Page 185 - Applied Petroleum Geomechanics

In situ stress regimes with lithology-dependent and depletion effects 179

Salz (1977) obtained the following linear relationship between the mini-
mum horizontal stress and the reservoir pressure (Fig. 5.12B):
s h ¼ 0:57p p þ 5385 (5.23)

where the minimum horizontal stress and the reservoir pressure are in psi,
and the stress path c ¼ 0.57.
Addis (1997) analyzed the stress-depletion response in several petroleum
reservoirs. The depletion-induced stress path (Ds h /Dp p ) is very different in
different fields. Furthermore, it can be different even in the same field, e.g.,
in the Ekofisk field, the North Sea, Ds h /Dp p ¼ 0.84 in the basin crest, Ds h /
Dp p ¼ 0.82 in the flank, but Ds h /Dp p ¼ 0.77 in the outer flank (Teufel
et al., 1991). Table 5.1 lists the measured stress paths in some petroleum

Table 5.1 The ratios of measured depletion-induced minimum stresses to the
reservoir pressures in some petroleum basins.
Stress
Field or measurement Stress path
formation Rock type method c (Ds h /Dp p ) References
Middle Bakken, Calcitic DFIT 0.79 Dohmen
ND dolomitic et al. (2017)
siltstone
Vicksburg Sandstone Shut-in 0.57 Salz (1977)
formation, TX
Waskom, TX Sandstone Shut-in 0.46 Whitehead
et al. (1987)
Magnus, North Sandstone Fracture 0.68 Shepherd
Sea opening (1991)
West Sole, Sandstone Shut-in 1.18 Addis (1997)
North Sea
Wytch Farm, Sandstone Wellhead 0.63 Colter and
UK injection Havard
(1981)
Ekofisk, North Chalk Shut-in w0.8 Teufel et al.
Sea (1991)
Tor reservoir, Chalk LOT 0.7 in the Zoback and
Valhall, North crest, Zinke (2002)
Sea. 0.84 in the
flank.
CPSE field, Sandstone Repeated 0.84 Nelson et al.
Brunei LOT (2005)
Gulf of Mexico, Sandstone LOT w0.65
USA