The collapse tension and fracture pressure for shale–sandstone have been computed across various elastic modulus and Poisson’s ratios to determine the safe density window. The Patchy Plane of Weakness criterion extends Jaeger’s single weak plane product by likewise dividing the failure of laminated shale into two distinctive, discontinuous areas. https://vertechs93570.suomiblog.com/about-wellbore-stability-in-drilling-57567805