Objective CO2 storage via the hydrate method is one of the potential carbon storage methods because of its stability and high gas storage capacity.The use of formation conditions in permafrost region has more unique advantages.CO2 is injected into the permafrost region,and solid-state CO2 hydrate is formed under specific temperature and pressure conditions to achieve long-term stable storage.Methods According to the temperature and pressure conditions of the formation in the permafrost region of China,the temperature(1.27 ℃ and 2.72 ℃)and effective pore water content(40％)corresponding to different formation depths(150 m and 200 m)and different initial injection pressures(3.5 MPa,4.5 MPa and 5.5 MPa)were selected.The characteristics of kinetic parameters such as temperature and pressure changes,storage rate,final water conversion rate and final storage ratio in the CO2 storage process via the hydrate method were analyzed.Results The results of the CO2 hydrate storage process under different initial injection pressures show that the higher the initial injection pressure,the shorter the induction time required for hydrate storage and the larger the pressure drop.Higher injection pressure results in a slower storage rate at the initial stage and a reduced duration of the slow storage period.The higher the injection pressure,the higher the hydrate storage ratio,the final water conversion rate,and the hydrate phase saturation at the end of the reaction.The higher the storage temperature,the more obvious the effect of pressure on the gas storage ratio.Conclusions The best CO2 storage effect was achieved under 40％water content at the depth of 150 m(the average temperature of the formation is 1.27 ℃)and 5.5 MPa.
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