煤层气解吸滞后特征分析

通过对不同变质程度的煤进行不同温度点的等温和吸附/解吸的实验，综合分析认为，煤层气在降压解吸过程中，随着压力的降低和煤阶提高，解吸滞后特征显著，温度增大解吸滞后现象不显著。不同变质程度煤的分子构成和孔隙结构导致了煤的物性差异，这是煤层气降压解吸滞后与升温解吸滞后差异的主要原因。实践中，在煤层气井排采后期，用升温解吸技术促进残余气解吸是提高煤层气采出率的重要途径。

Desorption hysteresis characteristics of CBM

The CBM desorption hysteresis characteristics were analyzed based on adsorption-desorption experiments of different metamorphic sequence coal under variable-temperature and isothermal condition.Comprehensive analysis shows that the desorption hysteresis characteristics are notable for improving coal ranks and reducing pressure，desorption hysteresis characteristics are not significant under increasing temperature.Differences of molecules and pore structure between high and low-rank coals lead to the difference of their properties which is the primary cause of desorption hysteresis difference.In practice，promoting desorption of residual coal-bed methane under deficient pressure is a research direction to improve CBM recovery.