Chang 9 Tight Oil Reservoir Prediction and Favorable Zone Selection in Yanchang Formation of Ansaipingqiao Area

This paper studies the lithofacies and logging facies of typical coring wells. The sandstone is tracked and compared horizontally on the basis of the types of sedimentary microfacies of the sandstone and its spatial evolution. The thickness data of the single sand body is accurately obtained and the distribution characteristics of the single sand body are thus described. Therefore, favorable target area of tight oil are optimized through the production dynamics. The results show that the tight oil in the study area is mainly distributed in the upper part of the Chang 9 oil layer group, dividing into three sets of sand bodies from the top to the bottom. The upper No.1 sand body belongs to the underwater distributary channel deposits, with a thickness of 1~3m. The reservoir distribution is limited and the development potential is small. The lower No. 3 sand body belongs to the underwater distributary channel deposition, and the thickness of the sand body is 6-12m. It is predicted that the central P149-6 well area, the southern H87-19 well area and the W328-8 well are the favorable zones for tight oil development. Among them, the central P149-6 well has stable oil layer distribution, and can be a pilot test area. The research effectively solves the problem of tight reservoir prediction in Pingqiao area, and provides reference for reservoir prediction in similar geological areas.