冀中坳陷束鹿潜山带油气成藏主控因素与成藏模式

Main controlling factors and models of hydrocarbon accumulation in the Shulu buried-hill belt,Jizhong depression,Bohai Bay basin

近年来,束鹿潜山带油气勘探取得重大突破,展现出冀中坳陷南部潜山较大的油气勘探潜力。但是,潜山带油气成藏主控因素与成藏模式还未开展系统研究和总结,严重制约了研究区下一步的油气勘探。本论文基于大量的钻井、测录井、地球化学资料、样品测试分析以及盆地模拟的方法,系统剖析了束鹿潜山带不同类型潜山的油气成藏条件,揭示了油气成藏主控因素,并建立了油气成藏模式。结果表明,束鹿潜山带油气成藏主控因素为供烃条件、输导体系以及保存条件,其中供烃条件一定程度上控制了油气成熟度与分布,输导体系控制了油气的运聚和规模,而保存条件控制了原油性质与富集。束鹿潜山带的洼中隆潜山经历了古近系沙河街组二段(Es2)沉积末期—东营期(Ed)和明化镇期(Nm)—现今两期油气充注过程,为近源断层输导断背斜聚集的油气成藏模式;而斜坡带潜山只经历了明化镇期(Nm)—现今一期低熟—正常原油充注过程,为远源不整合输导反向断块-高潜山聚集的油气成藏模式。研究成果可为研究区潜山带油气成藏机理的认识和油气勘探提供科学依据。

Significant breakthroughs have lately been made in oil and gas exploration in the Shulu buried-hill belt,showing great potential for oil and gas exploration in the southern Jizhong depression.However,the main controlling factors and models of hydrocarbon accumulation in the buried-hill belt have not been systematically studied,which limits the further oil and gas exploration in the area.In this paper,the hydrocarbon accumulation conditions of different types of buried-hill reservoirs,the main controlling factors and models of hydrocarbon accumulation in the Shulu buried-hill belt,Jizhong depression have been systematically analyzed based on numerous drilling,logging,geochemical data,sample testing and analysis,and basin modeling method.The results show that the main controlling factors of hydrocarbon accumulation in the Shulu buried-hill belt are source kitchen,migration system and preservation condition,among which the source kitchen controls the maturity and distribution of hydrocarbons to a certain extent,migration system controls the migration and accumulation,and the size of the reservoir,while the preservation conditions control the property and enrichment of oil and gas.The reservoirs in the paleouplifts experienced two stages of hydrocarbon charge events(late Es2 to Ed and Nm to present),characterized by near-source fault transport-faulted anticline accumulation system.The reservoirs in the slope area only experienced a single stage of low maturity-normal oil charge event from Nm to present,typical of far-source unconformable transport-reverse fault block accumulation system.The research results may provide scientific basis for understanding hydrocarbon accumulation mechanism and oil and gas exploration in buried-hill belts of the area.