Complex FPSO top chain replacement completed safely and efficiently
Project overview
Project overview
Mooring system maintenance
Location
North Sea
Solution
Mooring line top chain replacement
Intermoor, Acteon’s Moorings and Anchors business line, supported a major North Sea operator with project management, planning and offshore support for planned maintenance on its floating production, storage, and offloading (FPSO) vessel.
Ensuring operational integrity
We replaced the winch wire, three mooring line top chains and assessed the condition of the recovered chains. The work was complicated by large equipment sizes, tight design tolerances and restricted space, requiring precise execution under challenging conditions.
Delivering efficient mooring system upgrades through technical precision
Restricted space required a complex wire transfer with tight tolerances between an anchor handling vessel (AHV) and the FPSO to avoid bringing heavy machinery on-board.
The top chain changeout involved simultaneous operations (SIMOPS) across four vessels, handling of a large 152-mm chain and associated ancillaries, and executing a like-for-like system replacement.
Our onshore team provided detailed analysis and planning to support our experienced offshore tow masters and marine representatives, enabling tight heading control throughout. Our technical expertise in chain handling allowed us to develop procedures to maximise the use of mechanical aids, prioritising personnel and equipment safety.
Our collaboration with a specialist chain test house ensured that all components met target loading criteria, supporting long-term integrity planning and potential life extension of the existing mooring system-reducing the need for new component manufacturing.
The result
The operation was completed safely, on time and fully in line with regulatory and client expectations. Our expertise in complex offshore projects and SIMOPs enabled seamless execution while minimising project footprint and without interrupting production. The FPSO’s mooring system was successfully restored, improving operational confidence and lifecycle value.
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