The Role of Temperature in Shear Instability and Bifurcation of Internally Pressurized Deep Boreholes

This paper investigates localized shear deformation around a borehole due to internal pressure in the well such as by fluid injection. Using an elasto-visco-plastic formulation combined with damage mechanics for the effect of shear cracking, we first benchmark the model against analytical solutions and then provide bifurcation criteria for the onset of localized cracking at different temperature conditions. We report that at increased temperatures of the rock formation, hot fluid injection promotes shear stimulation, while cold fluid suppresses it. This counter-intuitive result can offer new pathways of effective stimulation in high-temperature environments, like those encountered in enhanced geothermal systems.