Five USGS gas hydrates scientists from the Woods Hole Coastal and Marine Science Center recently returned from more than five weeks spent supporting a drilling expedition in the Prudhoe Bay area of the Alaskan North Slope.
Woods Hole Gas Hydrates Project Scientists Participate in Alaskan North Slope Drilling Expedition
The expedition, which was sponsored by the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory and the Japan Organization for Metals and Energy Security (JOGMEC), drilled through more than 600 meters (2000 feet) of permafrost to retrieve hydrate-bearing sediments from great depths beneath the tundra surface.
Gas hydrate is an icelike form of methane and water that forms naturally at the pressures and temperatures characteristic of permafrost areas and deepwater marine continental margins. The USGS Gas Hydrates Project, which is jointly supported by the USGS Energy Resources Program and the Coastal and Marine Hazards and Resources Program, has for decades been an international leader in studying the energy potential, environmental impact, and hazards implications of natural gas hydrates.
Timothy Collett, a USGS research geologist at the Central Energy Resources Center in Denver, Colorado, played a key role in science operations at the North Slope drill site under the project management of ASRC Energy Services, LLC (AES), a wholly owned subsidiary of Arctic Slope Regional Corporation (ASRC). Collett spent nearly a decade working with the State of Alaska, Alaska’s Department of Natural Resources, DOE, and JOGMEC to develop the drilling program, building on more than 40 years of USGS research on North Slope hydrates.
Phase one of the project involved drilling of a test well in 2018. The second phase, which included the recent pressure coring, started in October 2022. The third phase, which is underway now, will focus on controlled breakdown of gas hydrate deep beneath the permafrost. Planning, execution, drilling, and data acquisition for the 2022-23 phase of the project is being conducted by AES. During phase two, Geotek, Ltd. carried out coring of sediments in the drillhole with special devices that preserve recovered material within the pressure range required to maintain the stability of gas hydrate.
The Woods Hole researchers participating in the drilling expedition were led by Gas Hydrates Project geophysicist Bill Waite. Geotechnical engineer Adrian Garcia, geologist Steve Phillips, and geochemists John Pohlman and Michael Casso were the other members of the USGS Science Party. During round-the-clock operations at the drilling site, the USGS scientists worked 12-hour shifts alongside Jun Yoneda of Japan’s National Institute of Advanced Industrial Science and Technology curating recovered cores, collecting sediment samples for later physical property and microbiological studies, and analyzing gas samples.
A highlight of the USGS scientific program on the North Slope was the first deployment of a USGS-designed, computer-controlled automated sample injection device that allows up to 16 gas samples to be analyzed in a single run. Lee-Gray Boze, a physical scientist with the USGS Gas Hydrates Project, supported the on-site team remotely from Woods Hole, logging in to manage the software he had written to control the automated sampler and data acquisition.
The participation of the Woods Hole scientists in the hydrate drilling expedition was supported by an interagency agreement between the USGS and the DOE National Methane Hydrates Research and Development Program. Throughout the effort, the USGS Alaska Region and its staff have been instrumental in providing in-state support for USGS Gas Hydrates Project activities and personnel.
Waite, Garcia, Phillips, and Pohlman will soon depart Woods Hole for Geotek’s headquarters in Salt Lake City, where the hydrate-bearing sediments retrieved in Alaska are being taken for further analysis. During the Salt Lake City phase, some of the cores will be packed in special USGS-built pressure chambers for overland transport back to Woods Hole. The cores will eventually be processed at the Gas Hydrates Project’s Hydrate Pressure Core Analysis Laboratory (HyPrCAL) in Woods Hole, with some samples to be imaged by Laura Stern of the USGS Earthquake Science Center using scanning electron microscopy (SEM). The data resulting from the USGS analyses will be used to refine reservoir models needed for the underway third phase of the Alaska North Slope expedition.
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