Reconstruction and seepage simulation of coal and rock pore fracture structure based on CT imaging

In order to explore the seepage characteristics of coal seam pressure water injection under different permeability and fracture conditions, CT scanning technology was used to scan coal samples and obtain the original image. The noise points are filtered by using the median filter function of MATLAB software, and then the original binary image is obtained. Finally, the two-dimensional model of coal body is reconstructed by using the interpolation function in COMSOL numerical analysis software, and the fluid-solid coupling model of coal body seepage process is established, and the seepage evolution process of pressure water is analyzed by numerical simulation. The results show that the pore structure of coal can be accurately described by processing CT scanning images with MATLAB analysis software; the two-dimensional model of coal can be finely characterized by COMSOL interpolation function; the flow of water in coal is mainly affected by pore structure, and the flow attenuation rate of main fissure water is very small, while in the coal matrix and sub-fissure inclusion area, the flow is basically not in the matrix part flow.