为了解决西南地区煤矿特殊复杂地质条件下石门揭煤瓦斯抽采布孔空间小、钻孔深度较长、难以保证打钻到位及封孔困难的问题,提出了石门揭煤多方位立体式预抽瓦斯消突方法,通过立体式、全覆盖钻孔布置方式,同时采用钻孔全程下套管,“两堵一注”水泥带压封孔瓦斯抽采技术,防止揭煤区域出现瓦斯抽采空白带,有效降低揭煤区域前方煤层瓦斯含量和瓦斯压力.工程试验结果表明:通过采用多方位立体式预抽瓦斯消突方法,揭煤区域煤体连续45 d抽采,累计抽采瓦斯量329 776.46 m3,瓦斯预抽率达70％,残余瓦斯含量和残余瓦斯压力分别降低为5.800 8 m3/t和0.25MPa;与抽采之前对比,分别下降了69％和79％,有效地治理了煤与瓦斯突出灾害,保障了石门揭煤安全.%In order to solve a small borehole layout space of the gas drainage boreholes in the cross-cut,long borehole depth,hard to ensure the drilling in the position and borehole sealing difficulty under the special complicated geological condition in Southwest China area,a multi directional 3D gas pre-drainage and outburst control method was provided for the seam uncovering at the cross-cut of the mine.With the 3D and full covered borehole layout method and a full borehole casing applied to the borehole drilling,the "two sealing and one grouting" pressurized cement borehole sealing and gas drainage technology was applied to prevent a gas drainage blanking zone occurred in the seam uncovering area and to effectively reduce the seam gas content and the gas pressure at the front of the seam uncovering area.The engineering test result showed that with the application of the multi directional 3D gas pre-drainage and outburst elimination method,a 45 days continued gas drainage was conducted in the seam uncovering area,a total gas drainage volume was 329 776.46 m3,the gas predrainage rate was reached to 70％ and the residual gas content and residual gas pressure were reduced to 5.800 8 m3/t and 0.25 MPa individually.In comparison with the gas drainage and gas pressure before the gas drainage conducted,the gas drainage and gas pressure ere reduced by 69％ and 79％ individually.The application of the technology could effectively control the coal and gas outburst disaster and ensure the safety of the seam uncovering at the crosscut.
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