Surveys of methane hydrate reserves beneath the Sea of Japan is now under way as part of an effort to give Japan a steady supply of natural gas for decades to come.
The surveys follow an earlier successful trial drilling in Pacific waters off Aichi Prefecture.
Known as “fiery ice,” the methane hydrate reserves are considered one of the few hopeful fossil fuels available in Japan.
Methane hydrate lies beneath the seafloor in the form of sherbet-like crystals that are made up of methane and water molecules. Its decomposition produces methane gas, which can be used as fuel. Experts have estimated that offshore reserves could cover natural gas needs in Japan for a century.
The surveys started in the waters off Joetsu, Niigata Prefecture.
The industry ministry said June 7 it plans to spend six weeks or so exploring areas extending to waters off Noto Peninsula before conducting more detailed geological surveys in selected zones this summer. A trial drilling is planned for fiscal 2014.
The ministry plans to survey broad offshore areas, ranging all the way from Hokkaido to waters around the Oki islands, during three years through fiscal 2015.
In March, Japan extracted natural gas from methane hydrate reserves off Atsumi Peninsula, Aichi Prefecture. But the reserves were contained in sandy sediment layers beneath the seafloor, whereas most of the reserves in the Sea of Japan are concentrated near the seafloor surface, which means that different drilling methods must be developed.