Page 44 - Principles of Catalyst Development

Part I: Reservoir Engineering Primer 25

Relative Permeability
The general definition of relative permeability is

= -^ (3.10)
k r
k
abs
where
relative permeability between 0 and 1 ,
k r
effective permeability [md]
k eff
absolute permeability [md]
k abs
Fluid phase relative permeabilities for oil, water and gas phases, respectively,
are

k ro-kjk tk^kjk tk r^kjk (3.11)

where k$ is the effective permeability of phase (!, & ri is the relative permeability
of phase d, and k is absolute permeability.

Mobility
Fluid phase mobility is defined as the ratio of effective phase permeability
to phase viscosity. Mobility for oil, water and gas phases respectively are

V — • ^ = — • V- (3.12)
U LI U,
~0 r*W ' g
is the viscosity of phase 1 Relative mobility is defined as relative
where |l f
permeability divided by viscosity [Dake, 1978]. Absolute permeability is not
a factor in the definition of relative mobility.

Mobility Ratio
Mobility ratio is defined as the mobility of the displacing fluid "k D behind
the front divided by the mobility of the displaced fluid K d ahead of the front,
thus

(3.13)