Page 161 - Reservoir Geomechanics
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a.
JOINT
Increase in shear deformation increase in permeability
SHEARED JOINT
ONSET OF DAMAGE
BRECCIATION IN SHEAR ZONE
b.
OIL STAINING
Figure 5.2. Schematic illustration of the evolution of a fault from a joint (after Dholakia, Aydin
et al. 1998). As shear deformation occurs, brecciation results in interconnected porosity thus
enhancing formation permeability. In the Monterey formation of California, oil migration is
strongly influenced by the porosity generated by brecciation accompanying shear deformation on
faults. This can be observed at various scales in core (a) and outcrop (b). AAPG C 1998 reprinted by
permission of the AAPG whose permission is required for futher use.
