NO VISCOUS FINGERS IN HETEROGENEOUS POROUS-MEDIA

We have carried out computer simulation of miscible displacements in p orous media in which the permeabilities vary spatially according to a fractional Brownian motion. This distribution induces long-range corre lations and has been found to describe the permeabilities of heterogen eous rocks. Our simulation shows that conventional viscous fingers, wh ich are the result of the contrast M between the viscosities of the di splacing and displaced fluids, and are usually found in laboratory exp eriments, do not exist. Displacement patterns and efficiency are contr olled by the heterogeneities, and the viscosity contrast M, varied her e between 1 and infinity, has essentially no effect.