Page 340 - Principles of Applied Reservoir Simulation 2E

Part V: Technical Supplements 325

Gas

(32.14)
d_'
dt B^ B,

The gravity and capillary contributions to the phase pressures have been
collected in the terms CG 0, CG W, and CG g:

CG„ = -V • K •Z V (32.15)

(32 16)
= -V • K -

and

,
CG„ = V • K - -* ego
-, , 144
JLtt
(32.17)

- V 1 A i \ n > V \P. t A A
I
COW
144 / S I 144
Essentially our task is to solve Eqs. (32.12) through (32.14) and saturation
constraint Eq. (4.20) for the four unknowns P 0,S 0,S W, and S g. All other physical
properties in the equations are known, in principle, as functions of the four
unknowns, or from field and laboratory data.

32,3 The Pressure Equation

The procedure used in WINB4D to solve the flow equations requires that
we first combine Eqs. (4.20) and (32.12) through (32.14) such that we have only