Page 183 - Fundamentals of Enhanced Oil and Gas Recovery

171
Thermal Recovery Processes

(Data: r to , r ci , r co , r h , α f , k hf , ε to , ε ci , k hcem )
21

r to r to ln r to =r ti 1 r to ln r co =r ci r to ln r hd =r co
U to 5 1 1 1 1
r ti h f k htub h nc 1h r k hcas k hcem
Approximation:
h f , k htub , and k hcas are large:
21

1 r to ln r hd =r co
U to 5 1
ð h nc 1h r Þ k hcem
Data (known parameters):
Injecting steam

T s 5 600 ( F)
Well completion
r to 5 0.146 (ft), r co 5 0.4 (ft), r ci 5 0.355 (ft), and r h 5 0.5 (ft)
Stagnant air at 14.7 psia in annulus
Formation characteristics

T e 5 100 ( F), L 5 3000 (ft),
Heat transfer parameters

k hf 5 1 (Btu/h ft F), k hcem 5 0.2 (Btu/h ft F),

ε to 5 ε to 5 0.9
2
α f 5 0.0286 (ft /h)
Mill scale: Iron oxides
1. Estimate U to from T to
2. Calc. f(t) (for t . 1 week)
p ffiffiffiffiffiffiffi !
α f t
ftðÞ 5 ln 2 0:29
r hd
!
p ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
ð
ð 0:0286Þ 504Þ
5 ln 2 0:29
0:5
5 2:43
3. T h ,

T s ftðÞ 1 T e k hf =r to U to
T h 5
ftðÞ 1 k hf =r to U to

ð
ð
ð 600Þ 2:43Þ 1 100 1= 0:146Þ 4:05ÞÞ
ð
ð
5 5 395 F

ð
ð
ð
ð 2:43Þ 1 1= 0:146Þ 4:05ÞÞ