不同瓦斯压力和孔隙率的原煤电阻率和渗透率变化规律研究

Study on variation laws of resistivity and permeability for raw coal with different gas pressure and porosity

为了解不同瓦斯压力和孔隙率下原煤的电阻率和渗透率变化及电阻率和渗透率的响应规律,以淮南矿区谢一矿51采区C15煤层煤体为研究对象,研究不同瓦斯压力和孔隙率下煤样三轴压缩全过程的电阻率与渗透率的变化规律。研究结果表明:孔隙率相同时,最小电阻率和最小渗透率随着瓦斯压力的增大先增加后减小,瓦斯压力在4 MPa时,最小渗透率基本为0;瓦斯压力相同时,最小电阻率和最小渗透率随着孔隙率的增大而增大;全应力应变过程电阻率和渗透率满足随应变的增大先减小后增大的规律,不同加载阶段电阻率变化和渗透率变化规律保持一致,渗透率变化幅度比-应变曲线拐点滞后于电阻率变化幅度比-应变曲线;可利用电阻率变化规律反映应力变化以及渗透率变化情况。

In order to understand the variation of resistivity and permeability for raw coal under different gas pressure and porosity and the corresponding response laws of resistivity and permeability,taking the coal body of C15 coal seam in 51 mining area of Xieyi mine in Huainan mine area as the research object,the variation laws of resistivity and permeability for coal samples in the whole process of triaxial compression under different gas pressure and porosity were studied. The results showed that the minimum resistivity and the minimum permeability increased first and then decreased with the increase of gas pressure Cthe porosity was same,and the minimum permeability was 0 basically with the gas pressure at 4 MPa. The minimum resistivity and the minimum permeability increased with the increase of porosity when the gas pressure was same. The resistivity and permeability in the complete stress-strain process decreased with the increase of strain,and the variation laws of resistivity and permeability in different loading stages were consistent. The inflection point in the variation amplitude ratio-strain curve of permeability lagged behind that of resistivity. The variation laws of resistivity can reflect the variation of stress and permeability.