The Sedimentary Microfacies And Reservoir Evaluation In 2+3 Of The Upper Second Member Of Shahejie Formation, Pucheng Oilfield

This thesis focus on heterogeneous reservoir geological characteristics and development situation, applying comprehensive information on exploration and development, basing on oil geology, modern sedimentology, reservoir geology, using modern reservoir description techniques and computer technology, to do detailed description of the 2+3 reservoir in the west of Pucheng Oilfield, providing a theoretical guidance for the next phase of development.Basing on the research of logging and cores, using the principles and methods of high-resolution sequence stratigraphy of research area, of high-resolution sequence stratigraphic framework, we divided 2 group into seven small sand layers, 3 group was divided into nine small sand layers. The paper analysis the formation and evolution of structures based on the use of geology, drilling and production performance data for 2 +3 fine structure research.Established a microtectonics model gradually get to the regional distribution and growth of small faults in a small micro-structure of the distribution. Based on the core observation in previous research and sediment deposition background, the depositional facies of the reservoir is terminal fans system. Three major depositional facies are identified consisting of proximal sub-facies, middle sub-facies and distal sub-facies. Middle sub-facies are the main depositional microfacies in 2+3 reservoir consisting of distributary channel, proximal overbank, distal overbank and mudflat.The sandstones are essentially litharenite, feldspatic litharenite and followed by lithic arkose, based on the anlaysis of diagenesis, pores structure and reservoir quality of 2+3 reservoir. In this paper, Scanning Electront Microscopy, X-ray diffraction and cathodoluminescene are used and many types of thin section (ordinary thin section, cast thin section and cathodoluminescene thin section) are available for studying the diagenesis and types of porosity. The diagenetic processes recognized include compaction, cementation, dissolution and metasomasis. Based on a variety of factors affecting reservoir quality, diagenesis, sedimentary and structures have a greater effect on the reservoir.In a comprehensive study of various macro-and micro-heterogeneous reservoir parameters on the basis of the reservoir quality, we launched a comprehensive evaluation to determine the evaluation criteria. The reservoir quality in 2+3 was divided into three types. The research shows that distribution of interlay and insulating layer is controlled by sedimentary microfacies. The developmental stages and the size of the sedimentary microfacies determine the plane and the vertical distribution of interlay and insulating layer. Generally, the distribution of interlay and insulating layer is relatively stable, controls the macroscopic movement of fluid.