Multi-objective Optimization of CO₂ Recycling Operations for CCUS in Pre-Salt Carbonate Reservoirs

This study evaluates the potential of recycling carbon dioxide (CO₂) in the associated gas for Carbon Capture Utilization and Storage (CCUS) in pre-salt carbonate reservoirs. We performed compositional subsurface modelling of a hypothetical field for multi-objective optimization, aiming at minimizing carbon emissions whilst maximizing the project's economics. Although no absolute reduction in total CO₂ emissions was met with economic improvement, all simulated CCUS scenarios yielded a lower carbon footprint oil, with 41% reduction in operational emissions and up to 20% increase in Net Present Value. The best CCUS case presented break-even oil price of 39.2 USD/STB and CO₂ abatement cost of negative 92.4 USD/tCO₂ abated, also showing significant reduction in number of squeeze treatments and cost of calcite scale management.