水分对含瓦斯煤渗透特性影响的试验研究

以贵州玉舍煤矿3号煤层煤样为实验对象,利用自行研发的三轴渗透仪,进行了不同含水率条件下恒平均有效应力—变温度的三轴渗流实验。研究结果表明:型煤渗透率受水分的影响较敏感,渗透率与水分成反相关关系,并服从指数分布,且含水率越高,型煤的渗透率降低幅度越大;各种实验条件下,含瓦斯煤烘干煤样的渗透率均大于含水煤样的渗透率,且烘干煤样与含水煤样渗透率之间的减小幅度与含瓦斯煤样所受的平均有效应力大小有关;随着温度的增加,干燥煤样和含水煤样渗透率均呈减小趋势,但在55℃后,含水煤样渗透率略有增大。实验结论为贵州瓦斯灾害防治和煤层气的开发利用提供了理论依据。

Experiment Study of Moisture Influence on Permeability of Coal Containing Methane

The coal samples from No.3 coal seam of Yushe Coal Mine in Guizhou Province was taken as experiment subjects,and taking use of self-made tri-axis permeability instrument,and to do tri-axis permeability experiments on constant average effective stress,various temperature field with different moistures.The experiment results show that coal samples’ permeability rates were sensitive to moisture,permeability rate has negative relationship with moisture,and the relationship between permeability and moisture conforms to exponent distribution,and in addition,the lower of coal sample’s permeability rate declines,the higher of coal sample’s moisture.On various experiment conditions,the permeability rate of stoving coal samples of containing gas is bigger than the permeability rate of coal sample of containing moisture,and the decline range of permeability rate between stoving coal sample and moist coal sample has the relationship with average effective stress that containing gas coal sample suffered.With the increase of temperature,the permeability rate of dry coal sample and moist coal sample is declining,but after 55℃,the permeability of moist coal sample is subtile augment.The experiment conclusion can be taken as theoretical fundament for exploration and utilization of coal bed gas and gas disaster prevention.