Since the confining pressure raises, the increase in resistance to longitudinal crack propagation ends in a gradual changeover of shale failure manner from longitudinal to inclined shear failure that demonstrates an escalation in rock plasticity. Once the confining pressure reaches 30 MPa, there remain nearby shear microcracks round the https://vertechs21.wixsite.com/vertechs21/post/revolutionizing-well-control-in-high-pressure-high-temperature-gas-drilling-environments