As being the confining tension raises, the increase in resistance to longitudinal crack propagation results in a gradual transition of shale failure manner from longitudinal to inclined shear failure that reflects an escalation in rock plasticity. If the confining force reaches 30 MPa, there are still area shear microcracks https://bookmarkfame.com/story21401262/an-unbiased-view-of-rock-mechanics-in-wellbore-stability