Effect of adsorption-induced matrix swelling on coal permeability evolution of micro-fracture with the real geometry  

作　　者：Ming-Yao Wei Jishan Liu Ying-Ke Liu Zhang-Hao Liu Derek Elsworth 

机构地区：[1]National and Local Joint Engineering Laboratory of Internet Application Technology on Mine,IoT Perception Mine Research Center,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China [2]State Key Laboratory of Coal and CBM Co-Mining,Jincheng 048012,Shanxi,China [3]School of Engineering,The University of Western Australia,35 Stirling Highway,Perth,WA,6009,Australia [4]Faculty of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China [5]Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,Hubei,China [6]Department of Energy and Mineral Engineering,G3 Center and Energy Institute,The Pennsylvania State University,University Park,PA16802,USA

出　　处：《Petroleum Science》2021年第4期1143-1152,共10页石油科学（英文版）

基　　金：supported by National Key Research and Development Program of China(2020YFA0711802);the China Postdoctoral Science Foundation(2019M661997);the National Natural Science Foundation of China(51774277);the Australian Research Council under Grant(DP200101293);the Science and Technology Major Project of Shanxi Province,China(20201102001);the Open Fund of State Key Laboratory of Coal and CBM Co-Mining(2018KF09)。

摘　　要：Gas transport in coal induces effective stress variation,matrix swelling/shrinkage,and significantly affects matrix and fracture deformation,resulting in porosity and permeability evolution.However,the heterogeneity and anisotropy of coal are neglected in dual porosity models,which can lead to the deviation from the real physical mechanisms.To uncover the permeability evolution,especially the influence of dynamic matrix-fracture interaction for real fracture distribution,advanced virtual simulation is proposed.In this study,real fracture geometry is taken into account in the physical model based on the CT-scan image,while the mathematical models for coal deformation and gas flow are established.Our calculations are verified against a long-term experimental data under the same boundary condition.Accordingly,the real matrix-fracture interaction caused by adsorption-induced matrix deformation has been visually exhibited,and some new insight into the behavior of fracture permeability in real materials is offered.The results indicate the non-uniform distribution of fracture geometry is responsible for the nonmonotonic change of permeability.It also found that injection pressure,Langmuir strain constant and initial matrix permeability have important influences on the fracture permeability evolution.This research provides valuable insight into the understanding of the permeability change for the real fracture spatial distribution in coal.

关 键 词：Geometry distribution Adsorption swelling Coal permeability Matrix-fracture interaction 

分 类 号：TD313[矿业工程—矿井建设]