Integrated experimental study of the impact of alteration on rock hydromechanical properties

Fluid-rock interactions play a key part in the evolution of our environment. They notably influence karst development, rock weathering and thus continental erosion, as well as coastal cliff retreat caused by water infiltration… These processes depend on climate conditions and the assessment of the impact of climate change on vulnerable areas will require considering the corresponding thermo-hydromechanical and chemical couplings.
Reactive transport modeling has undergone significant developments in the last two decades. However, we still lack a comprehensive understanding of the coupling with the deformations of the porous medium and of the impact on its hydromechanical properties. Integrating fluid-rock interactions in predictive large-scale models hence requires a better knowledge of the impact of reactive transport at the microstructure scale where the various processes occur. Most experimental studies focus on the evolution of porosity and permeability and few of them address the impact of flow conditions on mechanical properties (elastic moduli, acoustic velocities, failure strength).
The objective of this PhD is to develop an integrated experimental approach to study the impact of reactive transport on the porous structure and the hydromechanical properties of rocks. Various carbonate rocks (by nature highly reactive) showing different microstructures will be considered. Fractured samples will also be tested to address the key part of fractures-matrix interactions. Once validated the defined approach can be applied to any rock formation subjected to various reactive flow conditions and used to constrain chemo-hydro-mechanical models.

Keywords: rocks, hydromechanical properties, weathering, impact of climate change

• Academic supervisor    Prof., FORTIN Jérôme, Laboratoire de Géologie de l'ENS Paris (UMR 8538)
• Doctoral School    Earth and Environment Science and Physics of the Universe, https://ed560.ed.univ-paris-diderot.fr/en/the-doctoral-school/
• IFPEN supervisor    Dr., BEMER Elisabeth, elisabeth.bemer@ifpen.fr
• PhD location    IFP Energies nouvelles, Rueil-Malmaison, France
• Duration and start date    3 years, starting in fourth quarter 2021
• Employer    IFP Energies nouvelles, Rueil-Malmaison, France
• Academic requirements    Master's degree in Earth Sciences or Engineering Sciences
• Language requirements    Fluency in English, knowledge in French
• Other requirements    Interest in experimental and theoretical approaches, notions of thermochemistry...