Abstract Permanent CO2 storage is critical to global strategies to meet net-zero emission targets and decarbonise hard-to-abate sectors. The advancement of carbon sequestration programs in established basins of Cambay, India, depends on the accurate estimation of CO2 storage capacity in depleted reservoirs. This basin presents a more favourable prospect for large-scale CO2 storage projects due to its extensive history of hydrocarbon production and well-characterised reservoirs. This study presents a data-driven simulation methodology integrating historical reservoir performance with predictive modelling to evaluate CO2 storage potential. Source-sink matching (SSM) was initially employed to align major industrial CO2 emission points with storage-ready fields, thereby ensuring minimal transport requirements and improving project viability. Model development involves reconstructing production-depletion phases using available field data to create a realistic pressure and saturation environment. Various injection strategies were systematically simulated to identify optimal trapping mechanisms, including continuous CO2 injection, water-alternating-gas (WAG) injection, and huff-and-puff cycles. Advanced modelling incorporated capillary pressure effects, residual gas trapping, and CO2 solubility in formation brine, enhancing the accuracy of long-term storage estimation. Injection parameters were optimised under geomechanical constraints to ensure caprock integrity and operational feasibility. Plume migration patterns and pressure build-up profiles were also simulated to aid future monitoring and verification planning. Sensitivity analyses highlighted the influence of initial water saturation, permeability heterogeneity, and injection rates on overall storage security. Optimised SSM demonstrated that industrial clusters near the Cambay Basin could supply sufficient CO2 volumes for full-scale storage operations. Over a 50-year forecast period, the results showed that WAG had the highest storage efficiency with 45-55% of injected CO2 trapped residually and through solubility processes. Continuous CO2 injection scenarios showed greater plume migration risks, emphasising the importance of mobility control. These integrated approaches ensure effective evaluation of CO2 sequestration capacity and minimise operational risks in geologically complex reservoirs of the Cambay Basin.