Japan is the first country to have succeeded in extracting natural gas from frozen methane hydrate. Methane hydrates, also known as "flammable ice", are solid compounds similar to ice, formed when a large amount of methane is trapped within a crystal structure of water. Japan believes that frozen methane hydrate could provide an alternative energy source in order to cover the country’s energy needs. The extraction operation is carried out by energy explorer Japan Oil, Gas and Metals National Corp (JOGMEC).
The gas field where the extraction takes place is about 50km away from Japan's main island, in the Nankai Trough and production tests are expected to continue for about two weeks. Government officials have said that they aim to achieve commercial production of methane hydrate within six years.
According to a Japanese study, at least 1.1tn cubic metres of methane hydrate exist in offshore deposits. This amounts to more than a decade of Japan's gas consumption. Given the fact that Japan imports almost all of its energy needs and is the world's top importer of liquefied natural gas, the extraction will be a breakthrough for the country’s energy sector.
Other countries including Canada, the US and China have been looking into ways of exploiting methane hydrate deposits as well. However, releasing methane from gas hydrate fields includes significant risks since not only its extraction is difficult, but also the gas is unstable once it's removed from the high pressures and low temperatures of the deep sea. In addition, many geologists suspect that gas hydrates play an important role in stabilizing the seafloor and consequently, drilling could possibly destabilize the underwater ground.