Drillers in Utah and Colorado are poking into a massive shale deposit trying to find a way to unlock oil reserves that are so vast they would swamp OPEC.
A recent report by the U.S. Government Accountability Office estimated that if half of the oil bound up in the rock of the Green River Formation could be recovered it would be "equal to the entire world's proven oil reserves."
Both the GAO and private industry estimate the amount of oil recoverable to be 3 trillion barrels.
"In the past 100 years — in all of human history -- we have consumed 1 trillion barrels of oil. There are several times that much here," said Roger Day, vice president for operations for American Shale Oil (AMSO).
The Green River drilling is beginning as shale mining is booming in the U.S. and a report by the International Energy Agency predicts that the U.S. will become the world's largest oil producer by 2020. That flood of oil can have major implications for the U.S. economy as well as the country's foreign policy which has been based on a growing scarcity of oil.
The IEA report does not detail where the American oil will be coming from, but the largest deposit is the Green River formation which has yet to tapped in any significant way.
This tantalizing bonanza, however, remains just out of reach, at least for now. The cost of extracting the Green River oil at the moment would be higher than what it could be sold for. And there are significant environmental obstacles.
The operation might require so much water it would compete with Denver and agriculture for vital supplies, the GAO report warned, could pollute underground streams, affect fish and other wildlife, and kick up so much dirt it would leave national monuments in a cloud of dust.
Nevertheless, the federal government has authorized six experimental drilling leases on federal land in an effort to find a way to tap into the riches of the Green River Formation.
Day's American Shale has a lease on 160 acres 40 miles northwest of Rifle, Colo. It has already produced oil on a pilot basis, and now stands poised, if it gets the necessary government permissions, to produce on a larger scale.
Getting oil from Green River shale is a different proposition than getting gas and oil from other sites by using the controversial method of "fracking," fracturing the underground rock with pressurized, chemical-infused water.
The hydrocarbons in Green River shale are more intimately bound up with the rock, so that fracking cannot release them. The shale has to be heated to 5,000 degrees Farenheit before it will give up its oil.
Producers have been trying to accomplish that in one of two ways: Either they bring the shale to the surface and then cook it , or they sink a deep shaft and place an electric heater at the base, a process called in-situ. AMSO has been testing in-situ with mixed success.
"We put in a 600 kilowatt electric heater in, 2,100 feet below the surface," said Day. "The idea was that this would heat the shale and cause the conversion of solid hydrocarbons into liquid oil and gas. These, then, would be brought to the surface."
Things have not gone smoothly.
"We plugged it in the first week in January," said Day, referring to the heater. "It burned out like your toaster, only this is a toaster that costs several million dollars to repair. Just in the past month we've figured out what went wrong. We expect to re-install in December. If we're lucky, we'll put heat in the ground again before the end of the year."
If everything pans out and if AMSO gets the green light from the federal government, the company's half-dozen wells initially might produce about 1,000 barrels a day. Later, at peak production, Day estimates they could produce "100,000 barrels a day for 30 years."
Enefit, an oil producer headquartered in Estonia, has been producing oil from oil shale in Europe for more than 30 years, according to the CEO of its Utah subsidiary, Enefit American Oil. Rikki Hrenko says Enefit brings the shale to the surface, then heats it in retorts.
"It's more labor intensive to have to mine the shale," Hrenko said. "But the economics are still quite feasible." She puts the break-even price at about $65 a barrel. The cost of producing in Utah, she thinks, will be only slightly higher than in Estonia.
Enefit doesn't lease its Utah site from the U.S. government; it owns it. "We purchased it March 2011," Hrenko says. The company's goal is to have all the necessary permits by the end of 2016, start construction, and to be producing oil commercially in 2020 at the rate of 25,000 barrels a day.
Among the hurdles faced by would-be Green River producers are environmental costs, first among them being water consumption, according to the GAO report. Current estimates on how much water might be needed to realize the potential of Green River oil "vary significantly," the report admits. But water in the arid west already is in short supply, and ranchers and environmentalists eye warily the oil industry's potential thirst.
Water would be used not for fracking, but as a lubricant for drilling. Frank Rusco, GAO's director for energy and science issues, told ABC News water also would be used as steam "to stimulate the flow of oil." Water would also be neeeded, as at any work site, for dust control and cooling.
Day said he expects AMSO's in-situ wells will be water-neutral. Experiments so far suggest that the company may get a barrel of water from the rock for every barrel of oil extracted. AMSO intends to cool its operations using radiators, not water.
Rusco doubts substantial amounts of oil could be produced from Green River anytime soon because production is not yet economical. It costs more to produce a barrel of oil here than the oil can be sold for on the market.
GAO's report says commercial development of oil shale is "at least 15-20 years away."
Glenn Vawter, executive director of the National Oil Shale Association in Glenwood Springs, Colo., isn't so sure. Right now, he says, it costs his members somewhere between $40 and $80 to produce a barrel of oil from shale, depending on the technology they use. The price of oil, currently at $86 a barrel, has risen in the past over $100 a barrel and continues to fluctuate. Technology, he points out, is also evolving.
A Canadian oil producer has experimented with using radio energy to heat rock.
"The economics remain a bit speculative," Vawter said, but he thinks that "big production" might be only five to 10 years out.
There's no question, says Rusco, that the oil is there, all 3 trillion barrels of it.
"The technology for assessing oil reserves is pretty good," Rusco said. "I don't say there isn't a wide margin of error, but you can have great confidence that there is a very, very large amount of oil trapped down there that could be recovered. It's just that, so far, it can't be recovered at a profit."