Tech Talk: Conventional Mining of Oil Shale

So, there we have all this oil, sitting in these nice thick oil shale beds out West and just waiting to turn some local in Colorado into the next "world's richest person". All they have to do is to figure out how to get the oil out of the ground cheaply enough to make money from it. (And if you remember from the last post on the subject there are over 2,000 patents on ways to do this - if it were that simple there would not be nearly that many). Congress thinks so too, since the Energy Policy Act of 2005 called oil shale a strategically important domestic resource (pdf file). More recently, there is currently a House bill in Committee governing oil shale development.

This is another in a series of Sunday tech talks.

What's the big deal? Drill a hole down there and it flows - isn't that how you get oil out of the ground? Well not in this case. As I said last time the oil is really a waxy kerogen that does not want to flow at all. And there is also a problem with the rock. About 40 years ago a guy called Brace (Ref 1 - sorry I can’t find these on the internet) found that the cracks in a rock are related to the size of the grains of the material that make up the rock. A rock with large grains has large cracks, and this gives it a permeability, which is the joining of these cracks to give a path through which oil (or water or gas) can flow through the rock. It also gives the rock its porosity, which are the holes in the rock into which the oil can collect. Unfortunately the grain size of the average particle in oil shale is around 5.8 microns. This is about a tenth of the thickness of a human hair, medium human hair being about 60 - 90 microns wide. As a result the typical oil shale has very poor porosity, and it is only when it has a high oil content (above 50 gallons/ton) that permeability can be easily measured (Ref 2) , below 20 gal/ton it becomes very difficult, because it is so small. The average grade is around 25 gal/ton.

The simple message from those numbers is that oil will not normally flow into any holes that are drilled into oil shale. So where do we go from here? Well if you can't go to the mountain, then the mountain must come to you. In other words, let's mine the oil shale, bring it to the surface, and then get the oil out of it.

That’s what they do in Canada with the oil sands, and these beds are thicker. In fact the layers are thick enough so that they can be mined by a number of different ways , including surface mining, what we call room and pillar mining, and then by a third method that I will, for now, call sub-level stoping. Remember that we need to break the rock down into pieces no bigger than 3-inches in size for the retorts.

Union Oil (now Unocal) used the room and pillar method for their mine at Parachute Creek, where mining interest had, for a while, been growing again. Room and pillar mining was also used for the Colony Mine, which was the largest project in hand back in the 1980's . Since there have been a number of reasons suggested for the closing of that project, it might be appropriate to ask you to remember the words I quoted from Harold Carver last week.

What is needed is assurance that shale oil production will face a stable economic environment in which it can share in the spectrum of raw materials for our future energy needs.

And then read on:

Tosco's interest in the Colony project was sold in 1979, and again in 1980, to Exxon Company for the Colony II development. Exxon planned to invest up to $5 billion in a planned 47,000 bpd plant using a Tosco retort design. After spending more than $1 billion, Exxon announced on May 2, 1982, that it was closing the project and laying off 2,200 workers. . . . . . The economic incentive for producing oil shale has long been tied to the price of crude oil. The highest price that crude oil ever reached -- $87/bbl (2005 dollars) -- occurred in January 1981. Exxon's decision to cancel its Colony oil shale project came a year and half later, after prices began to decline and newly discovered, less-costly-to-produce reserves came online. . . . . oil had become plentiful, with about 8 to 10 million barrels per day in excess worldwide capacity, and the trend in rising oil prices had reversed after early 1981.

The failure, in short, at that time became one due to economics, rather than technology.

Using a machine to mine the oil shale poses some problems, since it is much stronger than, for example, the tar sands of Alberta, that can be scooped up with a shovel. Rather the rock has a strength that goes down as oil content goes up to a value of about 13,000 psi with an oil grade of 30 gal/ton, at which point it stabilizes even as the grade continues to increase. This means that the openings for mining can be quite large, as they need to be to achieve the tonnages planned. And there are ways to make them larger.

