A safe and economical solution for the structural maintenance of FPSO Hulls – Coldshield patch under test (photo: Cold Pad)
Bureau Veritas has approved in principle the repair of offshore structures using the bonded composite product Coldshield, developed by Paris-based start-up Cold Pad. Coldshield is a composite structural reinforcement specifically developed for the harsh environments of offshore units.
Matthieu de Tugny, Senior Vice-President and Head of Offshore, Bureau Veritas, says, "Coldshield offers a long awaited solution for the repair of corroded offshore structure without the need for welding or downtime. We have combined our expertise in marine composites and bonding with our experience of the hydrodynamic loadings and constraints of offshore units to assess Coldshield. We believe that Coldshield is the first non-welded structural repair method available for an FPSO hull.”
Marine offshore structures such as FPSOs are subject to a harsh environment combining high loads, fatigue and potential heavy corrosion. The typical method of repair by welding is not always possible, or needs long downtime. The idea of bonded structural composite repair has been under development for many years but bonding and composite repairs usually require a controlled environment, making them unsuitable for offshore structures.
Coldshield is a patented solution to make reliable structural bonded repairs. It is a complex product made of high standard composites, specifically chosen polymers, alloyed in a shield of Superduplex steel and fluorosilicon joints. Specific production techniques such as vacuum resin injection and structural bonding were optimised to reach the robustness necessary for on-board bonding in an offshore environment. The product was developed in partnership with Total and IFPeN.
Approval in Principle by Bureau Veritas confirms that the design is feasible, achievable, and that the research and development campaign is relevant to demonstrate the ability of the product to behave in accordance with its specifications. Bureau Veritas engineers verified the suitability to the environment for installation and product life, composite and polymer design, characteristics and ageing, test adequacy with the on-board loads and environment severity, structural efficiency and strength of the whole product.