The World Deepest Electrically Heat-Traced Flowline

Electrical heat tracing technologies for flowline applications have been in development phase for some time. Yet in recent years, the efforts to deploy this technology on real life applications have intensified, leading to several projects in the industry simultaneously adopting this solution. As often seen with technology development, implementing the serial number 1 of a technology requires one project with favorable conditions and parameters, but also the stakeholders willingness to face the challenge associated to being first, and having to cross the final gap between the qualification program and this real life application. This paper presents how a specific project met all the conditions to be the first to select and implement a deepwater EHTF® (Electrically Heat-Traced Flowline) solution. This paper presents the Project from the concept selection phase, to the execution and offshore installation of the final product. This provides an overview of why this technology was selected, and how the Project was executed, with a focus on the main challenges encountered and the associated solutions. The concept selection phase for this two-well development consisted of comparing subsea tie-in architectures to tieback architectures using one or several new risers. The EHTF® emerged as the highest value solution, offering the best compromise between technical, economical, risk and schedule criterion, as it enabled single line tieback, while significantly reducing the operational risks associated to such architecture. A FEED was launched to further define and accurately estimate the concept, in order to reach FID. Close collaboration between the Operator and the Contractor at every step of the process allowed the solution to be selected and developed in a fast track manner while enabling the Contractor to provide an optimized, tailor-made solution. The project execution involved many work sites, including the Vigra spoolbase in Norway for EHTF® fabrication, as well as the Seven Vega, which was a brand-new addition to the pipelay vessels fleet at the time of the Project. Many challenges arose during the project execution, as the qualification program was being completed, but adequate solutions were developed, allowing the Project to continue its course. Obviously, there were many lessons learned along the way, which will feed into further product development plans, in order to improve its technical performance and competitivity. Heat tracing solutions offer great opportunities for single line long tieback development which often come with elevated operating risk profile due to complex wax and hydrate management. Enhanced thermal performance of resistive heating systems makes it possible to operate with low power consumption, which is a key in today's world of energetic efficiency.