Semi-analytical Method for Modeling Wellbore Breakout Development

Abstract Borehole breakout initiation, progression, and stabilization are modeled using a semi-analytical method based on Melentiev’s graphical conformal mapping procedure, Kolosov–Muskhelishvili complex stress potentials. The only input data required the elastic moduli of rock, Coulomb strength parameters (cohesion angle internal friction), far-field stresses. stresses around borehole wall computed, region in which rock has failed is then “removed”, creating new shape. This process iterated until shape obtained for will progress no further, stable state been reached. modeling shows that flank evolve so as to reduce propensity shear failure, helps explain why width remains relatively constant throughout process, even deepens radially. area becomes smaller more localized, tip sharpens deepens. Using Mogi–Coulomb failure criterion, good match between geometry observed by Herrick Haimson laboratory experiments an Alabama limestone. leads correlation geometry, properties, situ stress. paper ends with critical discussion possibility inferring from geometries.