CO

2

storage in abandoned oil and gas reservoirs can reduce the direct emissions of greenhouse gases in the atmosphere

which is one of the effective ways to mitigate the greenhouse effect. Improving the conventional gas-liquid phase equilibrium theory and applying the thermodynamic equation of state to study the CO

2

-hydrocarbon-groundwater system are of great significance to reveal the dissolution mechanism of CO

2

buried in the subsurface. The research progress of thermodynamic equation of state in the phase equilibrium calculation of CO

2

-hydrocarbon-formation water system at home and abroad is summarized.The shortcomings in its practical application are pointed out

and its development trend is analyzed

including: the equation of state and mixing rules suitable for non-ideal systems should be further studied to accurately predict the change law of thermodynamic properties of the system; the expansion of the difference of formation water ions in the research system to make it consistent with the real CO

2

storage conditions; the physical process of phase change in CO

2

is coupled with the chemical process of mineral dissolution and precipitation in formation water.