A. S. Abou-Sayed,C. E. Brechtel,R. J. Clifton
Source: Journal of Geophysical research V 83, No B6, PP 2851-2862, June 10, 1978.
In situ stress determination by hydrofracturing: A fracture mechanics approach In situ stress determination by hydrofracturing: A fracture mechanics approach
Abstract
The in situ stress field was determined at a depth of 837 m (2745 feet) in Devonian Shale (‘gray’ shale) within the Rome Basin in West Virginia. Logging data and laboratory observations of core samples reveal vertical cracks oriented at N50°–60°E. Because of these cracks and their preferred orientation a new approach based on fracture mechanics concepts is used to evaluate the in situ stresses from the field and laboratory data. The resulting prediction of the maximum horizontal stress (σHmax) is compared to the maximum horizontal stress predicted by Haimson and Fairhurst’s (1967) method; the latter method appears to overestimate the value of this stress component because the effect of loading the faces of any preexisting crack is neglected.