中文摘要：

研究煤层的渗透率在煤层气开采的过程中随着孔隙内气体压力降低的变化规律.假设煤层气开采过程中煤层体积不变,研究在应力和煤基质收缩双重作用下,随着煤层内气体压力的降低,MATCHSTICK的应变变化情况,进而分析这种变化对渗透率的影响,并得出了渗透率的变化规律.通过对应变变化曲线与实验及现场生产中渗透率变化曲线的对比分析,验证了应用MATCHSTICK应变变化分析渗透率变化规律的合理性.

英文摘要：

With the decrease of gas pressure in cleat,changes occur in the absolute permeability of coal-bed methane（CBM）reservoirs during primary depletion.To investigate this variation,based on the volumetric balance among the factors of bulk coal,solid grains and pores,how the MATCHSTICK strain changes with pore pressure is studied in this paper first.Furthermore, how permeability varies with the strain changes is researched and then the regularity of permeability changes is proposed.The rationality of applying MATCHSTICK strain changes to analyze permeability is proved by the curves of strain and permeability changes obtained from production field and laboratory.