中文摘要：

基于现代测试技术和煤层气井实测排采数据，采用物理模拟和数值模拟研究方法，探讨了开采过程中煤储层渗透率动态变化效应。研究结果表明，试验模拟和数值模拟渗透率数值相差较大，可达1～2个数量级；煤储层渗透率动态变化效应呈现出两种相反的规律，即数值模拟渗透率随流体压力降低而衰减，试验模拟渗透率随流体压力降低而增大，两种模拟渗透率动态变化特征看似相互矛盾，实则相互衔接，预示煤储层渗透率在排采过程中会逐渐得以改善。根据分析，揭示了二者差异性的根本原因。提出在整个排采过程中，应采用动态渗透率指标，不断调整和优化工作制度。

英文摘要：

Based on the modem testing technologies and actual measuring data of coalbed methane （CBM） well, using physical and numerical simulation methods, the dynamic variation effect of coal reservoirs permeability during gas recovery has been discussed. The results indicate that permeability has larger difference, which may reach 1-2 order of magnitude; the two opposite regularities of dynamic variation of coal reservoirs permeability are presented between experimental simulation and numerical simulation; that is to say, numerical simulation permeability decreases with the decrease of fluid pressure; while experimental simulation permeability increases with the decrease of fluid pressure. Dynamic characteristics of permeability for two methods seem contradictory; but in fact interrelated. Coal reservoir permeability will be improved gradually during gas recovery. According to comparative analysis, the causes of differences between two methods are revealed. During the whole process, dynamic permeability index should be used to adjust and optimize the work system continuously.