ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Two-phase flow in porous media is described based on the extended form of Darcy's law, which ignores momentum transfer at fluid-fluid interfaces. Two forms of corrections to this simple description have been proposed in the literature: one on the relative permeability dependence on viscosity ratio; the other on the velocities assumed to be proportional to both phase pressure gradients and so introducing an additional saturation-dependent cross coefficient.In this article, to identify the correct form of transport equations, a simple cubic network model of 30 × 30 × 30 bonds is used. The cross section of the bonds is that of a four-cusp duct. The fluid interface in each duct is located by capillary equilibrium. The duct hydraulic conductances are then obtained as a function of viscosity ratio and phase volume fraction using a finite element calculation. These individual duct results are used in the network calculations for which a percolation algorithm is applied to simulate nonwetting phase displacing wetting phase, a process also known as initial drainage. Flow calculations show that both the nonwetting-phase relative permeability and the cross coefficient are strong functions of saturation and viscosity ratio. Also, the off-diagonal terms may contribute to a nonnegligible fraction of the flow. The proposed generalization of the Darcy equations is applicable to all problems involving multiphase flow in porous media. The current practices for relative permeability measurements and reservoir simulation may have to be reexamined in the context of the proposed transport equations.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690390705
Permalink
