KLurker, if you don't think that highly placed corporate executives suddenly selling off shares or any other subtle forms of "borrowing a lifeboat and abandoning ship in the middle of the night"; then you have plainly not been around long enough, or dating Polyanna too long.

Hmmm...looks like a dome to me. I think GN disagrees though. Maybe he is saying that Macondo is in close proximity to a dome but is not on the flank(??). In the mini-basin?

Macondo is about 16 miles away from where you have located it on that map.

Your map is not rectified properly and is in the wrong place.

I've had a properly located (rectified) map on this for a while (it's the same map, only rectified properly) if you want one. It's a KMZ file.

Lemme know.

Paintdancer:

I'm no oil-person, as my questions and comments have probably revealed all too well, but I would like to speak to your concerns about oil-person secrecy, and about the sudden reversal of direction on the cap that has concerned you and others.

My understanding of oil-person secrecy is that it is very real in certain, pretty well defined areas of their work. When, for example, they are trying to identify potential areas to explore, the seismic and other data they gather would be very helpful to their competitors, so they keep a tight lid on that information. I can believe also that with regard to certain techniques they've developed that give them an edge on competitors they might be very reluctant to share that with the competition. At the same time, I suspect that there is a huge reservoir of information that is pretty common knowledge in the industry, especially regarding most of the commonly used procedures for exploration, production and safety, including shutting down wells.

On the other hand, there can be so many variables involved, that there are likely to be easily defensible but mutually exclusive approaches to resolving a problem like this. My impression is that BP was so overwhelmed by this blowout, and the possibility that they might make the situation far worse if they made the wrong decisions, that they were reluctant to approach it in any but the most conservative fashion. I was of the profoundly un-informed opinion at the beginning, that the right approach would have been to immediately cut off the old BOP, and replace it with a functional one, much as they have done, only lower down. I still suspect that such a course of action would have saved the gulf from a considerable quantity of the leaking oil, but I'm not prepared to criticize them for moving the way they did, incrementally, especially because I'm aware now of some factors of which I was not cognizant earlier.

So I believe the path they chose was understandable, not nefarious, that as they gained more confidence in their understanding of what was going on they became more comfortable with capping it, rather than employing any of the other approaches that were available, including the ones they had already tried.tried.

It is so difficult to perceive the motivations behind behaviors, especially when we only have limited relevant data, that it is very easy to interpret actions as being almost the complete opposite of how they were intended. Is she being nice to me, or trying to set me up? Is he lazy or laid-back? What's behind that attractive mask, is it the devil? If I were the devil, I would call up someone and say "this is God speaking, here's what I want you to do." How would that person decide whether to follow those directions or not?

But it's time for me to go to bed and get some greatly needed beauty sleep. Would that the prospects were better.

Take care,

Dave

Regarding Lim's theory, let's just consider this for a moment, and give our government the benefit of the doubt. The people here have basically admitted that the WH does not have any people in the administration that know anything about oil, drilling, engineering, or geology and seismology. Chu's area of expertise is nuclear energy or physics, I believe, so he has been in over his head from the beginning.

So what if BP pulled the wool over our government's eyes? What if they told them in early July that in view of the carnage that was being perpetrated every day as a result of the pollution and the world seeing the gusher on every news channel, what if they told the WH or the coast guard or Chu or whoever is in charge that they had a cap that almost certainly would stop the leak until the relief wells were done? So the administration says, 'Okay that sounds great but what about all the rumors that have surfaced that the well has lost its integrity and is damaged down hole? Wouldn't it be dangerous to cap it if that were true?'

And what if BP then totally convinced the administration that they now had this great cap that would most probably work where all the others had failed and the American public will be overjoyed and can start getting on with their lives, and people including Obama, too, can go back to their normal day jobs because the relief wells are almost done within a few feet, and that very soon the well will be capped, the relief wells will finish the kill and that will completely be the end of the Macondo debacle. And so the administration thinks some more, and sees the benefit in the cap idea, but continues with inquiring about the rumors that have been coming from anonymous whistleblowers at BP and Senator Nelson's office that the well is damaged beneath the sea floor, and are still concerned that even the Thomas Jefferson has recorded some anomalies when it went out at the beginning of June that has the administration concerned. (Wasn't there a report, unverified possibly, that there were cracks in the sea floor?)

