杨柳煤矿割缝预抽后煤体孔隙结构变化特征  

Pore Characteristics of Coal with the Treatment of Hydraulic Slotting and Gas Pre-drainage in Yangliu Coal Mine

作　　者：刘厅[1] 林柏泉[1] 邹全乐[1] 朱传杰[1] 孔佳[1] 郭畅[1] 

机构地区：[1]中国矿业大学安全工程学院煤炭资源与安全开采国家重点实验室,江苏徐州221116

出　　处：《天然气地球科学》2015年第10期1999-2008,共10页Natural Gas Geoscience

基　　金：国家重点基础研究发展计划(编号:2011CB20120);国家自然科学基金项目(编号:51474211);"十二五"国家科技支撑计划(编号:2012BAK04B07)联合资助

摘　　要：为了系统分析割缝预抽后钻孔周围煤体孔隙结构变化特征,基于孔隙结构测试方法的敏感性和精确性及液氮吸附法和压汞法测定原理,提出将液氮吸附法和压汞法有机结合来表征煤体孔隙结构。结果表明：①二者的有机结合应满足填充临界孔径所需的实验介质体积相等且结合点平滑过渡;②随取样点与割缝孔距离的减小,小孔（10~100nm）所占比例显著降低,大孔（〉1 000nm）所占比例逐渐提高,中孔（100~1 000nm）和微孔（〈10nm）所占比例变化较小;③割缝预抽后煤体瓦斯放散初速度ΔP受取样点与割缝孔距离的影响。水力割缝与瓦斯抽采协同作用能够弱化煤体对瓦斯的吸附能力并显著提高瓦斯在煤体中的渗流能力。研究结果对于指导高压水射流割缝瓦斯预抽具有重要意义。To analyze the change of pore characteristics of coal around the borehole after hydraulic slotting and gas pre-drainage systematically, considering the sensitivity, precision and the test principles of Nitrogen Gas Adsorption（N2 GA） and Mercury Intrusion Porosimetry（MIP）, a method, combining the two means or- ganically, was put forward to characterize the pore structure. The results show that the combination condi- tion is that the volume of the testing mediums filling the critical pore should be equal and the bonding point transits smoothly. With the decrease of the distance between sampling point and the slotted borehole,the proportion of the minipore （10-100nm） decreases remarkably, the macropore（〉 1 000nm） increases gradually,the mesopore（100-1 000nm） and micropore（〈10nm） show little changes. The initial gas emission char- acteristic of the coal sample varies with the distance. The combined action of hydraulic slotting and gas pre- drainage can weaken the adsorptivity and strengthen the seepage capacity of the coal mass remarkably. The research results are of great significance to the gas pre-drainage after hydraulic slotting.

关 键 词：瓦斯抽采 水力割缝 孔隙结构 瓦斯放散特性 

分 类 号：TE122.2[石油与天然气工程—油气勘探]