Stress Corrosion Cracking of Corrosion Resistant Alloys in Brine Packer Fluids

There have been several recent failures of corrosion resistant alloy (CRA) tubing strings in brine packer fluids as a result of stress corrosion cracking (SCC). These failures have been unexpected based onearly studies that only examined the various brine fluids and common CRAs without concern for the impact of inhibitors added to the brine and the charging of the brine with acid gases from leaks in the tubing or packer connections. This paper presents laboratory work that demonstrates 13Cr and 22Cr alloys are very susceptible to SCC in brines charged with CO2 and H2S even at moderate temperatures but that the high nickel alloys, such as Alloy 825 are much more resistant.