Numerical Evolution of the Three-Dimensional Stress Field of the Heterogeneous Tight Reservoir—A Case Study of Y176 Area’ Bonan Sag

Abstract

In-situ stress is the fundamental basis for efficient exploration and development of tight reservoirs. Affected by regional fault structure and heterogeneous rock mechanical properties, the current stress field of tight oil reservoir in Y176 block of Bonan Oilfield varies complicatedly. In this research, 3D geological model is constructed based on high precision seismic interpretation data of 3D layers and faults. The heterogeneous rock mechanics parameters model of tight oil re-servoir is established by well logging data and seismic volume data sampling. The three-dimensional stress field simulation is carried out by using the structure strain coefficient method, and the re-sults are in good agreement with the measured in-situ stress magnitude and direction at the well site. The simulation results show that the in-situ stress is lower in southwest region and higher in northeast region for the Es 4 layer of Y176 block. The effect of fault structure and heterogeneous lithology on local stress field is significant. The in-situ stress fields change obviously within and between fault blocks. The numerical simulation of three-dimensional geostress in heterogeneous tight oil reservoirs provides accurate basic data for efficient exploration and development of tight reservoirs in Bonan Oilfield.