鄂尔多斯盆地南部镇泾地区典型油藏动态解剖及成藏过程恢复

Dynamic analysis and accumulation process recovery of typical reservoirs in Zhenjing region,south of Ordos Basin

利用孔隙演化史恢复、生烃史热模拟和流体包裹体分析等技术对鄂尔多斯盆地南部镇泾地区典型油藏进行了动态解剖。分析结果表明,研究区长8岩性圈闭形成时间为晚侏罗世以来(160Ma);长7主力烃源岩初始生烃时间为侏罗纪末(140Ma),大规模生烃时间为早白垩世末期(100 Ma);长8油藏为两期成藏,成藏时间分别为早白垩世中期(130 Ma)和晚白垩世早期(90Ma);圈闭形成期、主力生烃期和关键成藏期时间配置关系好,有利于长8油藏的形成。结合构造演化,恢复油气充注成藏过程,建立了油气成藏动态演化模式,即"多期成藏、中期为主、晚期调整定型"。

The dynamic analyses of typical reservoirs in Zhenjing region of the southern Ordos Basin have been carried out based on pore evolution history recovery,petroleum generation history thermal simulation and fluid inclusion analyses.The Chang8 lithologic traps were formed since the late Jurassic（160 Ma）.The Chang7 source rocks began to generate petroleum at the end of Jurassic（140 Ma） and achieved the peak at the end of early Cretaceous（100 Ma）.The Chang8 reservoirs were formed during 2 stages,including the medium of early Cretaceous（130 Ma） and the beginning of late Cretaceous（90 Ma）.The times for trap formation,petroleum generation and reservoir formation matched well,which was favorable for the formation of Chang8 reservoirs.The charging and accumulation processes of petroleum were recovered according to the studies of tectonic evolution.A dynamic evolution model illustrating the process of reservoir formation was made,characterized by ＂multiple stages of accumulation,mainly formed during the middle stage and late stage adjustment＂.