oleocene.org

energy_isere a écrit :On a déja vaguement parlé de l' huile de schiste ou "oil shale" en parlant des sables bitumineux du Canada ou "tar sand" (avec lesquel il ne faut pas les confondre).

j.jouet a écrit :- Shell a utilisé un processus appelé "extraction in situ", qui consiste à chauffer le schiste alors qu'il est encore dans le sol, au point que le pétrole suinte de la roche.

on a pu extraire 1 400 barils de pétrole à partir du schiste, directement dans le sol, sans avoir besoin de l'extraire.

Shell a depuis 2000 un projet pilote appelé Mahogany Research Project, initié suite à une étude de production sur site dans le bassin Piceance dans les années 1970. Ils chauffent certains puits électriquement (à une profondeur de 500 à 1000 pieds) durant une longue période (plusieurs années) pour générer du pétrole à partir du kérogène. Pour empêcher les infiltration d’eau qui perturberaient ce chauffage, ils congèlent les roches environnant le zone de production.. Shell ne donne pas beaucoup de données. Des rumeurs parlent de 10 barils par jour avec 50 employés sur le site (et une centaine au bureau) et d’une facture d'électricité 2000$ par jour ! Et la production totale serait de l’ordre de 2000 barils en 5 ans. Ils ne vont pas décider si ce projet pourrait être viable commercialement avant 2008. Le but est de démarrer une petite unité de production en 2010.

Oil shale may be fool's gold
Extraction hurdles are high
By Randy Udall and Steve Andrews

Buried underground in western Colorado are a trillion tons of oil shale. For a century, men have tried and tried again to unlock this energy source. But the rocks have proved stubborn, promising much, delivering little.

Recently, the U.S. Department of Energy published a new report on oil shale. It claimed that the nation could wring "200,000 barrels a day from oil shale by 2011, 2 million barrels a day by 2020, and ultimately 10 million barrels a day" from fields in Colorado, Utah and Wyoming. These predictions - both the production targets and their timing - are preposterous, as some industry experts admit.

But hyping oil shale is nothing new. As geologist Walter Youngquist once wrote, "Bankers won't invest a dime in 'organic marlstone,' the shale's proper name, but 'oil shale' is another matter."

California Rep. Richard Pombo and Utah Sen. Orrin Hatch are spearheading efforts to jumpstart the industry. "I find it disturbing that Utah imports oil from Canadian tar sands, even though our oil shale resource remains undeveloped," says Hatch.

In truth, oil shale presents a paradox. If these rocks are, as some claim, the richest fossil fuel resource on Earth, why has it been so difficult to unlock them?

The primary explanation is that oil shale is a lousy fuel. Compared to the coal that launched the Industrial Revolution or the oil that sustains the world today, oil shale is the dregs. Coal seams a few feet thick are worth mining because coal contains lots of energy. If coal is good, oil is even better. And oil shale? Per pound, it contains one-tenth the energy of crude oil, one-sixth that of coal.

Searching for appropriate analogies, we enter the realm of Weight Watchers. Oil shale is said to be "rich" when a ton yields 30 gallons of oil. An equal weight of granola contains three times more energy. America's "vast," "immense" deposits of shale have the energy density of a baked potato. Oil shale has one-third the energy density of Cap'n Crunch, but no one is counting on the Quaker Oats Company to become a major energy producer soon.

Historically, oil shale has been mined, crushed and roasted in large kilns, or "retorts." The slag, swollen in volume and contaminated with arsenic, must then be disposed. The process is so costly, laborious and polluting that global output has never exceeded 25,000 barrels a day, compared to 84 million barrels of conventional oil production.

In the last 150 years, humans have used 1 trillion barrels of conventional oil. The second trillion will be consumed in the next 30 years. Given projected demand for fuel, Royal/ Dutch Shell has been experimenting with a new way to produce shale oil, a way that is, at first glance, more promising.

Humor columnist Dave Barry once demonstrated that if you put a "strawberry Pop-Tart in a toaster for five minutes and 50 seconds, it will turn into a snack-pastry blowtorch, shooting flames up to 30 inches high." Putting a chunk of oil shale into your toaster would not offer similar excitement, but in a strange way, Shell's fascinating experiments near Rangely resemble something Barry might attempt if he had the money to build the world's largest underground toaster oven.

The plan is audacious. Shell proposes to heat a 1,000-foot-thick section of shale to 700 degrees, then keep it that hot for three years. Beam me up, Scotty, but first share some details. Imagine a 100-acre production plot. Inside that area, the company would drill as many as 1,000 wells. Next, long electric heaters would be inserted in preparation for a multi-year bake. It's a high-stakes gamble, but if it works, a 6-mile-by- 6-mile area could, over the coming century, produce 20 billion barrels, roughly equal to remaining reserves in the lower 48 states.


Although Shell's method avoids the need to mine shale, it requires a mind-boggling amount of electricity. To produce 100,000 barrels per day, the company would need to construct the largest power plant in Colorado history. Costing about $3 billion, it would consume 5 million tons of coal each year, producing 10 million tons of greenhouse gases. (The company's annual electric bill would be about $500 million.) To double production, you'd need two power plants. One million barrels a day would require 10 new power plants, five new coal mines. And 10 million barrels a day, as proposed by some, would necessitate 100 power plants.

