HYDROCARBON MIGRATION AND ACCUMULATION SYSTEM IN CARBONATE FORMATION, EASTERN CHONGQING
渝东碳酸盐岩区油气运聚体系

The characteristics of hydrocarbon migration and accumulation system in carbonate formation,eastern Chongqing can be traced from these factors: disturbance of multitectonics,lithologic character of carbonate formation and existence of abnormal pressure.Besides of permeable formations,plane of unconformity and framework of faults,karst cave is another important type of migration pathway according to the analysis of paleokarst cave,diagenesis and fault.Buoyancy and hydropower from release of overpressure drive the fluids to migrate in formation. The relationships between hydrocarbon migration stages and tectonic movements based on the data of burial history of well and fluid inclusions and the changes of fluid potential in all migration periods indicate that: Under the force of buoyancy and hydropower,hydrocarbon in Silurian and Permian migrated extensively in late Triassic and middle Jurassic.Silurian hydrocarbon was injected into Carboniferous again when late Yanshan extension movement took place in the end of late Cretaceous.And its accumulation place is Shizhu and other doming zones.Hydrocarbon sourced from Permian formed reservoir in itself.But hydrocarbon reservoir from Triassic destroyed due to the opened framework of faults.