Gas find could be US's largest fossil resource
Drilling tests in Alaska's North Slope have revealed ‘staggering’ deposits of gas hydrate that could contain 200,000 trillion cubic feet of natural gas. This is over a hundred times greater than most reserves, says the US Office of Fossil Energy's National Energy Technology Laboratory (NETL).
Gas hydrate is an ice-like solid that results from the trapping of methane molecules, the main component of natural gas, within a lattice-like cage of water molecules. Dubbed the ice that burns this substance releases gaseous methane when it melts.
The find, within the Milne Point unit of the greater Prudhoe Bay region of Alaska's North Slope, is a joint project of a consortium co-funded by NETL and conducted through the National Methane Hydrate R&D Program, which is a DOE-led collaboration.
Methane hydrate is the most abundant natural form of clathrate, a unique class of chemical substance in which molecules of one material, water in this case, form an open solid lattice that encloses, without chemical bonding, appropriately-sized molecules of another material, methane in this case.
In the 1960s, naturally-occurring methane hydrate was observed in Siberian gas reservoirs. As the understanding of natural methane hydrate grew, scientists realized that, given the ubiquity of both methane (the common by-product of bacterial breakdown of organic matter) and water in nature, methane hydrate could be present in vast quantities in any environment with suitable pressures and temperatures.
Today, the US Geological Survey estimates that methane hydrate may contain more organic carbon than all the world's coal, oil, and non-hydrate natural gas combined. But the global methane hydrate reservoir is in constant flux, absorbing and releasing methane in response to ongoing natural changes in the environment.
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