TY - JOUR
T1 - Stability analysis of vertical boreholes using the Mogi-Coulomb failure criterion
AU - Al-Ajmi, A. M.
AU - Zimmerman, R. W.
PY - 2006/12
Y1 - 2006/12
N2 - A main aspect of wellbore stability analysis is the selection of an appropriate rock failure criterion. The most commonly used criterion for brittle failure of rocks is the Mohr-Coulomb criterion. This criterion involves only the maximum and minimum principal stresses, σ1 and σ3, and therefore assumes that the intermediate stress σ2 has no influence on rock strength. As the Mohr-Coulomb criterion ignores the strengthening effect of the intermediate stress, it is expected to be too conservative in estimating the critical mud weight required to maintain wellbore stability. Recently, Al-Ajmi and Zimmerman [Relationship between the parameters of the Mogi and Coulomb failure criterion. Int J Rock Mech Min Sci 2005;42(3):431-39.] developed the Mogi-Coulomb failure criterion, and showed that it is reasonably accurate in modelling polyaxial failure data from a variety of rocks. We then develop a model for the stability of vertical boreholes, using linear elasticity theory to calculate the stresses, and the fully-polyaxial Mogi-Coulomb criterion to predict failure. Our model leads to easily computed expressions for the critical mud weight required to maintain wellbore stability.
AB - A main aspect of wellbore stability analysis is the selection of an appropriate rock failure criterion. The most commonly used criterion for brittle failure of rocks is the Mohr-Coulomb criterion. This criterion involves only the maximum and minimum principal stresses, σ1 and σ3, and therefore assumes that the intermediate stress σ2 has no influence on rock strength. As the Mohr-Coulomb criterion ignores the strengthening effect of the intermediate stress, it is expected to be too conservative in estimating the critical mud weight required to maintain wellbore stability. Recently, Al-Ajmi and Zimmerman [Relationship between the parameters of the Mogi and Coulomb failure criterion. Int J Rock Mech Min Sci 2005;42(3):431-39.] developed the Mogi-Coulomb failure criterion, and showed that it is reasonably accurate in modelling polyaxial failure data from a variety of rocks. We then develop a model for the stability of vertical boreholes, using linear elasticity theory to calculate the stresses, and the fully-polyaxial Mogi-Coulomb criterion to predict failure. Our model leads to easily computed expressions for the critical mud weight required to maintain wellbore stability.
KW - Drucker-Prager failure criterion
KW - Failure criteria
KW - Mogi failure criterion
KW - Polyaxial test data
KW - Wellbore stability
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U2 - 10.1016/j.ijrmms.2006.04.001
DO - 10.1016/j.ijrmms.2006.04.001
M3 - Article
AN - SCOPUS:33748523012
SN - 1365-1609
VL - 43
SP - 1200
EP - 1211
JO - International Journal of Rock Mechanics and Mining Sciences
JF - International Journal of Rock Mechanics and Mining Sciences
IS - 8
ER -