Gas Reservoir Accumulation Process of Qingxichang Fractured Reservoir in Northeastern Sichuan Basin

On the basis of analyzing local structural development history,gas genetic types and origin,fluid inclusion features and gas filling history,the gas reservoir forming process of Qingxichang fractured reservoirs was analyzed.The result indicates that thee gas in there was mainly originated from kerogen crackings of the upper Permian source rocks.Gas inclusions were mainly organic inclusions of the fractured reservoirs,and the gas was mainly charged during mid-late Jurassic system.The thrust of Daba mountain during Late Yanshan and Himalayan Movement result in the formations of Qingxichang anticline and fractured reservoirs,then gas of kerogen crackings is migrated along faults and fractures to fractured reservoirs and is accumulated as gas pool.The formation and scale of fractured reservoirs directly influence the natural gas charge history and accumulation scale.