基于分形建模的高煤级煤孔隙结构特征量化表征——以阳泉矿区山西组煤样为例  

Quantitative characterization of pore structure characteristics of high quality coal based on fractal modeling:taking coal samples from Shanxi Formation in Yangquan Mining Area as an example

作　　者：赵迪斐[1,2] 郭英海[1,2] WANG GEOFF 刘静[1] 王琳琳[4,5] ZHAO Difei;GUO Yinghai;WANG GEOFF;LIU Jing;WANG Linlin(Key Laboratory of Coal-bed Methane Resources and Reservoir Formation Process of Ministry of Education,China University of Mining and Technology,Xuzhou,Jiangsu 221008,China;School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Chemical Engineering,University of Queensland,Brisbane,Queensland 4072,Australia;Low Carbon Energy Institute,China University of Mining and Technology,Xuzhou,Jiangsu 221008,China;Jiangsu Key Laboratory of Coal-based CO2 Capture and Geological Storage,China University of Mining and Technology,Xuzhou,Jiangsu 221008,China)

机构地区：[1]中国矿业大学煤层气资源与成藏过程教育部重点实验室,江苏徐州221008 [2]中国矿业大学资源与地球科学学院,江苏徐州221116 [3]昆士兰大学化工学院,昆士兰州布里斯班4027 [4]中国矿业大学低碳能源研究院,江苏徐州221008 [5]中国矿业大学江苏省煤基CO2捕集与地质储存重点实验室,江苏徐州221008

出　　处：《东北石油大学学报》2019年第3期53-66,I0004,共15页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(41772130);国家重点基础研究发展计划(973计划)项目(2012CB214702);山西省煤基重点科技攻关项目(MQ201402);教育部中央高校科研业务专项基金(2017CXNL03);中国矿业大学煤层气资源与成藏过程教育部重点实验室开放基金资助项目(2015-007);中国矿业大学资源与地球科学学院大学生学术科研中心科研创新项目(CSA2019-07)

摘　　要：以阳泉矿区山西组煤样为例,根据高压压汞及分形建模,获取高煤级煤孔隙结构特征参数,结合氩离子抛光—场发射扫描电镜,识别微—纳米尺度的孔隙发育类型及结构特征,明确储集空间构成及孔隙结构对煤中气体的影响,构建气体行为与孔隙结构的关系。结果表明:阳泉矿区山西组高煤级煤储层孔隙结构复杂,在不同发育尺度具有不同的分形特征;基于孔隙结构特征、分形特征和多孔介质甲烷的分子动力学特征,将孔隙划分为3个大类(超微吸附孔隙、纳米扩散孔隙和微纳米渗流孔隙)和5个小类(超微孔隙、分子扩散孔隙、Knudsen扩散孔隙、层流滑移孔隙和紊流滑移孔隙),将基质孔隙气体的运移方式划分为吸附相—固溶相扩散场、Knudsen扩散场、层流场及紊流场,多数高煤级煤样品层流滑移孔隙的不发育表明层流场的弱势发育。量化高煤级煤储层微观储集空间,建立孔隙结构与煤层气渗流、运移的关系,为高煤级煤层气勘探开发、地质理论研究提供依据。Taking coal samples from the Shanxi Formation in Yangquan Mining Area as an example,the pore structure parameters of high-quality coal are obtained according to high pressure mercury injection and fractal modeling.Combined with argon ion polishing-field emission scanning electron microscopy,the pore development types and structural characteristics of micro-nano scale are identified,and the influence of reservoir space composition and pore structure on gas in coal is clarified by establishing the relationship between gas behavior and pore structure.The results show that the pore structure of high quality coal reservoir is complex and presents different fractal characteristics of different development scales.The reservoir pores are divided into 3 types(ultra-micro scale-adsorption pores,nanoscale-diffusion pores and micro-nano scale-seepage pores) and 5 subcategories(ultra-micro pores,molecular scale-diffusion pores,Knudsen diffusion pores,laminar slip pores and turbulent slip pores) based on the pore structure characteristics,fractal characteristics and kinetic characteristics of methane molecular in porous media.The migration modes of gases in coal matrix are divided into adsorption phase-solid solution phase diffusion field,Knudsen diffusion field,laminar flow field and turbulent flow field.The poor development of laminar slip pores in high-quality coal samples indicates the weak development of laminar flow field.Quantifying micro-reservoir space of high-quality coal reservoir and establishing the relationship between pore structure and migration of CBM will provide basis for exploration and development of high-quality coal-bed methane and geological theory research.

关 键 词：孔隙结构 分形特征 纳米孔 孔隙分类 高煤级煤 山西组 阳泉矿区 

分 类 号：P618.11[天文地球—矿床学]