Diffusion characteristics and loss amount of carbon dioxide gas in FS9 well

To evaluate the resources of carbon dioxide gas, this paper discusses the diffusion mechanism of carbon dioxide gas in strata, analyzes the diffusion characteristics of carbon dioxide gas in strata section. According to each diffusion parameters of carbon dioxide gas reservoir in FS9 well, this paper estimates the total loss amount of carbon dioxide gas diffusion in the gas reservoir. The result indicates that the molecules of carbon dioxide exist in water in the hydration form. The dissolving ability in water is affected by temperature, pressure and salinity. According to the change of solubility of carbon dioxide gas in water, the diffusion of carbon dioxide in strata section is divided into three parts, carbon dioxide gas diffuses strongly upward when its depth is less than 0. 5km, and diffuses downward when its depth is within 0. 5km to 1. 25km. Carbon dioxide gas diffuses weakly upward when its depth is more than 1. 25km. The maximum loss amount of carbon dioxide gas diffusion in FS9 well is 23. 5X108 m3. It is a-bout 17. 5% of its geological reserve.