Petroleum dynamic accumulation process and its implications in Kelasu structural belt, Kuqa Depression, Tarim Basin

The thermal evolution and dynamic accumulation process of hydrocarbon in the Kelasu structural belt were analyzed using various maturity parameters,microscopic observation of rock,reservoir bitumen testing,and particle fluorescence analysis techniques.Studies suggested that the crude oils in the study area are mature and high-mature.Mature oil charged during the early stage while high-mature and over-mature oils charged during the late stage.The subsalt ancient reservoirs formed in the early stage were destructed by faults during the late Neogene,and were partially forced by high-mature and over-mature oils into shallow anticlinal traps.As the plasticity of gypsum caprock enhanced,faults through salts disappeared,and high-mature and over-mature oils accumulated again in subsalt traps.The Bozi segment of the Kelasu structural belt has great exploration potential,and the shallow anticlinal reservoirs should be paid attention to.Therefore,the determination of petroleum maturity and the dynamic accumulation process are important for identifying oil and gas composition and exploration in petroliferous basins.