Given that the confining force improves, the increase in resistance to longitudinal crack propagation ends in a gradual transition of shale failure mode from longitudinal to inclined shear failure that demonstrates an escalation in rock plasticity. Once the confining force reaches thirty MPa, there are still neighborhood shear microcracks https://well-control-operations67654.wikihearsay.com/4388439/details_fiction_and_wellbore_stability_in_drilling