In a decisive response to escalating subsea risks, UK-based engineering firm Jee Ltd has successfully completed a high-priority pipeline remediation campaign in the North Sea, safeguarding vital offshore infrastructure from the growing threat of seabed scour.
The operation was triggered by routine subsea surveys that uncovered severe erosion around a key pipeline spool. The resulting freespans, unsupported sections of pipeline suspended above the seabed, posed a significant risk of vortex-induced vibration (VIV), a phenomenon that can lead to fatigue damage and eventual structural failure.
With the integrity of the asset at stake, the operator turned to Jee Ltd for urgent technical support. Leveraging their expertise in subsea integrity management, Jee’s engineering team rapidly deployed advanced finite element analysis (FEA) using ABAQUS software to assess the structural condition of the pipeline. Their models, developed in accordance with DNV-RP-F105 standards, accounted for critical uncertainties such as the positioning of protective concrete mattresses, whether they remained suspended or had settled on the seabed.
As new survey data emerged, Jee responded in real time, updating models and conducting interaction checks for closely spaced spans to assess compounded fatigue risks. These insights informed a targeted rock dumping strategy designed to restore seabed support and reduce the potential for future scour.
However, the campaign faced a significant challenge: the removal of concrete mattresses proved more complex than anticipated. Jee’s simulations confirmed that leaving the mattresses in place during rock placement would overload the pipeline. Working closely with field teams, the company explored alternative removal strategies, ensuring the operation progressed safely and without delay.
The remediation was completed successfully, with the pipeline remaining in service and the risk of fatigue failure significantly reduced. The client, impressed by Jee’s technical agility and hands-on support, has since commissioned the firm for further assessments across other high-risk assets in the region.
As the offshore sector continues to navigate ageing infrastructure and increasing environmental scrutiny, this project underscores the critical role of proactive integrity management. Jee Ltd’s blend of engineering precision, real-time responsiveness, and collaborative delivery highlights the value of expert partnerships in maintaining the resilience of the subsea networks that underpin global energy supply.
For more information, visit http://www.jee.co.uk or call +44 (0)1732 371 371.
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