Methane gas recovery method and carbon dioxide low emission power generation method, and methane gas recovery system and carbon dioxide low emission power generation system

摘要

A methane gas recovery method for recovering methane gas from a methane hydrate layer, wherein the methane hydrate layer is preheated by injecting heated seawater in which carbon dioxide is dissolved and that is heated into one or more injection wells that pass through the methane hydrate layer, and the methane gas is recovered from the preheated methane hydrate layer using a reduced pressure method at one or more production wells that pass through the methane hydrate layer and that are provided locations at a set distance away from the injection wells. After a set time period has passed, the injection well is used as a production well and the methane gas is recovered from the production well, and a new injection well is dug and heated seawater is injected into the injection well so as to preheat the methane hydrate layer.