Research Institute Company Limited, Henan Energy and Chemical Industry Group Henan Provincial Engineering
and Technology Research Center of Coal and Gas Co-Mining in Low Permeability and Outburst Seam

为了研究水力冲孔对钻孔周围煤体的卸压增透作用机理,以瓦斯压力观测法和抽采参数监测为技术手段,运用井下考察试验和数据分析的方法,研究了水力冲孔钻孔周围煤体卸压特征和瓦斯抽采规律,结果表明:中马村矿水力冲孔钻孔周围煤体的卸压影响范围为5 m,充分卸压范围为1.5 m,且水力冲孔钻孔的瓦斯抽采规律分2个阶段:瓦斯高效抽采期(抽采前5 d),该阶段瓦斯抽采量来源以充分卸压区煤体瓦斯快速解吸释放为主,解吸量大,衰减快,水力冲孔钻孔瓦斯抽采速率衰减呈幂函数规律;瓦斯稳定抽采期(抽采5 d后),该阶段充分卸压区煤体瓦斯解吸已完成,瓦斯抽采来源以卸压影响区域煤体瓦斯解吸运移为主,瓦斯抽采速率衰减稳定,呈指数函数特征。

In order to study the pressure released and permeability improved action mechanism of the coal around with the borehole by the hydraulic flushing, with the gas pressure observation method and the drainage parameter monitoring as the technical means, the underground mine investigation test and data analysis method were applied to study the pressure released features of the coal around the hydraulic flushing borehole and the gas drainage |aw. The results showed that in Zhongma Village Mine, the pressure released influence scope of the coal around the hydraulic flushing borehole was 5 m and the full pressure released scope was 1.5 m. The ga s drainage law of the hydraulic flushing borehole could be divided into two stages. The first stage would be a gas high efficient drainage period ( 5 days before the gas drainage operation) . At this stage, the sources of the gas drainage volume were mainly the rapid desorption and released coal gas from the fully pressure released zon e with large amount of desorption and fast decay and the attenuation of the gas drainage rate in the hydraulic flushing borehole would be in a power function linear law. The second stage would be a gas stable drainage period ( 5 days after the gas drainage) . At this stage, the coal gas desorption from the full pressure released zone W ould be completed, the sources of the gas drainage would be the coal gas desorption migration from the pressure released influence zone mainly and the attenuation of the gas drainage rate would be stable and in index function features.