辽西低凸起中段潜山油气差异富集及主控因素

Hydrocarbon Difference Enrichment and Main-Controlling Factors of Buried-Hill Reservoir in the Central of Liaoxi Low-Salient

以钻井、地球化学、流体包裹体及磷灰石裂变径迹等资料为基础,分析了辽西低凸起中段锦州25-1S和绥中36-1潜山油气成藏条件及差异性,重点对油气来源、成藏期次、油气充注过程以及保存条件进行了研究。结果表明:锦州25-1S和绥中36-1潜山虽然储层、油源和输导条件略有不同,但造成油气差异富集的主控因素是保存条件;锦州25-1S潜山发育优越的区域盖层,且边界断层的活动性与油气运移、成藏的匹配关系良好;绥中36-1潜山盖层条件较差,更重要的是边界断层在油气成藏时期活动性过强,造成油气向东营组调整,是绥中36-1潜山构造高部位没有大规模油气富集的主要原因。分析该地区潜山油气富集的主控因素,指出斜坡区是绥中36-1潜山勘探的重要方向,对该区潜山油气勘探具有一定的指导意义。

The drilling,geochemical analysis,fluid inclusion test,apatite fission track and other data are used to analyze the hydrocarbon accumulation conditions and differences of Jinzhou25-1S and Suizhong36-1 buried-hill structures in the central of Liaoxi low-salient. The hydrocarbon source,hydrocarbon accumulation stage,hydrocarbon charging and preservation conditions are mainly researched,which indicate that though there are slight differences in reservoir,hydrocarbon source and conduction conditions,the difference enrichment of hydrocarbon between Jinzhou25-1S and Suizhong36-1 buried-hill structures mainly results from preservation condition. Local high-quality caprock develops in Jinzhou25-1S area and the activity of boundary faults well match with hydro-carbon migration and accumulation,which leads to large-scale buried-hill oil reservoir of Jinzhou25-1S. Due to the poor quality of caprock in Suizhong36-1 area and more significant is the strong activity of boundary faults during hydrocarbon accumulation,which result in hydrocarbon migration to Dongying Formation. This is the key factor for no large-scale hydrocarbon enrichment in the high-part of Suizhong36-1 buried-hill structure. The analysis of main-controlling factors for buried-hill hydrocarbon enrichment in this area illustrates that the further buried- hill hydrocarbon exploration should focus on the slope area of Suizhong36- 1,which could provide certain guidance for the buried-hill hydrocarbon exploration in this area.