Page 283 - Fundamentals of Reservoir Engineering
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OILWELL TESTING 220
(a) (b) (c)
30 ft
15 ft
6 ft
0.25 ft
150 ft 150 ft 150 ft
15 ft
75 ft
Fig. 7.31 Examples of partial well completion showing; (a) well only partially
penetrating the formation; (b) well producing from only the central portion of
the formation; (c) well with 5 intervals open to production (After Brons and
19
Marting )
S b
28
24
20
16
12 10,000
h = 100
300
8 w r 20
50
10
4 5
2
1
0
0 0.2 0.4 0.6 0.8 1.0
b
19
Fig. 7.32 Pseudo skin factor S b as a function of b and h/r w (After Brons and Marting )
(Reproduced by courtesy of the SPE of the AIME)
19
Brons and Marting have shown that the deviation from radial flow due to restricted
fluid entry leads to an additional pressure drop close to the wellbore which can be
interpreted as an extra skin factor. This is because the deviation from radial flow only
occurs in a very limited region around the well and changes in rate, for instance, will
