000 bpd (420,00 gallons/day), the low estimate, to 30,000 bpd (over 1,000,000 gallons/day), the high estimate, so the 30,000 gallons was way off. They probably meant barrels.
The total spill was between 125 million and 370 million gallons. A great deal burned off in the early days and some was picked up but not nearly as much as is being recovered on this spill. Most of it drifted north and some hit beaches in Texas and Louisiana and there were reports of tar balls as far as Florida.
But even though it was the second worse spill in history it does not seem to have left a lot of lasting damage.
It was the first blowout and oil spill I ever saw and by far the most spectacular.
One thing parallels the discussion here is that even after the fact no one could agree on how much oil was spilled.
Anyone who tells you they can ACCURATELY (within 20% or less) estimate a spill flow based on sixty seconds of video of mixed gas/oil flow at over 2,000 psi ambient pressure, or from photos or direct observation of the slick, is either fooling themselves or trying to fool us.
It is clear it is a massive spill.
It is clear it is getting worse.
I'm certain it is now well over 5,000 bpd and I am just as certain it is less than 50,000 bpd. Try to pin me down to the most accurate guesstimate I can make - between 10,000 and 40,000 bpd.
is your estimate for all of the leaks? or just the one we have video of?
That is for all the leaks. And is a GUESSTIMATE.
The conventional wisdom is that the leaking riser represent 85% to 90% of the flow. I gather that as that flow has visibly increased over time, the other leak, which is much smaller, doesn't seem to have increased as much.
I think the estimate of 85% is based on guesses made from comparing ROV videos.
do you have a source on that 85% figure? i've been seeing 'guesstimates' of something closer to 50/50. a statement by a bp official or coast guard of something? where is that coming from?
also, what is your source for the statement 'flow has visibly increased over time'? we've only got the one video. remember they closed off the riser further upstream.
The 85% has been in the press for a number of days and I have been able to confirm it closer to the source. Again it is a GUESS just comparing videos. As far as I know there has not been any video released showing the smaller leak at the kink in the riser above the BOP so no one not directly involved has able to make a comparison.
The "flow has visibly increased over time" is the comparison of the riser end leak when they were trying to use the large containment dome vs the much more widely distributed video released in the last couple days. I think the 2 videos were about 4 days apart. Both videos at the same location but from different sides of the riser. Also both videos were probably less than 60 seconds, but the apparent difference is there, especially the sizable increase in gas.
Krondog: Ixtoc estimate in the literature are all over the place from 30000-50000 per day for the 6 months(225000000-378000000 gallons) it flowed to others that say 500,000 metric tonnes (170,000,0000 gallons. Yes one of the biggest. i remember it well and the slicks that worried Cuba and everyone else.(I am getting old)
Of course Saddam holds the release spill and on shore records as far as I can tell (and like the other spills the estimates are all over the place). Like the Admiral says "If you have a container you can figure out how much you spilled otherwise it is not an exact science".
But Ixtoc was one big mother.
Thank you for the replies. I think the main thing I am learning here is that estimating the size of the spill is certainly not exact science.
Reading about Ixtoc is very interesting.
OK, OK, very interesting. I'm probably embedding this in the wrong place, but people, it sounds like it's more than 5k bopd, maybe a lot more - Ixtoc was bad, but not the end of the world - I agree we can't calculate this very accurately from a short video of multiphase flow.
How about my central questions:
1) Is NOAA or USN surveying/sampling water column to find the subsea plume (if it exists)?
2) If not, shouldn't they?
3) What's the best way to do that?
There is this:
http://www.theadvertiser.com/article/20100507/NEWS18/100507007/Deep-sea-...
and I believe there are or will be other studies as well.
Don't know about NOAA, Coast Guard, or Navy.
Thanks for the link, yeah, and kudos to this group for changing their research plans unilaterally to address this issue. But really, it is totally ad hoc, one vessel makin' in up on the fly. Perhaps if they find significant concentrations deep below the surface, this will inspire a more concerted multi-vessel effort perhaps employing some more novel technology to make a 3-D sub-seasurface model of the plume(s).
