车拐斜坡区三叠系百口泉组油气成藏条件研究

Hydrocarbon Accumulation Conditions of Baikouquan Formation of Triassic in Cheguai Slope Area

针对车拐斜坡区三叠系百口泉组成藏条件认识模糊的问题,以钻测井、地震、微观测试分析为手段,对百口泉组油藏的烃源岩、储层、盖层、运移条件以及圈闭类型进行分析。结果表明,车拐斜坡区百口泉组油藏存在多套烃源岩为其供烃,以风城组和下乌尔禾组为主;存在物性较好的(水下)分流河道砂岩储层,同百三段发育的大套泥岩形成的盖层相互匹配,组成有利储盖组合;断裂、高渗砂体、古地貌以及异常压力环境为油气运移创造条件,控制油气疏导路径;形成高部位构造-岩性圈闭以及斜坡带和低部位岩性圈闭两种圈闭类型;利用古地貌、沉积相、断裂平面图以及压力系数平面图进行叠合,划分出3个有利成藏区,为百口泉组勘探提供方向,指出成藏Ⅱ区具有较大的勘探潜力。

The fuzzy recognition on hydrocarbon accumulation conditions in Baikouquan Formation of Cheguai slope area is a problem,which has been hindering deeper oil and gas exploration.Hydrocarbon source rock,reservoir,cap rock,migration conditions and trap types were investigated with drilling,seismic,well test and laboratory data.The study results show that many hydrocarbon source rocks supply hydrocarbon for Baikouquan oil reservoir,Fengcheng Formation and lower Wuerhe Formation being the major source rocks.Sandstone reservoirs of distributary channels(underwater)with good physical properties match well with mud-stone cap rocks developed in the three member ofBaikouquanFormation,all ofwhich made favorable reservoir-seal assemblage.Faults,hyper-osmotic sands,ancient landform and abnormal pressure create conditions for oil and gas migration and control migration path.There were two trap types named structural-litho-trap in high position and litho-trap in slope and low position.Congruent with ancient landform,sedimentary face,planar graph of faults and pressure coefficient,the result shows there are three favorable reservoir zones in study area which can supply exploration direction in Baikouquan Formation,and Ⅱ reservoir zone has the best exploration potential.