When CHOPS are not a dinner menu, but for heavy oil production

When the weather in the mid-West gets hot and humid, as it does at this time of year, it is pleasant to have the chance to head up to Maine, (along I might note with two solid streams of traffic from Boston all the way North). Thus it was that I could get up, this morning, and pick fresh raspberries for breakfast from the bush outside the window. Raspberries are, like cherries, one of the transient crops that one savors each year when they are in season and then waits until they appear on the bush again next year.

In this way they are a food resource when they grow, but if we don’t put additional work into their condition, they cannot be considered as a reserve for the longer haul. Unless that is, we are willing to make the time and money investment, by canning them, or making them into jam, they don’t count much toward the family food reserve (and note that I have, in the past, helped make raspberry jam).

The difference between a reserve and a resource is a relatively important distinction that often gets overlooked in the debate about our energy future. Some sources of energy are fairly easy to describe and to understand. Place a wind turbine in an area with a recognized wind pattern, or a solar collector array in the American South-West, and we can run tabulated data through simple calculations to understand the value of the returning energy on the initial investment. It is however, the amount of heavy oil that can be justified as a reserve volume that drives today’s post, and with very heavy oil we have to go the other way - in other words turn the consistency from something closer to jam back into something closer to juice.

As, we enter the second, declining part of the oil production curve, the definition of what counts as a reserve and what counts as a resource is going to become a lot more difficult. This is going to be particularly true as the size, nature and quality of remaining fields of oil and gas are considered.

Whereas on the front end of the production curve for oil and gas it was relatively easy and cost effective to produce oil, as we, over the next few decades, enter into the closing tail of oil and gas production, we will increasingly be faced by the economic return on investment, relative to the amount of oil/gas that we will be able to recover from a particular deposit.

As the best oil, the light and sweet crude, starts to become in shorter supply, we have to deal with heavier crudes, and as a Halliburton pdf points out, the problems that arise are not just because the oil is more difficult to transport. Industry has recognized this, and thus heavy oil has its own Science Center, as well as an an information site provided by Schlumberger.

The process for extracting the oil has to recognize that increased viscosity makes it more difficult to produce oil from a formation, and also makes it less likely that high rates of return will be achieved. Water flood becomes a less successful technique for driving oil to the well, since the water can more easily bypass the oil, and some of the earlier rules for production have thus to be modified. In the process a technology known as CHOPS, the Cold Heavy Oil Production with Sand has been developed. The process is an alternative to the use of hydraulic fracturing of oilwells – which came in for some criticism in a recent post, but, as with the more conventional practice, the disposal of spent liquids from the oil production program has to be satisfactorily planned for in agreement with regulatory agencies, before the process starts (as, for example, Raindog and Sorensen explained).

The CHOPS process involves a modified procedure for the control of crushed rock or sand coming from the well. In most oil producing practices the completion zone of the well is designed to retain the rock that is crushed around the well (sand), or disturbed by the oil flow to the well. This makes it easier to process the oil once it reaches the surface.

However with the heavier oils there is a need to extend the flow paths out from the well. One way to do this is to allow the sand to erode out into the well and carried away with the oil, creating flow paths, or wormholes through the reservoir. These still need to be controlled, and, as Chris West of BP has noted:

In CHOPS wells, high drawdown brings in sand. Most of this sand production comes from the creation of wormholes radiating out from the well; providing the horizontal component and increasing the productivity index (PI). . . . . . . . CHOPS operations produce a lot of sand; up to 50% at the start of production, reducing rapidly as a percentage over time. Early total production is very low; perhaps just 20 bbl of oil equivalent (per day) as the wormholes start to form. As wormholes develop, production rises while the proportion of produced sand reduces, typically to 1–2% after about 6 months. At Lloydminster, maximum oil production levels are usually reached within 6–12 months. Sand production requires special surface facilities, which BP is currently constructing. . . . . . Recovery factor (RF) is, as yet, unknown, but is expected to be in the range of 8–10% as is typical of CHOPS wells in Canada. BP is working to enhance recovery from the Ugnu pilot wells through a better understanding of the production process, imaging of the wormhole network and improved operating practices. . . . . . Once wormholes extend into water, they often stop producing oil. Using geosteering to optimally position horizontal wells should improve oil recovery close to the OWCs.

He also points out, in regard to spent fluid disposal

he company already operates the world's largest “grind and inject” facility, located 35 miles away from the new pilot site in Prudhoe Bay. Here, produced sand and solids are injected into a highly porous non-hydrocarbon bearing semi-brackish aquifer, a solution that meets with government agency approval.

