COMPUTER-SIMULATION OF RADIAL VISCOUS FINGERING IN 2-DIMENSION POROUS-MEDIA

A computer model of capillary and viscous fingering in a porous medium is presented which treats the medium as a square lattice connected wi th randomly chosen radius. The fractal properties of the model are stu died for circular shell-shell aggregation by a Monte Carlo simulation. The simulation results show that the dimension D increases with decre ase of the viscous ratio M and increase of the throat radius. It is fo und that the displacement process is stable when M = 1, and viscous fi ngering pattern of porous media in the limit M --> infinity is similar to the diffusion-limited aggregation pattern in a uniform system. For larger viscous ratio M and smaller positive integer k, the fluid is s ituated in the co-existence region of viscous and capillary fingering.