Then BP comes out with the erroneous fact that even if there is some 'minor' damage down hole the worst that can probably happen is that some gas and oil will flow into the rock formations beneath the sea floor, and maybe a couple little tiny seeps may also occur, but in light of the carnage that has already occurred, isn't that negligible, especially since seeps are naturally occurring in the GOM anyway?? So the gov't decides (with reservations) to let them cap the well and at first everything looks pretty good and people are overjoyed. Then those annoying little seeps start occurring but again BP has already reassured the gov't that this would be a probable result of capping the well, and anyway they are not related to Macondo, so they are nothing to be alarmed at. And what if the Coast Guard starts doing the seismic tests and realizes that there really are problems in the sea floor and that the leaks are getting worse and that the lack of rising pressure seems to indicate that the well lacks integrity?

Well what are the governments choices at that point?

At that point the gov't is literally between a rock and a hard place. If it forces BP to take off the cap, which if you recall it alluded to in the early days as a definite probability after the well was capped, then the public will be outraged. In addition, while I am not an attorney, I would think that the gov't could then be breaking some serious laws against the environment in requiring BP to remove the cap and allowing the vile stuff to spew again. Also the government would then become liable for all further financial damages since BP had managed to stop the leak and the pesky gov't made them take it off. So the WH or Coast Guard or Chu, or whoever is in charge decides to take its chances and hope that the earth beneath the seafloor will stay intact and that the seeps will be minimal and eventually the reservoir will deplete itself and that nothing horrible will happen even if the well is losing small amounts of gas and oil into the undersea layers. In fact, it would be a win-win for the Gov't , BP and the Gulf- or at least that's the way they'll rationalize the decision. The public never knows the danger, the gov't doesn't need to worry about evacuating millions and everyone lives happily ever after. Hopefully.

Interesting item this week was the fact that on Thursday House Speaker Nancy Pelosi (D-Calif.) stripped out authorization for an independent investigation into the Gulf disaster from HR 3534, The Clear Act, which passed in the House Friday by a small majority. Why? Why not give the American public some transparency if you have nothing to hide? Why not allow independent engineers, and scientists investigate rather than the government?

I think BP has trapped our government into a situation that is untenable. They (the administration) have had no choice other than to go along at this point and hope the relief wells and static kill will do the job required . They are playing against the clock.

The blobs just look like debris kicked up with bottom sediment by the rov. Normally the deep bottom of the Gulf is very fine mud that is easily disturbed. Unless a current is present it obscures vision from a sub or rov for a while.
At a drill site the bottom also has a layer of cuttings mixed with some discharged drilling fluids. It is common for a white bacterial film or mat to form on this material due to organic compounds in the drilling fluid. If disturbed the film breaks up in chunks. Oil seeping from the bottom looks very different. The bottom around the blown well will also have a layer of drilling mud on it from the failed top kill. Depending on how much stuff has been layered on top of natural mud, the cloud kicked up by rov's can be different place to place.

The term debris implies it's something similar to rubble. This refers to (usually small) pieces of the well's wall which fall in due to earth stresses or chemical effects (the rocks absorb water, swell, and pop out of the wall).

Well the fish that made this must feel relieved!

HOS -- Nope...the blow out well will never be a producer. But there was some talk about using the second RW if they don't need it. They could suspend the well and come back in a few years to drill and produce the reservoir. But a lot of ifs to get from here to there.

Actually if the top kill goes as I understand it the WW could be killed in a matter of hours. That would be great news and should end any further oil dumped into the GOM. But the ultimate plugging and abandoment of the well could take quit a few months.

No way the OH will ever be used, but sometime, down the road, a future operator would consider using the top hole sections of the relief wells to sidetrack back to the reservoir for producer wells. Of course that would be the smart thing to do to get full value, but PR might cause the relief wells to also be permanently plugged and unusable - will be interesting hear the sturm and drang over this -- if there's any noise, BP will P&A rather than TA, unfortunately degrading the value of the lease to no one's benefit.

Great summary at the top aeberman, but I think Wells is right and it's perfectly possible to bullhead this well in a day without seriously challenging the integrity of the casing. And thanks jinn for pointing out that it's the shape of the build-up curve that points to well integrity, not the final pressure. Stopped a long post getting even longer.

