Abstract：Carbon dioxide(CO2) is a kind of greenhouse gas，which causes near-surface temperature increased. Geologic disposal of CO2(injection of CO2 into aquifer) has been suggested as a promising means of reducing emissions of greenhouse into the atmosphere. Oil displacement by injection CO2 of into reservoir during enhanced oil recovery stage will not only increase oil throughput but also inject CO2 into reservoir. Oil displacement by CO2 injection is coupled multiphysics processes which incorporate cross-coupled fluid flow，energy conservation，mechanical equilibrium and mass conservation. A set of quadruply coupled equations(fluid flow，convection- diffusion，energy conservation and mechanical equilibrium) with a number of cross-couplings and coupled constitutive relations is formulated to quantify the multi-physics of oil displacement by CO2 injection，implemented into and solved by using FEMLAB. FEMLAB is the first engineering tool that performs equation-based multi-physics modeling in an interactive environment. With FEMLAB，the coupled multi-physics model can be solved simultaneously. The applicability of this model has been demonstrated through an example of simulations for a two-dimensional reservoir of size 1 000 m×1 000 m with one injection and one production wells. Model results illustrate the significant importance of the cross-couplings between individual(thermal，hydrological，chemical and mechanical) physics.
