
科学技术与工程

中国技术经济学会
Tracer Migration Characteristics of Complex Fractured Rock Mass under Fracture-porosity Dual Media Model
Jia-qi NING , Zi-jun FENG , Qi GAO
Science Technology and Engineering ›› 2025, Vol. 25 ›› Issue (7) : 2904 -2913.
In order to further study the connectivity and hydraulic connection between the injection and production wells in geothermal reservoir, a dual media model of fracture-porosity was constructed by using COMSOL Multiphysic. The effects of the aperture of the fissure group in fractured rock mass, the diffusion coefficient of the rock matrix, and the permeability on the tracer breakthrough curve(BTC) at different dip angles with the mainstream direction were analyzed. The results indicate that the convection of water in the fissure is the main factor influencing the concentration migration. With the increase of the fissure aperture, the migration rate and peak concentration of the tracer are enhanced, and the degree of the influence on the tracer migration by the fissure aperture decreases with the increase of the dip angle of the fissure group. The diffusion coefficient and permeability of the rock matrix have a significant impact on the temporal and spatial distribution of the tracer concentration. With the increase of the matrix diffusion coefficient, the delay effect of the tracer migration is elevated. With the increase of the matrix permeability, the anisotropy of the reservoir pressure and concentration distribution is reduced, and the concentration distribution at the outlet boundary becomes more uniform.
fracture-pore dual media model / tracer migration / convection and diffusion / breakthrough curve
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