How soon will we know whether Shell's technology is economic? The company plans to do more experiments, before making a final decision by 2010. If it pulls the trigger, it would be at least three or four years before the first oil would flow, perhaps at a rate of 10,000 barrels a day. That's less than one-tenth of 1 percent of current U.S. consumption. But if it turns out that Shell needs more energy to produce a barrel of oil than a barrel contains, bets are off. That's the equivalent of burning the furniture to keep the house warm. Energy is the original currency; electricity its most valuable form. Using coal-fired electricity to wring oil out of rocks is like feeding steak to the dog and eating his Alpo.

In a ham-and-egg breakfast, the chicken is involved but the pig is committed. With half the world's oil shale resources located here, our region is committed. Another recent report by the RAND Corp. warned that if oil shale developers "overstress the environmental carrying capacity of the area, we may never see more than a few hundred thousand barrels per day of production." Amen.

Large-scale development of the kind proposed by the U.S. Department of Energy and Pombo would be a disaster. The DOE casually dedicates all of western Colorado's surplus water to oil shale, proposes enormous open-pit mines 2,000 feet deep, and advocates retorting up to 6 billion tons of shale each year. That's twice the tonnage of all coal mined in the U.S. and China. This is not a vision, it is a nightmare.

Americans love panaceas. We want thinner thighs in 30 days, a pill to cure baldness, an ultrasonic carburetor that will double our mileage. A magic wand would be nice, because the nation faces serious energy challenges. Since domestic oil production peaked 30 years ago, the need for energy efficiency, conservation and renewable energy has been obvious. Instead, like an addict on a binge, we continue to pursue a policy of "strength through exhaustion." Drilling the Arctic National Wildlife Refuge before improving our woeful vehicle efficiency is one example of this brain-dead approach.

What contribution can oil shale make to energy security? Producing 100,000 barrels per day of shale oil does not violate the laws of physics. But the nation currently consumes that much oil every seven minutes. Improving the efficiency of our automobiles by 2 miles per gallon would save 10 times as much fuel, saving consumers $100 billion at the pump. The National Academy of Sciences has stated that cars, trucks and SUVs that get 30, 40 or 50 miles per gallon are doable. An aggressive national commitment to fuel efficiency is not optional, it's inevitable. In time, a more efficient fleet could save 20 times as much petroleum as oil shale is likely to ever provide.

All hype aside, oil shale is the poorest of the fossil fuels, containing far less energy than crude oil, much less even than hog manure, peat moss or Cap'n Crunch. A meager amount of energy, tightly bound up in an enormous volume of rock, oil shale seems destined to remain an elusive bonanza, the petroleum equivalent of fool's gold.


Randy Udall directs the Community Office for Resource Efficiency, a nonprofit energy office in Carbondale. Steve Andrews is a Denver-based energy expert.

Oil shale is a general term applied to a group of fine black to dark brown shales rich enough in bituminous material (called kerogen) to yield petroleum upon distillation. The kerogen in oil shale can be converted to oil through the chemical process of pyrolysis. During pyrolysis the oil shale is heated to 450-500° C in the absence of air and the kerogen is converted to oil and separated out, a process called "retorting". Oil shale has also been burnt directly as a low-grade fuel. The United States Office of Naval Petroleum and Oil Shale Reserves estimates the world supply of oil shale at 1662 billion barrels of which 1200 billion barrels are in the United States [1]. This is comparable to the amount of reserves of conventional oil.

Estonia, Russia, Brazil, and China currently mine oil shale, however production is declining due to economic and environmental factors.

1 Geology
2 Extraction
2.1 Mining
2.2 In-situ
3 History
4 Reserves
5 Economics
6 Environmental considerations
7 See also
8 References

Devenson a écrit :Un point sur les estimations de "réserves" de schistes bitumineux dans le monde et les différents projets passés et futurs :
http://www.energybulletin.net/5600.html

energy_isere a écrit :c'est curieux, quand on tape <oil shales> dans google actualité, il sort RIEN !

Mathieu G. a écrit : Si tu tapes juste "shales", tu obtiens tout de même un lien, assez intéressant d'ailleurs, même s'il parle plus du problème pétrolier en général que des schistes bitumineux : http://www.delaplanete.org/Au-dela-du-pic.html

Mais il y a un autre danger relatif à un pic potentiel de la production pétrolière mondiale : l’impact sur le réchauffement climatique. Certains ont avancé qu’une marche forcée hors de l’âge du pétrole rendrait l’économie mondiale dépendante de carburants qui rejettent encore plus de dioxyde de carbone dans l’atmosphère : shales pétrolifères , sables bitumineux et charbon qui sont tous extrêmement abondants et polluants.

energy_isere a écrit :un pdf de 11 pages sur les "oil shales" :
http://www.worldenergy.org/wec-geis/glo ... ia2002.pdf

<Global oil shales issues and perspectives
synthesis of the 2002 symposium held in Tallinn-Estonia >

Du pétrole à partir de schiste et de bitume !


Israël envisage la construction d'une usine capable de transformer du bitume et du schiste provenant de la région sud du Négev en pétrole. La technologie qui serait utilisée est connue depuis les années 90 et a été développée par deux israéliens d'origine russe. La consommation de 6 millions de tonnes de schiste et de 2 millions de tonnes de bitume produirait jusqu'à 3 millions de tonnes de pétrole. L'augmentation du prix du pétrole rend aujourd'hui possible la rentabilité de l'usine. Son coût de construction est évalué à 700 millions de dollars. Si le gouvernement donne son accord au projet, l'ouverture de l'usine est espérée pour l'année 2010.
(Src : BE - Ambassade de France)