By Juliet Eilperin
Washington Post Staff Writer
Wednesday, November 12, 2008
Federal scientists have concluded that Alaska's North Slope holds one of the nation's largest deposits of recoverable natural gas in the form of gas hydrates, a finding that could open a major new front in domestic energy exploration.
Researchers have speculated for years that gas hydrates -- a combination of gas and water locked in an icelike solid that forms under high pressure and low temperatures -- could provide an important source of natural gas in the United States and worldwide.
Today the U.S. Geological Survey will release a study estimating that 85.4 trillion cubic feet of natural gas can be extracted from Alaska's gas hydrates, an amount that could heat more than 100 million average homes for more than a decade.
Brenda Pierce, manager of the agency's energy resources program, called the find "groundbreaking" and said, "I don't want people to think our problems are solved, but this has real potential."
Part of the reserve's significance, federal officials said, is that gas companies will be able to tap into it with existing technology. A coalition of American and international experts conducted three tests on gas hydrates over the past five years in the United States and Canada and demonstrated that the gas can be extracted by reducing the pressure that binds them together. Gas hydrates have also been found in the Wyoming basin, Texas's western Gulf basin, and the San Juan basin in New Mexico and Colorado, as well as in several offshore areas.
"The assessment points to a truly significant potential for natural gas hydrates to contribute to the energy mix of the United States and the world," Interior Secretary Dirk Kempthorne said in a statement. "This study also brings us closer to realizing the potential of this clean-burning natural gas resource."
The prospect of extracting methane from gas hydrates, some of which lie below the permafrost of the Arctic National Wildlife Refuge, worries some environmentalists.
Athan Manuel, who directs the lands program for the Sierra Club advocacy group, said that the refuge should remain "inviolate" and that tapping into gas hydrates can harm less-pristine areas as well.
"The process is still pretty damaging to ecosystems," Manuel said, noting that companies must inject water into the reservoirs in the same way they extract methane from coal beds in the West. "Bottom line, this is a very destructive way to extract natural gas."
Pierce said the government will examine the potential environmental effects of tapping gas hydrates as "the next step" in its analysis. "Like every resource, it's going to have impacts," she said.
USGS Director Mark Myers said the process is likely to be less damaging than coal bed methane extraction because water is more plentiful on the North Slope and it will not take nearly as many wells to extract the gas. "The water disposal is not nearly so environmentally challenging," he said.
As conventional sources of domestic natural gas continue to decline, energy companies are eager to exploit what Myers called "innovative supplies." In August, ConocoPhillips received $11.6 million in funding from the Energy Department to test its gas hydrate production technology on the North Slope, and company spokesman Charlie Rowton said yesterday that "both globally and for the domestic market, methane hydrates represent a potentially huge new source of natural gas."
Even if industry manages to extract natural gas from these reserves -- long-term tests on hydrates will take place between 2009 and 2011 -- it will be years before companies will be able to send this gas to the lower 48 states. Such shipments probably would take place via the natural gas pipeline that Alaska Gov. Sarah Palin (R) has championed, which will not be complete for at least a decade.