Page 161 - Fundamentals of Enhanced Oil and Gas Recovery

149
Thermal Recovery Processes

In the above equation, A RD represents a dimensionless number for scaling the
steam zone.
s ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
ð350Þð144ÞQ s μ
A RD 5 st (5.43)
6:328πρ 2 ρ h t k st ρ
2
o st st
The values of steam viscosity and density are calculated using the following
equations (5.37):
0:9588
3 P s
ρ lb=ft 5 ; P s in psia (5.44)
st
363:9
24
μ cPðÞ 5 10 ð 0:2T s 1 82Þ; T s in F (5.45)
st
The radius and volume of the steam zone are calculated according to the following
equations:
r ffiffiffiffiffiffiffiffi
v s
R h 5 (5.46)
πh st
Q s t inj ρ Q i 1 H last
w
v s 5 (5.47)
vT s 2 T R Þ
ð
The previous method for estimation of the volume represented by Parts (2) in
which the remaining heat of previous cycles that accumulated in the reservoir was
considered. The above equation is a modification to it. The value of the injected heat
per unit mass of steam is calculated as follows:
ð
Q i 5 C w T s 2 T R Þ 1 L vdh f sdh (5.48)
To calculate the value of water enthalpy, latent heat of the steam, and isobaric
volumetric heat capacity of the steam, the following equations are represented
[2,34]:

1:24
T s
h w 5 68 ; T in F (5.49)

100
0:38
L vdh 5 94ð7052T s Þ ; T s in F (5.50)
ðÞ ð ð (5.51)
ρc 5 1 2 ϕÞM o 1 ϕ½ 1 2 S wi ÞM o 1 S wi M w
t
As the initial condition, the occupied heat in the reservoir is set to zero. Volume
of the steam and the mean temperature in each cycle are the basis for calculations.

H last 5 V s ρcðÞ ðT avg 2 T R Þ (5.52)
t