Simulation study on permeability variation law of coal creep process around injection well

Through the numerical simulation method of COMSOL software, the change law of permeability of the injected coal in creep process is studied.The influence of temperature on the mechanical parameters of coal is obtained by physical experiment.The temperature is analyzed for the creep of coal and the role of changes in its permeability.It is considered that if the temperature of the coal is higher than the threshold value of 383 K, the temperature rise will cause the coal skeleton to expand outward, and the initial permeability will increase; when the coal temperature is lower than the threshold value, the temperature increase will lower the initial permeability.After 20 days of heat injection, the creep deformation of the coal around the injection well is intensified, and its permeability is declining due to creep.