摘要：The migration of CO2 is stochastic in heterogeneous porous media. This paper considers the CO2 diffusion with the case of steady flow in heterogeneous porous media. The partial differential equations of CO2 diffusion in random velocity field are established based on the mass conservation equations of CO2- brine two-phase flow with the change of time scale and spatial scale under the influence of heterogeneity such as permeability and porosity. The random travel process of CO2 is quantified by joint probability distributions and joint statistical moments (mean and variance), and the diffusion model of CO2 particle in random velocity field is established under the condition of non-linear and immiscibility in heterogeneous porous media. The micro mechanism of diffusion in heterogeneous porous media is revealed by numerical simulation. The general conclusion of steady state flow of CO2 diffusion in heterogeneous porous media was verified by simulating Sleipner CO2-brine storage in Norway.
