Corrosion Management of the Karachaganak Gas/Condensate Field

The Phase II development of the Karachaganak Gas/Condensate field commenced production in 2004. The Karachaganak production fluids are characterised by historically low water cuts, relatively high levels of CO₂ and H₂S with a ratio close to 1 and a condensate API gravity of between 45 and 50.  In general, corrosion rates for the main production and processing facilities have been very low and these low rates of corrosion are attributed to the formation of a thin and adherent film of iron sulphide. From a review of the potential corrosion mechanisms that could occur in such systems where the CO₂/H₂S ratio is close to parity it has been possible to implement a targeted inspection programme at areas where sulphide film breakdown could occur. The results obtained from a structured approach to integrity management will be discussed and areas where corrosion has been successfully detected will be described.