煤层气解吸的温度效应

Mechanism of coalbed methane desorption at different temperatures

为了探索温度对煤层气解吸效果的影响,通过对沁水南部寺河煤矿3号煤的吸附/解吸实验,经过数学分析,获得该煤层气吸附/解吸的数学式与等量吸附热表达式。分析认为:随着储层温度升高,饱和吸附量减小;解吸过程滞后于吸附作用的原因主要是非物理吸附常数c值作用,随着储层温度增高,c值增大;降压解吸伴随吸热(温降),同时阻碍了持续解吸过程。通过提高储层温度来促进解吸过程,在理论上可行,工程中应该受到重视。

In order to investigate the influence of temperature on CBM desorptoin effect,by using adsorption and desorption experiment of coal seam 3 in Sihe mine at 6 temperatures,the adsorption and desorption formula of the coal seam was obtained,and isosteric adsorbed heat was calculated.It is considered in the analysis that the saturated adsorption amount decreased with the increased temperature of CBM reservoir;the main reason for delayed desorption process compared with adsorption was the action of non-physical adsorption constant C.The value C increased with increased temperature of reservoir;fall-off desorption was associated with heat adsorption（temperature drop） and in the same time hindered continuous desorption process.It is practical theoretically to accelerate desorption process by increasing temperature which should be taken into account in engineering application.