High-Precision Flow Numerical Simulation and Productivity Evaluation of Shale Oil Considering Stress Sensitivity

Continental shale oil reservoirs, characterized by numerous bedding planes and micro-nano scale pores, feature significantly higher stress sensitivity compared to other types of reservoirs. However, research on suitable stress sensitivity characterization models is still limited. In this study, three commonly used stress sensitivity models for shale oil reservoirs were considered, and experiments on representative core samples were conducted. By fitting and comparing the data, the "exponential model" was identified as a characterization model that accurately represents stress sensitivity in continental shale oil reservoirs. To validate the accuracy of the model, a two-phase seepage mathematical model for shale oil reservoirs coupled with the exponential model was introduced. The model was discretely solved using the finite volume method, and its accuracy was verified through the commercial simulator CMG. The study evaluated the productivity of a typical horizontal well under different engineering, geological, and fracture conditions. The results indicate that considering stress sensitivity leads to a 13.57% reduction in production for the same matrix permeability. Additionally, as the fracture half-length and the number of fractures increase, and the bottomhole flowing pressure decreases, the reservoir stress sensitivity becomes higher.