1. Fractures restricted to strongly cemented sandstone
Petrophysical Controls on Fault Damage Zone Width and Character: As Important as Displacement? Laurel B. Goodwin and Harold Tobin, University of Wisconsin - Madison Madison, WI 53706
To test our hypothesis that grain contact strength is a primary control on fault damage zone width and structural character, we are characterizing both sandstones and fault structures through a combination of image analysis and ultrasonic velocity.
Damage zones can significantly impact fluid flow in sandstones: open fracture networks enhance permeability, whereas shear deformation bands reduce permeability and slow production. Damage zone width as well as spacing and character of damage zone structures vary with lithology at the Moab fault, Utah.
Fractures restricted to strongly cemented sandstone
Shear deformation bands in less well cemented units. Deformation bands are narrower and more widely spaced in red, clay-rich units.