A coupla reasons this might be important:
1) estimate of total volume expelled (and related liabilities)
2) where the oil could surface down the road
3) basic research on a (so-far) unique "experiment" for deep-water blowouts
Check this out, lot of questions about deep water blowouts:
http://www.mms.gov/tarprojects/287/287AA.pdf
in terms of comparisons between the deepwater horizon leak and ixtoc, ixtoc had no issue water-column-wise, as it was 'only' in 160' of water. ixtoc was also not 60 miles off of the coast of louisiana (apologies to mexico for my u.s.-centric stance). lastly, we've got heavy crude instead of light sweet.
Diverdan: Thanks for the comments. I too am cautiously optimistic that the oilmageddon scenarios are hype and that the natural system is in some ways more robust than many realize, and that we haven't seen the worst case scenarios pan out on the coast, in the marshes and in the bays. But, I am still concerned that we don't know where all the oil went and where it might, in time, reach the surface. I'd like to see map view representations of the sampling results for the water column. This old report, largely speculative and model-based kind of freaked me out:
http://www.mms.gov/tarprojects/287/287AA.pdf
basically saying that large volumes of oil from a gas-rich deepwater blowout could be entrained deep in the water column and surface at surprising locations long after expulsion from the wellbore.
Any more information on the scope of the water column sampling below the surface?
How valid or significant is the following?
I hope the full story, what ever it is, comes out soon - the rumors are surfacing like tar balls from the deep.
Has the list of the 111 men who made it out alive ever been released? If so, did it identify the companies they were working for?
Today I finally saw memorial information on the eleven men who didn't make it out... I imagine it's been published elsewhere before.
http://www.huffingtonpost.com/2010/05/14/gulf-oil-rig-victims-a-me_n_575...
Rainy-
Thanks for the post of the day.
I love the oilfield and the people in it.
God bless them.
FF
Dave,
Not sure if all the points line up, but there are some interesting points. Nobody tests the BOP hours before P&A, so any pressure under the rams was not from cement pump which you use for testing BOP.
Part of our new checks that have been introduced in the past week, is to confirm everybody is aware of the proceedure to open rams / annular, ie have choke line open to bleed any pressure from under the rams before opening them. It seemed to be out of context with the rest of the checks at the time, but this post may explain it.
Reading the charts from the last 2 hours it does look as though the C&K would have been closed, pressure in drill pipe none on C&K, which fits your story. Though it is hard to see how the standpipe pressure could go straight up to 6k psi at the same time the rams / annular was opened. The SPP was increasing before the pit gain, inferring what ever let go occured while the BOP was closed in.
I am sure we will find bits of truth in all the stories, it is just hard to which bits in which stories.
In this version of the story then is this consistent with no emergency helicopter missions to evacuate Schlumberger personnel, no furious arguments or major disagreements, in fact no indication anything was seriously wrong at all (as far as the crew were concerned) until...
Someone opened the BOP with a blow-out having just happened un-noticed and already sitting contained under it????
It's feasable David. True or not I can't say.
"SLB gets out to the Deepwater Horizon to run the CBL, and they find the well still kicking heavily" Come on. How the hell these guys knew what the well was doing? The only the driller can tell if the well is kicking or not. Rubbish!
Well, when you run tools in the hole, you would probably notice the kick - and you can't run a bond log without running the tools in the hole.
It is the sole responsibility of the senior logging engineer to determine if the well bore is safe and secure to run the log. He evaluates the well bore condition with the driller, mud engineer and all other parties involved. If he feels conditions are risky he is required to get written confirmation of his recommendation from the coman. By signing that doc the coman acknowledges the loss of all tool insurance as well as hole loss. I’ve signed that form a number of times myself.
