温度作用煤岩力学渗流特性演化规律试验研究

Experimental study on evolution law of seepage characteristics of coal-rock mechanics under temperature action

本文利用自主改造的三轴试验装置,以山西马兰煤矿18506工作面的焦煤为研究对象,在恒定围压与瓦斯压力条件下,探讨实时油域加热煤样时不同温度对煤样力学及渗流特性的影响。研究结果表明:含瓦斯煤三轴压缩下,温度越高其三轴抗压强度越低,两者呈反相关关系,说明随着温度升高,原煤的抵抗变形能力越小;煤样在受偏应力影响下,轴向应变越大,渗透率呈“V”字演化即先减小到最低点后迅速增大,当处于同一应变条件时,高温度降低了瓦斯的渗透率,不利于瓦斯抽采;温度越高,煤样初始渗透率与最小渗透率呈下降趋势,同一温度下的初始渗透率与最小渗透率之间差值越小。表明温度越高,对煤样的渗透率影响程度越低。

Using the self-reconstructed triaxial experimental device,taking the coking coal of 18506 working face in Malan coal mine of Shanxi as the research object,under the condition of constant confining pressure and gas pressure,the mechanical and seepage characteristics of coal samples with different temperatures during real-time oil field heating coal samples are discussed.The results show that under the triaxial compression of gas containing coal,the higher the temperature,the lower the triaxial compressive strength,and the inverse correlation between the two,indicating that the lower the resistance of the original coal with the increase of temperature;the coal sample is subject to under the influence of partial stress,the larger the axial strain,the higher the permeability of the“V”is,the first is to decrease to the lowest point and then increase rapidly.When it is under the same strain,the high temperature reduces the permeability of gas,which is not conducive to gas.The higher the temperature,the lower the initial permeability and the minimum permeability of the coal sample,and the smaller the difference between the initial permeability and the minimum permeability at the same temperature.It indicates that the higher the temperature,the lower the influence of temperature on the permeability of the coal sample.