关键词: 焉耆盆地, 侏罗系, 含油气系统, 烃源岩, 油气系统演化

Abstract: Yanqi basin is a small basin in Northwest China,where the Badaowan formation of Lower Jurassic coal-bearing system is served as the main source rock and the Lower and Middle Jurassic as the main reservoir.The source rock and the reservoir had undergone the deep burial in Early and Middle Jurassic,the high uplifting in Late Jurassic and Cretaceous,and the secondary burial in Tertiary.Hence,the Jurassic petroleum system in Yanqi basin had two critical moments at the end of Jurassic and Tertiary periods which were consistent with the main generation and accumulation times of hydrocarbon.The Jurassic petroleum system in Yanqi basin had undergone three main evolution stages in geohistory.Jurassic is the formation stage of the system,during which the most paleo-oilfields were formed and their distribution was mainly controlled by the fluid potential.Cretaceous is the stage of system's destruction,and Tertiary is the period of system's regeneration.The Jurassic petroleum system was recharged and evolved in Tertiary from one system into two parts,with northern sag petroleum system with abundant hydrocarbon resources and southern sag petroleum system favorable for the distribution of lithologic oil and gas accumulation.

Key words: Yanqi basin, Jurassic period, Cretaceous period, Tertiary peroid, petroleum system, evolution of petroleum system