Method and device for evaluating physical damage of coal reservoir

The invention relates to the field of coal reservoir physical property damage evaluation, and discloses a coal reservoir physical property damage evaluation method and device. According to the method, the water flow velocity distribution of the near-well coal reservoir can be determined in the drainage and pressure reduction stage of the coal-bed gas well. The pulverized coal particles are classified based on the relationship between the particle size of the pulverized coal particles and the degree of difficulty of passing through the fissure pore throat to determine at least one boundary particle size. And determining each boundary particle size and the starting water flow velocity corresponding to the minimum pulverized coal particle size according to the stress analysis result of the pulverized coal particles in the water. The near-well coal reservoir is divided into a plurality of pulverized coal particle movement areas based on the starting water flow velocity and the water flow velocity distribution. An