CHOPS is also used in extraction of the very heavy crudes in the Faja region of Venezuela, as an earlier Rigzone article described. In that 2006 article it noted that the Orinoco production included:

Using CHOPS alone, Venezuela now produces about 625,000 barrels a day from the Faja, and the economics are good. The lifting costs of heavy oil production have dropped 70 percent since 1991, to just under one dollar per barrel today. The average well produces about 850 barrels a day on cold production, which is remarkable considering that at room temperature, the oil is as thick as peanut butter.

While economical, cold production alone recovers less than 10 percent of the oil in place. The government of Venezuela has now set recovery targets of more than 20 percent for all new heavy oil projects, which means that producers will be moving quickly to deploy current and emerging technology in a region rich in extra heavy oil.

The low rates of production and of recovery factor mean that this process has considerable potential for improvement and given the size of the heavy oil reserves around the world.(Venezuela alone is considered to have perhaps a trillion barrels of such oil) But while there are some techniques, such as thermal stimulation using Steam Assisted Gravity Drainage (SAGD) for example, that can improve recovery considerably these have limitations relating to oil depth and condition.

I have suggested, in the past, that one might consider a form of remote mining of some of this oil, since it is a way that the Canadians have shown can recover virtually all the oil, even from the extremely heavy oils of the Canadian Oil Sands.

It may be that neither of these methods is realistically practical as a future means of significantly enhancing the production and recovery factors for heavy oils, but given the volumes that are there, the poor recovery rates and production rates of existing wells, it would certainly seem an area where larger investment in research might return a satisfactory return.

A valuable primer on heavy oil, particularly the explanation of the tradeoffs involved in extracting more of the oil in place.

The Venezuelans have 1 trillion barrels of oil, and much of it can be extracted for $1 a barrel? Um. Um. Um. Um. I realize it's not that simple....still. Um.

Once you've extracted the oil, you have to refine it into a usable form (ie into normal, lighter crude). That costs more money.

$1 per barrel to extract? That's it, folks! Peak Oil has been officially CANCELLED for the forseeable future.

Fire up the Hummer production lines!
Pave over those organic victory gardens with fresh asphalt!
Let the American consumer know it's time to end the "psychological recssion" and start SPENDING!!

Regulars here should donate their Paul Erlich, Matthew Simmons & Kunstler books to the library and stock up on Julian Simon, Duncan Clarke & Larry Kudlow.


Yes good news. Time to get back to skydiving.
I'll guess I'll go back to reading junkscience.com and the CO2 problem now.

There is always something on the internet that can destroy the world as we know it.

You just have to use the FSE to find it.

Over and out.

$1 per barrel to extract? That's it, folks! Peak Oil has been officially CANCELLED

False Dichotomy Fallacy

There's a world of choices between "we're doomed" and "we're saved", and they're pretty much all more valid than either.


The world has an enormous amount of heavy oil. Producing heavy oil requires an enormous amount of infrastructure. Infrastructure doesn't magically appear overnight, even if you have the money to pay for it.

It's not easy to get high flow rates from heavy oil.

It's entirely possible that the world will be producing increasing amounts of heavy oil for decades to come, and that doing so will have virtually no effect on the timing of peak oil. That doesn't make it a savior and it doesn't make it useless; it just makes it another factor to consider.

You know I was being facetious, right?

The quote was from 2006, and times and costs have changed considerably since then, but what I was trying to use the quote for was rather than showing how much they had, how slowly there were likely to be able to produce it.

As the remaining oil to be extracted goes from the thinner sweeter crudes to the heavier ones so it flows less easily and production problems will increase. Being able to produce something at low cost, if the yield is also slow will not be a great help in the future, even if the reserve is large.

Very good presentation HO. About 20 years ago a piece of down hole equipment was developed to produce those "wormholes". It was a series of water jets that quickly cut channels back (60' or so) into the formation. The high flow rate described is rather unique from my limited experiences with heavy oil. Commonly a lack of reservoir drive energy is as much a problem as the viscosity. The subject formation must have had a strong drive. In south Texas there are hundred of millions of bbls of stranded oil that’s actually high quality but unrecoverable due to its viscosity. Here, too, water flooding doesn’t work due to bypass. Perhaps CHOPS is worth investigating for those fields. Some of the oil is as shallow as 400’ and demands a premium price over WTI.

