knowledge of the orientation of horizontal in situ stresses is important to some areas of oil and gas field development plans. borehole breakouts observed in image logs and drilling-induced fractures are the main parameters for the determination of the stresses’ directions in situ. in this work, the orientations of borehole breakouts were investigated as a function of depth in oil wells a and b...

Knowledge of the orientation of horizontal in situ stresses is important to some areas of oil and gas field development plans. Borehole breakouts observed in image logs and drilling-induced fractures are the main parameters for the determination of the stresses’ directions in situ. In this work, the orientations of borehole breakouts were investigated as a function of depth in oil wells A and ...

Few in the Australian oil patch were familiar with the term 'borehole breakout' when David Lowry alerted PESA Journal readers to this phenomenon (1990, v.17, p. 43-44). Ten years later, few are unfamiliar, with breakouts having been reported in every Australian basin subject to significant drilling activity. This change witnesses the dramatically increased awareness of borehole geomechanics in ...

Investigating the shear failure caused by concentration of compressive stress around noncircular boreholes is important both in field and laboratory. This article deals with numerical analysis elliptical under a nonisotropic situ using Mogi–Coulomb nonlinear criterion. The purpose presented model to simulate progressive (breakout) borehole investigate impact eccentricity on stability depth widt...

Different strategies and tools are available at the oil and gas industry for detecting and analyzing tension and possible fractures in borehole walls. Most of these techniques are based on manual observation of the captured borehole images. While this strategy may be possible and convenient with small images and few data, it may become difficult and suitable to errors when big databases of imag...

Observations of crustal stress orientation from the regional inversion earthquake focal mechanisms often conflict with those borehole breakouts, possibly indicating local heterogeneity, either laterally or depth. To investigate this we compiled SHmax estimates previous studies for 57 near-vertical boreholes measured breakout azimuths across Los Angeles region. We identified subsets established ...

Breakout is a shear failure due to compression that forms around the borehole stress concentration. In this paper, breakout theory model investigated by combining equilibrium elasticity equations of with two Hoek-Brown and Fairhurst generalized fracture criteria, both which are based on Griffith criterion. This provides an explicit equation for width, but depth obtained solving quartic equation...