## 5 Methodology and Results
### Geomechanical Results
The significance of this finding extends beyond mere observation; it underscores the critical need for precise geomechanical modeling before the implementation of monitoring strategies. While the highest delta pressure remains near the injection point, the most substantial uplift occurs in a different location, influenced by the reservoir's structural nuances. This highlights the heterogeneous nature of the reservoir's response to CO2. Insights like these help with accurately determining the optimal placement of monitoring instruments, such as tiltmeters, within the so-called Area of Review, as described in the Introduction. To illustrate the dynamic nature of ground displacement associated with CO2 injection, Figure 12 shows the displacement rate (millimeters per year) at various times. It is particularly noteworthy that the highest displacement rate undergoes a significant shift in a relatively short period. Initially, the greatest displacement rate is observed in the vicinity of the CO2 injector. However, as time progresses, this zone of maximum displacement migrates away from the injector, reaching a point further from the wellhead and above the center of the reservoir in a period of 3 months. This pattern is evident as early as 3 months into the injection process and becomes more pronounced at the 3-year mark. At the injection shutoff, 20 years, the displacement is substantially pronounced, while by the 21 st year, there is a significant reduction in displacement velocity, indicating the beginning of stabilization. It is important to point out that after CO2 injection is stopped (after 20 years), the ground movement near the wellhead drops below 1 mm/year, which might be too small for some sensors to detect. Such observations are critical for understanding the temporal and spatial evolution of deformation, thereby aiding in the optimal placement of monitoring equipment. Figure 10: Seabed vertical displacement at wellhead (red) and reservoir center (blue) over time. Negative values indicate upward movement. Figure 11: Vertical cross-section showing reservoir deformation at 20 years. The color gradient represents the magnitude of uplift, with the CO2 injector indicated by the dashed line and the point of maximum uplift highlighted in the central region, offset from the injector. Figure 12: Vertical displacement rates in mm/year at intervals following CO2 injection start. Panels (**A–D**) show the seabed vertical displacement rates at 3 months, 20 years, and 21 years, respectively. As we conclude this section, we have laid a robust foundation for a simulation framework that not only highlights the critical insights gained from monitoring ground deformation and pressure dissipation but that also underscores the intricacies of CO\({}_{2}\) redistribution within the geological storage. These insights are paramount for the development of effective and secure Carbon Capture and Storage strategies and to further refine our understanding of geomechanical responses to CO\({}_{2}\) storage. Moving forward, this study will embark on a series of sensitivity analyses. This next phase is designed to evaluate how variations in key parameters--such as the mechanical properties of rocks, caprock permeability, and CO\({}_{2}\) injection rates--impact our findings. The sensitivity analyses aim to further refine our understanding of geomechanical responses to CO\({}_{2}\) storage, ensuring that the conclusions drawn are robust and applicable across a range of scenarios. This will enhance the predictive accuracy of our models, contributing to the optimization of CO\({}_{2}\) sequestration practices and the advancement of monitoring technologies.