Aboard the Uncle John — When this semi-submersible drilling vessel enters the Gulf of Mexico later this month it will embark researchers on a 35-day voyage of discovery that is part of an effort to map a virtually inexhaustible supply of energy – the methane hydrate that may represent up to 200,000 trillion cubic feet of natural gas.
The expedition will take the next major step in understanding a potentially huge energy resource trapped in methane hydrate, called the “ice that burns” because it releases a flammable gas when it melts. The resource is found far beneath the surface in waters along the U.S. coast and the permafrost of Alaska. Today’s recoverable non-hydrate methane resource pales in comparison at an estimated 1,400 Tcf.
The Uncle John’s 2005 voyage is part of a wider effort to better understand methane hydrate. The U.S. Department of Energy (DOE) has funded the Gulf of Mexico Joint Industry Project, a 4-year, $13.6 million, cost-shared effort to develop technologies that locate and safely drill through or near the hydrate. The joint project, one initiative in DOE’s overall National Methane Hydrate R&D Program, has been led by ChevronTexaco in cooperation with DOE’s National Energy Technology Laboratory (NETL).
The Joint Industry Project began in 2001 and focused on two Gulf of Mexico sites: the Keathley Canyon and Atwater Valley areas on the outer continental shelf off the coasts of Texas and Louisiana. These locations, at a depth of 4,300 feet, were selected after an evaluation of seafloor geologic features and an estimation of the presence of methane hydrates.
While the potential of methane hydrates as an energy source for the United States is enormous, researchers must continue to study its characteristics, evaluate drilling safety issues, and weigh its effect on global climate change, while finding ways to cost-effectively transport the gas to the surface before wide-scale production can take place.
Although these gas-bearing, ice-like formations occur in great abundance within seafloor sediments—and in Arctic permafrost as well—methane hydrate is sensitive to temperature changes. Because of this, producing warm oil and gas from reservoirs below methane hydrate accumulations could make the seafloor and well-bore unstable.
During the expedition, researchers plan to drill two sets of deep well pairs in the Keathley Canyon and Atwater Valley locations to collect drilling, logging, and coring data. One well pair at each location will be drilled in an area expected to contain large volumes of methane hydrate.
The second well pair at each location will be drilled where less methane hydrate is indicated, for baseline data. Comparing the data from the two areas will provide important information about the nature of the methane hydrate in the seafloor and provide a true test of our ability to estimate reserves prior to drilling. The research team will subsequently evaluate all data and integrate it into the existing database and seismic information.
A significant activity of the expedition will be the collection and preservation of methane hydrate samples for laboratory testing. The results will ultimately provide researchers with the data needed to validate gas hydrate models and improve drilling safety procedures.
In addition to NETL and ChevronTexaco, other partners in the Joint Industry Project are ConocoPhillips; Total E&P USA; Schlumberger Data & Consulting Services; Halliburton Energy Services; U.S. Minerals Management Service; the Japan Oil, Gas & Metals National Corporation; and India’s Reliance Industries Limited. Academic participants include the Georgia Institute of Technology, Rice University, the Scripps Institute of Oceanography, and Texas A&M through the Joint Oceanographic Institute.