Fracture Development Characteristics in Tight Sandstone Oil Reservoir and Its Inspiration on Remaining Oil Recovery: A Case Study on the Chang-72 Layer of Yanchang Formation in Xin’anbian Area, Ordos Basin

LU Xiangwei1, DU Shuheng2,3,†, ZHENG Kui1, ZHANG Huanguo1, SUN Tong2,3, WANG He2,3

1. The 6th Oil Production Plant, Changqing Oilfield Company, Petrochina, Xi’an 710299; 2. School of Earth and Space Sciences, Peking University, Beijing 100871; 3.Oil and Gas Institute, Peking University, Beijing 100871; † Corresponding author, E-mail: dushuheng@pku.edu.cn

Abstract Through the core observation, inter-well tracer test and water flooding front test, the fracture development characteristics of Chang-7 tight sandstone reservoir in Xin’anbian area of Ordos Basin are studied.

NE60°‒80°. The results show that maximum horizontal principal stress direction of Chang-7 tight sandstone oil reservoir in

NE75°‒85°, 70°‒85°. Xin’anbian area is The fracture type is mainly high angle fractures or vertical fracture, and fracture direction is the dip angle is Dynamic monitoring data analysis shows that the micro fracture research area of tight sandstone oil reservoir developed widely and plays an important role in increasing the seepage channel and improving the permeability of matrix, water channeling easily along the fracture formation, resulting in the production of well water is fast. 3D geological modeling results show a high degree between oil saturation of tight sandstone oil reservoir in the study area and the degree of fracture development, which can effectively support the fracture of oil and gas reservoir and accumulation. Key words tight oil; fracture; water drive frontiers; geological modeling