– A half mile below the ground at Prudhoe Bay, above the vast oil field that helped trigger construction of the trans-Alaska pipeline, a drill rig has tapped what might one day be the next big energy source.
The U.S. Department of Energy and industry partners over two winters drilled into a reservoir of methane hydrate, which looks like ice but burns like a candle if a match warms its molecules. There is little need now for methane, the main ingredient of natural gas. With the boom in production from hydraulic fracturing, the United States is awash in natural gas for the near future and is considering exporting it, but the DOE wants to be ready with methane if there's a need.
"If you wait until you need it, and then you have 20 years of research to do, that's not a good plan," said Ray Boswell, technology manager for methane hydrates within the DOE's National Energy Technology Laboratory.
The nearly $29 million science experiment on the North Slope produced 1 million cubic feet of methane. Researchers have begun the complex task of analyzing how the reservoir responded to extraction.
The U.S. Energy Department describes methane hydrate as a lattice of ice that traps methane molecules but does not bind them chemically. They are released when warmed or depressurized.
Methane comes from buried organic matter after it's ingested by bacteria or heated and cooked. The gas migrates upward, under high pressure and low temperature, and can combine with water to form methane hydrate.