The BP Research Centre at Sunbury built a test rig to evaluate elastomer seals for offshore oil and gas service, and its main component is a large autoclave manufactured in Ferralium® 255 (UNS S32550, Alloy 255, DIN 1.4507, ASTM F61). The alloy was chosen for its high strength and its ability to resist the wide range of conditions involved in the tests.
Degradation of the elastomeric materials used for gas lift hose linings, hose coupling seals, wellhead seals, and umbilical, downhole safety valve and pump seals can cause severe operational problems and costly loss of production. The programme tests these elastomers and then evaluates their mechanical properties and dimensional stability across a wide variety of wellhead seal environments.
The autoclave is shown with its threaded closure member and associated control and monitoring equipment. The wellhead environments tested include hydrocarbons, hydrogen sulphide, carbon dioxide, and potentially aggressive fluids such as brine, scale inhibitors, corrosion inhibitors and bactericides. The autoclave can be pressured to 20,000 psi and operated at 200oC, but normally functions at around 5,000 psi and 80oC.