When a well is unstable and trying to kick everyone on the rig, including the cook (really...no sh*t) knows. I've been woken up a number of times by a variety of hands and told I should "put my car keys in my pocket". That's our not so subtle secret code: you can’t take anything into an escape capsule that doesn’t fit in your pocket. I once spent 6 days logging a DW well with SLB during which time some of the hands slept in the escape capsules when they were off tower. As I said once before hand has a simple choice: stay with it or find another job.
"SLB gets out to the Deepwater Horizon to run the CBL, and they find the well still kicking heavily" Come on. How the hell these guys knew what the well was doing? Onlythe d riller can tell if the well is kicking or not. Rubbish!
Science Project
You too can have an oil slick in your bathtub. It’s probably best not to tell your mother (or the Coast Guard) you are going to do this.
First fill your bathtub with water.
Be sure the water is calm so you can see the results
Use an eyedropper to drop a few drops of oil (30w or 40w is probably a reasonable model for light crude) on the water, better yet reach down to the bottom of the tub (be sure the water is calm so you can see the effect) and press out a few drops so you can see them float to the surface.
On reaching the surface the oil will immediately spread across the water surface and also coat your arm and leave a ring around the tub. If you happen to be a typical offshore hand with hairy arms that reach to your knees then you may be able to demonstrate how an absorbent boom works. In that case you made need to add a few more drops of oil to perform the next step. (There is another type of offshore hand that show up for a beer after crew change whose arms don’t reach their pockets).
Assuming you still have an oil sheen after removing your arm then take a clean eyedropper (or clean the one you have) and drop a couple drops of Palmolive, or other dishwashing detergent, (dispersant) on the surface.
The oil sheen on the water will disappear immediately.
But your arm and the ring around the tub will require scrubbing or the liberal application of a powerful stream of water to come clean.
This demonstration highlights the fact that it is easy to use dispersant on the oil while it is on the water surface and dispersed oil allows Mother Nature and her microbes, etc to go to work on the spill. But once it reaches the beach or anything else it can coat (like a bird) it is much more difficult to remove.
Rockman said: "And there is constant interaction between these different hands. Lots of eyes out there. Lots of cross chatter. Very few secrets."
Exactly! It's amazing to me that PR peeps still think they can control or spin the story in this day and time of instant info, internet communication and Iphones.
Instead of SLB, right now I am thinking about Haliburton. Remember from the report after the negative tests, the Haliburton hands were put on standby while the "heated debate" occurred. All 4 hands survived. Where were they while "on standby"?
Interesting about the info or(rumor or spin) going around about the BP employee. Wasn't there an early post on here that said there was a Senior Company Man having a heated argument with 2 BP engineers because 1 of the engineers insisted on going ahead with the seawater? When and if all that info is made public, it will be interesting to see if the pro-salt water engineer was on the rig or in Houston.
WHO... amongst us will reduce their energy usage by 50%? 25%? 10%? 5%? say... tomorrow?
WHO... amongst us will pay more for their enrgy usage by 5%? 10% 25% 50% say... tomorrow?
WE... as consumers of energy... are all responsible for this spill...
wouldst we all have been happy to pay... say $5/gal to fill our tanks for the last 35 years... since the OPEC oil embargo... wherein we waited in line for hours and hours... sometimes to get only 5 or 10 gallons...?
not that the extra dollars would have been diverted to "clean" energy... nor would the dollars been used for "safe" energy... they would have been scooped up by a) the oil companies and b) the government in fees and taxes....
my POINT is... we are not "paying" anywhere near the total cost of oil... at the pump... this... the mine disater... the iraq and afghan wars... are all "true" costs...
in the computer biz - there's a concept of TCO - Total Cost of Ownership - with respect to Computer Networks - in the 80's they were terribly expensive to implement - by the mid 90's the "costs" to set up a local / wide area network decreased exponentially.
