Field scale impacts of spatially correlated relative permeability in heterogeneous multiphase systems

Abstract

Two-dimensional numerical simulations of two-phase (DNAPL-water) flow in spatially correlated random fields demonstrate the influence of nonwetting phase (NWP) relative permeability–saturation ( k r,N– S W) relationships correlated to porous media intrinsic permeability ( k). Both the volume of porous media invaded by the NWP and the length of time during which the NWP is migrating are under predicted if k r,N– k correlation is not accounted for in the model formulation. Not accounting for the k r,N– k correlation resulted in under predicting the volume of porous media invaded by up to approximately 10%, which is likely not significant for many practical applications. However, not accounting for the k r,N– k correlation resulted in under predicting field scale migration times by up to a factor of 4, which is likely significant in that the migration times are on the order of years to several decades for the DNAPL (1,2-DCE) considered in this study. The under prediction of migration times was greater for lower permeability aquifers.