Summary

Fracture distribution and strain were measured in a pair of beds adjacent to a normal fault in an effort to establish relations among lithology, fracture density, aperture, and structural position. The outcrop study demonstrates that markedly different fracture distributions can be found in beds within the same sedimentary sequence. Whereas one bed exhibits intense fracturing and a dramatic increase in fracture-related strain in the vicinity of the fault zone, the neighboring bed reveals a decrease in fracture intensity and strain. Although faulting may contribute to localized fracturing in adjacent wall rock, the intensity of fracturing will vary from one bed to the next. Therefore, aspects of mechanical stratigraphy must be taken into account if one wishes to estimate fracture intensity in faulted reservoirs.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas