为研究顺层瓦斯抽采钻孔合理封孔长度，基于瓦斯-空气双气体模型，采用有限元模拟软件建立三维钻孔抽采模型，对封孔段煤层瓦斯压力进行监测分析，通20915运输巷现场试验，考察不同封孔长度瓦斯抽采效果。结果表明：受到负压衰减效应，钻孔抽采负压呈指数函数分布，并且钻孔不同位置煤层瓦斯压力减少幅度不同，越靠近封孔位置瓦斯压力减小幅度越小；封孔段瓦斯压力峰值与封孔长度成正相关；根据现场测试，封孔距离为10 m瓦斯抽采浓度在130 d后减小到约10%；而封孔长度为20 m将保持在约30%，封孔30 m的钻孔130 d后抽采浓度保持在60%以上。

In order to study the reasonable sealing length of bedding gas drainage boreholes, based on the gas-air dual gas and the negative pressure attenuation effect of boreholes, a three-dimensional borehole drainage model was established by finite element simulation software to monitor and analyzed the gas pressure of coal seam in the sealing section. Through the field test of 20915 haulage roadway, the gas drainage effects of different sealing lengths were investigated. The results show that under the negative pressure attenuation effect, the negative pressure of borehole drainage is exponential function distribution, and the reduction of gas pressure in coal seams at different positions of borehole is different, and the closer to the sealing position, the smaller the reduction of gas pressure. The peak gas pressure in the sealing section is proportional to the sealing length. According to the field test, the gas drainage concentration decreases to about 10% after 130 days when the sealing distance is 10 m. The sealing length of 20 m maintains at about 30%, and the extraction concentration of the borehole with sealing length of 30 m maintains at above 60% after 130 days.