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North Slope methane hydrate well has been successfully completed
Alan Bailey Petroleum News
The drilling of a new methane hydrate test well on the North Slope has been successfully completed, the U.S. Department of Energy announced Jan. 23. The well was drilled from a small, existing gravel pad, adjacent the North Slope Spine Road, about one mile north of Z pad, in the western part of the Prudhoe Bay unit. DOE says that its National Energy Technology Laboratory formed a partnership with Japan Oil, Gas and Metals National Corp., the U.S. Geological Survey and Petrotechnical Resources of Alaska for the drilling of the well. BP, operator of the Prudhoe Bay unit, oversaw the drilling.
The Alaska Department of Natural Resources has also been facilitating methane hydrate research - in 2013 DNR signed a memorandum of understanding with DOE for collaboration over the research efforts.
Long-term testing The objective of the new well is to conduct long-term testing of gas production from hydrates. DOE said that the well has confirmed the presence of hydrates in two reservoirs that are suitable for the testing - temperature and acoustic monitoring devices were fitted in the well as a precursor to future field experiments.
The success of this test moves us closer to characterizing, evaluating, and confirming the potential for gas hydrates production on the North Slope, said Steven Winberg, assistant secretary for fossil energy. We look forward to continue working with our partners to conduct world-class gas hydrates research on the Alaska North Slope.
Methane hydrate is a solid in which molecules of methane, the primary component of natural gas, are concentrated inside a lattice of water molecules. Huge quantities of the material, which remains stable within a certain range of relatively high pressures and low temperatures, are known to exist around the base of the permafrost under the North Slope. There are also extensive hydrate accumulations in other parts of the world, including in the seabed of the Gulf of Mexico and offshore Japan. The hydrates greatly concentrate the gas, relative to accumulations in conventional gas reservoirs.
Production possibilities It is thought that natural gas could be produced through some combination of elevating the temperature or reducing the pressure in a hydrate reservoir. However, although short term gas production has been achieved from previous test wells, sustained production has yet to be demonstrated. In addition to the technical feasibility of hydrate gas production, it will also be necessary to evaluate the economic viability of the production process.
The site of the new test well offers the benefit of year-round access via the North Slope road system - DOE has said that there is the potential to use the well for conducting experiments over many months. In contrast, this kind of long-term testing is impractical in offshore locations, or at undeveloped Arctic onshore sites, DOE said.
Methane hydrate has the potential to be a major source of natural gas from the North Slope region. In 2012 the U.S. Geological Survey estimated that there may be something in the range of 25 trillion to 157 trillion cubic feet of technically recoverable gas trapped in the form of hydrates under the Slope.
- ALAN BAILEY
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