Chain removal completed on a major platform without the use of an AHV
Project overview
Location
Gulf of Mexico
Developer partners
Major oil and gas operator
Water depth
Ultra-deep water
Solution
Chain removal and structural engineering
Intermoor, Acteon’s Mooring and Anchors business line, removed a permanently installed platform and installation chain from a floating production unit in ultra-deep water, without the use of an anchor handling vessel (AHV).
Structural innovation for ultra-deep water chain removal
A unique, AHV-free approach to removing heavy mooring chain required engineered structural aids, coordinated logistics, and precision offshore execution to meet the operator’s payload optimisation goals.
Our solution
Integrated engineering with a safety-first mindset
This project involved the removal of 5,200 ft of 5-in mooring chain that was originally installed with no intention of removal during its operating life. Our engineers researched and developed a method that eliminated the need for an AHV or heavy lift vessel, significantly reducing operational complexity and risk for this mooring integrity campaign.
In-house structural and installation engineers collaborated to design and fabricate bespoke structural aids without modifying the existing platform. These were produced at our Morgan City, Louisiana facility and tailored for installation safety and integrity.
As the scope expanded to include procurement, fabrication, offshore operations, and third-party coordination, our ability to manage complex, multi-vendor campaigns became critical. Even amid the continued challenges of Covid-19 logistics, our flexible delivery ensured the safe and successful removal of the mooring chain, meeting the operator’s mooring integrity goal of increasing topside payload and tieback capacity. Our role as a reliable, insight-driven partner helped the client manage risk and deliver results under tight timelines.
Subtle process efficiencies and portable tooling played a key role. The use of remotely-operated cutting equipment enabled safe, precise work in confined areas and reduced offshore personnel exposure – demonstrating how thoughtful tooling integration can reduce field time and improve safety margins.
Innovations in action
- Selected a Diamond Wire Surface Saw and Tyrolit SB pulling saw to overcome hot work restrictions on the platform’s column tops
- Operated the saws remotely to keep personnel safely away from heavy mooring chains
- Used compact, portable equipment to carry out cuts safely and efficiently in a confined space
- Designed custom structural aids in-house to avoid making any modifications to the platform
- Partnered with IntegriCert to perform portable load testing and confirm each column top lift frame was safe and fit for use
The result
We deployed remote-operated tooling and man-portable equipment, enabling a low-risk, cost-efficient mooring integrity campaign. We successfully delivered the client’s topside payload target on schedule and without incident.
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