Modeling size effects associated with tensile fracture initiation from a wellbore

This paper investigates different tensile fracture initiation criteria on the plane-strain configuration of a defect-free openhole wellbore. It aims to model the effect of the internal pressurization of a wellbore drilled in the direction of one of the principal stresses. We compare a brittle initiation model that accounts for both the necessary stress and energy conditions (mixed criteria) for the development of a fracture with a bilinear...