关键词: 前陆冲断带, 断源储盖组合样式, 控藏作用, 库车坳陷, 塔里木盆地

Abstract: Fault development plays a vital role in all the factors controlling gas accumulation in foreland thrust belt, which determines the migration and accumulation of oil and gas, the formation of trap, and the sealing capacity of caprocks. Therefore, the combinations of faultsource- reservoir-cap, of which fault development is the core, determine the channel capacity of oil and gas, the sealing features and the fullness degree of traps, and ultimately control the accumulation of gas. According to the structure characteristics, the association of sourcereservoir- cap, the main controlling factors of accumulation and the analysis of the known hydrocarbon reservoirs in different regions of the foreland thrust belt in Kuqa Depression, the combinations of fault-source-reservoir-cap were founded and the control of different combinations on gas accumulation was elaborated in this paper. The combination of fault-source-reservoir-cap in Keshen is the most optimal, which is connected with Jurassic gas at the bottom and does not cut through Kumugelemu's gypsum-salt cap on the top. Not only does it act as a good channel of gas accumulation and migration, but also the closure of caprock is not destroyed, resulting in the continuous distribution of gas. In Kelasu region the fault cuts through both Bashenjiqike’s reservoir and gypsum-salt cap. For these reasons, whether the closure of the cap can accumulate gas is the lateral sealing trap. Gas is accumulated above gypsum-salt rocks in Dawanqi, thus the main factors for gas accumulation are channel capacity of faults that cut through gypsum-salt rocks and suprasalt trap effectiveness. Ichicklick’s source and reservoir are in the same region, so the key factors of gas accumulation are the sealing ability of the updip faults which control the trap and the lithology joint relationship of each wall.