曹妃甸A油田沙二段缓坡微古地貌对沉积砂体的控制作用

针对渤海曹妃甸A油田沙二段储层沉积横向变化快、储层分布预测难等问题,通过沉积相分析、古地貌恢复等手段,开展沙二段沉积相和砂体展布特征的研究,并对微古地貌对砂体的控制作用进行了分析。结果表明:曹妃甸A油田沙二段目的层为缓坡带三角洲前缘沉积,发育水下分流河道、河口坝、分流间湾等沉积微相;沉积期缓坡古地貌的地势形态与物源匹配较好,近端前缘主要发育水下分流河道沉积,远端发育河口坝和远砂坝等沉积;近端微凸起对三角洲前缘扇体的沉积起分流作用,微凸起范围内发育分流间湾泥岩,周边低势区为沉积砂体的输导通道,是有利砂体的富集区。

Control effect of gentle slope micro paleogeomorphology on sedimentary sand body in the second member of Shahejie formation in Caofeidian A oilfield

In view of the problems such as fast lateral change of reservoir sedimentation and difficult prediction of reservoir distribution in the second member of Shahejie formation in Caofeidian A oilfield of Bohai sea,by means of sedimentary facies analysis and Paleogeomorphology restoration,the sedimentary process of the second member of Shahejie formation is studied.The results show that the target layer of the second member of Shahejie formation in Caofeidian A oilfield is delta front deposit of gentle slope zone,and sedimentary micro-facies such as underwater distributary channel,mouth bar and inter-distributary bay are developed.During the deposition period,the topography and provenance of the gentle slope paleogeomorphology match well.The underwater distributary channel deposits are mainly developed in the near front,and the estuary bar and distal sand bar are developed in the far end.The near end micro bulge has a distributary effect on the deposition of the delta front fan.The mudstone in the distributary bay is developed in the micro bulge,and the surrounding low potential area is the dredging channel of the sedimentary sand body,which is the favorable enrichment area of the sand body.