Here's my stab at rate and pressure calculations for the static kill. Disclaimer: I've taken the input numbers from postings here and elsewhere, but not checked them for exactness and some are from memory. This is an order-of-magnitude test so unless it leads to a borderline answer, it doesn't matter if some of the numbers are 10% or even 100% off. In the spirit of order-of-magnitude calculation, I'll assume that the average density of the static oil column in the well is the same as when it is flowing, and ignore friction.

Assume that the wellhead pressure is 7000psi. I recall 4000psi as a flowing wellhead pressure before the cap was put on, but maybe there was a 2000psi somewhere as well, depending on erosion, cutting off the riser, reservoir depletion etc. Let's split the difference and say 3000psi, 4000psi below the shut-in pressure. Assume that this represents the drawdown on the reservoir when the well was flowing 40,000 barrels per day. That's a productivity index (P.I.) of about 10 barrels per day per psi. BP/Gov has quoted a reservoir permeability of 300mD from the pressure pressure build-up test currently being conducted (the Horner plot Wells referred to). Possibly disappointing to those who worked on the exploration prospect, but not unreasonable if the sand is fine-grained/cemented/clay-bearing. The main reservoir sand is 60ft thick which gives a permeability-height (kh) of 18,000mDft. Not unreasonable for the well rate observed. Like the P.I. of 10 it's not world-class, but it's the pressure that makes the rate. In a shallow, normally pressured reservoir you'd be lucky to see 10,000 barrels per day.

Looks OK so far. Dimitry suggests that the slow build-up suggested a low permeability reservoir, but it's the kh that determines the build-up rate and at 18,000mDft it will take weeks to fully stabilise. Remember these gauges are accurate to a tiny fraction of a psi, kh is calculated from the build-up rate, and late in the test pressure rises very slowly (asymptotically). In a normal PBU, all you want to know is the kh and reservoir pressure so you'd stop a test on an 18,000mDft reservoir after a couple of days and extrapolate the Horner plot. Here they also want to look for deviations from the extrapolated trend, which might indicate leaks. Plus of course no-one wants to start polluting the Gulf again.

Suppose they start pumping mud at 10psi above the shut-in pressure. They'd have to be really unlucky for a weak point to hold at 7000psi but fail at 7010. With a P.I. of 10 that should give 100 barrels per day flow back into the reservoir. In 6 hours they'll have pumped 25 barrels, about 1% of the quoted well volume of 2,000barrels. They're pumping at the sea floor, so there's about 13,000 vertical feet of hole above the reservoir and 1% of that is 130ft. Replace 130ft of oil (say 0.5 S.G) with 13ppg mud (say 1.5 S.G.), a differential of 1 S.G. which corresponds to a difference in pressure gradient of about 0.5psi/ft. The wellhead pressure is now 65psi below your starting point (and 55psi below the shut-in pressure so you're already safer than you were at the start). You could then add 50psi at the wellhead for a 60psi pressure differential at the reservoir, giving 600 barrels per day flow into the reservoir. In six hours you've replaced another 150 barrels of oil with mud for a total of nearly 10% of the wellbore volume or 1,300ft vertically. Now your wellhead pressure is down 650psi from startup and you could add another 500psi. With a P.I. Of 10 and > 500psi pressure differential at the reservoir, you'll get > 5,000 barrels per day inflow and displace the remaining oil (90% of 2,000 barrels) to mud in under ten hours. At which point the well is dead and it's all over bar the cementing.

In practice the staging would be more gradual and in my example I've ignored the increasing bottom-hole pressure during each stage, as oil is replaced by mud. You'd have to choke back the mud supply otherwise the flow rate back into the reservoir would run away as the oil column was displaced. I assume they want to take it gently and retain control rather than just 'let it rip'. But all in all, it seems perfectly do-able.

Billyd

I’m new here too and can see that you have some reasonable questions. I’m no expert, but I may be able to help. I’m sure someone will jump in to straighten both of us out if I goofed up too badly.

First, I watched the video and your summary is spot on.

Regarding questions 1 and 2, I think Mr. Wells got a bit confused. Seems he made a presentation that has errors and it should be disregarded. Between July 21 and today a lot has changed. In addition to being wrong the update presented then does not reflect current plans

Regarding question 3, it probably is possible to formulate such a mud. But, this mud still needs to act like a normal drilling fluid because there are other formations all along the well bore that potentially could have communication with the well. You want the mud to be able to gum up a porous rock. They do that by adding bentonite (at least in my day). The overpressure against a porous rock would cause the rock to act as a filter. Mud would try to pass into the rock causing what is called a filter cake to build up on the surface and filtrate would pass into the rock relatively close to the well bore. The filtrate is mainly just saline water. The filtration process would end when a thick enough filter cake built up to seal off the formation. If you still want mud to enter the formation you can increase pump pressure sufficient to fracture the rock. You could also inadvertently fracture another rock and pump the mud into the wrong place.

