As being the confining stress raises, the increase in resistance to longitudinal crack propagation ends in a gradual transition of shale failure manner from longitudinal to inclined shear failure that demonstrates an escalation in rock plasticity. When the confining force reaches 30 MPa, there are still nearby shear microcracks https://wellcontrol36919.thebindingwiki.com/9178714/an_unbiased_view_of_shale_wellbore_stability