Page 49 - Principles of Applied Reservoir Simulation 2E

34 Principles of Applied Reservoir Simulation

'"_-
® r P - ... (4,10)
(A 1 A\
o
a^
a
_a_
r P - W /A 1 1 \
w w w , , > (4.11 j
dx

(4.12)

2
2
where g is the acceleration of gravity in ft/sec , andg c is 32.174 ft/sec (WINB4D
assumes g - g c). These equations should be valid for describing fluid flow in
porous media even if g and g c change, such as on the Moon, Mars, or the space
shuttle. Similar expressions can be written for the>> and z components.
The phase mobility A e is defined as the ratio of the relative permeability
to flow of the phase divided by its viscosity, thus

A, = V»*i (4.13)
The phase densities are related to formation volume factors and gas solubilities
by

= +
Po — [Po*c ^oPff*J' (4.14)

(4.15)

(4.16)

Besides fluxes, we also need concentrations. These are given by

C
o = 4»Po,A/* 0» (4.17)

(4.18)