Rooms mined with the rock were some 55-ft wide, with 58-ft pillars. It also means that the machines to grind the rock from the solid will need, either to be jet-assisted, or of relatively large size. One of the first proposed (for you EROI fans) was designed to produce 17,500 tons per 2-shift day, with an oil content of 40 gal/ton, and with 6.5 operating hours in a shift. Machine power requirements would be 37,500 kwh per working day (Ref. 3).

The advantage of the large mining machines, over drill and blast methods, which remain the most common practice, is that the operation is continuous, with rock being carried away by conveyors, and production need not stop to ventilate away the products from the use of explosives. On the other hand the use of explosives to fragment the rock does provide a relatively effective way to fracture it (though with less size control). One of the questions that I have always had, though, in doing EROI on explosive use is whether to count the energy input as that required to make the explosive, or that liberated when it is set off.

In the days when the industry was last planned, the throughput for single plants was considered to be on the order of 100,000 tons/day. A ton occupies 16 cubic feet (Ref 4) and so if the mine is 30 ft high, a cubic foot of floor space would have 2 tons of rock on it. This would translate into having to mine 2.5 acres of rock per day. The point has been made, however, that underground mining of layers of rock one slice at a time down through the deposit would be inefficient and energy intensive. Further that it would be restricted only to mining the high grade layers.

The matter of mining, by underground methods, the rich, deep oil shale beds in the center of the basin probably needs little consideration because better methods of producing the resource appear to be at hand. If our civilization has any conscience and if it has any regard for posterity it cannot give serious consideration to any method of production of shale oil from the center of the basin that does not result in substantially complete recovery. Our civilization has passed the stage in which it can kill the whole buffalo merely to consume the tongue and liver as was done in this area less than a century ago.

What he is arguing against is the intent to set up the mine to mine out the rich layers, so that when our grand-children have to mine the rest they must work in the dangerous conditions of a partially mined volume, with only the poorest grades of shale as a reward.

In contrast he argues that the area should be strip-mined since even with a 1,000 ft cover, the thickness of the oil shale would justify the process as a means of recovering the entire volume of oil from the deposit. Part of the problem comes, of course, not only from the fact that a hole a mile in diameter and 3,000 ft deep has been created, but that also all the material that has been mined, has to be stored before being returned. And this is one of the significant problems that mining the deposit either by strip mining or by underground mining generates, that of the waste volumes and condition.

For a long time mining has used some of the waste rock that has been mined to pump back into the mine and fill the holes left. By mixing a small amount of cement with the rock powder it can be made strong enough that the rest of the valuable ore can be mined, and the roof is held up by the newly placed columns. However, when you mine and mill the rock it is broken into small pieces. These bulk in volume by about 60% on average, over the original volume of the rock, and so even with the use of the mine to put back some of the rock there will be about 40% of it left for disposal somewhere else. (Note that this does not include the thermal swelling that occurs when the rock is heated - I will get to that in a couple of posts).

But it should be pointed out that there is already some 50-odd years of experience in dealing with this waste in the area, and while I am not familiar with the problems and their solution, the general mining practice with waste fills is ultimately to cover and seed them so that there is a binding vegetation - unfortunately this, as with some of the other parts of the extraction process, requires considerable water, and that is an issue that we haven't reached yet. But, on the other hand, we don't seem to hear much about the piles that already exist.

Again I am going to pause here, since the post may otherwise get too long, but next time I will talk a little bit about the nuclear option, which might otherwise be forgot.

Ref. 1 Brace W.F. "Dependence of Fracture Strength of Rocks on Grain Size," 4th Symposium on Rock Mechanics, Penn State, 1961,

Ref. 2 Thorne H.M. "Bureau of Mines Oil-Shale Research", First Symposium on Oil Shale, CSM, 1964.

Ref. 3 Hamilton W.H. "Preliminary Design and Evaluation of the Alkirk Oil Shale Miner," Proc. 2nd Annual Symposium on Oil Shale, CSM, 1965.

Ref. 4 Ertl T. "Mining Colorado Oil Shale", Proc. 2nd Annual Symposium on Oil Shale, CSM, 1965.

Heading Out, great post but I was greatly disappointed by your ending. You completely left out: In Conclusion...

