Bio-Geo-Chemical Processes Control the Composition of Fluids Leaking from Underground Carbon Sequestration Reservoirs

However small, the risk of failures during CCS operations and underground sequestration exists. To assess the environmental risk of a potential leakage from geological CO₂ storage reservoirs, it is crucial to understand the potential composition of the leaking fluids reaching the seabed and the processes that contribute to mobilization or immobilization of contaminants. In general, the leaking fluids contain CO₂ plus impurities, which includes 1) impurities in the captured CO₂ stream, 2) chemicals released due to geochemical reactions, 3) chemicals released due to biological activity, and 4) chemicals picked from the saturating fluids in storage reservoirs. This article categorizes the potential sources of various harmful chemicals that may be introduced into the seabed environment due to CCS operations and emphasizes the need for further investigations into the potential environmental risks associated with CCS considering the toxicity of all the potential chemicals.