松辽盆地长10区块扶余油层源外斜坡区油成藏规律

Research into oil accumulation law in slope region outside source—F oil layer of Chang 10 block in Songliao Basin

通过油藏解剖分析及其与成藏条件空间匹配关系,对长10区块扶余油层油分布成藏模式和主控因素进行研究.结果表明:长10区块扶余油层油主要分布FⅠ油层组,平面上,沿断裂密集带分布,由构造低部位至构造高部位含油层位由多变少;剖面上,上油下水主要分布在断裂密集带北部,上水中油下水和上水中气、油下水主要分布在断裂密集带南部.油运聚成藏模式为三肇凹陷青一段源岩生成的油在超压作用下通过源断裂向扶杨油层"倒灌"运移,在浮力作用下通过2个断裂密集带输导通道向长10区块侧向运移,主要在断块和断层岩性等圈闭中聚集成藏.油成藏与分布主要受到3个因素的控制:(1)2个断裂密集带分布控制着油聚集区域;(2)断裂密集带内断层—岩性和断块圈闭有利于油聚集成藏;(3)距三肇油源区越近越有利于聚集成藏.

By oil reservoir anatomy analysis and research on spatial matching relation between it and reservoir-forming conditions,oil migration and accumulation mechanism and main controlling factors in Fuyu oil layer in Chang 10 block was studied.It was considered that oil was mainly distributed in FI reservoir group in Fuyu oil layer in Chang 10 block,and oil was distributed along fault condensed zone in the plane.Oil bearing formations reduce from lower location of the structure to the higher.On the section oil upper-water lower is mainly distributed in the north of fault concentrated belt.Water upper-oil middle-water lower and water upper-gas and oil middle-water lower were mainly distributed in the south of fault concentrated belt.Oil migration and accumulation model is that oil generated by K1qn1 source rock in Sanzhao depression migrated downward to F,Y oil layers through source faults under the action of overpressure,then migrated laterally to Chang 10 block through transporting pathway formed by 2 fault zones under the action of buoyancy,and finally accumulated in traps such as fault block or fault lithology traps.Accumulation and distribution of oil is mainly controlled by the following 3 factors.1.Distribution of 2 fault zones controls the place and horizon of oil accumulation.2.Fault-lithology and fault block traps in 2 fault zones are favorable for oil to accumulate.3.The shorter the distance to fault traps,the more favorable it is for oil accumulation.