China has successfully extracted gas from gas hydrates—also known as ‘fire ice’ or ‘flammable ice’—in the northern part of the South China Sea, the China Geographical Survey said on Thursday.

Gas hydrate, methane hydrate in particular, is a cage-like structure of crystallized ice, inside of which are trapped molecules of methane, the chief constituent of natural gas. If methane hydrate is either warmed or depressurized, it reverts back to water and natural gas.

According to the U.S. Department of Energy (DOE), global estimates vary, but the energy content of methane in hydrates is “immense, possibly exceeding the combined energy content of all other known fossil fuels”. But no methane production other than small-scale field experiments has been documented so far.

Today, the China Geographical Survey said that it managed to collect samples from the Shenhu area in the South China Sea in a test that started last Wednesday. Every day some 16,000 cubic meters (565,000 cubic feet) of gas, almost all of which was methane, were extracted from the test field.

China is not the only country that is testing ‘fire ice’ deposits discovered in their waters. Japan, for example, has been studying for years the potential recovery of methane hydrate, and launched last month preparations to carry out a second production test to extract methane gas from gas hydrates with two wells. Related: Venezuela’s Oil Production On The Brink Of Collapse

Last week, Japan’s Ministry of Economy, Trade and Industry (METI) said that on May 4 the Agency for Natural Resources and Energy (ANRE) had launched a gas production test to dissolve methane hydrate and extract natural gas offshore Japan, and confirmed the production of natural gas.

The U.S. also has a methane hydrate program to develop technologies that could allow safe methane production from arctic and domestic offshore hydrates.

In July last year, the U.S. Geological Survey said that large deposits of potentially producible gas hydrate was found in the Indian Ocean for the first time, in a joint research project with the governments of India and Japan.

By Tsvetana Paraskova for Oilprice.com

More Top Reads From Oilprice.com: