PA 12 for Flexible Flowlines and Risers
In their supply chain strategy in 2003 Wellstream decided to expand the application of Nylon (PA) grades for off-shore use in order to move away from a single source supply. Degussa have developed a new grade of PA 12 for use in offshore applications, such as flexible pipes. In a joint effort Wellstream International Limited and Degussa AG have performed a qualification test programme on this new grade. On the basis of these tests Wellstream has obtained a Lloyds “Certificate of Material Qualification for the Use of Polyamide 12 Grade - VESTAMID® LX9020 in non-Bonded Flexible Pipes”. Since this certificate was obtained in June 2006 additional test results were obtained which confirm the outstanding material properties and long term performance of the new material. This presentation focuses on results from long term ageing and compatibility experiments of PA 12 in air, in water with different CO2 levels, in crude oil with different TAN, in methanol and other oilfield additives. Some of these tests have been performed over a period of almost three years. The presented data is relevant to predict the long term performance of PA 12 in flexible pipe service.