By Lisa Raffensperger @ http://discovermagazine.com/2014/jan-feb/19-fuel-from-fire-ice
Global fuel supplies may soon be dramatically enlarged thanks to new techniques to tap into huge reserves of natural gas trapped under the seafloor. In March, Japan became the first country to successfully extract methane from frozen undersea deposits called gas hydrates.
These lacy structures of ice, found around the globe buried under permafrost and the oceanfloor, have pores filled with highly flammable gas. By some estimates, hydrates could store more than 10 quadrillion cubic feet of harvestable methane — enough to fulfill the present gas needs of the entire United States for the next 400 years.
The following is from Wikipedia, under methane clathrates.
Methane clathrates are common constituents of the shallow marine geosphere, and they occur both in deep sedimentary structures, and form outcrops on the ocean floor. Methane hydrates are believed to form by migration of gas from depth along geological faults, followed by precipitation, or crystallization, on contact of the rising gas stream with cold sea water. Methane clathrates are also present in deep Antarctic ice cores, and record a history of atmospheric methane concentrations, dating to 800,000 years ago.[4] The ice-core methane clathrate record is a primary source of data for global warming research, along with oxygen and carbon dioxide.
The sedimentary methane hydrate reservoir probably contains 2–10 times the currently known reserves of conventional natural gas, as of 2013[update].[25] This represents a potentially important future source of hydrocarbon fuel. However, in the majority of sites deposits are thought to be too dispersed for economic extraction.[18] Other problems facing commercial exploitation are detection of viable reserves and development of the technology for extracting methane gas from the hydrate deposits.
A research and development project in Japan is aiming for commercial-scale extraction near Aichi Prefecture by 2016.[26][27] In August 2006, China announced plans to spend 800 million yuan (US$100 million) over the next 10 years to study natural gas hydrates.[28] A potentially economic reserve in the Gulf of Mexico may contain approximately 100 billion cubic metres (3.5×1012 cu ft) of gas.[18] Bjørn Kvamme and Arne Graue at the Institute for Physics and technology at the University of Bergen have developed a method for injecting CO2 into hydrates and reversing the process; thereby extracting CH4 by direct exchange.[29] The University of Bergen's method is being field tested by ConocoPhillips and state-owned Japan Oil, Gas and Metals National Corporation (JOGMEC), and partially funded by the U.S. Department of Energy. The project has already reached injection phase and was analyzing resulting data by March 12, 2012.[30]
On March 12, 2013, JOGMEC researchers announced that they had successfully extracted natural gas from frozen methane hydrate.[31] In order to extract the gas, specialized equipment was used to drill into and depressurize the hydrate deposits, causing the methane to separate from the ice. The gas was then collected and piped to surface where it was ignited to prove its presence.[32] According to an industry spokesperson, "It [was] the world's first offshore experiment producing gas from methane hydrate".[31] Previously, gas had been extracted from onshore deposits, but never from offshore deposits which are much more common.[32] The hydrate field from which the gas was extracted is located 50 kilometres (31 mi) from central Japan in the Nankai Trough, 300 metres (980 ft) under the sea.[31][32] A spokesperson for JOGMEC remarked "Japan could finally have an energy source to call its own".[32] The experiment will continue for two weeks before it is determined how efficient the gas extraction process has been.[32] Marine geologist Mikio Satoh remarked "Now we know that extraction is possible. The next step is to see how far Japan can get costs down to make the technology economically viable."[32] Japan estimates that there are at least 1.1 trillion cubic meters of methane trapped in the Nankai Trough, enough to meet the country's needs for more than ten years.[32]
