Two-dimensional hydrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic fluid flow through porous media

The behavior of two-dimensional binary and ternary amphiphilic fluids under flow conditions is investigated using a hydrodynamic lattice-gas model. Af ter the validation of the model in simple cases (Poiseuille how, Darcy's la w for single component fluids), attention is focused on the properties of b inary immiscible fluids in porous media. An extension of Darcy's law which explicitly admits a viscous coupling between the fluids is verified, and ev idence of capillary effects is described. The influence of a third componen t, namely, surfactant, is studied in the same context. Invasion simulations have also been performed. The effect of the applied force on the invasion process is reported. As the forcing level increases, the invasion process b ecomes faster and the residual oil saturation decreases. The introduction o f surfactant in the invading phase during imbibition produces new phenomena , including emulsification and micellization. At very low fluid forcing lev els, this leads to the production of a low-resistance gel, which then slows down the progress of the invading fluid. At long times (beyond the water p ercolation threshold), the concentration of remaining oil within the porous medium is lowered by the action of surfactant, thus enhancing oil recovery . On the other hand, the introduction of surfactant in the invading phase d uring drainage simulations slows down the invasion process-the invading flu id takes a more tortuous path to invade the porous medium-and reduces the o il recovery (the residual oil saturation increases).