IstoPore Seminar – by Rabie Fehrat Hamida

Abstract

The geological subsurface has long been used for extracting natural resources (water, heat, gas, useful mineral substances, etc.) or for injecting or storing undesirable compounds (industrial water and desalination brines, oil brines, radioactive waste, acid gases, CO2, etc.). For this, reactive transport processes in porous and fractured geological environments need to be understood and managed on various spatial and temporal scales. Our aim is to understand the physical and chemical mechanisms at the interface of different phases (mineral/water), by studying the precipitation and dissolution processes of carbonate and sulfate minerals at the pore scale. We do this by controlling parameters that can affect reaction rates, such as pH, temperature and alkaline earth mineral concentration. Reactive transport coupling dissolution-diffusion-precipitation mechanisms will improve our knowledge of carbonation kinetics for CO₂ storage applications by understanding its interaction with gypsum in a saturated fluid () and subsequently the effects of this process on the porosity and permeability evolution of the geological reservoirs, since the gypsum-calcite reaction is negative volume. GLoCs devices have been used in combination with various in-situ characterization techniques (i.e., high-speed optical imaging, con-focal microscopy and Raman spectroscopy) to study different mechanisms involved in gypsum carbonation.