Comparative Analysis of Seepage Law of Gas and Water in Coal Body at Microscopic Level

The long-flame coal slice data image was obtained by CT scanning, and the three-dimensional reconstruction was performed by Avizo. The target area of 60 μm×80 μm×120 μm was intercepted and processed to obtain the coal sample model with real pore structure. The method of the model, the inlet and outlet pressure difference is set to 3 MPa, the low pressure gas and water seepage simulation are carried out, and the seepage characteristics are compared and analyzed. The results show that the overall change trend of gas and water injection seepage is consistent, and the trend of flow velocity and mass flow rate is also consistent. The maximum average flow velocity of xy section appears near the seepage outlet, which is the 114th section. The maximum mass flow rate appears on the inlet section. In contrast, the flow rate of gas seepage is much larger than that of water, and the mass flow of water is much larger than that of gas.