摘要
煤微观连通孔隙团是煤体渗透性能的决定性因素,其特殊的拓扑结构非均质性是煤体渗透各向异性的根本原因。为了揭示煤微观连通孔隙团拓扑结构的非均质特征,针对鄂尔多斯盆地低阶煤进行X-ray μCT扫描,重建煤孔隙微观空间结构模型,采用AVIZO软件提取最大连通孔隙团,并构建其等效孔隙网络拓扑结构,分析孔隙形状因子与孔隙等小直径和表面积的关系,探讨连通特性和分形维数在空间中的变化规律。结果表明:孔隙形状因子与等效直径存在指数关系,与孔隙表面积存在线性关系;连通孔隙团内部渗流孔隙空间越大,其形状越不规则,非均质越强;低阶煤连通孔隙团各断面的欧拉数变化较大,连通性具有更强的非均质性,孔隙离散程度更高,但粗糙度较低。
The microscopic connected pore clusters of coal are the decisive factor of coal permeability, and its special topological structure heterogeneity is the fundamental cause of coal permeability anisotropy. In order to reveal the heterogeneous characteristics of the topological structure of connected pore clusters, X-ray μCT scanning is performed on low-rank coal in Ordos Basin, and the micro-spatial structure model of coal pores was reconstructed. The largest connected pore cluster was extracted using AVIZO software, and its equivalent pore network topology was constructed. The relationship between the pore shape factor and the small diameter and surface area of the pore is analyzed, and the change law of the connection characteristics and the fractal dimension in space is discussed. The results show that: the pore shape factor has an exponential relationship with the equivalent diameter,and a linear relationship with the pore surface area. The larger the seepage pore space inside the connected pore cluster, the more irregular its shape and the stronger the heterogeneity. The Euler number of each section of the connected pore group of low-rank coal varies greatly, the connectivity has stronger heterogeneity, the degree of pore dispersion is higher, but the roughness is lower.
作者
车禹恒
CHE Yuheng(China Coal Technology and Engineering Group Chongqing Research Institute,Chongqing 400037,China;State Key Laboratory of the Gas Disaster Detecting,Preventing and Emergency Controlling,Chongqing 400037,China)
出处
《煤矿安全》
CAS
北大核心
2021年第8期33-38,共6页
Safety in Coal Mines
基金
“十三五”国家重点研发计划资助项目(2018YFC0808305)。
关键词
低阶煤
煤渗流孔隙
连通孔隙团
拓扑结构
非均质性
low-rank coal
coal seepage pore
connected pore cluster
topology structure
heterogeneous
