Perpustakaan Digital ITB

4.85 billion tCO2 in depleted oil and gas reservoir within the country (MEMR Indonesia, 2024) with a carbon economic value (NEK) potential of US$6.6 billion (Indonesian Petroleum Association, 2022). Furthermore, actively producing mature wells can gain additional benefits in addition to CO2 storage, by increasing oil production volume, which is expected to improve the economic value of the field with CO2 enhanced oil recovery. With the implementation of the existing regulations by Indonesia's government to support the CCS/CCUS, along with proper technical and non-technical planning, Indonesia will have a major role in reducing the world's carbon emissions while also increasing the value of Indonesia's energy sector. This study performed a simulation analysis aimed to investigate the impact of CO2 injection rate and volume on oil recovery, response time, and CO2-EOR metrics relevant to CCUS analysis. This study also aimed to comparatively evaluate continuous CO2 injection and CO2-Water Alternating Gas (WAG) injection on the oil recovery and CO2-EOR metrics. The model and base scenario used is based on the recent study of inter-well CO2 injection at “S” field as one of the stages towards full-scale implementation of CO2-EOR. The results of this study indicate that lower injection rates resulted in higher cumulative oil gain, but CO2-EOR metrics favored higher rates. CO2 storage efficiency increased with lower injection rates but showed minimal impact on utilization factor. Larger CO2 volumes enhanced oil displacement and storage but decreased retention slightly. Continuous CO2 injection yielded similar oil recovery to 2-cycle CO2-WAG with specific ratios (1:2 and 1:1). Notably, CO2-WAG with water injection improved CO2 storage compared to continuous injection. Overall, a higher total CO2 volume positively impacted oil gain and storage but had minimal influence on retention. The study highlights the interplay between injection parameters and the importance of considering both oil recovery and CO2-EOR metrics objectives in relevant to CCUS analysis.