Study on reservoir heterogeneity of Chang 8 reservoir in Hongde Oilfield, western margin of Ordos Basin and knowledge of fine stratification development practice

Abstract In view of the problems of reservoir heterogeneity and unclear understanding of main control factors in Chang8 reservoir of Hongde Oilfield in the middle part of Tianhuan, Ordos Basin, efficient development and stable production are restricted by a large number of drilling, core data and log comparative analysis, using core observation, microscopic rock slice identification, scanning electron microscopy, mercury injection and phase infiltration experiments, etc. Based on the understanding of sedimentary facies and diagenesis, the quantitative analysis of Chang 8 in the study area is carried out from the macro intra-layer, interlayer, plane heterogeneity and microscopic heterogeneity. Finally, it is concluded that Chang 8 reservoir in Hongde Oilfield presents strong heterogeneity, and sedimentary microfacies, different clastic components of sandstone, diagenesis and other main factors affecting its strong heterogeneity. At the same time, in the development practice of De 5 area of Hongde Oilfield, the multi-stage sedimentary cycle division and step production and development were taken as a breakthrough, and the differential reservoir seepage theory was innovatively used to reduce the section/plane contradiction caused by reservoir heterogeneity, and a technical system such as regional fine stratified production, differentiated reservoir fracturing and reconstruction, single sand body fine injection and production control and stratified water injection was formed. The high efficiency development and utilization of strong heterogeneous reservoir is realized.