天然气水合物是由天然气中小分子气体(甲烷、乙烷等)在一定的温度、压力条件下和水作用生成的一类笼型结构的冰状晶体。形成天然气水合物的主要气体成分为甲烷,甲烷气体体积超过99.9%的天然气水合物通常称为甲烷水合物,它是一种典型的Ⅰ型水合物,广泛分布于海底以下0～1500m深的沉积带或陆地上的永久冻土带中,是自然界中甲烷存在的一种重要方式。迄今在世界各地海洋及大陆冻土带中已探明的天然气水合物 Natural gas hydrate is a kind of cage-like structure of ice crystals produced by the action of small and medium-sized gas (methane, ethane, etc.) under certain temperature and pressure conditions. The main gas component that forms the gas hydrate is methane. Gas hydrates with a methane gas volume of more than 99.9%, commonly known as methane hydrate, are typical Type I hydrates and are widely distributed below 0-1500 m below seafloor Belt or land permafrost, is an important way of existence of methane in nature. To date, proven gas hydrates in oceans and continental tundra around the world