Finite Element Numerical Simulation Research on Fractured Horizontal Well in Stress-dependent Tight Reservoirs Based on Heat Transfer Theory

Abstract

We present an efficient numerical method to handle stress-dependent behavior for fractured wells in tight reservoirs using the large-scale general finite element software ANSYS as the platform. A new similarity criterion is deduced to describe the seepage flow based on the similarity principle. The similarity criterion is a key parameter to transfer unstable heat problems to well performances. Then a comparison between the numerical and history-matched results is made to validate the accuracy of the results, by which effective stress-dependent coefficient calculated by numerical simulation is in agreement with that from experiment. The result shows that it is feasible to apply the ANSYS function of temperature field analysis in the computation of the unstable seepage flow considering permeability change in stress-dependent tight reservoirs. Finally using a certain field data and history-matched reservoir model, the influence of the fractures on horizontal well is investigated, including fracture spacing, fracture length and parameters of fracture with included angle on the basis of the new method. The results from the model considering the stress-dependent factor are significantly different from that without considering the factor. This work provides reservoir engineers with a simple and feasible method for optimizing the fracture parameters of tight oil development.