摘要
为了定量研究不同煤体结构煤的孔隙连通性和渗透能力的差异性,以渭北煤田韩城矿区为研究区,通过显微CT三维空间分析技术,采用多孔介质三维逾渗理论,开展了不同结构煤的孔隙三维建模分析,实现了对不同煤体结构煤中孔隙分布三维可视化的精细表征。结果表明:构造变形对煤的孔隙结构有深刻的影响;不同变形机制对煤的孔隙度、孔隙团数和最大孔隙团规模有着不同的影响,导致逾渗概率发生明显的变化;三维逾渗概率表明煤孔隙连通性和渗透率随变形程度增加呈现先升后降的变化趋势。碎裂煤孔隙团连通性最好,渗透性最强;糜棱煤孔隙团连通性最差,渗透性最弱。研究认为脆性破坏可促进外生孔和微裂隙的发育程度,加强孔裂隙间的连通性,提升煤岩渗透性;在脆韧性-韧性变形作用下,孔隙、微裂隙、矿物以及煤岩分布的非均质性明显增强,造成孔隙连通性变差,渗透率降低。
In order to quantitatively study the difference of pore connectivity and seepage capacity in coals with different coal-body structure,advanced 3D visualized model of pores for coal samples with different structure collected from Hancheng Mine,Weibei coalfield was done using a 3D-modeling technique and applying the theory of porous media 3D percolation. The spatial visualization of pores indicates that tectonic deformation has significant influence on coal pore structure. The different deformation mechanisms variously affect the porosity,pore clusters and the max pore cluster,resulting in obvious change in percolation probability. Variation of percolation probability show that pore connectivity and permeability of coals present an inverse-U-shaped relationship with the increase in tectonic deformation. The cataclastic coal has the best pore connectivity and the highest permeability,while the smallest values for these two parameters occur in mylonitic coal. The study show that brittle failure may induce the expansion of microfractures and exogenous pores,and thus results in good connectivity and high permeability. The milonitic coal has poor pore connectivity and low permeability due to the uneven distribution of pores,fractures,minerals,and maceral caused by brittle-ductile and ductile deformation effect.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2014年第6期1127-1132,共6页
Journal of China Coal Society
基金
国家科技重大专项资助项目(2009ZX05062-009
2011ZX05062-009)
国家自然科学基金和煤炭联合基金资助项目(U1261102)
关键词
孔隙
煤体结构
显微CT
煤层气
逾渗
孔隙团
pore
coal-body structure
micro-CT
coalbed methane
percolation
pore clusters
作者简介
李伟（1987-），男，山西乎遥人，博士研究生。E—mail：pingyaoliwei@126．com。
通讯作者：要惠芳（1959-），女，山西临汾人，副教授。E-mail：yhf5908@163．com
