Submarine gas hydrate mining method and system

摘要

PPROBLEM TO BE SOLVED: To provide a method and a system in which a gas hydrate in a submarine stratum existing thinly and widely is mined efficiently. PSOLUTION: A spread region along the sea-bottom surface 4 of a gas-hydrate layer 2 in a submarine ground 1 is investigated, a mining base 10 equipped with a boring device 11, in which a drilling angle is operated freely, is submerged at a stable ground site in the spread region and a transport route is installed between the base 10 and a marine section. A plurality of horizontal wells 30 are drilled to the gas-hydrate layer 2 from the base 10, warm heat or a kicker is sent into the layer 2 through the wells 30 and the gas hydrate is decomposed and the decomposition-product gas of the layer 2 is gathered by the wells 30, the base 10 and the transport route 19. Seawater heated by energy from the marine section on the base 10 is sent into the layer 2 including an energy transport route 18 to the base 10 from the marine section to the route 19. Alternately, an energy conversion device converting a part of the decomposition product gas into energy may also be installed to the base 10. PCOPYRIGHT: (C)2004,JPO&NCIPI