基于帷幕注浆理论的瓦斯抽采钻孔封孔技术研究及应用

Research and Application of Gas Extraction Drilling and Sealing Technology Based on Curtain Grouting Theory

瓦斯抽采钻孔封孔效果直接决定了矿井瓦斯治理效果,是高瓦斯突出矿井安全生产的重要保障。为解决主焦煤矿2301工作面瓦斯抽采底板巷围岩裂隙发育、钻孔封孔难题,基于矿井防治水经验提出瓦斯抽采钻孔帷幕注浆封孔技术。首先通过数值模拟和钻孔窥视法确定了2301工作面底板巷松动圈范围为0.8~1.7 m。然后根据矿井注浆扩散半径设计施工帷幕注浆钻孔,利用巷道围岩帷幕注浆技术提高瓦斯抽采钻孔的封孔效果。经过现场应用取得了良好效果,71.1%的瓦斯抽采浓度较原抽采浓度得到大幅提高,对类似地质条件的瓦斯抽采岩巷钻孔封孔具有很好的指导意义。

The sealing effect of gas extraction boreholes directly determines the effectiveness of gas control in mines,and is an important guarantee for safe production in high gas and outburst mines.In order to solve the problems of crack development and borehole sealing in the surrounding rock of the gas extraction floor roadway in the 2301 working face of the main coking coal mine,a gas extraction borehole curtain grouting sealing technology is proposed based on the experience of mine water prevention and control.Firstly,the range of loose zone in the floor roadway of the 2301 working face was determined to be 0.8-1.7 m through numerical simulation and drilling observation method.Then,based on the diffusion radius of mine grouting,design construction curtain grouting boreholes,and use the tunnel surrounding rock curtain grouting technology to improve the sealing effect of gas extraction boreholes.After on-site application,good results have been achieved,with 71.1%of gas extraction boreholes having significantly increased extraction concentration compared to the original,which has good guiding significance for sealing boreholes in gas extraction rock tunnels with similar geological conditions.