MACRODISPERSION FOR 2-PHASE, IMMISCIBLE FLOW IN POROUS-MEDIA

Two-phase immiscible flow in a heterogeneous porous media is studied. The permeability is given as a log-normal random function with a given mean, variance and correlation. A set of up-scaled model equations wi th a new effective macrodispersion tensor is derived for such models. The macrodispersion solution is compared with high-resolution solution s of the original equations, based on several realizations in the perm eability. It is shown that the average solution gives a very accurate approximation of the flow. A model with a two-scale permeability field is also studied where the variation on the largest scale is kept in t he averaged equations. Here too the macrodispersion solution is compar ed with high-resolution solutions and the result is very promising. Ca pillary diffusion effects on the macrodispersion is also discussed.