Since you are obviously well informed on this subject, what are your conclusions as to the economics of mining the Green River Shale? Or what are your conclusion as to other attempts to extract the kerogen from the marl? I am dying to know.

Ron P.

That's because I have two more posts, at least, on the subject before I'm done with it for now. I do plan on getting there, but I wanted the historical context to be understood first.

Heading Out, in that two more posts, will you also write something about extracting shale oil with chemicals ? I refer to the comments on your tech talk article about oil shale from 14 februari.

Actually, what is the use of this exercise? We are just digging out fossil fuel hole deeper and deeper until mother nature stops us with nasty climate change events:

James Hansen: Storms of My Grandchildren

Great, now even HO's weekley tech talks are getting attacked by the climate change faction. I guess with an agenda, arrogance knows no bounds.

Actually Steve, I don't think Matt was attacking the article, he was attacking the strip mining of shale to extract the kerogen.

That being said, it is my sincere opinion that the effects of peak oil and other environmental degradation will knock civilization down long before global warming causes the seas to rise very much.

Ron P.

Death to HO!!! If we don't kill the messenger how will we ever change what can't be changed.

I'm not discounting the environmental concerns. But I have an absolute and unflapable view of the the future: the economies will do whatever possible to maintain BAU even if it ultimately damages the lives of 10's of millions. Thus we're left with choosing the best of a number of bad choices. I don't tend to read much about oil shales...bores me to be honest. But the bottom line: what's worse for the environment: oil shale development or burning more coal? Coal is easy...coal is cheap...coal will probably make more sense then oil shales. To me it's very simple: inhibit every other form of FF production and it will be replaced by burning more coal.

Liquefaction, you mean. Unless you think we'll have boilers grafted onto our cars.

The pitface approach to CTL is interesting, in that it might prove economical and have lower upfront costs, shortening build out time. I don't think people will have the patience to wait for full bore exploitation of coal for liquid fuels.

The little known sequel to Henry VI (Henry VII?) suggests "The first thing we do is kill all the geologists". Now that would really solve our least for a couple of years.

It would do no good laddie...they breed like roaches.

inhibit every other form of FF production and it will be replaced by burning more coal.

That's true to a point. I agree that we will burn coal, if the alternative is to turn out the lights, or pay a large cost penalty.

But, I believe people will be willing to pay a modest premium for a low-emissions substitute. Fortunately, we have that, in electric transportation (and heat pump space heating) powered by wind-generated electricity.

Yes, an interesting article on shale, but a set of conclusions would have definitely added something. My two cents is, if we are down to needing shale oil, tar sands, heavy oil deposits in Venezuela, and other oil deposits high in sulphur, it seems even the most in denial group about peak oil should now see the impending the descent from peak is either upon us or soon will be.

With all the piles of sulphur building up at these various dig and drill sites, I wonder if a thin sedementary layer of sulphur will be the telltale sign to future geologists a few million years from now regarding the end of the oil age.

"Ah, do you see Wilson, this thin layer of sulphur deposit is a clear indication of when their oil age was ending. A micro thin layer that is part of an overall layer which includes, all sorts of toxic substances."

"Yeah Stickler, but why are we only finding this sulphur layer in certain select spots?"

"They all coincide with locations of shale, tar sands, and heavy oil."

"What a sick civilization!"

"They didn't know how to make enough clean energy at that time, and that's what led to the end of their civilization. Sad isn't it?"

"Sure is."

I think this story is supposed to end by the two archeologists touching antenna and flying off to their lair under the kitchen sink.

Lets not forget New York and Pa. has large shale deposits as well . There is a lot of Oil but nobody wants the oil industry in their back yard the environmental impacts are grate but can be controlled at a cost . How ever when Greed and need peak your going to see holes this is the American way in the name of profit we stand . One of the bigger concerns is water table pollution from the injection proses and some of the chemicals used to break down the oil for extraction .

What kind of shale deposits are in New York and Pennsylvania? The Green River shale is not shale oil but marl. Marl is basically dirty limestone. That is it is limestone that contains variable amounts of clays and aragonite and formed in shallow freshwater lakes. The Green River shale contains neither gas or oil but only kerogen, which when heated, hot enough, or long enough, produces ordinary oil and associated gas.