Regarding question 4, again the animation is now 10 days old and things have changed. It is misleading in that now they appear to want to pump mud all the way down to the bottom. There is talk that they may have to fracture the formation with pump pressure just to get the oil back into the reservoir. That sounds risky to me. Let’s hope it is not necessary. Since they can’t circulate mud out of the hole, if they want to pump cement the only place for the mud to go is indeed into the formation. I don’t think they could verify by direct measurement any cement location below the top of the hardened cement plug. I guess they could re-enter the hole, shoot some holes through all of the casings just above the cement top and try to squeeze some cement. In my opinion this would add information, but would not be definitive.

Regarding question 5, I just looked up his phone number with an internet search. Easy to do. I called the number and the guy on the other end claimed he is not THAT Kent Wells, but I knew better. I gave him a good tongue lashing for both of us.

Hope this helps!

Billyd,

I found your questions from this morning.

If the static top kill succeeds in cementing the reservoir then, yes, it would seem to obviate the need for the relief well..as long as it could be verified by some test that the cement seal were sufficient. It seems that it would be necessary to get in there with a drill string to test for flow and pressure.

The way that I understand it (and somewhat contrary to Cecil B. De Well's video), if you could force oil and then back into the reservoir--and I'm still not convinced that this is feasible but think that the mud must swap volumes with oil in the well--it would occur by exceeding the fracture gradient of the formation, in which case porosity and permeability shouldn't matter too much. I really doubt that the oil can be pushed back into the reservoir through 300 md maximum rock with high pressure coming the other way without fracturing based on the petrophysics that I understand. There are obviously commenters who don't think that this is a problem. None of the drilling engineers that I consult with think it is reasonable either, for what it's worth.

The lower-than-expected mud weight question has been addressed by other commenters for the most part. I think it is a viscosity issue--it takes more pressure to pump down heavier mud against lighter fluids under buoyancy. It is probably the minimum mud weight that was calculated to kill the well with all of the mud foot-pounds, etc. that were mentioned in a previous comment.

I don't think that cement will be injected until after the well is killed or at least until they are confident that they can pump under the pressures required without exceeding burst capacities.

I hope that this helps.

Art

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They should have done a full top kill in May, which is why Chu was alone in his decision to stop it then. He was wrong and the pending success of the top kill will prove it.
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You have no way of knowing that. Your claim is not supported by any facts.

If BP had first installed a capping stack in May then the probability that a top kill would have worked in May is about the same as now. But for a top kill to work with no cap requires much higher pumping pressures to overcome the pressure losses out the riser.

Here we go again, why not take a aimless potshot at Chu, right? It's free...There is nothing more important in this world than putting down a democrat.

Your basic understanding of pressures and corresponding mudweight for RW kill is flawed. The total height that determines the pressure is the same - including the leg to the surface. All that is needed is a little back pressure at the wellhead to compensate for pressure difference - a lot less than they have been subjecting the wellhead to all the time during "well integrity tests". For an "ideal" mudweight for RW kill, the WW wellhead pressure is a bit above 3 ksia.

I think it is undisputed that the RW kill requires less pressure at the wellhead than the "static kill", though this pressure increase is temporary.

"Having a direct connection to the surface means they can use gravity to do a very slow and gentle top kill using 13 ppg mud."
"Mutliply 13 x 18,000 to get desired ft-lbs at the formation. With the well filled with mud and 5,000 feet of ocean above you have 13,000 x 13 + 5,000 x 8.5 which ain't enough"

""Mutliply 13 x 18,000 to get desired ft-lbs at the formation."

These number quoted here are not correct at all13 times 13000 == 234000lbs.+5000 =239000 botom hole pressure. NFW . 13 ppg mud does not give 13 lbs per foot pressure. Actually 13 Ppg gives only 0.67 ppft

At the top of the water the pressure to over come would be 7000Lb flowing pressure plus 2000' of sea water8.45x 5000 2250 or about 9500psi. 13.5 mud at 18000 gives about 12600 psi bhp