Fractal Study on Stress Sensitivity of Fracture Permeability

The seepage problem of fractured reservoirs under stress has important research value in engineering fields such as oil and gas exploration and development. Based on the application of fractal theory and fluid mechanics, a fracture permeability prediction model considering stress sensitivity was established. The correlation between fracture permeability and rock mass lithology under effective stress rock was studied by defining normalized permeability. The prediction model did not use any empirical constants, and each parameter had a clear physical meaning. The prediction results of the model were in good agreement with the related experimental data, which verified the effectiveness of the model. Theoretical analysis results showed that the normalized permeability of the fluid in the fracture decreased significantly with the increase of the effective stress. Rock mass with the larger Young’s modulus and Poisson’s ratio and the smaller fractal dimension of tortuosity will get a larger normalized permeability. The proposed model can effectively describe the seepage characteristics of fluid in fractures under stress.