辽西凸起斜坡区风化壳油气运移特征及控藏作用  

Hydrocarbon migration characteristics and its controlling effect on hydrocarbon accumulation of weathering crust in slope area of Liaoxi Uplift

作　　者：李虹霖 郭涛 张如才 杨传超 张明升 Li Honglin;Guo Tao;Zhang Rucai;Yang Chuanchao;Zhang Mingsheng(Tianjin Branch of CNOOC Ltd.,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《地质科技通报》2022年第4期109-116,共8页Bulletin of Geological Science and Technology

基　　金：中海石油(中国)有限公司“七年行动计划”重大科技专项课题“渤海油田上产4000万t新领域勘探关键技术”(CNOOC-KJ135ZDXM36TJ08TJ)。

摘　　要：随着勘探程度的提高,小型复杂断块圈闭已成为当前凸起区油气勘探的重点领域,为了明确辽西凸起断块圈闭油气差异富集的原因,利用三维地震、测录井、薄片等数据资料,通过三维流线定量模拟的方法,分析凸起斜坡区潜山顶面风化壳特征,建立“壳-断”耦合油气运移模式,刻画斜坡区油气优势运移路径,从而明确风化壳运移对凸起断块油气差异富集的控制作用。结果表明:①研究区潜山历经多期构造运动,且潜山岩性主要为下古生界碳酸盐岩和太古界花岗岩,岩性性质较脆,易被风化剥蚀,风化壳溶蚀孔隙及构造裂缝普遍发育,且分布稳定,形成斜坡区油气侧向长距离运移的主要通道;②斜坡中带受反向断层控制形成断隆构造,油气沿风化壳的运移受斜坡断隆带遮挡,形成“壳-断”耦合油气运移模式,断隆带断距大小控制风化壳油气侧向运移能力;③利用三维流线定量模拟的方法,刻画出研究区四级油气优势运移通道,明确不同级别油气运移通道对凸起断块油气富集程度的控制作用。该研究成果有效指导辽西凸起油气勘探实践,并填补了富油凹陷成熟凸起区油气成藏认识及研究方法。With the improvement of the exploration degree,small complex fault block traps have become the key field of oil and gas exploration in the current uplift area.To clarify the reasons for the differential enrichment of oil and gas in the fault block trap in the West Liaoning uplift,the characteristics of weathering crust on the top of the buried hill in the uplift slope area are analysed by using three-dimensional seismic,logging,thin section and other data through three-dimensional streamline quantitative simulation.The"crust-fault"coupling migration model is established to describe the dominant migration path of oil and gas in the slope area to clarify the control effect of hydrocarbon migration along weathered crust on the differential enrichment of oil and gas in the convex fault block.The results show that①the buried hill in the study area has experienced multistage tectonic movements,and the lithology of the buried hill is mainly lower Paleozoic carbonate rock and Archean granite.The lithology is brittle and easily weathered and denuded.The denudation pores and structural fractures of the weathering crust are widely developed and stably distributed,forming the main channel of lateral long-distance migration of oil and gas in the slope area.②The middle zone of the slope is controlled by reverse faults to forma fault uplift structure.The migration of oil and gas along the weathering crust is blocked by the slope fault uplift zone,forming a"crust-fault"coupling oil and gas migration model.The fault throw of the fault uplift zone controls the lateral migration ability of oil and gas in the weathering crust.③Using the method of three-dimensional streamline quantitative simulation,the four-level dominant oil and gas migration channels in the study area are characterized,and the control effect of different levels of oil and gas migration channels on the degree of oil and gas enrichment in convex fault blocks is clarified.The research results effectively guide the practice of oil and gas exploration in the Liao

关 键 词：风化壳 断隆带 “壳-断”耦合运移 油气运移 斜坡区 辽西凸起 

分 类 号：P618.13[天文地球—矿床学]