中文摘要：

为了研究煤层瓦斯抽采过程中的煤体渗透性变化规律,基于Kozeny-Carman方程,利用表面物理化学与含瓦斯煤的有效应力理论,建立考虑有效应力变化、瓦斯解吸和煤基质收缩效应的煤层渗透率动态变化模型,并结合数值模拟分析煤层瓦斯抽采过程中煤体透气性动态演化规律。研究结果表明：（1）所建立的煤层渗透率动态演化模型能较好地描述煤层瓦斯抽采过程中的煤体透气性动态演化规律。（2）煤体渗透率与煤体孔隙压力之间呈现出＂V＂字型变化趋势,低瓦斯压力阶段煤基质收缩效应占主导地位,煤层渗透率随瓦斯压力降低而增大;高瓦斯压力阶段有效应力作用占主导地位,煤层渗透率随瓦斯压力降低而减小。（3）从煤层内部逐渐接近抽采钻孔过程中,煤层瓦斯压力较高时,煤体渗透率先减小后增加;煤层瓦斯压力较低时,煤体渗透率不断增大。研究结果可以为我国煤矿瓦斯治理和煤层瓦斯抽采提供理论支撑,具有指导性意义。

英文摘要：

In order to investigate the variation of permeability during the gas drainage in coal seams,a model of variation of coal permeability was established based on the Kozeny-Carman equation,the theories of surface physical chemistry and effective stress of the coal containing gas. The effects of the effective stress,gas desorption and coal matrix shrinking were taken into account in the model and the permeability variation during the gas drainage in coal seams was analyzed using the numerical simulation method. The proposed model was found to describe effectively the variation of permeability during the gas drainage in coal seams. The relationship between the permeability and gas pressure displayed a＂V＂-shape trend of variation. The coal matrix shrinking was the dominant factor in the low gas pressure stage,and coal permeability increased with the decrease of gas pressure. The effective stress effect was the dominant factor in the high gas pressure stage,and coal permeability increased with the increase of gas pressure. If the distance between the specific point in coal body and the gas drainage hole wall decreased gradually,the coal permeability dropped firstly and then went up when gas pressure was relative high,and the coal permeability increased continuously when the gas pressure was relatively low.