ANALYSIS ON THE FORMING MECHANISM OF THE CARBONIFEROUS GAS RESERVOIRS IN THE KAIJIANG PALEOHIGH REGION OF EAST SICHUAN AREA

East Sichuan area is a relative structre mobile belt in the stable blocks of the Sichuan Basin,in which ten lines of high steep structural belts were developed and major gas bearing structural belts are located in the Kaijiang Paleohigh region.The explored reserves of natural gas in East Sichuan area are about 60% of those in the whole Sichuan Province.This makes East Sichuan area,especially the Kaijiang Paleohigh region become the main producing zone of natural gas in Sichuan Province and even in China.In this paper,the forming mechanism of three kinds of the Carboniferous grouped gas reservoirs formed in the Kaijiang Paleohigh region was analysed emphatically.It was pointed out that the pool formation of the Kaijiang Paleohigh in the early stage and the rich Carboniferous gas sources laid a solid foundation for the formation of present great gasfields and grouped gas reservoirs,the Datianchi structural belt in the top of the Kaijiang Paleohigh is the most favorable gas enriched structural belt,and the grouped gas reservoirs of the inheritance anisotropic type are the main gas enriched type.