Abstract:
Underground hydrogen storage in porous formations (UHSP) subjects reservoir rocks to long-term cyclic effective stress variations, potentially altering storage capacity and injectivity. Advancing UHSP requires a better understanding of the interaction between time-dependent and cycle-dependent behavior of reservoir rocks. However, these two mechanisms cannot be reliably distinguished by conventional constant-stress creep tests or constant-amplitude cyclic loading tests alone. In this study, a specific creep-fatigue interaction test, combining stabilized creep and subsequent cyclic loading at identical peak stress, is conducted on Saint-Maximin limestone samples to distinguish cycle-dependent ratcheting deformation from time-dependent creep. Are “fatigue” and “cyclic creep” equivalent processes? Is a elasto-visco-plastic constitutive model sufficient to capture the full mechanical response of reservoir rocks? What are the dominant controls on cycle-dependent deformation in porous rocks? This seminar will provide new insights into these questions based on the latest experimental observations.
Short bio:
Zhaochen began his PhD at Laboratoire Navier in October 2023 after graduating as an engineer from Ecole Nationale des Ponts et Chaussées, under supervision of Prof. Jean SULEM and Dr. Philipp BRAUN. His research focuses on the hydro-mechanical behavior of porous reservoir rocks in the context of geological hydrogen storage.
