Sorption and Migration of CO2 in Porous Media

-

CO2 sequestration, or storage, in deep geological structures involves combined complex physical as well as physico-chemical processes on many length- and time-scales simultaneously. This is why it is important to reduce the complexity of CO2 storage and c apture, and focus on a set of relevant phenomena, and subsequently include results from those together into larger encompassing models. The project focus on physical processes that are of key importance for the optimization and understanding of CO2 trans port into the ground. CO2 storage in a water saturated porous materials, such as sandstone in a sedimentary basin, relies on different mechanisms of confinement that act on different time scales. First, an impermeable caprock (often including clays) that keeps the fluid from escaping upwards is needed. This is because of the upwards buoyancy that acts on the supercritical CO2 fluid. Second, the solubility of the CO2 will cause it to absorb in the water, which then becomes denser than the surrounding wat er. At this stage the CO2 may sink and the caprock may become redundant. Third, intercalation (absorption) into clay nanopores, or adsoption onto outer clay grain surfaces, both represents complex mechanisms that may bind CO2 to the clay present in porou s structures and formations. Fourth, and last, chemical reactions that bind the carbon in mineral form to the rock, will take place. These processes, that take place over increasing time spans, also produce increasingly stable storage of the CO2. The pr oject will study physical phenomena in porous materials in the context of soft and complex materials physics. The project is ideally suited for educating MSc and PhD candidates in experimental and/or computational basic physics relevant for CO2 storage. The project involves national cross-institutional (NTNU, UiO; IFE) in Norway, and international collaborations, in particular with researchers in France and USA