大采长工作面中部煤层预抽瓦斯以孔代巷技术应用

Application of Borehole Instead of Tunnel Technology to Extract Gas in Middle Coal Seam of Long Mining Face

为解决治理大采长工作面回采区域瓦斯需要施工多条岩石抽采巷和大量穿层钻孔,采用大采长工作面中部煤层预抽瓦斯以孔代巷技术,利用自主研制的轻型定向钻机在己15-17-12110工作面开展了现场工业性试验,分析了定向穿层钻孔覆盖工作面中部的范围及瓦斯抽采效果。结果表明:大采长工作面中部煤层预抽瓦斯以孔代巷技术可以为大采长工作面减少岩石抽采巷和穿层钻孔工程量,节约施工成本;在中抽巷和机抽巷各施工79个定向钻孔,钻孔总工程量13 806 m,其中定向钻孔岩孔8 022.5 m,水力冲孔煤孔5 783.5 m,累计冲煤量2 965.7 t,平均冲煤量0.51 t/m;定向穿层钻孔卸压抽采后,可有效提升瓦斯抽采浓度;工作面回采期间的瓦斯浓度在0.6%以下,保证了工作面安全回采。

To solve the problem that multiple middle rock drainage roadways and a lot of cross-layer boreholes need to be constructed to control the long mining face,the technology of borehole instead of tunnel technology was used to extract gas in the middle coal seam of long mining face.Self-developed light directional drlling rig was applied to conduct the field test in VIis-17-12110 work-plane,the regional and gas drainage effect in the middle of directional cross-layer borehole covered work-plane were analyzed.The research results show that the technology of borehole instead of tunnel technology by directional cross-layer borehole to extract gas in the middle coal seam of long mining face can reduce the amount of rock drainage roadway and cross-layer boreholes for long mining face,save construction costs.79 directional boreholes are constructed in the medium and machine drainage roadway.The total length of boreholes are 13806 meters,of which 8022.5 meters are rock directional boreholes.The length of hydraulic flushing coal holes are 5783.5 meters,the cumulative coal flushing amount is 2965.7 tons and average coal flushing is 0.51 t/m.The gas extraction concentration can be effectively improved by directional cross-layer borehole after releasing pressure.The gas extraction concentration is less than 0.6%during the mining period of work-plane.The safe mining of work-plane is ensured by this technology.