Feasibility of measuring water transport distance in coal by resistivity method

Abstract

To quantitatively test the migration distance of water in coal, this paper develops the resistivity measurement technology and discusses its feasibility. The results show that the water transport distance measured by layered electrode arrangement method and color indicator method increase with the increase of time. With the increase of migration time, the change of coal sample resistivity can be divided into three change processes, which are sudden change process, rapid change process and gradual change process. The migration distance measured by resistivity method and color indicator method are basically the same, and the relative error is between -4.2% and 5.8%. The methods of arranging comb electrodes, arranging layered electrodes and arranging test electrodes with vertical holes at one end can be used to test the migration distance of unloaded confining pressure cylindrical samples, loaded axial pressure/surrounding constrained samples and loaded axial pressure/confining pressure samples, respectively.

Keywords

• resistivity method
• migration distance of water
• color indicator method
• porous media
• water-methane-coal