Subsea umbilicals are used to control the subsea structures such as wellheads from the platform control stations by supplying control signals and injecting chemicals. UNS S32750 super duplex stainless steel has been widely used as umbilical material due to its excellent corrosion resistance and high fatigue properties since it was introduced in 1993. Recently, UNS S33207 hyper duplex was also introduced for umbilical applications, which exhibits higher mechanical properties and better corrosion resistance [1]. Recently, due to the worldwide demand for more oil and gas, some oil and gas reservoirs have been explored in deeper waters with water depth often greater than 1500 meters and pressure rating above 103.4 MPa. In addition, several factors have lead to increased temperatures within the umbilical, which can exceed the critical crevice temperature of the super duplex. With these increasingly hostile environments and operators seeking ever greater design lives for field components, it becomes important to better characterize materials for service. This is also important because, despite the excellent corrosion resistance of the high alloy steels used in umbilicals, they often limit the temperature service range for the entire umbilical. This temperature limitation can seriously influence the design of the umbilical, and can amount to tens of thousands of dollars per degree when considering the total cost of the umbilical. This study seeks to demonstrate the temperature limits for using UNS S32750 super-duplex and UNS S33207 hyper-duplex stainless steels as umbilical materials due to localized corrosion such as pitting and crevice corrosion This abstract is posed courtesy of Industeel, a supplier of alloys used in this type of application.

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• Industeel

• Alloy Steel

• Umbilical Tube

• Corrosion

• Abstract