Assessment of CO2 Storage Capacities and Identification of Operational Risks Using Large Basin-Scale Multi-Physics Simulation on Unstructured Mesh

Abstract The assessment of safe and permanent CO2 storage is of outmost importance to both International and National Energy Companies. Large-scale and robust geological carbon storage projects align with Net-Zero strategy of government and private companies, solidify the response to climate change, and establish entities as major global player in the advance for decarbonization. These aspirations are in line with the Paris Climate Change Agreement, and they offer major economic opportunities to elevate the national and private entities to the forefront of a nascent global decarbonization economy. A major hurdle for geological carbon storage is ensuring that detailed numerical simulations of the CO2 plume evolutions and the induced geomechanical rock deformations demonstrate safe and permanent storage for several centuries after the injection has stopped. A multiphysics approach combining flow and geomechanics is necessary for a detailed assessment of storage capacity. Combining flow in porous media with rock mechanics over large areas (greater than 60,000 km2) and long periods of time (1,000 years) calls for advanced numerical methods and tools designed for high-performance computing. Safe storage of the injected CO2 requires detailed modelling of all physical phenomena involved in injection and trapping, and a complete risk assessment using uncertainty quantification methods calls for fast simulations. CO2 geological storage simulations must therefore quantify: The migration of the CO2 plume (saturation) and the associated pressure changes,Well performance and injectivity near injection points,Global and local changes in stress (leading to possible fault activation, cap rock fracturing),CO2 dissolution in the brine, and its mineralization,Surface expressions due to the injection, and induced seismicity risks.