problem was - the "costs" to maintain them - the support people - software licenses - down time - maintenace contracts - air condidtioning systems - power management systems - was going through the roof - year over year - it was found the initial costs was 10% of the TCO - year over year costs to operate were 90% -
we - humans - want - cheap energy - we want to fly from brussels to london in a few hours - nevermind it uses thousands of gallons of jet fuel...
i live in so florida... florida has like a $60 billion tourism industry... this isn't residents of florida spending $60B every year...
living in florida... would be impossible at all... w/o a/c... and... every friggin house has a pool outside... used probably 10 hours a year... but the pumps and chemicals are going 24/7/365...
would we be willing to bring back the 55mph speed limit...?
the buikding i work in is a state owned building... tomorrow they're cutting over the circuits to include a new roof full of solar electric panels... they say sfter the final pahse they will be able to go 100% solar electric... and bill back the local power utility as well... but... this is one building... and the state has a lot of money... individuals don't... and who knows the capital / expense breakeven payback...
most people won't but a 22-25K+ prius... when a 10-12k sedan is availble with much lower mileage... there's not the economic incentive...
when this thing... IF this thing... gets under control...
there is always the possiblity the resevoir can't be capped... can't be side drilled... and the whole damn thing will have to empty before it stops...
when this is all over... wonder what the popular discussion will be...
how many 4x4's will you see tomorrow... gunning down the road...? from what i see... not too many people are making the connection with... say blogging from the comfort of home... on a highly energy intensive internet (some google server farms use a as much electricity as the city of honolulu)... not making the connection from what we do today... now... and this oil pouring into the gulf of mexico...
outrage is fine... what are WE gonna DO... that's the question.
Agreed, some worthy questions.
It's a good thing ellipses are a renewable resource.
form over substance... that's why we're where we are... this is a forum on energy... not grammer... ya might look into great literature too while you're at it...
as for comedy... send this to sarah palin... heard tell she's cheap moneygrubbing at stand up now...
the american way... AVOID the discussion... mock the discusser...
oh well... (pun intended i guess).
WHATE
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POSTS
If everyone posted like you this place would be a fricking nightmare. Form is there for a reason, it aids the presentation of the substance. What your posts yell at me is you don't care about either your message or the recipient.
Actually some of us are well on the way to doing all of the above. Unfortunately we are still an extremely small minority. My question is how do we get more people on board?
I too live in Florida and currently drive an old compact car less than 5K miles a year, my monthly electric bill is less than $50.00 a month. I walk and ride my bike whenever possible even when its hot outside and I fear for my life from SUV drivers I have to share the road with, note, I'm 57 years old. I'm also part owner of a solar energy company. Etc.. Etc.. I'd be willing to drive 50 mph if it were mandated and pay $10.00 a gallon at the pump and think it should be rationed. So how am I going to get you to do the same? Then how am I going to do even better myself?
You are right every single one of us is complicit but the people who are still stuck on BAU and most especially those people who keep saying that alternatives like solar and wind are not viable because we cant maintain BAU with them should be slapped real hard. Of course we can't maintain BAU with them and we need every last drop of oil to transition to a new paradigm. So what are we going to do? Keep whining?!
Just curious, since BP is throwing away lots of our oil, what do the lease terms say about their paying us for the lost oil? If they are obligated to pay, then they have a significant financial benefit from refusing to find out how much oil is getting lost.
plover -- Hell of a good question. In 35 years it has never occured to me. I'll check with one of my reg consultants.
Since BP is not getting a financial benefit I doubt they would pay tax. It is no different than not allowing to explore or produce on a known reserve. Also they are paying a significant price to kill the well and of course they lose this one. Even with no cleanup there will easily be $500 million down the drain (or in the gulf). Add the cleanup even without any legal costs and payments. They have also said they will not use moneys from the cleanup fund ........
And of course trying to accurately gauge the amount and at what price to use as this would not have been produced for a couple years or more.
Wouldn't that be small change compared to all other claims ?
I feel the biggest factor is PR - esp comparisons to Valdez spill.
