关键词: 煤成气藏, 天然气聚集, 生气强度, 分布特征, 富集因素, 储集层, 鄂尔多斯盆地, 四川盆地, 气藏形成, 煤系

Abstract: More than 40 coaliferous gas pools and gas-bearing structures have been discovered in our country,mainly distributed in six basins,ie:Sichuan,Ordos,Bohai Bay,Songliao,Qiongdongnan and the East China Sea Basins,and in five series:Ordovician,Carboniferous-Permian,upper-Triassic,Jurassic-Cretaceous and Tertiary.According to the relationship between these gas reservoirs and coal seams,the coaliferous gas pools can be divided into three types,i.e.,"source and reservoir beds in the same formation","lower source and upper reservoir formation" and "upper source and lower reservoir formations".There are mixed gas reservoirs formed by both coaliferous gas and other type of gases in the basins with multiple source formations.Four primary factors of thire evolution and accumulation have been summarized in this paper by analysing basic geological conditions in the Known coaliferous gas pools.