Oil & Natural Gas Projects
Exploration and Production Technologies
Rural Alaska Coalbed Natural Gas: Application of New Technologies to Explore
and Produce Energy
The project was selected under a non-competitive five-year cooperative agreement
with the University of Alaska-Fairbanks (UAF) to conduct arctic energy research
in two broad categories: fossil energy and remote electrical power generation.
The DOE Arctic Energy Office and UAF are collaborating with the energy industry
and state agencies to better identify Alaska's unique research needs.
The objectives of the project are to 1) determine the actual coalbed natural
gas energy requirements and surface facility needs for a medium-sized rural
village such as Fort Yukon (population ~650), 2) determine if low-rank coals,
are capable of CBNG production, 3) determine if slimhole drilling technology
can be used to greatly reduce gas production and dewatering costs, 4) determine
if production of low volumes of gas at temperatures well below freezing during
winter months can be achieved, and 5) assemble a database of information on
gas and water flow rates, gas content, coal seam properties, well drilling,
completion and stimulation techniques, and pumping and injection systems for
dewatering and water management.
University of Alaska
Alaska Division of Geological and Geophysical Surveys
U. S. Bureau of Land Management (BLM)
U. S. Geological Survey (USGS)
The study found that Fort Yukon needs 250-450 thousand standard cubic feet per
day (Mscfd) of gas through 2015. The overall rate of return for conversion from
diesel to CBNG as a fuel source is estimated at 3-12%. Phase I results suggest
that slimhole drilling should be successful, and operational tests were to be
conducted in the Summer of 2005.
Preliminary results of gas content analysis put the Fort Yukon coals' gas saturation
levels at an average of 20-30%. Such low gas saturation levels may require drilling
a greater number of wells or pumping large volumes of water from the coal seams
in order to sustain commercial gas production. Early analysis indicates that
the water is potable and could be marketed for beneficial use.
One side benefit of the project may help improve the local environment while
cutting project costs. The project team is seeking approval from the Alaska
Department of Environmental Conservation to spray drilling waste over an old
landfill near the site, a step that could help seal the landfill in order to
close it out.
Coal is widely distributed in Alaska, but most remote power generation depends
on diesel electric generators. Over 37 rural Alaska villages are situated on
or adjacent to coal fields that are potential CBNG sources. CBNG production
wells, particularly from low-rank coals, may offer an alternative energy source,
but the cost of drilling production wells must be reduced to make CBNG economic.
Exploiting the nearby CBNG resource could provide a long-term source of low-cost,
clean energy to rural Alaskans, who usually must reply on diesel-fueled generators
for heat and power. The logistics of supplying liquid fuels to these remote
locations drive rural Alaskans' energy costs to more than five-fold that in
Fairbanks and Anchorage.
The project calls for a three-year program to test the producibility of these
low-rank coals at Fort Yukon, using slimhole drilling technology to significantly
reduce mobilization and drilling costs. The success of initial drilling and
testing results could lead to development of an innovative production scheme
whose feasibility would be tested in the second and third years of the program.
Economic analysis of the fuel gas and surface facility requirements at Fort
Yukon were tested in the first year of the project. Fort Yukon is about 120
miles northeast of Fairbanks. With Fort Yukon needing 250-450 Mscfd of gas through
2015, the conversion from diesel to CBNG for a fuel source would cost $5-7 million.
At $8 per Mcf, the overall rate of return for the project would be 3-12%, depending
on the tax status of the project.
The Phase 1 field season was completed in 2004. Initial drilling started in
August 2004, and cores were collected beginning with the first coalbeds encountered
at 1,280 feet. Coal cores were analyzed for gas content and composition, and
coal seam water was sampled for chemical analysis. In Phase 2, slimhole drilling
began in the summer of 2005. Production wells are planned for a five-spot pattern
of closely spaced, small-diameter wells, with a central production well surrounded
by four dewatering wells.
Current Status (August 2005)
A peer-reviewed final report on the application and feasibility of small-diameter
CBNG well technology in rural Alaska was due at the end of the September 2005.
Project Start: June 29, 2003
Project End: June 30, 2006
Other Government Organizations Involved
DOE Contribution: $1,049,997
Performer Contribution: $1,003,672 (49% of total)
NETL - James Hemsath (email@example.com or 907-453-2672)
Alaska DGGS - Jim Clough (firstname.lastname@example.org or 907-451-5030)
UAF - David O. Ogbe (email@example.com or 907-474-7998)
Slimhole drilling is under way to test the Fort Yukon CBNG resource.