Perpustakaan Digital ITB

Carbon dioxide (CO2) sequestration in saline aquifers is a key strategy for climate change mitigation, with longterm storage security heavily dependent on the residual trapping mechanism. This study investigates the fundamental influence of hysteresis—modeled using the Land's Trapping Coefficient—on the efficiency of CO2 trapping in the Utsira Formation. Through a series of numerical reservoir simulations, four scenarios were analyzed: a base case without hysteresis and three cases with varying Land's Coefficient values. The simulation results show a strong positive effect between the Land's Coefficient and the amount of residually trapped CO2. Furthermore, the analysis reveals an inverse relationship between hysteresis and dissolved trapping; the base case trapped the most dissolved (CO2), while the other case trapped the least. This occurs because hysteresis reduces plume mobility, thereby decreasing the contact area between the CO2 and formation brine and slowing the rate of dissolution. Pressure analysis also illustrates that scenarios with a higher final average reservoir pressure impact greater amounts of residual and supercritical trapping but with lower amounts of dissolved trapping. In conclusion, accurate hysteresis modelling is critical for estimating CO2 storage security as it significantly enhances residual trapping, a dominant mechanism for long-term CO2 immobilization.