In the context of addressing climate change and achieving carbon neutrality, carbon dioxide capture and storage (CCS) technology is widely used to reduce greenhouse gas emissions. However, the surface uplift caused by CO2 injection still lacks systematic theoretical understanding and quantitative prediction methods, especially in the early stages of the project, which is limited by complex geological conditions and insufficient data. As an analytical solution method, the Geertsma model provides a possibility for the preliminary evaluation of CCS surface deformation with its high efficiency and simplicity.
Based on the Geertsma analytical model, this study established a multi-site surface uplift prediction framework, selected five representative CCS projects, In Salah, Sleipner, Weyburn, Gundih and Saskatchewan, as research objects, collected their field geological parameters, applied full factorial design to evaluate the sensitivity of the model input parameters to the prediction results, and compared and verified them with the CMG-GEM numerical simulation results. The results show that the Geertsma model can reasonably reflect the impact of pressure changes on surface deformation under the assumption of a uniform elastic medium and a disc-shaped reservoir. Sensitivity analysis further revealed that reservoir thickness, pressure change, and reservoir depth are the key factors affecting the amplitude of surface uplift. While the influence of Poisson’s ratio is relatively small.
Through multi-site analysis and model comparison, this study verified the applicability and limitations of the Geertsma model in early site selection assessment and parameter sensitivity analysis of CCS. It provided a theoretical basis and technical reference for improving the safety and prediction ability of CO2 geological storage projects.