This project is part of the ministry's 16-year plan to discover whether or not methane hydrate can be produced on a commercial basis and serve as a natural gas substitute in order to minimise its dependence on imports.

Methane hydrate is a hybrid of water and methane that can be ignited. A recent estimate said that enough methane hydrate can be found in Japanese waters to supply the country for the next century or so.

The plan calls for, according to officials from the ministry, "a series of test-drills at locations off coastal areas extending from Mie to Shizuoka prefectures." Data from these test wells will then be evaluated by the ministry's scientists "to confirm how widely and densely the ice-like substance lies under the ocean floor," said the officials.

The actual drilling work will be done by a consortium made up of the Japan Petroleum Exploration Co and Teikoku Oil Co. This joint venture is expected dig from between 300 to 400 metres into the ocean floor - to depths of around 700 to 2,000 metres below the surface.