下向穿层钻孔综合水力化防突技术研究

Study of Outburst Prevention Technology by Comprehensive Hydraulic Drilling Downward Through Coal-Seam

针对近距离、低透气性、极松软突出煤层群区域防突难题,提出了下向穿层钻孔综合水力化防突技术。理论分析了下向穿层钻孔综合水力化防突技术防突机理。模拟了注水润湿前后不同孔径钻孔周围煤体应力分布规律。结果表明:水力冲煤孔径增加,钻孔卸压范围增加;相同孔径,注水软化同时增加卸压范围;增加水力冲煤孔径的卸压效果优于注水软化的卸压效果;卸压影响范围与水力冲煤半径负倒数存在指数函数关系。根据技术原理,研发了下向穿层钻孔综合水力化技术工艺,建立了技术防突效果指标考核体系。该技术在青东煤矿得到成功应用,为该条件下区域防突提供新的技术途径。

Aiming at the difficulty of regional outburst prevention in closed distance, low permeability and loose outburst coal seams, the outburst prevention technology by comprehensive hydraulic drilling downward through coal seam was proposed. We theoretically analyze the outburst prevention mecha-nism of this technology. The stress distribution of coal body around different diameters borehole before and after water infusion and wetting was simulated. The results show that released range of borehole in- creasing with the diameter of hydraulic flushing borehole growing. The released range increases after water infusion and softening under the same diameter condition. Pressure relief effect of increasing di- ameters is better than water-infusion softening. There is exponential function relationship between the released range and negative reciprocal borehole radius. This outburst prevention technology process was researched. The assessment index system of outburst prevention effect was established. The technology, which has been successfully applied in Qingdong mine, provides a new technical way for regional out- burst prevention in this condition.