Three layer polypropylene (3LPP) pipeline coatings failed prematurely in the oilfields of Abu Dhabi in the United Arab Emirates (UAE). A failure investigation and analysis into this phenomenon was instigated. The coating disbondment has been found to be due to high residual stress concentration and adhesion loss.
In this paper, failure analysis methodology will be applied to the principal mechanisms by which FBE coatings fail during long term service; with specific application to case studies involving blistering. The case studies apply standard failure analysis techniques to determine the primary causes and modes of failures.
This paper begins with a brief discussion of essential properties of all pipeline coatings, and a listing of multi-layer systems designed to meet specific needs. It then focuses on special considerations regarding application parameters for multi-layer systems that use fusionbonded epoxy as the primer.