Removal of LNAPL (oil) from an aquifer is described using a multi-phase flow model. At the well boundary seepage face conditions are imposed. These conditions are implemented in a numerical model and withdrawal in a two-dimensional domain is simulated for two different geometries of the oil lens and for varied values of the physical parameters. Assuming vertical equilibrium, the oil flow equation is reduced by vertical integration. The well boundary condition is approximated by imposing zero oil lens thickness. Similarity solutions of the reduced equations for the two geometries show good agreement with the numerical results in most cases.

Free boundary problems (msc 35R35), Finite elements, Rayleigh-Ritz and Galerkin methods, finite methods (msc 65M60), Flows in porous media; filtration; seepage (msc 76S05), Two-phase and multiphase flows (msc 76Txx)
Modelling, Analysis and Simulation [MAS]

van Dijke, M.I.J, & van der Zee, S.E.A.T.M. (1997). Analysis of oil lens removal by extraction through a seepage face. Modelling, Analysis and Simulation [MAS]. CWI.