库车东秋里塔格构造变形期与生烃期匹配关系

THE MATCHING RELATIONSHIP BETWEEN STRUCTURAL DEFORMATION STAGE AND HYDROCARBON GENERATION STAGE IN EASTERN QIULITAGE TECTONIC BELT OF KUQA DEPRESSION

中生代以来库车拗陷东秋里塔格构造带经历了复杂的构造演化,形成了复杂的地质构造,阳霞凹陷的烃源岩同样经历了复杂的演化过程。烃源岩生烃期与构造圈闭形成期的匹配关系,对油气成藏的意义重大,在构造圈闭形成期或之后形成的油气有利于聚集成藏。通过平衡剖面分析和生长地层分析,厘定了库车拗陷东秋里塔格构造带主要构造活动期是上新世库车期和第四纪。利用PRA软件对阳霞凹陷阳1井和人工1井进行了烃源岩成熟度史数值模拟,结果表明,从上新世库车期至今,阳霞凹陷三叠系烃源岩和侏罗系部分烃源岩分别处于生湿气—干气阶段和生凝析气阶段,与东秋里塔格构造带主要构造活动期存在良好的匹配关系。

In eastern Qiulitage Tectonic Belt of Kuqa Depression,there exist complex geological structures as the result of the complicated tectonic evolution,the source rocks in Yangxia Sag have also experienced complex evolution since Mesozoic.It is important to hydrocarbon accumulation that the generation time of source rocks matches the formation time of structural traps.The hydrocarbon generated at the same time as or after the structural traps form is favorable for accumulating.Through analyzing the balanced profile and the growth strata,it is found that the main stage of tectonic movement of the Eastern Qiulitage Tectonic Belt in Kuqa depression was from Kuqa stage of Pliocene to Quaternary.Then the maturity history of source rocks of Triassic and Jurassic in the Yang well 1& artificial well1 is simulated,and it is found that Triassic source rocks generated wet gas and dry gas and Jurassic source rocks generated condensate gas from Kuqa stage of Pliocene to present.Thus,in the structural deformation period,there is a good matching relationship with the hydrocarbon generation stage of source rocks in Yangxia sag,and the structural traps in the studied area should have captured massive gas that generated in Yangxia Sag.