Microfacies characteristics of No.2 & 3 sand-beds groups of Saertu oil-bearing layers,Taikang area of northern Songliao basin

According to the data from seismic,well logging,mud logging and coring,by applying the principles and the methods based on sedimentology and seismic stratigraphy the paper clarifies the microfacies characteristics of No.2 and 3 sand-bed groups of Saertu oil-bearing layers in Taikang area of northern Songliao basin.The types of the sedimentary microfacies developed in No.2 and 3 sand-bed groups of Saertu oil-bearing layers of Taikang area primarily contain shore-lake and shallow-lake mud beach sedimentary microfacies,delta front channel mouth bar and distal bar sedimentary microfacies,and lake bottom fan sedimentary microfacies caused by shallow lake gravity flow.In the plane,these sedimentary microfacies can be divided into two sedimentary facies districts-the eastern and the western sedimentary facies districts.The western sedimentary facies district develops delta sedimentary facies which comprise the sinuosity delta in the north part and the braid river delta in the south part.While the eastern sedimentary facies district develops lake sedimentary facies which develop mainly shale and also contain many sediments from gravity flow sedimentation.The conclusion is that No.2 and 3 sand-bed groups of Saertu oil-bearing layers in Taikang area of Songliao basin develops large areas of delta sandbodies and gravity flow sandbodies which not only have good reservoir conditions,but also may potentially form a lithologic trap.