ON THE USE OF CONVENTIONAL COCURRENT AND COUNTERCURRENT EFFECTIVE PERMEABILITIES TO ESTIMATE THE 4 GENERALIZED PERMEABILITY COEFFICIENTS WHICH ARISE IN COUPLED, 2-PHASE FLOW
Rg. Bentsen et Aa. Manai, ON THE USE OF CONVENTIONAL COCURRENT AND COUNTERCURRENT EFFECTIVE PERMEABILITIES TO ESTIMATE THE 4 GENERALIZED PERMEABILITY COEFFICIENTS WHICH ARISE IN COUPLED, 2-PHASE FLOW, Transport in porous media, 11(3), 1993, pp. 243-262
In the case of coupled, two-phase flow of fluids in porous media, the
governing equations show that there are four independent generalized p
ermeability coefficients which have to be measured separately. In orde
r to specify these four coefficients at a specific saturation, it is n
ecessary to conduct two types of flow experiments. The two types of fl
ow experiments used in this study are cocurrent and countercurrent, st
eady-state permeability experiments. It is shown that, by taking this
approach, it is possible to define the four generalized permeability c
oefficients in terms of the conventional cocurrent and countercurrent
effective permeabilities for each phase. It is demonstrated that a giv
en generalized phase permeability falls about midway between the conve
ntional, cocurrent effective permeability for that phase, and that for
the countercurrent flow of the same phase. Moreover, it is suggested
that the conventional effective permeability for a given phase can be
interpreted as arising out of the effects of two types of viscous drag
: that due to the flow of a given phase over the solid surfaces in the
porous medium and that due to momentum transfer across the phase 1-ph
ase 2 interfaces in the porous medium. The magnitude of the viscous co
upling is significant, contributing at least 15% to the total conventi
onal cocurrent effective permeability for both phases. Finally, it is
shown that the nontraditional generalized permeabilities which arise o
ut of viscous coupling effects cannot equal one another, even when the
viscosity ratio is unity and the surface tension is zero.