I agree. You really hear little about the Mexico well even though it was close. Valdez and those Otters are the gift that keeps on giving --especially if one is anti oil. Funny I have friends in Alaska who back then and until recently said to "let them drill in the Gulf as it was a cesspool any way. Likewise I have many California friends and relatives who said all the beaches in the Gulf coast were nothing compared to theirs.Both would even pooh-pooh the seafood from the Gulf. Now of course they have changed their tune as they join in to the attack against the evil "Big Oil" companies that intentionally try to destroy the world. I wonder if they would be happier if it was an independent "Small Oil" company?
Interesting thought.
If this is similar to onshore leases with the BLM or MMS then the royalty is paid on sales.
No royalty on lost oil that is never sold.
BUT, does that mean that any oil recovered and refined is "sold"? Maybe, then the MMS (us) would be due the royalty.
Small potatoes in the overall disaster but interesting nonetheless.
Maybe they should pay tax on what they deliver to the coast?
Warning, my opinion below and I am not a land man:
The US gov being a royalty owner is entitled to a certain percentage of oil sold to market. How much oil is sold determines how much they are entitled to. Assuming the recovered oil is not sold to market with proceeds going back to BP, the US gov is not entitled to any money from the spilled oil. Lease terms would not cover oil production, only royalty terms. Lease terms cover the damages caused by the oil spill, but BP is already paying that. In my layman way, that is what I understand.
Actually, I do happen to be qualified in this area. You're right - normally the royalty owner gets a percentage of the market value of the oil. If the oil doesn't go to market, the royalty owner gets a percentage of nothing.
If any oil was reclaimed and then sold, however, the company would owe royalties on it.
Of course, a government could write any rules it wanted to, but most likely it didn't. The US government has been bending over backward to get oil companies to drill in the GOM, and the rules are quite generous to them.
Hey guys, an a non-petroleum engineer I'm facinated by the thread. Great job.
I just heard about the Purdue U estimate and since I know this dude from having to deal with his work in my own industry I HAD to do my own calculation and figure out what the hell he was talking about.
1. Estimating the flow from that video, as many of you have challenged is crazy. What is the percentage of oil in the mixture? Is the rate constant, the video is short? Tracking particle velicities from that video can't be that accurate. Some of you say it may be 50% off; it could way be more.
2. The flow of the "mixture" not just the oil, is a function of the upstream P (reservoir), downsteam P (the ocean at that depth), the density of the mixture, the minimum pipe area (the flow is resticted, NOT the casing pipe size we see) and the losses associated by the flow path.
3. The biggest unknown here is the upstream pressure. Based on the numbers you have floated around the restriction has to be quite small even to pass the 70K barrels Purdue is talking about. I kind of think that is the case.
4. Therefore, we are talking about and unknown pipe restriction size and a VERY small pressure differential. Otherwise, the whole gulf would be full of oil by now.
5. I have been in the thermal hydraulics analysis business long enough to not to be that stupid to throw out a number when I'm missing TWO variables. There is just not enough information avaialble.
6. In this casse I normally use my experience and intuition. Knowing the Purdue folks, I'm willing to bet they are wrong because they have shown me in the past to be too quick on the trigger. The atro physics prof out west (what the hell they know about thermo fluid analysis?) maybe closer to the number (I get a similar number with credible 2 guesses!!). But that is all bull because we do not know enough.
7. So, I have to rely on the gut feeling of you all experienced "oilers." You probably can guess better that us techies can.
Love the chat!
Cool story bro!
Charlie Rose is exploring the Oil Spill 11 PM EDT on PBS.
He is interviewing Prof. Steve Werely from Purdue who made the higher flow estimate.
Draft of Werely's comments:
Today I used a 20 year old 75 watt solar panel, a 20 year old 12vdc water pump (salvaged from a wrecked RV) and a 250 gal. water tank (also from salvage) to build an irrigation system for my new expanded garden. I grew tired of beating this dead horse. Returning to TOD I find a huge number of posts on the subject of this oil spill debacle. I'm glad that my energy was spent on something usefull,,,, at least to me and mine.
