This poster on the UKCCSRC Call 2 project The Development and Demonstration of Best Practice Guidelines for the Safe Start-up Injection of CO2 into Depleted Gas Fields was presented at the CSLF Call project poster reception, London, 27.06.16. Grant number: UKCCSRC-C2-183. Highly-depleted gas fields represent prime potential targets for large-scale storage of captured CO2 emitted from industrial sources and fossil-fuel power plants. Given the potentially low reservoir pressures as well as the unique thermodynamic properties of CO2, especially in the presence of the various stream impurities, the injection process presents significant safety and operational challenges. In particular, the start-up injection leads to the following risks: • blockage due to hydrate and ice formation following the contact of the cold CO2 with the interstitial water around the wellbore; • thermal stress shocking of the wellbore casing steel, leading to its fracture and ultimately escape of CO2; • over-pressurisation accompanied by CO2 backflow into the injection system due to the violent evaporation of the superheated liquid CO2 upon entry into the wellbore.
