Christophe Tournassat, University of Orléans, France
Roman Makhnenko, University of Illinois at Urbana-Champaign, USA
Thomas Gimmi, University of Bern and Paul Scherrer Institut, Switzerland
Clays and clay-rich rocks have important roles in subsurface systems of relevance to the extraction of energy resources and the storage of energy byproducts. Clay-rich geological repositories are candidates for the long-term disposal of nuclear waste and clayey formations can serve as caprocks for the long-term sequestration of CO2 in subsurface geological formations. Clay-rocks, including shales, are also important for the extraction of hydrocarbons that are increasingly accessible by hydraulic stimulation methods. Fluid and solute transport processes in clay-rich media remain challenging to understand and to model because these very low permeability, nanoporous systems exhibit a remarkable array of strongly coupled macroscale behaviors including swelling and ion-selective transport. This is especially true for fractured shales, in which the main transfer paths depend on the nature of fluids and aqueous solutes, with strong implications for the prediction of water quality in above-mentioned subsurface applications. In this session, we will highlight presentations that elucidate the couplings between hydrology, chemistry, and the structure of clay materials with an eye toward seemingly anomalous properties. We invite contributions highlighting new experimental, theoretical, and numerical investigations, across scales and ranging from fundamental studies to research focusing on emergent behavior.