Multi-field coupled mathematical modeling and numericalsimulation technique of gas transport in deep coal seams

Coalbed gas production contributes to energy diversification and effectively mitigates the risk of mine gas outbursts. However, the complexity and nonlinear characteristics of multifield coupled gas migration in deep coal seams pose significant challenges that traditional prediction and control methods struggle to address. This paper explores the effects of coupled multi-physics fields on gas migration and reviews a numerical simulation method that integrates fractal theory with discrete fracture network modeling, aiming to overcome the limitations of conventional models in capturing the interactions among seepage, heat transfer, stress distribution, and gas adsorption/desorption. The study highlights the interactions between fractures and pores, as well as the coupling effects between fluids f low, heat transfer, and solid mechanics. It further presents a more accurate prediction method to enhance the simulation accuracy of gas migration in deep coal seams. Document Type: Perspective Cited as: Wang, Q., Ji, M., Liu, G., Fan, S. Multi-field coupled mathematical modeling and numerical simulation technique of gas transport in deep coal seams. Advances in Geo-Energy Research, 2025, 15(1): 87-90. https://doi.org/10.46690/ager.2025.01.09 References Abushaikha, A. S., Gosselin, O. R. Matrix-fracture transfer function in dual-medium flow simulation: Review, comparison, and validation. Paper SPE 113890 Presented at the Europec featured at EAGE Conference and Exhibition, Rome, Italy, 9-12 June, 2008. Blokhina, L., Koptev-Ovornikov, V., Lomize, M., et al. Principles of classification and nomenclature of the ancient volcanic clastic rocks. International Geology Review, 1959, 1(12): 56-61. Ge, S., Hao, S., Zhang, S., Zhang, X. Status of intelligent coal mining technology and potential key technologies in China. Coal Science and Technology, 2020, 48(7): 28-46. Hao, J., Liang, B., Sun, W. Experimental study on the thermal effect during gas adsorption and desorption on the coal surface. ACS Omega, 2021, 6(2): 1603-1613. Hsieh, P. A., Neuman, S. P., Stiles, G. K., Simpson, E. S. Field determination of the three-dimensional hydraulic conductivity tensor of anisotropic media: 2. Methodology and application to fractured rocks. Water Resources Research, 1985, 21(11): 1667-1676. Isaev, R. Hydrodynamic and thermodynamic special characteristics of unsteady-state nonequilibrium filtration processes of multiphase mixtures in fissured-porous media. Fluid Dynamics, 1971, 6(1): 111-118. Liu, G., Ye, D., Yu, B., et al. A study on gas drainage considering coupling process of fracture-pore microstructure and coal deformation. Fractals, 2021, 29(2): 2150065. Wang, B., Wang, D., Cao, W., et al. Review of the hydrogeological controls on coalbed methane (CBM) and development trends. Geofluids, 2021, 2021(10): 1-14. Whitelaw, P., Uguna, C. N., Stevens, L. A., et al. Shale gas reserve evaluation by laboratory pyrolysis and gas holding capacity consistent with field data. Nature Communications, 2019, 10(1): 3659. Wilson, C. R., Witherspoon, P. A. Steady state flow in rigid networks of fractures. Water Resources Research, 1974, 10(2): 328-335. Zhu, X., Liu, G., Gao, F., et al. A complex network model for analysis of fractured rock permeability. Advances in Civil Engineering, 2020, 2020(1): 1-10.