Venezuela is a natural focus for such efforts given its proximity. About 15 years ago a company bought a field in Vz making around 400 bopd. A redevelopment with horizontal well bore quickly increased production to 40,000 bopd. Unfortunately the company had no incentive to increase production any further. Their contract with the Vz gov’t required the gov’t to receive 100% of all production greater than 40,000 bopd. Given the current Vz gov’t the technical difficulties may be overshadowed by the politics.

$1 to extract - sounds pretty good - so in these cases it's as expensive to extract as light sweet crude.

What is the extra processing cost? And if this oil peanut butter is shipped to be processed, that adds a lot more weight and volume - thus costing more to ship. I wonder how much that adds.

Probably all depends on how heavy.

The lifting costs of heavy oil production have dropped 70 percent since 1991, to just under one dollar per barrel today.

Is this a red herring? $1 to lift but what are the other costs? It is clearly not $1 all in - if so this has to have a huge EROI. What are the initial capital costs requirements, employee costs, overhead, etc? Perhaps this heavy oil is very near the surface so technically the joules required to lift it ARE very small.

Is Venezuela just lacking expertise and infrastructure? Something doesn't sound right in that quote - it's like a dieter saying all he ate for dinner was a cracker but he had a smoked duck and a tray of brownies for lunch.


To a large degree lifting cost per bbl is more a function of how much oil your producing then the total cost. There is usually a big fixed cost load whether it's 10 bopd or 500 bopd. I assume the $1/bbl LC is for the high volume wells they refer to. If there's no natural gas available (and commonly not with these types of reservoirs) lifting is done via diesel motors....not very cheap these days.

There's also a wide range of quality in "heavy oils". A lot of what comes out of Vz is called Orinoco CRUD…and for good reason. They usually have to mix it with water in order to just pump it. There are refiners in the Gulf Coast set up to handle it. It has the lowest value of any liquid hydrocarbon I know of. But there are better grade heavy oils in Vz but I have no idea of the percentages.

As with many things in life, it's all about the size of the denominator. :)

Isn't the heavy oil in Venezuela more profitable than the tar sands in Canada? And of slightly better quality as well?

So what are the Venezuelan government doing? Aren't there any plans to scale up as much as possible? And what production level might be possible in the next 10-15 years if going full-steam ahead with extracting?

Raspberries are, like cherries, one of the transient crops that one savors each year when they are in season and then waits until they appear on the bush again next year.

It's hot and dry here in NW Arkansas. I am currently picking Kiwi Gold Raspberries and Triumph Strawberries. These ever bearing plants provide nice garden nibbles throughout the summer and fall.

I just picked two gallons of triple crown blackberries an hour ago before the next wave of rain comes. Easy to grow and huge yields. I'll air layer a few branches and plant more in a month.

It's also important to note that triple crowns are a thornless blackberry. They also make huge canes that can go out 20'. I grow them too and mine are just getting ripe.


Heading out is an unfailing optimist, to the point of where the cons are hardly ever mentioned in his articles, to the dismay of many that prefer to take a more objective view.

Um! I don't think that pointing out that the recovery for heavy crudes in some of the resource areas that have been promoted as being long-term saviors, is currently only running at 10% is particularly optimistic - but then I guess opinions can differ.

What are the risk of collapsing the formation with this technique? I'm not real strong in my knowledge of reservior dynamics, but I thought the who point of frac sand injection was ensure that these "wormholes" don't form from sand production and then collapse into less permeable layers? Would someone educate me?

You're right Greg. I'm going to research it but it sounds like the idea is to get an immediate sand flow. Gotta tear up the tubulars a bit but I assume they adjust for that. Let you know what I find.

I notice there are several bad links in that article, looking at the source they are simple typos, e.g. hef instead of href.

Running an HTML checker, I get over 300 errors on this page. Perhaps running an HTML check should be a matter of course, like running a spell check?

I have never used an HTML checker. What do you recommend, given that this is Drupal HTML?

HTML is standard Gail, it's not that it's Drupal HTML, Drupal is just the interface. I usually do the HTML checking, so it's my fault.

HO has had notoriously bad HTML forever, I usually edit his each time, but I was traveling and didn't a chance to do it. I think I fixed most everything now though.

Bob, you can always mouse over those links and try to figure out where they're going, it's not that hard.

Thanks for your efforts PG, works fine now.

Bob, you can always mouse over those links and try to figure out where they're going, it's not that hard.

Nope. If the syntax of the HTML is wrong, you don't get anything. One has to look at the HTML to figure it out, which is hard for the average user.