The Barnett shale, and other such shale deposits, is true shale that contains primarily natural gas but little recoverable oil. The shale gas can be recovered by “fracking” the shale.

Will "Shale Gas" Save the Environment or Wreck It?

The clever drilling involves horizontal bores that can reach more gas-bearing rock than the vertical kind. The brute force is hydraulic fracturing – or "fracking" in the trade – which involves shoving a mix of water, sand, and chemicals into the formation to loosen up the source rock.

So when we speak of "shale" we need to identify which type of shale we are talking about, shale or marl, the kerogen producing kind or the gas producing kind.

Ron P.

Dog gone it're starting to sound more like a geologist every day. Tread carefully my're risking your credibility.

Not to worry Rockman, me and Wikipedia got it covered. If I screw up I can just blame it on Wiki. ;-)

You might have misread me Ron: being mistaken for a geologist might hurt your credibility...especially amongst engineers.

He's probably talking about the Marcellus Formation. I've never heard of it being a target for oil exploitation; the staggering volumes of the Unita/Piceance/etc preclude that. Also the Marcellus doesn't seem to be oil prone in the first place:

Geochemical analyses of the Millboro Shale in Virginia indicate there is an organic richness sufficient to generate commercial quantities of hydrocarbons, that the shale contains a kerogen type that is more likely to generate natural gas than liquid oil, and that the shale is in the gas generation phase of maturity.

Abstract: Hydrocarbon Potential of the Devonian Millboro (Marcellus) Shale in the Valley and Ridge Province of Virginia, by C. B. Enomoto; #90095 (2009) The Marcellus is a sub-unit of the Millboro.

USGS: "Assessment of Appalachian Basin Oil and Gas Resources: Devonian Shale–Middle and Upper Paleozoic Total Petroleum System"

USGS Fact Sheet 009-03: Assessment of Undiscovered Oil and Gas Resources of the Appalachian Basin Province, 2002

Oil Shale Development in the United States. Prospects and Policy Issues. Prepared for the National Energy Technology Laboratory of the United States Department of Energy (PDF)

Other Oil Shale Deposits in the United States
The oil shale deposits of the Green River Formation have been extensively studied and overshadow all other deposits based on considerations of both abundance and richness. Once oil shale technology becomes commercial, a few operations may occur outside the Green River Formation. In particular, an early target for development might be the estimated 200 million barrels of fairly high-grade oil shale located in deposits near Elko, Nevada (Schmitt, 1987).

Black, organic-rich shales, produced during the Devonian period, underlie a large portion of the eastern United States, where they are known primarily as a potential source of natural gas. The richest and most accessible deposits are found in Kentucky, Ohio, Indiana, and Tennessee. When heated, these Devonian shales produce oil, but the organic matter yields only about half as much oil as the organic matter in the Green River shales (Dyni, 2003).

Because of considerations of grade, yield, and processing costs, eastern oil shale deposits are not likely candidates for development for the foreseeable future and are not further discussed in this report.

Oil shale economics - Wikipedia, the free encyclopedia

Good information on how companies have historically removed the kerogen bearing rock from these mountainous areas. I thought most would have been strip mined like the coal in central Wyoming.

But, the idea that further extraction of this rock can use strip mining on a large scale is probably no more than wishfull thinking due to the waste rock volume and the later restoration of the terrain. Two factors will hinder any effort at strip mining: the degradation of the local environment (this area is a watershread for the Colorado River and Snake River) and need for water in mining/retort operation then restoration efforts.

That leaves the question of EROEI for subsurface mining, can it compete with other oil extraction methods? Probably not since no energy companies have firm plans to exploit these areas of the US even with oil over $60 per barrel for the last year.

It seems like the EROEI would have to be pretty dreadful for operations like this. If extra water needs to be brought in, that would seem to add to energy costs.

An interesting post.
The Estonian oil shale industry which has been operating for 100 years produces electricity(9 Twh)for about 4EU per 100 Kwh or 6 cents per Kwh. It also produces 4400 bpd of shale oil and 2.1 bcf of shale gas per year.
Half of the 22 million tons per year(1997) of oil shale comes from underground mines and the rest from surface mines, which are decreasing. Estonian oil shale is quite rich(2630 Btu/#) at 80-120 gal per ton(25 gal per ton is the DOE cutoff).

