Numerical Simulation of Fracture Propagation Law of In-Fracture Temporary Plugging and Diverting Fracturing in Tight Reservoir

In-fracture temporary plugging and diverting fracturing is an important means to improve the re-fracturing effect of tight reservoirs. However, the fracture propagation mechanism of in-fracture temporary plugging and diverting fracturing is unclear. It is necessary to study the fracture propagation law of in-fracture temporary plugging and diverting fracturing in tight reservoirs. Based on the theory of damage mechanics, a numerical model of flow-stress-damage coupling fracture propagation is established, which can simulate matrix failure and new fracture propagation after in-fracture temporary plugging and diverting fracturing. This model is experimentally verified and the research on the influence of reservoir geological parameters and fracturing construction parameters on the fracture propagation law of in-fracture temporary plugging and diverting fracturing is conducted. It is shown that the larger the displacement and viscosity of fracturing fluid, the more obvious the fracture deflection effect; under the condition of low horizontal stress difference, the fracture will deflect at a greater angle and are more complex. While the horizontal stress difference increases to 15 MPa, the fracture is almost not deflected; the reservoir heterogeneity affects the local propagation path of the fractures, but has little influence on the overall trend of fracture propagation. The research results provide an effective guidance for the construction parameters optimization of the in-fracture temporary plugging and diverting fracturing.