Coupled Assessment of Injection Pressure–Driven Risk, Trapping Evolution, and Cost Uncertainty in Geological CO 2 Storage

Scaling geological CO 2 storage requires simultaneously controlling plume migration, pressure buildup, geomechanical integrity, and monitoring cost under deep subsurface uncertainty. Yet early‐stage assessments often treat these elements in isolation, obscuring the decision‐critical couplings between pressure‐defined regulatory exposure and storage economics. Here, we present a verified reduced‐complexity integrated assessment workflow that couples (i) analytical, superposed pressure solutions for confined, leaky, and bounded aquifers, (ii) a plume‐coupled trapping model tracking mobile, residual, dissolved, and mineralized CO 2 , (iii) probabilistic geomechanical screening using slip tendency and Coulomb stress proxies, and (iv) a techno‐economic analysis in which monitoring cost scales explicitly with the computed pressure‐based area of review (AoR). Applied uniformly to seven benchmark projects and a Gulf of Suez case (Hammam Faraun [HF] Member, Egypt), the framework reveals a consistent bifurcation of limiting constraints: High‐transmissivity open systems tend to be plume/monitoring‐footprint limited, whereas semi‐closed or compartmentalized systems are pressure‐ and integrity‐limited. For HF, deterministic simulations indicate modest well overpressure, but Monte Carlo propagation yields a heavy‐tailed AoR distribution with probability of 0.84 during operations, showing that regulatory exposure can be dominated by basin‐scale hydraulic uncertainty rather than plume size. Trapping evolves from injection‐era mobility to postinjection immobilization dominated by dissolution, and mineral trapping remains negligible over 100‐year horizons. By explicitly coupling AoR uncertainty to monitoring obligations, we show that regulatory footprint is a first‐order driver of risk‐adjusted levelized storage cost and portfolio ranking, providing a computational bridge from sparse site data to decision‐relevant probabilities and design trade‐offs.