基于多物理场耦合的瓦斯抽放半径确定方法  

Determination method of gas drainage radius based on multi-physics coupling

作　　者：郝富昌[1,2] 刘明举[1] 孙丽娟[2] 

机构地区：[1]河南省瓦斯地质与瓦斯治理重点实验室--省部共建国家重点实验室培育基地(河南理工大学),河南焦作454000 [2]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《煤炭学报》2013年第A01期106-111,共6页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(50904024);国家科技支撑计划资助项目(2012BAK09B02-1)

摘　　要：为确定合理的瓦斯抽放半径,建立了考虑煤的流变特性、渗透率动态变化和吸附特征的渗流-应力耦合模型,对比分析了软硬煤层钻孔孔径的变化规律,研究了抽放过程的渗透率的动态演化规律,确定了软硬煤层的有效抽放半径,找出了瓦斯抽放半径的影响因素。研究结果表明:由于含瓦斯煤的流变特性,软硬煤层钻孔均会随时间发生缩孔现象,软煤层钻孔在短时间内就可能被堵塞,硬煤层钻孔直径虽有缩小但仍处于稳定状态,并不堵塞瓦斯抽放通道,在确定抽放半径时,应首先分析钻孔的孔径变化规律以确定有效抽放时间;瓦斯抽放过程中煤的渗透率会随时间的推移逐渐增大;煤体硬度、埋藏深度、初始瓦斯压力、初始渗透率和钻孔孔径等是影响瓦斯抽放半径的主要因素。In order to determine reasonable gas drainage radius,the hydro-mechanical coupling model considering rheological properties,permeability dynamics and the adsorption characteristics had been developed in this study.Therefore,the borehole aperture variations of hard and soft coal seam were comparatively analyzed,the dynamic evolution of penetration was studied,the effective gas drainage radius in hard and soft coal seams were determined,and the main influence factors of gas drainage radius were found.The results show that：shrinkage phenomenon of borehole in hard and soft coal seam occurs over time because of rheological properties,the borehole in soft seam will be blocked in a short time,although the borehole diameter in hard coal seams reduces,but borehole is still in stable condition,the gas drainage channel is not blocked.It is necessary to analyze borehole aperture variation and determine effective drainage time before determining gas drainage radius.Coal permeability during gas drainage is gradually increasing over time.The main influence factors of gas drainage radius is：coal hardness,burial depth,initial gas pressure,initial permeability and hole diameter.

关 键 词：瓦斯抽放半径 多物理场耦合 渗流场 应力场 流变特性 软硬煤 

分 类 号：TD712.6[矿业工程—矿井通风与安全]