The PhD student Atefeh Vafaie defends her thesis titled "Experimental and numerical study of chemo-hydro-mechanical effects of CO2 injection on permeable limestone" Language: English
The PhD student Atefeh Vafaie, from the Groundwater and Hydrogeochemistry group, will defend her thesis on 7th July at 11:00h in the Aula Carmina Virgili of the Faculty of Earth Sciences at the University of Barcelona.
Title: Experimental and numerical study of chemo-hydro-mechanical effects of CO2 injection on permeable limestone
Directors: Jordi Cama and Josep M. Soler
Thesis Committee: Maarten Saaltink, Enrique Gómez Rivas and Fidel Grandia
Abstract:
Geological carbon storage (GCS) in saline aquifers is a means required to arrive at the net-zero CO2 emission target and climate change neutrality. Injected CO2 in aquifers acidifies the resident brine, inducing mineral dissolution and precipitation. These reactions may alter the pore structure and hydromechanical properties of the rock, particularly in carbonate reservoirs with considerable amounts of fast-reacting calcite.
Improving the current understanding of the form, extent, and governing mechanisms of such interactions is central to optimizing and securing the implementation of GCS which is the main goal of this thesis. To achieve this goal, this study combines (i) percolation experiments with CO2-saturated water and HCl solutions on highly permeable limestone cores with (ii) 3D Darcy-scale reactive transport simulations.
Effluent chemistry analyses, X-ray Micro Computed Tomography (XMCT) imaging, and measurements of the hydromechanical properties of cores are used to quantify acid-induced alterations in these two acid-rock systems. Further, a digital rock physics method is developed to construct heterogeneous permeability maps of intact specimens that feed into reactive transport models to consider the effect of pore space heterogeneities on carbonate rock response to acidic fluid percolations.
