黔西突出煤的微观孔隙分形特征及其对渗透率的影响  

Micro-pore fractal characteristics of outburst coal in Western Guizhou and its influence on permeability

作　　者：薛海腾 李希建[1,2,3] 陈刘瑜 刘钰 XUE Haiteng;LI Xijian;CHEN Liuyu;LIU Yu(Mining College,Guizhou University,Guiyang 550025,China;Engineering Center for Safe Mining Technology Under Complex Geologic Condition,Guiyang 550025,China;Institute of Gas Disaster Prevention and Coalbed Methane Development of Guizhou University 550025,China;China Power Construction Group Guizhou Electric Power Design and Research Institute Co.,Ltd.,Guiyang 550003,China)

机构地区：[1]贵州大学矿业学院,贵州贵阳550025 [2]复杂地质矿山开采安全技术工程中心,贵州贵阳550025 [3]贵州大学瓦斯灾害防治与煤层气开发研究所,贵州贵阳550025 [4]中国电建集团贵州电力设计研究院有限公司,贵州贵阳550003

出　　处：《煤炭科学技术》2021年第3期118-122,共5页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51874107);贵州省科技计划资助项目(黔科合平台人才[2018]5781号)。

摘　　要：煤层气的运移、赋存与煤体内部孔隙结构密切相关。为研究贵州突出煤体的微观孔隙对其吸附性能及渗透能力的影响,以黔西青龙煤矿和兴隆煤矿的构造煤与原生煤煤样为研究对象,利用全自动氮吸附仪测得煤样的低温液氮吸附曲线,根据分形理论、毛细管平均迂曲度分形模型、渗透率模型计算得到了煤样的孔隙分形维数D_(f)、毛细管平均迂曲度分形维数D_(T)、渗透率K,并从分形的角度研究了黔西突出煤的微观孔隙分形特征与其吸附性能及渗透率的关系。研究结果表明:黔西突出煤孔隙度较低,迂曲度τ较大。随着毛细管平均迂曲度分形维数D_(T)、迂曲度的增大,瓦斯的最大吸附量V_(L)增加,Langmuir压力P_(L)降低,瓦斯吸附速度增大。渗透率K与D_(T)有较好的负相关关系。煤的渗透率低、瓦斯吸附能力强是贵州省矿区频发煤与瓦斯突出的主要原因。The migration and occurrence of coalbed methane are closely related to the internal pore structure of coal.In order to study the influence of the microscopic pores of the prominent coal bodies in Guizhou on their adsorption performance and permeability,the structural coal and primary coal samples of Qinglong and Xinglong Coal Mines in Western Guizhou were taken as the research objects and the coal samples were measured by an automatic nitrogen adsorption instrument.The low-temperature liquid nitrogen adsorption curve was calculated based on the fractal theory,capillary mean tortuosity fractal model and permeability model,the pore fractal dimension D_f,capillary mean tortuosity fractal dimension D_T,and permeability K are calculated according to the fractal theory.The relationship between the microscopic pore fractal characteristics of outburst coal in Western Guizhou and its adsorption performance and permeability was studied.The results show that outburst coal in Western Guizhou has low porosity and large tortuosity(τ).As the fractal dimension(D_(T))and tortuosity of capillary mean tortuosity increase,the maximum gas adsorption capacity V_(L) increases,the Langmuir pressure P_(L) decreases,and the gas adsorption speed increases.There is a good negative correlation between permeability K and D_(T).Low coal permeability and strong gas adsorption capacity are the main reasons for frequent coal and gas outburst in mining areas in Guizhou Province.

关 键 词：构造煤 原生煤 孔隙结构 迂曲度 分形维数 吸附能力 渗透率 

分 类 号：P618.11[天文地球—矿床学]