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| North Slope gas hydrates starting to look feasible |
| 2005-03-03 |
| According to a 2001 report by the Minerals Management Service as much as 519 trillion cubic feet of natural gas could lie under the permafrost of northern Alaska in the form of gas hydrates. With the prospect of a gas export line from the North Slope, could any of this vast resource be brought to market? A team from industry, government and university is taking the first steps towards the use of gas hydrates on the North Slope by investigating known deposits of the material in the central North Slope. BP Exploration (Alaska), ASRC Energy Services, Ryder Scott Co., the U.S. Geological Survey, the U.S. Department of Energy, the University of Alaska Fairbanks and the University of Arizona are all collaborating in this project. The team has completed the first phase of its work, Robert Hunter of ASRC Energy Services and Dr. Timothy Collett of the USGS recently told a joint meeting of the Alaska Geological Society and the Geophysical Society of Alaska. Phase one included reservoir characterization, reservoir engineering, petroleum engineering and reservoir economic modeling. Gas hydrates concentrate huge volumes of methane gas by combining methane with water under certain temperature and pressure conditions. "Typically we have a methane molecule within a lattice of water and this forms a solid substance within the pores in the subsurface," Hunter explained. "The gas storage capacity's tremendous — that's one thing that makes hydrates very attractive as an unconventional gas resource." When gas hydrate crystals break down or disassociate they can yield 164 to 180 times their volume of free gas, Hunter said. Gas hydrates occur in many places worldwide, in deep-ocean or Arctic conditions where low temperatures and elevated pressures enable their formation. However, the U.S. Department of Energy has taken a particular interest in gas hydrates in the Gulf of Mexico and onshore Alaska, Hunter said. These areas offer economic potential because they're associated with known petroleum systems and they contain existing oil and gas production infrastructures. Also there are known technologies for extracting gas from hydrates in these areas and established business models for gas production. Under the North Slope there is an approximately 900 meter thick zone of temperature and pressure within which gas hydrates can exist as stable crystals, Hunter said. "On the North Slope of Alaska 
that pressure/temperature regime in which gas hydrates can exist is anywhere north of the Brooks Range," Collett said. The gas hydrate stability field extends from inside the permafrost zone to well below the permafrost, he said. |
| Posted by:phil_b |
| #1 Envirowhacko whining in 5, 4, 3,... |
| Posted by: PBMcL 2005-03-03 2:29:08 PM |