Session: 29, Room:
Geochemical reactions play an important role in CO2 geological storage environments. CO2-brine-rock interactions will be enhanced in low pH environment, because of acidity in reservoir being strengthened due to CO2 dissolution. TOUGHREACT is used conduct kinetic batch modeling and reactive transport modeling in Shihezi formation in Ordos basin, where the first CCS project is carried out in China. Simulations are based on the core data, which are focused on effects of CO2 for pH, gas saturation, geochemical interactions, porosity and permeability in formation. Results show thath K-feldspar and albite, main components of alkaline feldspar, are dissolved, while ankerite and siderite are precipitated. Quartz, calcite and dawsonite are dissolved first and then precipitated, whose reaction mechanisms are associated with environment pH value, temperature and electrolyte existing. These results are consistent with observations in laboratory experiments. For CO2 squestration, whether minerals are dissolved and precipitated, amount of CO2 will be consumed, which will promote CO2 dissolution in formation resulting in CO2 sequestrated underground. These processes may be very slow, but dissolved and mineralized deposits are ideal CO2 storage.
Fri, 09/06/2019 - 13:21 to 13:24
Flash presentation in Energy technologies and sustainability