NUMERICAL SIMULATION OF HYDRAULIC FRACTURING BY A MIXED METHOD IN TWO DIMENSIONS

Hydraulic fracturing is widely used in exploitation of shale gas nowadays. It is of great significance to study the mechanism of fracturing process by numerical simulations. We present a mixed numerical model to solve hydraulic fracturing problems based on Continuous-Discontinuous Element Method (CDEM) and Finite Volume Method (FVM). In the mixed model, the CDEM is used for analysis of stress field and fracture propagation, and the FVM is used for analysis of pressure field in fracture. The three fields are all solved by explicit schemes and the coupling of them is implemented through data exchange. The model is verified against the classic KGD analytical solutions. Thereafter, it is validated by the results from a distinct element simulation. Finally, a hydraulic fracturing example related to complex fracture network is studied on the mechanism of fracturing process. The example shows bright future of the mixed numerical model for simulation and mechanism study of hydrauling fracturing.