We had gulf shrimp for dinner.
People like RedDan and that 'professor' are just confusing the people without getting their math right. What's worst is that they don't list their assumptions or how they came out with their uncertainty ranges!!
What difference in oil/gas slip velocities are they assuming?
What cross-sectional area are they choosing to come up with their volumes?
Are they assuming slug, annular, mist flow?
What PVT and compositional properties are they assuming?
And if we want to play with basic calculations, let's play:
A typical 6" pipe has a capacity of 0.0296 bbl/ft (you can also calculate it assuming an ID of 5.524 in). That is, a flow rate of 5000 bbl/d means an average velocity of 5000/0.0296 = 168918.92 ft/d = 1.96 ft/s or 0.6 m/s
Repeat the same calculation for a 4.5" pipe and you will get an average velocity of 3.6 ft/s or 1.1 m/s
From the video, some people state that they have calculated a velocity of 1 m/s. Which is what I just calculated above. IN OTHER WORDS, it is possible to get those speeds with 5000 bbl/d and a cross-sectional area of 4.5"!!!
Of course, this does not include calculations on flow regime (laminar, turbulent, annular, slug, etc.) or the true cross-sectional area occupied by the relative fractions of oil/gas/water/sand present in the stream or the different slip velocities between phases or the PVT variations due to an obstruction. All of which ARE NOT BEING TAKEN INTO ACCOUNT by these so called 'fluids' experts.
In my point of view, THESE SPEEDS ARE POSSIBLE with flow rates of 5000 bbl/d. People that keep playing with their pseudo math are just looking for press.
I wonder where BP is getting their numbers? The well pressure in this new field? Pressure variations in the formation due to variation in overlying depths due to the Mississippi river delta sedimentation?
http://www.businessweek.com/news/2010-05-11/bp-relief-wells-bring-risk-o...
hasn't it been firmly concluded that we are talking about a 21" inside diameter riser pipe? why are you running calculations on 6" or 4.5"? how does that apply? the riser is past the bop, not below it.
You can call my 4.5" an average or effective cross-sectional area occupied by the relative fraction of oil moving in that pipe. Remember v = q/A. The main controversy here is what to use as A to back calculate q (flow rate).
Not everything that is moving in that pipe is oil so we should not use the inner diameter as a base for our calculations. You also have gas, sand, etc. flowing in the same pipe and they all flow at different velocities. To distinguish the relative fluid fractions from this video is not straightforward. But even if you assume that half of what you see is oil, you would be talking about 10,000 bbl/d, not 70,000 bbl/d.
Just for background for the calculating experts:
Well schematic
http://www.roughneckcity.com/uploads/ProbertTestimony_5-11-2010.pdf
BP's new relief well diagram:
http://www.deepwaterhorizonresponse.com/go/doc/2931/551163/
No well pressure data has been released that I can find.
I believe BP did get pressure measurements from the well side of the BOP and also from the leak side. Perhaps they also have some idea of the diameter of the leak orifice from their scan. I am thinking that the drill pipe is broken where the riser is kinked at the BOP and the flow is traveling through the riser from that point. The leak from the end of the drill pipe that was capped was probably residual flow through transiting the break. This is my conjecture anyway. Didn't Shelburn quote the well pressure up thread?
excerpt from unconfirmed / anonymous report from a week ago, whole link may be worth a read :
It is way outside of my field ( SWAG) , but it appears the lighter gas bursts( structure collapse?) on the video could be coming from outside of the drill pipe, possibly from the casing, and possibly the heaver oil liquid flow from just the drill pipe ID.
Some anonymous reports have cited 16# mud, but someone posted details from a scout report over on drillingclub forum. Report shows there was a lost circ. event at 18260 with 14.4# mud. That would give you bottom hole fluid pressure of about 13,650 psi.
