In the year 2030, Indonesia has set ambitious goals to produce 1 BOPD (Barrels of Oil Per Day) by employing
secondary an tertiary recovery methods. Concurrently, Indonesia is committed to reducing GHG (Greenhouse
Gas) emissions by a range of 29% to 41%. To attain these targets, the Indonesian government has initiated plans
for the implementation of Carbon Capture and Storage (CCS) as well as Carbon Capture, Utilization, and
Storage (CCUS) technologies. The CCUS technology is the most viable solution for Indonesia to increase oil
production and reduce GHG emissions, as CCUS can enhance the recovery factor from 5% to 15% and reduce
carbon emissions by 0.5 to 1.5 tons of CO2 per ton injected.
This study was conducted in oil field located in East Java, Indonesia, which features a carbonate reservoir. This
study utilized CMG GEM 2021 to analyze the impact of CO2 injection rate and the location of injection
perforations as crucial parameters influencing the effectiveness of CCUS implementation. This analysis
encompassed a sensitivity study involving various CO2 injection rates and perforation locations within the gas
cap, oil zone, and aquifer zones. The outcomes of this sensitivity analysis were evaluated based on oil recovery
factor, CO2 storage, and CO2 plume migration.
The study concluded that the CO2 injection rate has an almost linear relationship with the oil recovery factor.
Thus, higher rates of CO2 injection correspond to a more rapid horizontal migration of CO2 plume, thereby
covering a wider area. Consequently, a larger number of wells experience CO2 breakthrough, resulting in
reproduction of CO2 alongside oil and gas production. Furthermore, concerning the sensitivity analysis of
perforation location, the highest oil recovery factor was observed in the oil zone perforations, reaching to
38.37%. This can be attributed to the increased contact between CO2 and oil within this zone. Conversely, the
most effective location for CO2 storage was found to be the aquifer zone perforations, primarily due to the
substantial CO2 trapped via residual and solubility trapping mechanisms, which are considered safer than
structural trapping. The perforation location also influences the migration of CO2 plume, as there are variations
in horizontal and vertical permeability across the different perforation zones. The CO2 plume tends to migrate
through layer with higher permeability.