MOEKey Lab of Coalbed Methane Resources and Reservoir Formation Process School of Resources and Geosciences,China University of Mining and Technology

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。

in the drainage process of the caled methane wel.the dynamic variation of the permeabiliy would determine the migration and cutput of the coalbedmnethane and woud be the key factor to conrol the production capacityof the coalbed metrane well n the drainage process.an analysis was conducted on the dynamic variation factors aff cted to the permeatility the dynanic vaiation law of the pemeablity and other aspects.The paper summarized the general understanding and new progress on the dynanic variation of the permeability at home and abroad and pointed out the problems existed in thestudy proces and thelatedevelopment tendency.The effective stess.cal matix shrinkage and Kinkenberg effect were mainly affeced to the coalbed metiane well inthe drainage pro.es and could cause the permeatiliy to genesally have an asymmetric U type variaton with reduction frst and then rising. /n combinaton with the unitary emphasis acion stage neglected,bias thery to the model hanged and othe problems existed in the study proc.ss the paper held that in a further conbination with the actual drainage data to fine the diferent action stage of each ifluence facto to stess the anal ysis on the efifctive permeatilit rate and the relevant permeability variation law affected to the gas and water capacity an to improve the dynanic seepage process ofthe reservoir in dinension could provide the rliable theoretical support to the fine and quantitative drainage control and would be the late study emphasis.

国家科技重大专项资助项目(2016ZX05044)；国家自然科学基金资助项目(41272178,41572140)；