为研究穿层钻孔倾角与煤层气抽采效果的关系，基于钻孔围岩应力分布规律及瓦斯流动规律的相关研究，分别从孔卸压效果、钻孔瓦斯流动情况及钻孔抽采长度三方面探讨了钻孔倾角如何影响煤层气抽采效果，并给出了钻孔倾角对煤层气抽采影响的数学模型。经理论分析及现场试验对比，结果表明：钻孔围岩应力和钻孔倾角间存在三角函数关系，围岩应力分布的不同导致钻孔周围煤层透气性的改变；随钻孔倾角的减小，煤层段钻孔长度增加，钻孔暴露煤体增大，有助于煤体瓦斯的解析。且钻孔与煤层割理交集变大，瓦斯流通通道增加；钻孔倾角对煤层气抽采效果有着不可忽视的作用。%In order to study the relationship between angle of penetration boreholes and gas drainage effect, based on the related research on laws of stress distribution in coal body around boreholes and gas migration in the coal seam, the influence by angle of boreholes on coalbed gas drainage effect was discussed from three aspects, namely the pressure relief effect by boreholes, the gas migration state and the extraction length of boreholes, and a new mathematical model on influence by angle of boreholes to gas drainage effect was established.On the contrast of field test and theoretical analysis, the results showed that:(1) there is a triangle function relationship between the stress in coal body around boreholes and the angle of boreholes, and the difference of stress distribution in coal body around boreholes will lead to the change in permeability of coal seam around boreholes.(2) With the decrease in angle of boreholes, the boreholes-length in coalbed increases, and the exposed coal body around boreholes increa-ses, which contributes to the desorption of gas.In the meanwhile, the intersection of boreholes and coal seam be-comes larger, and the channel for gas flow increases.(3) The influence by angle of boreholes on drainage effect of coalbed gas cannot be ignored.
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