Application of Borehole Breakouts to Geothermal Exploration and Development: An Example from Cove Fort-Sulphurdale, Utah

Abstract

Borehole breakouts form in response to in situ stresses an define the principal stress orientations. Horizontal stresses imposed on the rock are concentrated at the borehole margin, perpendicular to the direction applied. Breakouts result from tensile and shear failure at the stress concentration points. At the Cove Fort Sulphurdale field breakouts define fault bounded blocks of rock with independent stress fields related to a particular fault system. Stress directions change between wells and change abruptly across faults within wells. The following is concluded.: different stresses on either reside of a fault may tend to keep permeability high; stress orientation will determine whether injected fluids return to production fractures; knowledge of stress orientation is required for planning hydrofractures stimulation and directional drilling.