Case study
Integrated subsea inspection and monitoring extends offshore energy platform life
North Sea
Client
E&P Operator
Date
September 2024 to October 2024
At a major offshore energy platform designated as the future site of one of Europe’s largest CO₂ storage hubs, Fugro delivered a fully integrated subsea campaign aligned with the project’s operational goals. By combining inspection, monitoring, and engineering expertise in one streamlined package, we installed in-house motion sensors and deployed our patent-pending anode clamps. This approach reduced offshore time and costs, provided real-time insights into asset motion and stability and helped minimise HSE exposure while strengthening the protection of critical infrastructure.
Planning, feasibility, conceptual design
Design
Construction
Operations and maintenance
Decommissioning
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Challenge
A long-serving energy platform required its annual subsea inspections along with the installation of motion sensors on the wellhead caisson (WHC) to monitor structural movement. As one of the region’s longest-operating offshore assets, protecting its integrity and extending its operational life was a critical priority. The project required a retrofit anode solution that could be installed quickly and safely in an offshore environment with restricted access. Traditionally, multiple scopes are carried out across separate campaigns, which can extend timelines, increase mobilisation requirements, and limit opportunities to make the most of vessel time.
DeepData motion sensor pre installation
operational days saved
less fuel saved
Solution
Fugro delivered the campaign as a single, integrated operation – combining inspection, monitoring and engineering expertise. With a single contractor and project manager overseeing the entire scope, we reduced offshore time, simplified coordination and delivered a more efficient result for the platform operator.
Scope of work included:
General visual inspection and cathodic protection (CP) surveys across subsea structures, pipelines, and platform assets
Capturing valuable in-service measurements of the subsea caisson motions, later analysed in-house for comparison with project expectations
Design and deployment of our patent-pending retrofit anode clamps, for fast, reliable installation with a remotely operated vehicle (ROV)
The campaign also included valve operations, battery change-outs, multibeam echosounder surveys, and internal mini ROV inspections – ensuring full asset coverage, improved data quality, and fewer interventions. To help extend asset life and protect structural integrity, we installed 12 new retrofit anodes to restore CP on the flex joints of cable stays and support jacks.
Deploying our patent-pending anode clamps by the ROV using the manipulator wrist to transfer the torque to the D-handle interface
Innovative Highlights
Two innovations defined this campaign, our retrofit anode clamps and DeepData subsea measurement pods.
The retrofit anode clamps, developed in-house for the project, were tailored to meet the requirements of the platform’s subsea infrastructure. Their compact, ROV-deployable design enables efficient installation of new anodes that suit a large variety of requirements. Engineered to fit securely to any webbing, cross member or flat plate, the clamps are installed using a seven-function manipulator. Spring-loaded pins pierce the coating and maintain tension over time, ensuring a durable electrical connection.
A removable handle adds flexibility, allowing direct access to the lead screw by an API Class 2 interface. The design reduces snagging risks and simplifies maintenance, while delivering long-term protection in harsh subsea environments. Following its success in this scope, the retrofit anode clamps are now positioned for future use in subsea projects across the industry.
Our industry-leading DeepData subsea measurement pods were deployed to capture precise relative motion data, enabling the operator to compare in-service performance with design expectations. Backed by over 20 years of offshore monitoring expertise, our advanced processing techniques and software delivered trusted insights to the client.
DeepData pods provide high precision data on subsea assets in harsh marine environments all over the world
Impact
This integrated campaign delivered significant efficiencies, saving operational time, reducing costs, and protecting critical offshore assets. Originally scheduled for 20 operational days, we completed the scope in just 14 – reducing offshore time, minimising health, safety, and environment (HSE) exposure and reducing carbon footprint. By completing the work ahead of schedule, we used approximately 30 m³ less fuel. Operating a single vessel for the integrated scope avoided multiple mobilisations and demobilisations, while the clamp’s fast installation meant fewer vessel days and smoother operations.
New anodes installed on flex joints of cable stays and support jacks improved the safety and integrity of the offshore energy platform. Our in-house structural monitoring expertise and rental equipment allowed the client to readily understand the in-service behaviour of the asset and manage risk effectively.
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Daniel Jones
Global lead - Subsea inspection, repair and maintenance
Subsea inspection, repair and maintenance
In some ways, offshore assets are like cars. To make sure they’re running safely and efficiently, they need regular inspection, repair, and maintenance. Through inspection, we find faults and defects, including internal corrosion, before they become a problem. This prevents the need for costly major repairs. Or even costlier replacements. Whatever your challenge or concerns may be, we tailor our methods to your project. We believe that’s the best way of protecting and fixing your assets. And it’s the best way of saving you time and money in the long run.