Imenco Lifting & Engineering department was nominated to find a new solution for a Thruster Replacement System onboard Alvheim FPSO. After a study had been carried out, Imenco was chosen as a partner for this scope, and started the detail engineering process in cooperation with our customer. One of our very experienced partners produced all items for Imenco, and we also performed a very successful FAT with our customers and their third party representatives from LOC (London Offshore Consultancy) present at production site. Imenco supervised all offshore modifications and installation of the TRS.
Engineering & Development department developed a new 25Te (WLL) lifting latch for this specific project.
The thruster was to be replaced by a offshore construction vessel on site, lifting the thruster on board the OCV with the three thruster tie in lines attached would give an increased risk of damage and injuries as the OCV and the FPSO would be tied together during the Thruster replacement operation. Imenco E&D was asked to provide a solution that could connect and disconnect the three tie-in lines from the thruster by use of ROV subsea, to make the operation much safer. The challenge was to create a tool for a high lifting load, with limited dimensions as it had to run through the FPSO bottom tubes without getting hooked. By using basic principles from standard Imenco products and including new smart solutions, a Lifting latch was custom made for this operation. The lifting latch is now a part of our Imenco products ready for new lifting operations where slender design, subsea connection/disconnection and safe lift is required.
The offshore replacement operation was executed successfully, and is alleged to be the first ever FPSO thruster replacement to be undertaken without shut-down or reduction in production. Feedback from customer after a successful operation is very good, they are satisfied with the quality of the products and the smart solutions that Imenco has provided throughout the project.