Abstract
Oil and gas wells frequently pass through bedded rocks. It is widely recognized that failure of these anisotropic formations is a common cause of operational difficulties. Consequently, predicting the behaviour of bedded formations is an important component in the process of optimizing oilfield procedures.
This paper presents a semi-analytic model which predicts the conditions under which failure occurs around a borehole in bedded formations. The model idealizes the problem by considering a cylindrically circular cavity emdedded in a homogeneous tranversely isotropic elastic medium. Rock failure is modelled using a generalized form of the Mohr-Coulomb criterion (Casagrande and Castillo, 1944), where strength is a smooth function of the failure properties normal and parallel to bedding. There is no restriction on the orientations of both the in-situ stress state and plane of transverse isotropy with respect to the borehole axis.
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© 2002 Springer Science+Business Media Dordrecht
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Atkinson, C., Bradford, I. (2002). Effect of Inhomogeneous Rock Properties on the Stability of Wellbores. In: Karihaloo, B.L. (eds) IUTAM Symposium on Analytical and Computational Fracture Mechanics of Non-Homogeneous Materials. Solid Mechanics and Its Applications, vol 97. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-0081-8_13
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DOI: https://doi.org/10.1007/978-94-017-0081-8_13
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-5977-2
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