顶板定向长钻孔卸压瓦斯抽采技术研究

Study on Pressure Relief Gas Extraction Technology of Directional Long Hole in Roof

为有效解决小回沟矿2202工作面回采期间回风流内和上隅角周围瓦斯浓度问题,提出利用顶板定向长钻孔对采后卸压区域裂隙带内部的瓦斯进行精准抽采,分析了定向长钻孔代替普通高位钻孔抽采卸压瓦斯的原理,并通过理论分析、相似材料模拟等方法掌握了2号煤层的裂隙带发育高度。2号煤层上方0~25 m为冒落带,25~36 m为裂隙带,大于36 m为弯曲下沉带。通过现场工程实践得出:采用定向长钻孔开展卸压瓦斯抽采后,最大单孔瓦斯抽采浓度为90.2%,单孔最大混合流量为9.86 m^(3)/min,单孔最大纯流量为4.61 m^(3)/min,2202工作面回采期间回风流内的最大瓦斯浓度为0.29%,上隅角最大瓦斯浓度为0.22%.

In order to effectively solve the problem of gas concentration in the return air flow and around the upper corner of the 2202 working face of Xiaohuigou Mine during mining,it is proposed to use the directional long borehole on the roof to accurately extract the gas in the fracture zone of the post-mining pressure relief area.According to the field engineering practice,after pressure relief gas extraction by directional long drilling,the maximum gas extraction concentration of single hole is 90.2%,and the maximum mixed flow of single hole is 9.86 m^(3)/min,the maximum net flow of single hole is 4.61 m^(3)/min,the maximum gas concentration in the return air flow of 2202 working face during mining is 0.29%,and the maximum gas concentration in the upper corner is 0.22%.