Perpustakaan Digital ITB

Carbon capture and storage in deep saline aquifers faces a pressure limit, because injected CO2 raises reservoir pressure toward the fracture threshold and caps the volume a formation can accept. Production formation brine relieves this pressure and expands storage, but it adds cost and lowers operating profit. This study optimizes that trade-off for a saline aquifer modeled on the Gorgon Dupuy Formation, Australia. A synthetic compositional model was built in CMG GEM and optimized with particle swarm optimization in CMG CMOST over a 25-year horizon. Two decision variables, the CO2 injection rate and the brine production rate, were tuned against two objectives, cumulative CO2 storage and cumulative operating profit. The study ran two production cases, one allowing zero brine production and one enforcing a minimum rate and read the results through three stakeholder perspectives on a Pareto front. The results show a direct storage-profit trade-off. At maximum operation the model stores 16.42 MMt of CO2 for an operating profit of USD 8.57 million, while the operating profit optimum in the unconstrained case stores almost nothing. Enforcing a minimum brine production rate lowers peak operating profit by about 10% but raises stored CO2 several fold, and the knee of the Pareto front gives a balanced point near 11 MMt stored at about USD 11.5 million. Both wells operate at their pressure limits, and the CO2 plume stays confined during injection.