As being the confining pressure boosts, the increase in resistance to longitudinal crack propagation leads to a gradual changeover of shale failure mode from longitudinal to inclined shear failure that reflects an escalation in rock plasticity. If the confining stress reaches 30 MPa, there remain community shear microcracks throughout https://medium.com/@vertechs/revolutionizing-well-control-in-high-pressure-high-temperature-gas-drilling-environments-c212cb28aedd