Extending onshore pipeline repair to offshore steel risers with carbon–fiber reinforced composites

In the last 15 years, glass fiber hoop reinforced composite systems emerged as an acceptable, successful method for repairing corroded and mechanically-damaged onshore pipelines where the primary load is internal pressure. The feasibility of extending these repairs to offshore pipes such as risers require a thorough understanding of the complex combined load profiles; overlay of significant tension, bending, internal and external pressure. Herein an innovative design based on integrated computational models and full-scale tests is presented to address the viability of reinstating capacity to offshore pipelines and risers. The experimental program was based on a collaborative test matrix developed with the participation of composite repair manufacturers. The outcome guided and led to an easily deployable carbon–fiber composite repair system which was based on limit analysis methods and strain-based design techniques. It is anticipated that the results of this program will foster future investigations by integrating operator’s insight and in situ data gathering to extend composite repair for offshore needs.