Estonian oil shale is the richest in the world.

Burning oil shale for electricity has drawbacks.
First, oil shale produces a lot of CO2 and Colorado oilshale contains lots of limestone so it would release a lot of CO2 per btu. It also is about +45% ash whereas most coal is less than 15% ash. US bituminous coal is 6-12% ash, lignite is 6-19% ash. Indian coal(4th largest proven reserves(10% of proven reserves) is a problematic 25-35% ash. It also contains significant amounts of chlorides and sulfides which must be scrubbed.

It is likely that the Colorado oil shale as lignite( at 1600 btu per #) totals at least 100 billion tons (200 Gb x42/30 gal per ton?). The heat requirements of a retort to extract shale oil are about 400 Btu per pound.

Ordinary lignite is 4000-8000 btus per #. Dried wood is 7000 btu per pound.

As for shale oil, the Colorado oil shale has about the same
characteristics as Lothian(Scotland) which continuously produced 5 million tons per year from 1880 to 1940 a period where oil prices stayed at $10-20 per barrel.

The Narva oil shale new circulating fluidized bed(CFB) power plant's performance is convered in this review by Foster Wheeler. At .5 Mwh per ton, oil shale is only 25% as efficient at bituminous coal at 2 Mwh per ton. These plants produce +90% of Estonia's power.

Given that Estonian oil shale has 1.66x the energy per # of colorado oil shale, burning pure colorado shale in circulating fluidized bed power plants might be uneconomical but I would guess mixing in 50% lignite and 50% colorado oil shale would produce results like Narva.
However it maybe that Narva's production will not be profitable if a carbon tax is applied.

...but I would guess mixing in 50% lignite and 50% colorado oil shale would produce results like Narva.

Not to be contentious, but given the volume of actual lignite under Montana, and that it's all on the "proper" side of the Continental Divide relative to where most coal is burned these days, why would the US use oil shale as a replacement for coal? At least for a few decades?

It extends lignite as a source of energy.
100 billion tons of lignite = 60 year coal supply at
100 billion tons of lignite plus 100 billion tons of colorado oil shale = 76 year coal supply.

But you're right that using oil shale for coal seems besides the point.

The EROI theory holds that a btu is a btu but clearly
a btu of oil is more valuable than a btu of coal.
100 billion tons of Colorado oil shale(there is more than 3340 billion tons of various grades) would produce 72 billion barrels of oil, 10 years of US consumption.
Retorting shale oil extraction has a positive EROI of +4.
Adding 800,000 Btus worth of heat to a ton of oilshale produces ~25 gallon (3,200,000 btus).

We had a relatively small scale shale oil mine in Australia at Newnes in the Blue Mountains region West of Sydney well over 100 years ago.Conventional underground mining as was a later one at Glen Davis nearby.This operated over the WW 2 period but closed when it could not compete with oil.There is still a problem with waste piles and probably leachate here into a wild river running through the Wollemi National Park.

Much more recently there was a proposal,even to the extent of actually building a pilot plant,to mine shale at Rundle,near Gladstone in Queensland.This was open cast.It came up against a lot of opposition and eventually closed.The economics weren't too flash either,and,given the mad resource exploitation attitude in Australia that was probably the reason it closed.

There was recently another propsal to mine shale in the Proserpine area in North Queensland but this was jumped on and kicked to death by locals and environmentalists.

Oil shale mining is an extremely dirty process and the EROEI would be marginal at best.

Better to leave the rotten stuff in the ground.

Hi Thirra
Same comment as above by Mccain for the USA. Australia has so much coal (and coal seem gas) that it will be dug up and sold overseas and burned in Australia for decades.
The economics for Australian oil shale do not warrant exploitation (yet and if ever). That's why both those deposits you mentioned were not exploited.
I don't think that the environmental lobby and locals have much impact against the government and their masters the Energy and coal interests.
Every resource that can be ripped up and sold will be. Check out the Hunter valley open cut coal mines on what used to be prime farming land.
Where are Australias non existent renewable energy plans. Apart from the Snowy Hydroelectric System, now almost 50 years old, there are none.
Burn coal baby and tell the people that we lead the world in Clean Coal technology.
BAU Big time.

