长距离定向钻孔瓦斯抽采技术在青龙煤矿的应用

贵州省煤矿地质构造复杂、瓦斯含量高、煤层松软,瓦斯治理难度大。为了提高该区域瓦斯治理水平,在青龙煤矿21601工作面运输巷Y3点向前5~205 m处,利用千米钻机进行长距离顺层条带定向钻孔瓦斯抽采技术的现场应用。通过定向钻进技术和分支孔控制技术保证钻孔轨迹控制精度,避免了盲钻、盲抽等现象。应用结果表明:2次煤样检测得到的瓦斯可解吸量分别为1.7729,2.1913 m 3/t;残余瓦斯含量分别为4.7739,5.1704 m 3/t,均小于8 m 3/t,满足矿井瓦斯抽采的基本要求;平均瓦斯抽采纯量达到1.26 m 3/min,比原来提高了12%;与常规钻孔相比,采用定向钻孔抽采的瓦斯体积分数提高了50%,瓦斯治理效果显著。

Application of long-distance directional drilling gas drainage technology in Qinglong Coal Mine

The coal mines in Guizhou Province have complex geological structures,high gas content,and soft coal seams,making gas management difficult.In order to improve gas management level in the area,at the range of 5-205 m forward from Y3 point of the transportation roadway of 21601 working face in Qinglong Coal Mine,the kilometer drilling rig is used for field application of gas drainage technology of long-distance directional drilling along layer.The directional drilling technology and branch drillings control technology are used to ensure drilling trajectory control accuracy and avoid blind drilling and blind pumping.The application results show that the desorbable gas from two coal samples are 1.7729,2.1913 m 3/t,and the residual gas content is 4.7739,5.1704 m 3/t,both are less than 8 m 3/t,which meet the basic gas drainage requirements of mine.The average gas drainage volume reached 1.26 m 3/min,which is 12%higher than the original value.Compared with conventional drilling,volume fraction of the gas extracted by directional drilling increased by 50%,and the gas treatment effect is significant.