【摘要】 在盖层封闭天然气机理及影响因素分析的基础上,对盖层对CO₂气和CH₄气封闭的差异性进行了研究。结果认为:盖层对CH₄气的毛细管封闭作用强于其对CH₂气的毛细管封闭作用;CO₂气的扩散作用强于CH₄气的扩散作用,但二者的扩散方向有所不同,CH₄气的扩散方向总是由地下至地表,而CO₂气只有在近地表或地下深处扩散方向是向上的,在二者之间扩散方向应是向下扩散的;CO₂气对盖层微渗漏空间的愈合能力比CH₄气对盖层微渗漏空间的愈合能力差。更多还原

【Abstract】 Based on analysis of the mechanism and affecting factors of sealing natural gas by caprock, the difference of sealing CO2 and CH4 gas by caprock is studied. It is thought that the capillary sealing effect of caprock on CH4 gas is stronger than that of CO2 gas; the diffusion effect of CO2 is stronger than that of CH4, but showing different directions. CH4 always diffuses upward, while CO2 only shows upward diffusion at near surface or in deep formation, and diffuses downward in between; CO2 gas has poorer healed ability to micro leaking caprock than CH4 .更多还原