A major part of the current issue of The American Oil & Gas Reporter (Feb issue) is focused on shale production. Unfortunately they only put up their cover story, which is "Enhanced Recovery" on their website. The section on oil shales references different methodologies and the economics, which the authors of that piece rank as favorable. Like Rockman, this pretty much puts me to sleep - I have no interest in any of the methods to do anything with oil shale, some of which is inspired by the fact that I don't have the money to do anything that futile anyway.

For those truly interested in this, most libraries in oil producing areas get the publication. I get it as a part of my affiliation with a trade association.

Good reading ten sentences at a time just before falling asleep, IMHO.

Good idea woody. I keep a ollection of westexas' post for night's when I have trouble sleeping (just seeing if he's following the oil shale thread)

Rockman, it seems like all of that material to help you sleep would be good if you are still offshore watching people work.

Since I did not have anyone to watch work, I looked over the article - just scanning, not ready to go back to sleep yet - and the reasonably optimistic authors show a cumulative benefits inset, with three cases and various metrics for why we should proceed. Their best case shown calculations show 12.8 GB over that 30 years. They do not show a cost for that, but certainly it would be a sum which would make Bernie Madoff proud. (Note that 12.8GB over 30 years would be about 1.169 million barrels a day. Remembering that kind of ties into the later calculations of 2.5 million barrels / day, as they calculate the water needed, referred to below.)

At the end of the article, they get into the environmental impacts. Interjecting into my thoughts all of the other stuff I've heard and read, or what I remember from those sources, it seems to me that they are using the old technique of using big numbers and hoping that their audience do not try to look at what those numbers translate to. First, they estimate that the oil shale retorting process will require one to three barrels of water per barrel of shale oil. Their estimate is that the overall industry there would produce 2.5 million B/D and require 182,000 to 420,000 acre feet of water / year for retorting. Their final sentence (those usually tell something about the optimistic or pessimistic tone of a proposal) is, "Recycling and reusing process water will help reduce water requirements." Everything I have read elsewhere has referred to the need for water in the production process as well, so I will guess that this is about one-half of the actual water needs of the overall project spread over four states. Using that estimate, I will round things off to the point that my tiny mind can handle the numbers, and say that the water requirement will be about 600,000 acre feet of water per year - relying on their detailled number crunching. This does not seem as large as the numbers I have heard, but word problems are not my strong suit - but doubling the amount of water they have so precisely calculated to estimate the amount required for all processes would be about 400 million gallons a day, and will come from a very dry watershed. One of the great minds on here should be able to translate all of this into the reality of what it means to the people of one of the burgs downstream, like Los Angeles. Any problems here? (Other than the shortage of about 50% of their estimates of the amount of oil produced over this 30 year period, of course. I hope they were not using a conversion process allowing for 50+% shrinkage due to EROEI or something. (Wait, maybe if we take into account all of the holidays allowed workers by the State of Texas, with vacations and weekends off as well, their 12.8 number is correct. I was always envious of those State employees when I was in school in Austin.))

Rockman, I don't mean to be limiting the possibilities for where you will be watching people work over the next 30 years by throwing cold water on the summaries presented in the referenced article, but I don't think the presently large number of people in LA will want you watching work on these oil shale projects, unless you would want to pipe some of that ocean water to the four corners area. The terrain would be rough for that, of course, but we really do need the oil. I mean, Aramco had to figure out how to build pipelines across the desert so surely we can deal with those mountains.

Actually woody just spent the last 2 weeks on a barge in S La. watching people work. In truth, sleeping is seldom a problem for me. My cohorts were constantly amazed how I could close my eyes, lean back in my chair and nod off for a hour or two. Naps help: didn't lay down in a bed for 12 days.

