Reservoir Architecture Of The Upper Part Of Shahejie Formation Second Member In Xin 16 Fault Block In The Northeast Of Dongying Depression

The upper part of Sha 2 Member is the main oil-bearing stratum explored and developed at Xin 16 fault block of Dongxin Oil field.As the development of oil field enters the stage of high water-cut,the spatial superimposed of sand bodies has caused complex oil-water relationships,leading to sharp conflicts in injection-production among layers.Therefore,deepening the understanding on the internal structure of the reservoir is the key problem in the exploration of Sha 2 Member reservoir in Xin 16 fault block.Based on the correlation and division of sequence stratigraphy in the upper part of Sha 2 Member in Xin 16 fault block,this thesis comprehensively analyzes materials such as seismic data,cores,and logging,and clarifies characteristics of sedimentary facies and evolution patterns in the study area,as well as discovers the sedimentary microfacies of the delta plain subfacies are mainly distributary channels and inter-distributary areas.Laterally,distributary channels extend from southeast to northwest;vertically,the upper part of Sha 2 Member shows a normal cycle.The upper part of Sha 2 consists of seven sand layers and the average thickness of each layer is between 37 m and 71 m.These layers are further subdivided into 53 small layers with an average thickness between 2.0m and 11.2m,including 24 main oil-bearing small layers and the lithology of the reservoir is sandstone.Through analyzing the characteristics of lithology and well logging,the thesis has identified the boundaries of different grades of reservoirs vertically and laterally,and explained four types of superimposition relationship for architecture units: isolated pattern,docked pattern,spliced pattern and superimposed pattern.Among them,spliced sand body features good connectivity and its single sand body is over 2.5m thick with several hundreds of meters wide.Isolated sand body has the poorest connectivity and its single sand body is less than 1m thick,as well as several to dozens of meters wide.Hence,the thesis carefully depicts the sand body of distributary channels and conducts a quantitative analysis of the vertical and horizontal extension scope of one single sand body.