Lattice Boltzmann simulations of wetting and its application to disproportionate permeability reducing gel

The binary fluid lattice Boltzmann method is a promising numerical scheme t o simulate the flow of two immiscible fluids at the pore level. In particul ar, the method minimizes an appropriate free energy functional thus ensurin g a thermodynamically consistent behaviour in equilibrium. Pie present an e xtension of this method, such that walls with different wettability can be included. This is done by adding a "background chemical potential" to the f luid chemical potential. A calibration of the wettability is given, showing how the equilibrium contact angle depends on the background chemical poten tial. Next, the method is used in a qualitative study of gel-placement in a fractional-wet porous medium model. The presence of gel shows to reduce th e water permeability more than the oil permeability. Thus, the wanted dispr oportionate permeability reduction (DPR) effect applies. (C) 1999 Elsevier Science B.V. All rights reserved.