OT - GeoNola
If you would like to meet this weekend or some other time, let me know. Saturday evening I am going to catch Irvin Mayfield's new jazz composition at the free concert @ Washington Park.
Are you my neighbor down, and across the street ?
Best Hopes,
Alan
Yeah, that's me, Alan. We'll try to make it down to hear NOJO tonight - I'll look for you.
Regards.
With a 4.5" diameter pipe, the observed 1 m/s velocity gives a flow rate of 5000 barrels per day. I agree.
But the column of oil coming out of the pipe is clearly much bigger than 4.5" diameter. Therefore, the flow rate is clearly much bigger than 5000 barrels per day.
QED.
The video provides fuzzy but useful constraints on both velocity and cross-sectional area. If you think 5000 bpd is possible, you need to be able to look at that video and say that the oil plume is a few inches across, or that it's moving at 3 inches per second, or that the black stuff coming out is only 10% oil, or a combination of these. I dunno about you, but I can't do that with a straight face.
I suspect the perdue prof watched the wrong video and used excessive flow area, reasonable velocity.
This vdeo shows the drill pipe that carrys the oil into the 21 riser, where it reverses and exits in a plume.
http://bp.concerts.com/gom/cofferdam_video.htm
The drill pipe clearly blocks the riser exit. It is located across the riser exit, and then bends severly as it enters the riser.
Goodmanj: Just doing it in my head, wouldn't the GOR of 3000 cu.ft of gas per barrel be about 10% of the volume coming out at depth or something like that? (Isn't the pressure at the sea floor 78 ATM so 38.5 cu.ft of gas per 5.6 cu.ft of oil). Don't know, just asking.
http://www.mms.gov/tarprojects/287/287AA.pdf
I read the whole thing. It basically says 1500m deepwater blowouts freeze out all their gas into hydrates that have a lower buoyancy than oil and therefore do not create the plume dynamics that drive oil to the surface. The study mentions nothing about dispersants - especially dispersants sprayed at depth, so I assume a good part of this slick is underwater and yet to be fed into the Loop Current or appear at its final destination.
The loop current is what cleanses the eastern gulf. Loop current uptake is the best hope for the gulf coast, but some other folks may not be too happy about that. However, since the bulk of gulf oil is refined and pipelined to the atlantic seaboard, some may say it is only fair. I would never say that, but some may.
http://ocg6.marine.usf.edu/~liu/Drifters/latest_rtofs.htm
Thad Allen quote,"He said an X-ray type analysis of the failed blow out preventer indicated that it had worked partially and was limiting flow from the well to some degree. He said officials had been able to measure the pressure, learning that oil was flowing into the device at 8,000 to 9,000 pounds per square inch and flowing out into the Gulf at around 2,650 pounds per square inch."
From http://blog.al.com/live/2010/05/national_incident_commander_oi_1.html
How much oil is that?
The water pressure at that depth is about 2200 psi. That means that your pressure differential is 450 psi.
Using a 4.5" hole (as quoted elsewhere here; folks the diameter of the pipe we see on the video does not mean crap if we are calculating the flow based on pressure differential, only the size of the limiting hole in the flow path from the pressure source) and assuming the density of crude oil (which we know this is not the case because this is a mixture of oil and gas) you get almost half a million barrels per day! That tells you that the hole may be smaller. However, if you believe BP's flow, the hole would have to be 10 times smaller. These calculations, however, assume the flow is all oil, which is not. If you assume the density of natural gas the hole size calculations increase by a factor of 3! That is why BP is saying that it is difficult to estimate the amount of oil escaping; we have a two phase mixture of oil and gas, of an unknown composition and density escaping through an unknown hole size.
The pressure data you provide is useful to come up with guesstimates but even those are just educated guesses. Reading from you experienced oil men out there it seems to me that the leak may be somewhat bigger than what BP indicates and the guessing calculations kind of confirm that. But I think the 70,000 number seems way on the high side. We will probably never know for sure and really, who cares, the important thing is that they get it stopped.
