The Remaining Oil Distribution Study Of Fluvial Facies Sandstone Reservoir In Yangerzhuang Oilfield,Dagang

At present,the old oilfields in eastern China generally enter the high water cut and super-high water cut development stage.The distribution relationship between underground oil and water is complex and three contradictions of oilfield development are outstanding,remaining oil distribution is characterized by "overall decentralization and partial concentration".In this paper,the reservoir is the main research object in the super high water cut period of theYangerzhuang oilfield.In view of the contradiction of the contradiction from interlayer and inner contradiction into the inner building structure in the sand body,the remaining oil distribution is complex,and the original sedimentary microfacies based geological model can not effectively solve the development process of the current oil field.Under the guidance of the fine reservoir architecture theory,the paper dissected the internal structure of the sand body,established the fine geological model based on the reservoir architecture,combined the reservoir engineering analysis and the reservoir numerical simulation research method,summed up the distribution pattern of the remaining oil and the control factor,and established the distribution pattern of the remaining oil in the study area,provided the basis for the adjustment of the two development plan of the old oilfield.The main research results obtained in this paper are as follows:There are three types of meandering rivers in the study area— flake meandering river,interlaced strip and isolated meandering river and four single channel space superposition mode—deep overlay,shallow and interstaggered,non undercut and isolated.There is one type of braid river—deep perennial braided river,and four types of flow belts —deep and large-area overlay;shallow cutting,small area superposition;non undercutting laminated superstructure and isolated type.The internal architectures of single point bar(heart Beach)and point bar(heart Beach)were quantitatively dissected for different types of meandering river(braided river).The distribution of remaining oil is affected by faults,microstructures,architecture elements,reservoir heterogeneity,injection production pattern,perforation type and well type.The plane remaining oil is mainly distributed in the side of the single channel side,river channel cutting place,high part of structure and nearby abandoned channel.The vertical remaining oil is mainly distributed in the upper part of superimposed sand body,upper part of point bar and upper part of the oil layer with a large well distance and poor water flushed degree.Based on the single factor control of remaining oil distribution,this paper optimized the key factors and summarized multi factorscontrolled remaining oil distribution pattern in the study area.The remaining oil distribution pattern in the meandering river include four types.fault-micro structurecompound channel-injection production relationship;compound channel-sand body superposition-injection production well network-injection production relationship;complex channel-sand heterogeneity-injection production relationship;single channel-compound channel-the side layer-injection production relationship.The distribution pattern of the remaining oil in the braided river includes fault-micro structure-compound channel-injection production relationship;compound channel-sand body superposition-injection production well network-injection production relationship;compound channel-silt layer-injection production relationship.