Study on sedimentary microfacies of Chang 8_1 reservoir of Yanchang Formation in Zhen 53 well field

Chang 8 reservoir in Zhen 53 well field is one of the key horizons for exploration,evaluation and development in Zhenbei region,Ordos Basin.Based on core description and well logging data analysis,it is considered that the main sandstone in the study area is feldspathic litharenite,and the reservoir is mainly delta front.The main sedimentary microfacies include subaqueous distributary channel,mouth bar and distal bar.The subaqueous distributary channel sands and mouth bar constitute the dominated reservoir.The relationship between sedimentary microfacies and reservoir physical property is analyzed.The result shows that the reservoir physical property is controlled by sedimentary microfacies,and the subaqueous distributary channel is the favorable microfacies.