Three-dimensional analysis for allowable breakout width in vertical well

In drilling operation, breakout formations with allowable width can be accepted although it is a type of formation damages. The study presents a geomechanical analysis which mimics field conditions using a new 3D geomechanical model to predict the allowable breakout width in vertical wells using Mogi-Coulomb criterion with the linear elastic consecutive solution of Kirsch. The classical Moher-Coulomb criterion is used to verify the effect of the intermediate principal stress in determining the breakout width. The impact of the rock parameters and in situ stresses are studied in different in situ stress regimes. It has been found that the friction angle, cohesion, and the minimum horizontal stress are the most critical parameters on the breakout width formation. The studied fields show that using Mogi-Coulomb law gives results within the applied field conditions. Furthermore, adopting the classical Moher-Coulomb failure criterion in the analysis will raise uncertainty in borehole breakout width predictions.