煤矿分层开采工作面立体式瓦斯抽采技术及应用

Three dimensional gas drainage technology and its application in slicing face of coal mine

为解决煤矿分层开采下分层回采过程中工作面上隅角或回风巷瓦斯超限的难题,通过分析采煤工作面瓦斯治理要求,研发了分层开采井上下立体式瓦斯抽采技术,其涵盖地面井预抽、工作面顺层钻孔抽采和采动区地面井抽采、高位钻孔抽采及采空稳定区瓦斯抽采。根据准备煤量、回采煤量,以及不同回采时期,提出了具备接续的综合立体式瓦斯抽采实施方法及技术体系。该技术在山西晋城岳城煤矿的应用结果表明:采用综合立体式瓦斯抽采优化布置后,采动区地面井平均抽采瓦斯流量为1.15万m^(3)/d,平均抽采瓦斯浓度为44.5%,工作面推至地面井附近时抽采瓦斯纯流量显著增大,地面井在采煤工作面回采阶段抽采瓦斯总量约为245.5万m^(3);同时,井下高位钻孔单孔平均抽采瓦斯浓度为80.61%,平均抽采瓦斯纯流量为1.33 m^(3)/min,平均运行时间约60 d,平均单孔抽采瓦斯总量为11.65万m^(3);采动稳定区埋管平均抽采瓦斯纯流量为0.29 m^(3)/min,抽采瓦斯总量约为200.8万m^(3)。在立体式联动抽采瓦斯措施下,回采过程中回风巷的瓦斯浓度在0.50%以下,工作面回风巷瓦斯浓度平均降幅为58.8%,上隅角瓦斯浓度平均降幅为56.0%,保障了煤矿生产安全。

In order to solve the problem of gas overrun in the upper corner of working face or return airway in the process of sublevel mining under slicing mining,based on the analysis of gas control requirements of coal mining face,the three dimensional gas drainage technology is developed,which includes pre-drainage of surface wells,bedding drilling in working face,surface well drainage in mining area,high-level drilling drainage and gas drainage in mining area in goaf.According to the prepared reserves,workable reserves and different periods of coal mining,the implementation method and technical system of continuous comprehensive three-dimensional gas drainage are put forward.The technology has been applied to Yuecheng Coal Mine in Jincheng of Shanxi Province.The test results show that:after adopting the optimized layout of comprehensive threedimensional gas drainage,the average gas drainage amount of surface wells in mining area is 11500 m^(3)/d,and the average gas concentration is 44.5%,when the working face is pushed near the surface wells,the pure amount of gas drainage increases significantly,and the total amount of gas drainage of surface wells in the mining stage is about 2455000 m^(3);at the same time,the average extraction concentration of single hole in the underground high-level borehole is 80.61%,the average extraction pure quantity is 1.33 m^(3)/min,the average operation time is about 60 days,the average total amount of gas extracted by single hole is 116500 m^(3);the average pure flow rate of gas extracted from buried pipes in the mining stability area is 0.29 m^(3)/min,and the total amount of gas extracted is about 2.008 million m^(3).Under the three-dimensional linkage gas drainage measures,the gas concentration in the return airway is less than 0.50%,the average decrease of gas concentration in the return airway is 58.8%,and the average decrease of gas concentration in the upper corner is 56.0%,which ensures the safety of coal mine production.