Post Independent (Colorado): Oil shale developers showcase technology at Rifle open house

Donna Gray
Post Independent Staff
April 5, 2006
RIFLE – Three companies hoping to move forward with their oil shale research, development and demonstration projects in the Piceance Basin showcased their technologies Tuesday in Rifle. Hosted by the Bureau of Land Management (BLM), the companies – Shell, Chevron and EGL Resources – have fundamentals in common in their methods to produce oil from rock.
The BLM will review environmental assessments of the three projects before awarding the 160-acre leases in Rio Blanco County.
The goal, said Kent Walter, BLM Meeker field office manager, “is to make sure they are economically viable and environmentally sound.”
The research leases can be expanded to 5,120-acre commercial leases if the various oil shale extraction technologies prove workable. The companies have 10 years to prove up their methods.
All three plans involve heating the oil-bearing rock to a point where the oil or kerogen becomes liquefied and can be pumped out of the ground.
But the methods of heating differ.
EGL will use steam circulated around the wells in pipes to heat the rock and release the kerogen, said Gordon Harris, a professor of chemical and petroleum engineering at the University of Wyoming, who is a consultant to the EGL project.
A similar process, called “steam flooding,” is used in the production of oil, except the steam is injected directly into the ground, Harris said.
“The challenge will be to make sure there is efficient heat transfer” between the enclosed steam and the rock, “so we can quickly raise the temperature of the oil shale,” he said. It takes from one to two years for heating to liquefy the kerogen.
The same steam-flooding technology is being used successfully in western Canada to extract oil from tar sands, Harris said.
Although also using an in-situ, or in place, method to extract oil, Chevron will fracture zones of oil shale using heated carbon dioxide and other chemicals that will raise the temperature of the rock.
Chevron will start with five injection/production wells on their plot, said senior engineer Mark Looney. He said that with certain chemicals added to the carbon dioxide it may be possible to liquefy kerogen at 300 degrees Fahrenheit rather than the usual 600 degrees.
“If we can retort (process) it at lower temperatures there will be less (harmful) environmental byproducts” produced, Looney said.
“We're approaching this slowly and methodically,” said Dan Johnson, manager of government and public affairs for Chevron. “There's a lot of work to be done.”
Shell has been testing its technology on land it owns in the Piceance Basin but wanted to expand to federal lands because the oil shale deposits are richer, said Shell spokeswoman Jill Davis. It has applied for three 160-acre contiguous plots. Since the plots are closer to the center of the basin than its private holdings, the oil shale is thicker and richer, Davis said.
Shell plans three separate tests on each of the three plots. One will combine all the technology it has researched since 1996 on its own land. Another will look at advanced heating technology, and a third will test extraction of nahcolite as well as oil shale. Nahcolite, or sodium bicarbonate, overlays the oil shale in much of the Piceance Basin and must also be developed if it occurs in the BLM leases.
The method it has been testing on its own land involves heating the rock with electrically powered heaters. Shell has said it is now able to recover 60 percent of the oil, which comes to the surface as diesel or jet-grade fuel, from the rock. “That's double the traditional recovery rate,” Davis said.
All three companies acknowledge ground water will be a problem, namely keeping it free of potentially harmful chemicals associated with oil shale production.
Exxon, which also applied for a 160-acre research plot, is no longer under consideration, Walter said. Exxon was a major developer of oil shale during the 1980s in Garfield and Rio Blanco counties. It was dropped by the BLM because according to its plan it would not be producing oil for eight years. It also applied for a 160-acre plot in what the BLM considers a “multimineral” zone containing both oil shale and nahcolite, both of which must be produced, Walter said.
“Their proposal was to develop the oil shale at the expense of the (nahcolite),” he said. “That's not consistent with our resource management plan” for the Piceance.
Walter said the environmental assessments for the three projects are set to be completed by the end of April, followed by a 30-day public comment period, and a final decision about awarding the leases is due in May or June.

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