If an oil company found a sustainable field delivering 70,000 bbls of oil/day in the GOM, it's share price would double overnight. Get back on the planet.
OK, If I use Diverdan's gas to oil ratio of 38.5 cu ft of gas per 5.6 cu ft of oil I can do a two phase flow calculation and come up with 8000 barrels per day at a 450 psi dp and 4.5" hole. Now, I can by that! No need to bore you with details but I use average mixture density and a mixture void fraction based on the volume ration.
Can any of you oils guys can confirm that ratio at a mile deep? If you can, I would say BP can be off by as much as a factor of 2 but not 14 as the Purdue U geniuses claim!
No, by all means bore us with your details. In other words: Show all work or no credit will be given.
LOL, you want a lesson in two-phase fluid flow?
Go to your local library and get a book in fluid flow (or dust off college book if you are an ME, Che, NE, or similar). You can probably get the equations on the INTERNET too.
Use the DP that I quoted. Use the hole diameter that I quoted. Use a loss coefficient of 1 (sudden expansion); no more accuracy required.
Look up the density of crude oil. Look up the density of natural gas.
Using the volumetric ratio I quote, calculate the void fraction (look that in the book as well). Using the void fraction, calculate the mix density.
Plug all these numbers in the flow/dp equation. Get the mix flow. Calculate the oil flow from the mix flow, void fraction, and densities. Convert to barrel.
A junior in a good engineering school should be able to do this. If they can't, they should ask for the money back.
The calculation is ridiculously simple, IF you have all the variables, which we only have estimates of.
I get 8104.8 BPD. What do you get? I have computer programs that can better simulate two-phase flow but who cares, these are guesstimates based on input data guesses. Still better than looking at a video from flow out of a sewage pipe based on somebody pissing and flushing god knows how far back upstream.
GO FLYERS!
LOL, YOU want to troll yourself up here anonymously and dispute what another respected, non-anon, working within his field, engineer says? Well then, the onus is on you to back up your claim.
Hey number 27182, I'm not anonymous and you can e-mail me anytime at a90aac@aol.com. I'm not disputing anybody either. I'm just stating the FACT that if you assume the pressure DP, gas/oil ratio, and orifice size DOCUMENTED elsewhere in this thread you get about an 8000 BPD leak. If you can't reproduce it is because you know as much about two-phase flow as I know about brain surgery.
Regarding flow estimates using the BP video, think about this:
Take a garden hose, with a nozzle, and spray water horizontally. Then, place a 20" 5' pipe over it at one end. Then film the droplets as they leave the other end of the pipe. How accurately can you deduct the flow from the nozzle from that? The drops are now mixed with the surrounding air, some of them hit the pipe, blah, blah, blah. The same with this oil gas/mix leaking out who knows how far back from the 20" pipe exit. The oil/gas mix is leaking out of the well leak and venting/expanding into this bigger pipe and even entraining sea water. This big water/oil/gas mix is what you see in the film. Anyone deducting the well leak flow from that video must be designing accelerator pedals for Toyota.
I'm not the one that claims to know anything about two-phase flow.
Nah, you think about it some more.
I'm just a concerned citizen....No technical nothing.
May 13th TOD Congressional Hearing posted the Transocean?? rig stats on Apr 20th.
Around 20:00 GPM IN and GPM OUT were equal: 1 K/gpm
Is it a long shot to assume that is the approx rate of leak? 1 K/gpm
or
35 K/bpd?
or lower estimate approx 20 K / bpd?
In case it hasn't come up have they considered squeezing the pipe with hydraulic jaws? I imagine that the pipe is pretty tough, but everything becomes plastic under the right conditions. It should be possible to make a c clamp structure pretty quickly and use an explosive charge to deform the tube hydraulically.
That is what one part of the BOP is meant to do.
Given the leak at the BOP, doing it downstream may (speculation) raise fears of a complete blowout.
Alan