By Sean Cockerham
WASHINGTON — The Department of Energy has successfully completed an unprecedented test of harvesting the vast storehouse on Alaska’s North Slope of methane hydrate, essentially natural gas locked in ice crystals under the permafrost.
Producing methane hydrate is still a long way from being commercial, but the potential is huge. The U.S. Geological Survey has estimated that the North Slope of Alaska holds 590 trillion cubic feet of methane hydrate, potentially at least three times as much as the huge amount of conventional natural gas on the North Slope. The Department of Energy said there is the potential to eventually unlock massive reservoirs of methane hydrates that are believed to exist under the ocean floor in the Gulf of Mexico.
The Department of Energy conducted the small-scale test at Alaska’s Prudhoe Bay between Feb. 15 and April 10 and released the results Wednesday, saying it had safely extracted a steady flow of natural gas.
The department declared that “methane hydrates may exceed the energy content of all other fossil fuels combined; could ensure decades of affordable natural gas and cut America’s foreign oil dependence.” Harvesting methane hydrates remains in the research phase, though, and much more needs to be worked out before it’s clear whether the process is economically feasible.
“It’s great news, certainly a reminder for all those who make fun of federal research that it does have value. But that is a long-term effort, we need to keep that in mind,” said Larry Persily, the federal coordinator for a proposed natural gas pipeline project aimed at bringing Alaska’s conventional gas to market.
The Department of Energy conducted the test with help from ConocoPhillips and the Japan Oil, Gas and Metals National Corp. The technology was developed in the lab by ConocoPhillips working with the University of Bergen in Norway.
“It’s certainly exciting; it was a successful test,” said ConocoPhillips spokeswoman Amy Burnett. “But we’re still a long way off from getting commercial production.”
Here’s how the test worked: Researchers injected a mixture of carbon dioxide and nitrogen into the hydrate formation, which took in the carbon dioxide and released the methane. Researchers lowered well pressure to make the hydrate flow and get the gas out.
“We just completed the test, just plugged the well last week, but we’ve got 30 days of production data, which is considerably longer than any field test anyone in the world has ever done,” said Christopher Smith, deputy assistant energy secretary for oil and natural gas. “We’re headed back to the laboratory to analyze that, and we’re excited about the early results.”
Smith said the process has potential for storing carbon dioxide from the atmosphere as well as producing the natural gas.
The Department of Energy said the next step in its research effort will be testing gas hydrate production over longer periods, with the eventual goal of making a sustained harvest possible. It’s offering $6.5 million in research grants and requesting $5 million from Congress for an additional testing effort.
The $5 million would be for more research on Alaska’s North Slope with a longer test of producing the natural gas, Smith said.
©2012 the McClatchy Washington Bureau