瓦斯抽采钻孔合理封孔参数优化

Optimization of Reasonable Sealing Parameters of Gas Drainage Boreholes

抽采钻孔的封孔质量是决定抽采效果的关键因素之一,而封孔参数则直接影响封孔质量。为了研究抽采钻孔的合理封孔参数,在分析山西王家岭矿巷道围岩应力及裂隙分布的基础之上,采用现场实测和数值模拟的方法,对抽采钻孔的始封深度、封孔长度和注浆压力等关键参数以及封孔效果进行了全面研究。研究结果表明,煤层抽采钻孔的合理封孔参数为始封深度不应小于4 m,封孔长度范围为8~12 m,注浆压力应达到3 MPa。现场应用表明,在始封深度和封孔长度均满足要求的情况下,采用3 MPa注浆压力封孔的钻孔封孔质量良好,而常压注浆封孔部分钻孔封孔质量达不到要求,进一步验证了封孔参数的合理性和有效性,对同类条件下的煤层瓦斯抽采钻孔封孔有借鉴和指导作用。

The sealing quality of gas drainage boreholes is one of the key factors to determine the effect of gas drainage,and the sealing parameters directly affect the sealing quality.In order to study the reasonable sealing parameters of gas drainage boreholes,based on the analysis of stress and fracture distribution in roadway surrounding rock of Wangjialing coal mine,the key parameters such as start sealing depth,sealing length,grouting pressure and sealing effect of gas drainage boreholes were comprehensively studied by field measurement and numerical simulation.The results show that the reasonable sealing parameters of gas drainage boreholes are that the initial sealing depth should not be less than 4 m,the sealing length range is 8~12 m,and the grouting pressure should reach 3 MPa.Field application shows that the sealing quality of boreholes with 3 MPa grouting pressure is good,on the other hand the sealing quality of boreholes with deadweight pressure of slurry can not meet the requirements.The result further verifies the rationality and validity of sealing parameters,so they can be used for reference and guidance gas drainage drilling for coal seam under similar conditions.