So where does this link go?

Google of course ;-)

<a herf="www.google.com" rel="nofollow">So where does this link go</a>

Thanks for taking care of this, Prof. I was somewhat remiss in not checking this more carefully but am still travelling around a fair bit. And my apologies to the readership.

HTML should be HTML, or in this case XHTML 1.0 Strict. So http://validator.w3.org/ should work.

If Drupal use some broken or non-standard HTML I would ask them about it.

Thanks, I'll try it.

John hasn't been the same since he got his brains scrambled http://www.youtube.com/watch?v=zrX9Ca7LSyQ

Thanks, I feel much better now:)

Now that's what I'm saying...a nice Peak Oil roundhouse slap to the head ;)

If there are 1 trillion barrels of heavy oil in Venezuela, and we if could extract it and burn it, how much oxygen would be available to breathe?

well that would depend if it were burned over 100 years or 3 hours, among other things.

Interesting question. A quick back of the envelope:

1 trillion barrels is about 1.4x1011 tonnes of oil. Assuming it was all carbon and converted to CO2, that's about 2.8x1011 tonnes of oxygen. The atmosphere contains about 1x1015 tonnes of oxygen, so it would consume about 0.03% of atmospheric oxygen.

More importantly perhaps, it is 14 years worth of carbon emissions at current annual rate.

Here's an interesting heavy(but not super-heavy) oil story.
Why the GOP don't want to fill the SPR with much cheaper heavy crude is quite intriguing. Would it cut down on Big Oil's profits? Am I just being paranoid?

Republicans Block Provision to Alter Strategic Oil Reserve Mix

July 24 (Bloomberg) -- The U.S. House defeated a Democratic proposal to substitute heavy crude oil for light petroleum in the Strategic Petroleum Reserve, after White House officials threatened a veto of the measure.

The measure, at least the fourth energy bill to fail under suspension of rules in the last month, would have directed that 10 percent of the reserve be released into the market over six months and replaced with heavier oil over a five-year period. Considering a bill under suspension of House rules means that the bill needs a two-thirds majority in order to pass.

``The Strategic Petroleum Reserve is an incredible weapon to be used in order to protect the American consumer from being gouged at the pump,'' said Massachusetts Democrat Edward Markey, the chief sponsor of the measure on the House floor.

The bill, which failed 268-157, is one of a series of measures the Democrats have brought up in an effort to address skyrocketing energy prices. Both gasoline and oil have fallen off of records set earlier this month. Crude oil futures touched a high of $147.27 a barrel on July 11.

Republicans have argued that Democratic energy measures have ignored what is really needed, domestic oil production. White House officials today recommended President George W. Bush veto the measure.

The SPR was established as ``the nation's energy insurance policy,'' White House spokeswoman Dana Perino said. ``We don't think it should be weighted for purposes to try to manipulate price. It hasn't worked.''

The Government Accountability Office has reported that filling 10 percent of the reserve with heavier crude, instead of light crude, could save taxpayers $1.2 billion.

An Energy Department report last week advised cutting the supply of light sour crude in the inventory by 70 million barrels, and substituting that with heavy crude.

Currently the reserve holds 706 million barrels, or 35 days worth of average U.S. oil consumption. The inventory includes 424 million barrels of light sour crude and 282 million barrels of light sweet crude, the department said.

Thanks for a lucid explanation of this innovative process to extract haevy oil. What about the negative impact of the effluents if any?

Depending on where you are, there are various ways of disposing of the different components, but as noted above, in most cases they are re-injected back deep into the ground.

Yep...effluents are a huge environmental liability....lots of salts and toxic heavy metals. As already mentioned, the typical oil field solution it to inject water into subsurface formations. In most areas there are even commercial businesses that do this for a living. This is also a huge problem with current Canadian tar sand production. The volume of effluents coming off the process is too great for the injection solution. And it can't be discharged on the surface. I've seen estimates of the 100's of sq miles of retention ponds which would be required to expand production to 5 mmbopd. Just one more of the big hurdles that must be dealt with before the TS's can have a big impact.

I think cavitation at the bore tip has lead to overestimates of sustainable flow in water drilling. I recall one uncapped artesian well regularly discharged so much sand it looked like a beach though far from the sea. Place called Padthaway, Australia. The blackberry connection is that the sand contained what looked like thorns but were actually small sharks teeth. Any way the wells were capped and flow meters installed. What was free water now has to be paid for.

Padthaway whites are very nice.