Page 93 - Reservoir Formation Damage
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76 Reservoir Formation Damage
1.0
100% WW
66% WW
50% WW
25% WW
(a)
— 0%WW
1.0
(b)
.* 0.4
0.0
Figure 4-6. Relative permeability curves for a range of a) fractionally-wet and
b) mixed-wet systems (McDougall and Sorbie, ©1995 SPE; reprinted by
permission of the Society of Petroleum Engineers).
Donaldson et al. (1987) propose a hyperbolic expression for capillary
pressure as:
A +
Pci = (4-16)
where A, 5, and C are some correlation parameters.
During formation damage the wettability index and the capillary
pressure and relative permeability curves vary continuously. Therefore,
