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CBM tests begin in village State, federal and university team plans core drilling east of Yukon River village through known coal seams to test for gas Patricia Liles Petroleum News Contributing Writer
Using a recently purchased core rig now owned by the state of Alaska, state, federal and university researchers plan their first drill program in late July to test the potential of coalbed methane for an energy source in a rural Alaska village.
One core hole will be drilled this summer on a site with known coal seams about one mile east of Fort Yukon, a village of about 800 residents on the Yukon River in eastern Interior Alaska.
Researchers hope to drill down to 2,400 feet, passing through two coal seams detected by prior seismic and drilling work, according to Jim Clough, geologist with the Alaska Division of Geological & Geophysical Surveys.
Tests will be conducted on-site this summer to test for the presence and the quantity of methane gas in the coal seams, he said, estimated to be each about 60 feet thick.
The work is scheduled to begin in late July and run for roughly two weeks, said Clough, an ardent advocate of developing coalbed methane as an energy source for rural Alaska villages.
Through its Arctic Energy Office, the U.S. Department of Energy is funding much of this summer’s $500,000 drill program, which includes financial matches from the state of Alaska and the University of Alaska Fairbanks. Total DOE funding for the two-year program is $700,000, with a cost share match of $593,672, according to the University of Alaska Fairbanks’ Arctic Energy Technology Development Laboratory.
Additional federal funding from the U.S. Bureau of Land Management allowed the state to purchase the Christiansen CS 1000 P6L core rig and accessory equipment, totaling $267,344, Clough said.
The research team, made up of DGGS, UAF, geologists from the U.S. Geological Survey, BLM and GW Scientific, hopes to conduct additional core drilling for coalbed methane testing next summer at Fort Yukon, provided the work this year produces positive results.
The group has also applied for $10 million in federal funding through U.S. Sen. Ted Stevens, R-Alaska, which, if approved, would allow additional drilling in Fort Yukon, as well as initial test drilling in two other communities, Clough said. “That’s a lot of money so we could go and do more field work.” Prior drilling produces gas shows Fort Yukon was selected as the first coalbed methane test because of a prior, unrelated research hole drilled there 10 years ago, which encountered coal at 1,280 feet. When pulling samples up, those drillers observed bubbling and popping, indicating gas presence, Clough said.
Researchers plan this summer to re-enter that old hole using the slim-hole core rig, which can drill down to 3,000 feet. In addition to the coal seam at 1,280 feet, the group believes another coal seam is present at 1,600 feet, Clough said, based on 8.5 line miles of seismic data gathered in the area surrounding Fort Yukon by researchers in 2001.
That work indicates continuous coal seams in the area, including under the village, Clough said.
The state-owned drill rig, similar to models used in conventional mineral exploration work, will produce a 2.5-inch core sample. At the end of the drill test this summer, the group plans to ream out the hole to four inches in diameter and conduct hydrological tests on the formation. Reducing power costs in rural Alaska Clough believes coalbed methane could solve the problem of high electric costs in rural Alaska. In Fort Yukon, electric power costs about 46 cents per kilowatt hour, more than five times the rate available in Alaska’s largest communities. The community consumes about 360,000 gallons of diesel a year to produce that electricity, and burns another 260,000 gallons for home heating purposes.
Calculating a usage range and growth rate, the village’s diesel consumption could be replaced by a coalbed methane project that produces 250,000 to 500,000 cubic feet of gas per day, according to the research team.
Estimated costs to develop such a project total $5.064 million, according to the research project’s presentation, although a more realistic range is $8 to $10 million, Clough said. Other villages offer potential sites Fort Yukon is one of about 40 remote villages in Alaska that are on or near known coal resources. Two other communities, Wainwright on the North Slope and Chignik on the Alaska Peninsula, are also high priority targets for the coalbed methane exploration program.
Coal at Wainwright, detected by past oil and gas exploration, is known to be gassy, Clough said. But the costs to drill and develop that resource are higher than at Fort Yukon, he said.
DGGS also tested samples taken from a water well drilled to a depth of 720 feet near Chignik, in southwestern Alaska, almost two years ago. Although samples included carbonaceous shales, it did not encounter coal at that location, Clough said.
DGGS and USGS are also investigating coal resources in Cordova, McGrath and Unalakleet, through field studies this summer.
Originally, the group proposed drilling one test well at Fort Yukon in the first year of the program, then in the second year, drilling up to five wells in the Mat-Su area, in order to test production of coalbed methane using the slim-hole rig. That plan has been altered, due to a community outcry against coalbed methane production in the more populated area, according to the Arctic Energy Technology Development Laboratory’s director, Dennis Witmer.
“The decision was made to go drill directly in Fort Yukon, where current energy prices are much higher and people actually want the gas,” he said. “This had led to some changes in budget and scope, but the project is moving forward this summer.”
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