TESTING STUDY ON SEEPAGE PROPERTIES OF METHANE GAS IN COAL UNDER THE ACTION OF GEO-ELECTRIC FIELD
地电场作用下煤中甲烷气体渗流性质的实验研究

The geoelectric field in geophysical field is effective on seepage properties of coalbed gas. The seepage properties of Methane gas in coal under the action of geoelectric field are investigated by triaxial compression and seepage test in this paper. The testing results indicate that seepage velocity of methane gas under geoelectric field is much larger than that with no geoelectric field,and increases linearly with the pressure gradient of methane gas. Under geoelectric field,the quantity of methane gas seepage in coal increases approximately linearly with voltage or electric field strength. The higher the degree of coal metamorphism is,the better the conductivity of coal is and the clearer the electric effect of methane gas in coal is. The equivalent gas permeability ke in coal can be expressed by )1(eEkkb+=. The testing study makes a foundation to further investigation on coalbed gas seepage and flow laws.