Given that the confining strain improves, the increase in resistance to longitudinal crack propagation ends in a gradual transition of shale failure method from longitudinal to inclined shear failure that reflects an escalation in rock plasticity. Once the confining tension reaches thirty MPa, there are still nearby shear microcracks https://cristianodset.jasperwiki.com/7935853/not_known_facts_about_wellbore_stability_issues