Dissolved CO2 Storage: A Novel Solution for CCS in the Red Sea Rift Basins

The west coast of Saudi Arabia has large industrial areas with significant CO2 emissions, necessitating effective carbon storage solutions along the Red Sea margin ( Figure 1 ). The onshore rift basins located at proximity to CO2 sources, including Yanbu, Jiddah and Jizan basins, are mostly small half-grabens filled by syn- to post-rift siliciclastics with minor evaporites and/or volcanics. This study explores the feasibility of an innovative approach: dissolved CO2 storage in shallow post-rift clastic reservoirs, to increase the carbon storage potential in these basins. By co-injecting CO2 and water into shallow saline aquifers ( Addassi et al., 2024 ), the CO2 rapidly dissolves in water forming a dense, CO2-saturated solution that migrates downward into the reservoir, where the CO2 becomes permanently sequestered through solubility trapping. This method eliminates the need for a caprock and mitigates risks associated with dry-out and salt precipitation. This study presents a case study from a rift basin in southwestern Saudi Arabia to demonstrate the potential of dissolved CO2 storage as a viable solution for CCS deployment in these challenging geological settings.