A wellbore stability model for formations with anisotropic rock strengths

Lee, Hikweon; Ong, See Hong; Azeemuddin, Mohammed; Goodman, Harvey

doi:10.1016/j.petrol.2012.08.010

Cited by 121 publications

(55 citation statements)

References 25 publications

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“…In anisotropic rocks bedding plane slip may have a significant effect on borehole and casing stability (Addis et al 1993;Dusseault et al 2001;Gazaniol et al 1995;Økland and Cook 1998;Russell et al 2003;Skelton et al 1995;Willson et al 1999) and has been estimated previously (e.g., Daemen 1983; Gallant et al 2007;Lee et al 2012;Vernik and Zoback 1990). However, the considerable effect of elastic anisotropy has been ignored so far in these analyses.…”

Section: Introductionmentioning

confidence: 93%

Influence of Bedding Angle on Borehole Stability: A Laboratory Investigation of Transverse Isotropic Oil Shale

et al. 2014

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The stability of wells drilled into bedded formations, e.g., shales, depends on the orientation between the bedding and the borehole axis. If the borehole is drilled sub-parallel to bedding, the risk of borehole instabilities increases significantly. In this study, we examined the formation of stress-induced borehole breakouts in Posidonia shale by performing a series of thick-walled hollow cylinder experiments with varying orientations of the bedding plane with respect to the borehole axis. The thickwalled hollow cylinders (40 mm in diameter and 80 mm in length containing an 8 mm diameter borehole) were loaded isostatically until formation of breakouts. The onset of borehole breakout development was determined by means of acoustic emission activity, strain measurements, ultrasonic velocities and amplitudes. The critical pressure for breakout initiation decreased from 151 MPa by approximately 65 % as the bedding plane inclination changed from normal to parallel to the borehole axis. The finely bedded structure in the shale resulted in an anisotropy in elasticity and strength from which the variation in strength dominated the integrity of the thick-walled hollow cylinders.

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Section: Introductionmentioning

confidence: 93%

Influence of Bedding Angle on Borehole Stability: A Laboratory Investigation of Transverse Isotropic Oil Shale

et al. 2014

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“…15. Schematic diagram of the thickness of the shear layers for different β in direct shear tests (the thickness of the shear layer is the distance between the red lines).…”

Section: Theoretical Analysis Of the Anisotropic Shear Strengthmentioning

confidence: 99%

Experimental and theoretical study of the anisotropic properties of shale

Heng

Guo

Yang

et al. 2015

International Journal of Rock Mechanics and Mining Sciences

196

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“…It is implemented by projecting borehole stresses onto the surface of the weak plane and obtaining the resultant shear and effective normal stresses. An extensive discussion on the implementation of this criterion is provided by Lee et al 11 The slip failure criterion (MC w ) is given by:…”

Section: Wellbore Stability Analysismentioning

confidence: 99%

“…8 Tien and Kuo 9 discuss the failure of TI rocks is governed by failure of the rock matrix and sliding along the discontinuity of weak bedding planes. Matrix failure coupled with slip failure effect on optimum drilling mud weight for inclined boreholes is discussed in literature, 10,11 but isotropic stress models are used and no timedependent analysis is discussed. Observed anisotropic shear failure around the borehole caused by matrix and slip failures and their effect on estimating in-situ stresses is analyzed by Lee et al 12 However, the authors do not consider anisotropy in mechanical properties, and a homogenous isotropic rock is assumed throughout.…”

Section: Introductionmentioning

confidence: 99%