Thanks for cooking all those numbers. Like you, they seem light to me by maybe 2X at least. But as you imply, being short by 1X doesn't make being short at 2X much worse. Folks have been predicting very big water rights battles in the future. A big push to shale oil might just might just be that war's Pearl Harbor.

I resemble that remark!

My plan is to use the virtually limitless supplies of gold in the world's oceans to pay for extracting the virtually limitless supplies of oil from oil shales.

I don't recall the exact dates or all of the details but sometime during one of the early oil crisis I read about Huntington Hartford and his Oil Shale Corporation. I was busy with my own profession and did not know much about oil and gas. Oil Shale sounded hot and I bought a small amount of stock. As I recall it was very volatile. It was down but recovered, if memory serves because of ownership of a refinery that could handle Alaskan crude. I sold it near even. I had no idea that it was not really oil or that extraction would be so difficult. I was also interested in companies that had large coal reserves. The US had peaked and some experts, Earl Ferguson Cook for example, thought that the world might peak around 1995.

I came up with a figure of 6.2 to 1.
Must be the calculator's fault.
Has anyone got the real figure?

Getting the kerogen out is just the start, and even heating it enough to liquify long enough to be pumped out of the ground doesn't mean that you've got "oil" yet - there is a lot more high-energy processing required to break it down into useable liquid fractions.

It would seem to me to make a lot more sense to just think in terms of burning the stuff to produce heat to drive a generator. That would seem to me to technically be a whole order of magnitude less of a challenge, and the EROI would surely have to be higher, whichever approach you ended up taking.

Finding a way to create an underground retort and burn it in situ would seem to me to be a promising approach, but I'm sure there would be a great many challenges and downsides to it as well.

That's next weeks topic.

It's been tried. Most everything has been tried.

Process for forming an in situ oil shale retort - Patent 4447090 1984

Method of igniting in situ oil shale retort with fuel rich flue ... 1977

Potential Ground Water and Surface Water Impacts from Oil Shale and Tar Sands Energy-Production Operations (pdf) covers all and sundry methods. The Shell Vinegar is about the only new kid on the block.

Petrobras has been retorting for years with a retorting tech they term Petrosix and were interested in the US oil shale; don't know how they've progressed on that front.

Again I am going to pause here, since the post may otherwise get too long, but next time I will talk a little bit about the nuclear option, which might otherwise be forgot.

Interesting how no one has yet commented on the closing statement. Considering the horrendous environmental toll caused by mining, processing and burning shale oil and tar sands, I don't understand why so many here are vehemently opposed to nuclear, especially when the technology has moved forward a great deal on efficiency and safety since 3 Mile & Chernobyl. Shale oil, tar sands and coal gives us massive loss of forests/mountain tops/overburden, enormous waste of water and FF to process, and release of mercury, CO2, sulfur & acid rain from burning it. By contrast, Gen-IV nuclear reactors can "burn" most of their own waste (and waste left behind by earlier reactors), and what's left is radioactive only for a half-life on the order of human-timescales. They can also be built smaller, cheaper (lawsuits from anti-nuke activists notwithstanding) and more modular in design. This could allow us to localize power generation and make smaller, less inviting targets for terrorists.

Gen-IV nuclear is of course no magic bullet and I am no techo-Cornucopian, but it could very well be a much better "bridging" energy source to get us throught the coming PO & population bottleneck.

A valid point HARM especially if you believe as I do that increased coal burning will replace any loss of other FF. Pick your poison: nuclear coincidentals or many times the CO2 production we see today. I can't offer a comparison of which is worse. But ignoring the prospect of a significant increase in coal consumption seems to limit the debate uinfairly.

Interesting article about Shell's northwest Colorado water grab in today's Denver Post:

Shell drops bid for Yampa River water - Denver Post, February 24, 2010 By Mark Jaffe

"Shell Exploration and Production Co. has dropped its bid for a 15 billion- gallon water right on the Yampa River, citing a slowdown in its oil-shale development program.

Shell said in a statement it has decided not to pursue the Yampa water right at this time "in light of the overall global economic downturn that has affected our project's pace."

The controversial proposal — seeking about 8 percent of the Yampa's average spring flow — drew opposition letters from 27 businesses, environmental groups and federal, state and local agencies."