The geological sequestration of greenhouse gas

CO

2

is an important means to cope with carbon peaking and carbon neutralization. However

the depleted gas reservoirs are the significant targets for the storage of CO

2

. Due to the different forms of CO

2

in gas reservoirs

the effective CO

2

storage calculation method of gas reservoirs is established based on the theoretical CO

2

storage calculation method

which can be used to estimate the CO

2

storage potential of the depleted gas reservoirs. Meanwhile

the model of low permeability gas reservoir is established for the CO

2

storage in the later stage of the development. Considering the diss

olution of CO

2

in formation water and the mineralization reaction of CO

2

between water and rock

the error of supercritical buried stock

dissolved buried stock and mineralized buried stock is 2.81 %

7.37 % and 6.25 %

respectively

and the error of effective buried stock is only 3.06 % by comparing the calculated results with the numerical and analog results.