RELATIVE PERMEABILITY MODEL OF TWO-PHASE FLOW IN ROUGH CAPILLARY ROCK MEDIA BASED ON FRACTAL THEORY

In this paper, the gas-water two-phase flow characteristics of rock media are studied based on fractal theory and the relative roughness model, and the analytical model of gas-water relative permeability of rock pores with relative roughness is derived. Through numerical simulation, it is found that the maximum flow velocity in the rough microchannel is greater than the maximum flow velocity in the smooth microchannel, but the average flow velocity in the rough microchannel is less than the average flow velocity in the smooth microchannel. The theoretical model results show that the dimensionless permeability of gas-water two-phase flow is inversely proportional to the fractal dimension of relative roughness and tortuosity, and the relative permeability of gas-water two-phase flow is inversely proportional to the relative roughness. The correctness of the model is verified by comparing it with the relevant experimental data.