Effect of rock strength variation on the estimated borehole breakout using shear failure criteria

One of the primary goals of wellbore stability analysis is the estimation of the shear failure onset or borehole breakout. Estimation of borehole shear failure requires selecting an appropriate failure criterion. Numerous failure criteria have been used for rock failure analysis, but there is no common agreement of which criterion to select for wellbore stability analysis. In general, rock failure criteria mainly depend on rock mechanical...