Methane Hydrate: The World's First Offshore Production Test
Resource-starved Japan is looking to methane hydrate as a new energy form. Large reserves of methane hydrate have been confirmed in the seas around Japan, but methane hydrate does not flow under its own pressure like natural gas, which greatly hinders its development. To address this problem, the world's first offshore production tests were conducted in 2013 during which the effectiveness of a depressurization method, developed by AIST, was demonstrated.
It has long been known that methane hydrate, also known as fiery ice, a massive undeveloped energy resource, lies under the ocean floor off Japan's coasts. Unfortunately, it is difficult to develop the technology to break down the methane hydrate and collect methane gas, and little progress had been made toward a practical solution.
At AIST, we have been developing and advocating a production method known as depressurization. This method works by drilling a well down into the methane hydrate layer below the seabed surface and pumping out water to lower the pressure in the methane hydrate layer. The depressurization dissociated methane gas and water from the methane hydrate. The methane gas that rises up the well shaft is then collected as a natural gas resource.
The depressurization method was used in the world's first offshore production tests in March 2013. The six-day test confirmed the production of 120,000 cubic meters of gas, leading to hopes that this will pave the way to future commercial production.