煤层气吸附解吸规律研究进展

调研了煤层气吸附理论与实验、水对煤层气吸附解吸过程的影响与煤层气液固吸附理论体系等3方面的研究进展，总结了气相吸附理论在煤层气吸附研究中取得的成果以及水对煤层气吸附的影响作用，分析了气相吸附理论在解释煤层气吸附状态时存在的问题，介绍了最新的液相吸附理论及在此基础上的煤层气复合解吸理论。不同相态的水对煤层气的吸附作用不同，煤样含水饱和度较低时，气相的平衡水可以显著降低煤层气的吸附量；当含水饱和度达到一定临界值时，含水量对煤层气吸附量变化的影响不大；而煤样中含水进一步增大时，注水煤样中液相水可以增加煤层气的吸附量。煤层气的赋存状态与气相吸附规律并不相符，而煤层气的液相吸附理论可以同时解决煤岩在水环境下生烃的条件及气相吸附没有临界解吸压力的问题；在液相吸附的条件下，煤层气的解吸过程是由气相及液相解吸共同控制的复合解吸过程。

The Adsorption and Desorption of Coal Bed Methane: A Review

In this study, we investigated progress in the following three aspects of coal bed methane(CBM) research:adsorption theory and experiments, the effects of water on adsorption and desorption, and liquid-solid adsorption theory. We summarized the achievements of gas phase adsorption theory in studying CBM adsorption, and, in particular, the influence of water. In addition, existing complications in gas phase adsorption theory with regards to CBM adsorption were analyzed, and the new liquid phase adsorption theory and CBM compound desorption model built on its basis were introduced. Different water phases have a variable impact on CBM adsorption. When water saturation is low in the coal sample, equilibrium moisture in the gas phase can significantly reduce the amount of CBM adsorbed. As water saturation reaches critical levels, water content has little effect on the amount of CBM adsorbed. Upon further increase in water content in the coal sample, liquid-state water in the injected coal sample increases the quantity of CBM adsorbed. The occurrence of CBM is not in agreement with the existing gas phase adsorption model. In contrast, the liquid phase adsorption model explains both the hydrocarbon generation condition of coal in an aqueous environment and the absence of critical desorption pressure in gas phase adsorption. Under the conditions of liquid phase adsorption, the desorption of CBM is a compound desorption process controlled by both gas phase and liquid phase desorption.