气固耦合作用下温度对煤瓦斯渗透率影响规律的实验研究

为得到温度对煤瓦斯渗透率的影响规律，在实验室通过改装三轴渗透仪，进行了不同温度条件下煤瓦斯的渗透率测定实验。实验结果表明，在不同温度下，渗透率随有效应力的减小均呈二次抛物线趋势，即渗透率先减小后增大。在卸载初期，温度较低时煤瓦斯渗透率下降梯度比高温时大，渗透率值较高；卸载后期，较高温度时煤瓦斯渗透率上升梯度比低温时大，渗透率值大。由实验可知，煤层气开采过程中，对于不同温度，煤瓦斯渗透率的变化关系均具有典型煤层气开采的三阶段主导作用特征。有效应力、气体吸热和煤固体受热是影响煤体渗透率的重要因素。在卸载初期，煤固体受热膨胀及有效应力对渗透率起主导作用，卸载中后期，气体滑脱和气体吸热对渗透率起主导作用。实验分析后认为，开采煤层气时采用先压裂后注热的方式将有助于提高煤层气的产量。

EXPERIMENTAL STUDY OF EFFECT OF TEMPERATURE ON COAL GAS PERMEABILITY UNDER GAS-SOLID COUPLING

To observe the effect of temperature on coal gas permeability,an experiment of coal gas permeability was carried out at different temperatures through a three-axial penetration instrument.The results show that,at different temperatures,the permeability of coals assumes a trend of quadric parabola,that is,the permeability first decreases and then increases as the effective stress decreases.In the early unloading,the degressive gradient of coal gas permeability is greater at lower temperature than at high tem...