The invention discloses a low-permeability reservoir
carbon dioxide flooding numerical
simulation method based on Maxwell-Stefan cross
diffusion, and belongs to the technical field of reservoir numerical
simulation and
recovery efficiency improvement. Comprising the following steps: establishing a
mass conservation equation of each component based on an oil reservoir thermodynamic field, a rock
physical property field, an
effective diffusion coefficient matrix and reaction kinetic parameters; a
diffusion flux item is expressed by a generalized Fick law based on a Maxwell-Stefan theory so as to describe a multi-component cross
diffusion effect; a reaction source convergence item is determined by a COand
crude oil reversible miscible phase
kinetic model so as to describe a miscible phase and split phase dynamic process; sequentially executing a diffusion transmission step and a
chemical reaction step for solving by adopting an operator splitting method to obtain an updated concentration field, and synchronously updating the thermodynamic field, the rock
physical property field, the reaction kinetic parameters and the
effective diffusion coefficient matrix; repeatedly iterating until each field and parameter change meet a convergence condition, and completing
simulation of each chemical component concentration field; according to the method, the physical simplification defect in low-permeability simulation is overcome, and high-precision prediction of the displacement process is achieved.