Icy crystals may be next big energy source
Alaska has vast reserves of hydrates
WASHINGTON – Frozen crystals packed with concentrated natural gas and buried 2,000 feet below the permafrost on Alaska’s North Slope could become the next major domestic energy source, according to an assessment released Wednesday by the U.S. Geological Survey.
The study finds that in the North Slope, frozen methane-and-water crystals known as hydrates contain as much as 85.4 trillion cubic feet of recoverable natural gas. That’s enough to heat 100 million homes for as long as 10 years, Interior Secretary Dirk Kempthorne said.
New research into how to extract those resources has moved the possibility of recovering the usable energy from the realm of “science and speculation” to that of the “actual and useful,” Kempthorne said Wednesday.
Globally, “hydrates have more potential for energy than all other fossil fuels combined,” he said. “This can be a paradigm shift.”
Government research is beginning to show that it may be possible to extract hydrates using depressurization, a technique used to get at more conventional fuel sources. Simply boring into the ground may be enough to change the pressure to extract it, said Steve Rinehart, a spokesman for British Petroleum in Alaska. Or the pressure could be changed by pumping.
Gas hydrates exist all over the world, including offshore, but a combination of cold and pressure makes them especially prevalent in the Arctic, where there’s also an existing oil and gas infrastructure to study them. The Department of Energy described them as “ice-like solids that result from the trapping of methane molecules within a lattice-like cage of water molecules.” Hydrates release gaseous methane – the main component of natural gas – when they melt.
Two of the biggest North Slope producers, ConocoPhillips and BP, have been involved in some of the government studies. ConocoPhillips has largely been researching whether it’s possible to inject carbon dioxide into wells to replace the hydrates. That also would allow the carbon dioxide, a greenhouse gas, to be sequestered in the wells.
BP participated in government studies last year that drilled for core samples of hydrates. So far, there have been no tests of producing hydrates as commercially viable natural gas. That’s next, but BP and ConocoPhillips remain skeptical. There are tremendous conventional natural-gas deposits in Alaska to consider first, Rinehart said.
There’s room for “healthy skepticism” on the environmental front, too, said Mike Daulton, the legislative director of the National Audubon Society. The extraction could threaten the stability of the permafrost in Arctic Alaska, Daulton said, and there also are concerns that there’s a risk of releasing vast amounts of methane in the process of extracting a relatively clean-burning fuel.
“There’s a lot that still needs to be proven with regards to the safety,” Daulton said.