含瓦斯煤岩导电特性研究综述

Review of Conductive Characteristics of Gas-bearing Coal

随着中国煤炭开采及瓦斯抽采向更深层开发,对含瓦斯煤岩的导电特性评价技术要求更高,尤其是利用导电性预测深部高瓦斯煤层。系统梳理了近年来国内外含瓦斯煤岩导电性研究的相关文献,着重分析了应力变化、孔隙特征、变质程度以及煤岩吸附和解吸瓦斯过程中煤电阻率的变化机理,得出主控因素有:导电方式、残余形变、水-气置换等。为了实现从定性划分瓦斯带分布到定量计算瓦斯含量、煤矿安全开采过程中高瓦斯带预警以及瓦斯抽采过程中瓦斯含量精准预测,应从地球物理测井角度出发,深入剖析煤岩瓦斯含量与电阻率变化量间的定量关系,明确含瓦斯煤岩的导电机理,将是未来该领域的研究方向和发展趋势。

With the deeper development of coal mining and gas drainage,the demands of the evaluation techniques of gas-bearing coal electrical conductivity are getting higher and higher,especially,the electric conductivity is used to predict the deeper coal seam with high gas content.The relevant literature on the electrical conductivity of gas-bearing coal at home and abroad in recent years was fully investigated,the variation mechanism of the coal electrical resistivity with stress change,pore characteristics,metamorphism of coal,adsorption and desorption process of gas-containing coal were analyzed with emphasis.It is concluded that the main reasons for the changes are conductive mode,residual deformation,water-gas replacement and so on.For the safety of coal mine production,high gas zones were given early warning and of the gas contents were predicted accurately,from qualitative division of gas distribution to quantitative calculation of gas content can be achieved.From geophysics logging point of view,it is the research direction and development tendency of this field to detailed analyse the quantitative relationship between the gas content and the change of coal resistivity,and formulate the conduction mechanism of gas-bearing coal.