Simulation of subterranean heating of coal by passing electrical current through electrothermal breakdown channel

The paper describes a mathematical model that simulates the heating of an underground coal bed by passing electrical current through electrothermal breakdown channel. The breakdown channel, which is a heat source, is formed between two electrodes located in the wells inside the subterranean formation. The electrodes are connected by cables to the aboveground electrical equipment. The diameter of electrothermal breakdown channel at the time of formation is small, and it expands as the coal is heated and carbonized in the vicinity of the channel. The distance between the electrodes is set to 0.5 meters. The values of dielectric and thermal properties are taken on the basis of experimental and literature data for the coals of the Republic of Kazakhstan. The time dependences of the temperature in the center of the heated part of the reservoir at different heating powers are obtained. The images of the thermal field in the heated region and its immediate vicinity are shown. The results of calculations of electrical parameters of required for heating electrical equipment, and changes in these parameters over time as heating, is given.