【摘要】 煤层气井排采过程中,渗透率的动态变化决定着煤层气的运移和产出,是控制煤层气井产能的核心因素。从排采过程中渗透率动态变化影响因素、渗透率动态变化规律等方面进行分析,总结了国内外关于渗透率动态变化的普遍认识和最新进展,并指出了研究过程中所存在的问题及今后的发展趋势。煤层气井排采过程中主要受到有效应力、煤基质收缩和克林肯伯格效应的影响,导致渗透率总体呈现"先降低、后升高"的不对称"U"型变化。结合研究过程中存在的侧重点单一、作用阶段忽视、变化模型偏理论化等问题,认为进一步结合实际排采数据,细化各影响因素的不同作用阶段,着重分析影响气、水产能的有效渗透率和相对渗透率变化规律,完善储层尺度上的动态渗流过程,为精细化定量排采控制提供可靠的理论支撑将是今后的研究重点。更多还原

【Abstract】 In the drainage process of the coalbed methane well,the dynamic variation of the permeability would determine the migration and output of the coalbed methane and would be the key factor to control the production capacity of the coalbed methane well. In the drainage process,an analysis was conducted on the dynamic variation factors affected to the permeability,the dynamic variation law of the permeability and other aspects. The paper summarized the general understanding and new progress on the dynamic variation of the permeability at home and abroad and pointed out the problems existed in the study process and the late development tendency. The effective stress,coal matrix shrinkage and Klinkenberg effect were mainly affected to the coalbed methane well in the drainage process and could cause the permeability to generally have an asymmetric U type variation with reduction first and then rising. In combination with the unitary emphasis,action stage neglected,bias theory to the model changed and other problems existed in the study process,the paper held that in a further combination with the actual drainage data,to fine the different action stage of each influence factor,to stress the analysis on the effective permeability rate and the relevant permeability variation law affected to the gas and water capacity and to improve the dynamic seepage process of the reservoir in dimension could provide the reliable theoretical support to the fine and quantitative drainage control and would be the late study emphasis.更多还原