Fluid Mechanics of CO2 and Hydrogen Storage in Geological Formations
The geological storage of carbon dioxide (CO2) and hydrogen is a key technology for climate change mitigation and the transition to a low-carbon energy system. Both applications involve complex multiscale transport phenomena in porous geological formations, where fluid flow, heat and mass transfer, geochemistry, geomechanics, and biological processes interact across pore, reservoir, and basin scales. Developing predictive models that consistently connect these scales remains a major challenge in mechanics and applied mathematics.
This CISM course provides a rigorous introduction to the mechanics and mathematical modelling of geological CO2 sequestration and underground hydrogen storage. It combines fundamental theory with modern applications, emphasizing multiscale modelling, transport processes, stability analysis, and numerical simulation. Participants will develop a unified understanding of the governing physical mechanisms controlling multiphase flows in porous media, from pore-scale dynamics to Darcy-scale and regional-scale descriptions.
The course begins with the governing equations for single- and multiphase flow in porous media, including conservation laws, constitutive relations, and closure models. Buoyancy-driven convection, dissolution trapping, mixing, and transport enhancement are analysed through scaling arguments, stability theory, and nonlinear flow dynamics. These concepts are complemented by hands-on FluidFlower experiments that visualize convective instabilities and CO2 dissolution under ambient laboratory conditions.
Subsequent lectures address the influence of heterogeneity, anisotropy, and dispersion on flow and mixing, and present multiscale approaches linking pore-scale experiments and simulations to continuum and field-scale models through upscaling techniques. Coupled flow-geomechanics problems, including poroelasticity, stress evolution, fault stability, and reservoir integrity, are introduced together with advanced numerical methods and high-performance computing approaches. The course also covers reactive transport, microbial processes, and biofilm formation, illustrating how biochemical phenomena modify the hydraulic and mechanical properties of porous media.
A dedicated module focuses on underground hydrogen storage, highlighting similarities and differences with CO2 sequestration, including multiphase behaviour, reactivity, and mechanical effects. Current research challenges and industrial applications are discussed throughout the course. A visit to a borehole geophysics test site, part of the FUSE project - Open Infrastructure on Future Underground Hydrogen Storage - complements the lectures.
The course is intended for graduate students, PhD candidates, postdoctoral researchers, and faculty in applied mathematics, fluid mechanics, geophysics, computational science, and engineering, as well as industrial practitioners seeking a rigorous understanding of multiscale modelling, simulation, and experimentation for geological energy storage.