State issues methane hydrate seismic permit

Alan Bailey

Petroleum News

Alaska’s Division of Oil and Gas has issued a land use permit to SAExploration Inc, allowing the company to conduct a seismic survey for the methane hydrate test well that was drilled in the Prudhoe Bay unit in December. The idea is to obtain a vertical seismic profile for the well, as part of a project to determine whether methane hydrates can become a technically and commercially viable unconventional natural gas resource.

The well was drilled from a small, existing gravel pad in the western part of the Prudhoe Bay unit. The U.S. Department of Energy has said 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 purpose of the well is to conduct long-term tests of gas production from hydrates in the subsurface.

The division says that a geophone for recording the seismic signals was placed downhole in the well during the drilling operations and that no geophones will be placed on the tundra. Four vibrator units, operating in pairs, will move in a circular pattern around the project area to generate the seismic signals.

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. It is thought that natural gas could be produced through some combination of elevating the temperature or reducing the pressure in a hydrate reservoir, but the long-term technical and economic feasibility of this process has yet to be demonstrated.

- ALAN BAILEY