抽采钻孔周围煤层瓦斯压力分布理论分析及应用  

Theoretical analysis of coal seam gas pressure distribution around drainage hole and its application

作　　者：齐黎明[1] 祁明 陈学习[1] QI Liming;QI Ming;CHEN Xuexi(School of Safety Engineering,North China Institute of Science ＆ Technology,Beijing 101601,China)

机构地区：[1]华北科技学院安全工程学院

出　　处：《中国安全科学学报》2018年第7期102-108,共7页China Safety Science Journal

基　　金：国家自然科学基金资助(51204070);河北省自然科学基金资助(E2015508053);中央高校基本科研业务费资助(3142018028)

摘　　要：在煤层瓦斯抽采工艺中,抽采钻孔周围煤层瓦斯压力分布状况决定了最佳抽采时间和抽采半径。为研究抽采钻孔周围煤层瓦斯压力分布情况,通过理论分析和数值模拟,构建抽采钻孔周围煤层瓦斯流量表达式;应用达西渗流定律,推导出抽采钻孔周围煤层瓦斯压力解析表达式;采用瓦斯抽采半径随抽采时间的变化速率作为确定瓦斯抽采最佳时间的依据,给出临界值,并进行工程应用。结果表明：随着测定点与钻孔中心距离的增加,煤层瓦斯压力逐步上升,最终趋于原始值;随着抽采时间延长,瓦斯压力大致呈指数规律下降;瓦斯抽采半径随抽采时间的变化速率临界值可暂定为0.47。In the coal seam gas extraction technology,the distribution of gas pressure around the drainage borehole determines the optimal extraction time and extraction radius. In order to study the law of gas pressure distribution in coal seam around drainage borehole,an expression of gas flow around drainage borehole was worked out by theoretical analysis and numerical simulation,and an analytical expression of gas pressure around drainage borehole was deduced by applying Darcy＇s seepage law. The rate at which the gas extraction radius changes with the extraction time was taken as the basis for determining the best time for gas extraction,a critical value was obtained,and an engineering application was carried out. The results show that with the increase of distance between the measuring point and the borehole center,the gas pressure of coal seam increases gradually,and finally tends to the original value,with the extension of extraction time,the gas pressure decreases exponentially,the critical value of gas extraction radius changing with extraction time can be tentatively set at 0.47.

关 键 词：瓦斯抽采 瓦斯流量 瓦斯压力 抽采半径 分布规律 抽采时间 

分 类 号：X913.4[环境科学与工程—安全科学] TD712.5[矿业工程—矿井通风与安全]