DISCUSS ON CONCENTRATION OF GAS DIFFUSION
浓度对天然气发生扩散作用的影响

Based on analyzing the influencing factor of gas diffusion,this paper considered the concentration was the basic factor for gas to diffuse. Different concentrations are fit in with different geological conditions. Concentration in free phase is fit in with diffusion of gas in no water-filled rocks. Concentration dissolved in water is fit in with diffusion of gas in water-saturated rock. Total contraction dissolved in wa- ter is more fit in with actual situation of gas diffusion in underground rocks than the concentration of gas mterstitially dissolved in water molecules is . Diffusion amounts of gas calculated by the concentration in free phase is larger than the actual value. The diffusion amount of gas calculated by the concentration of gas mterstitially .in water molecules is smaller than the actual value. The diffusion amount of gas calculated by the total concentration of gas dissolved in water is fit in with the actual geological situation. Therefore, the total concentration of gas dissolved in water is the concentration causing gas to diffuse in underground rocks.