预测相变位置对封存CO 2泄漏过程的监控和风险评估具有重要意义.针对泄漏通道中CO 2的非等温流动相变过程,提出了Span-Wagner状态方程与等效比热法的耦合计算方法描述CO 2泄漏过程中相变过程,研究了焦耳-汤姆逊效应、黏性耗散效应以及地层传热效应对CO 2泄漏相变过程的影响,阐明CO 2泄漏过程中相变过程的影响因素及其作用.研究表明:虽然焦耳-汤姆逊效应和黏性耗散对泄漏通道温度的作用相反,但两者均使泄漏CO 2液气相变位置向深层移动;增强泄漏通道与地层之间换热将使泄漏通道温度降低,焦耳-汤姆逊效应和地层换热的共同作用将进一步降低泄漏通道的温度,导致泄漏CO 2液气相变位置向浅层移动,泄漏通道出口处CO 2的泄漏流率增大.%It is of significant importance to predict the location of phase transition during CO2 leakage. A coupled computation method was established to describe CO2 phase transition during leakage based on non-isothermal flow and phase transition of CO2 along a leaky pathway, in which the Span-Wagner equation and the equivalent specific heat method were combined. The influence of the Joule-Thomson effect, viscous dissipation effects and heat transfer effects on CO2 leakage were investigated. Major factors and their relative effects on phase transition during CO2 leakage were elucidated. The results show that although the Joule-Thomson effect and the viscous dissipation effect have opposite effects on temperature distribution along the leaky pathway, both factors enable the location of CO2 phase transition moving towards deeper subsurface. The increase of heat exchange between the leaky pathway and its surroundings decreases the temperature of the leaky pathway. The combination of the Joule-Thomson effect and heat exchange further decreases the temperature of the leaky pathway, which leads the CO2 phase transition location moving towards shallower subsurface, and the flowrate at the outlet of the leaky pathway increases.
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