SubC recently successfully replaced selected buoyancy modules on the live riser via ROV on Maersk Oil GP3 FPSO. 

SubC Partner recently completed an EPCI project on the Maersk Oil GP3 FPSO in the Dumbarton field in the North Sea, 230 kilometres northeast of Aberdeen. successfully replaced selected buoyancy modules on the live riser via ROV while avoiding a costly shut down of oil production.

The EPCI project was awarded by Maersk Oil UK in March 2015. The brief was to replace selected buoyancy modules on a live riser without shutting down oil production. The existing buoyancy modules on the riser had slipped and were no longer maintaining the riser position and shape in the water, which were now outside design specifications.

Traditionally, such an operation to replace buoyancy modules would require disconnection of the riser and a complete halt to oil processing during the work – making it a very costly operation. This project, the first of its kind, developed an ROV solution to perform operations from outside the swing circle of the FPSO and eliminated the need for the FPSO to stop production.

Our organisation took up the challenge and in only five months had developed the concept, carried out detailed design work and manufactured the Subsea Flexible Riser Repair-Solution. Extensive factory acceptance tests followed the manufacturing and comprehensive wet tests were performed in Esbjerg.

We mobilised a work class ROV at its facilities and rented an area of the harbour in Esbjerg to simulate the entire offshore operation. This comprehensive harbour simulation allowed all the developed tools to be tested in real life conditions. Any risks were identified and eliminated and operators had the opportunity to familiarise themselves and train with the state-of-the-art engineering tools.

In September, following completion of the wet tests, the vessel Polar King was mobilised and works started immediately after at the Dumbarton field. Approximately 55 people in total were deployed offshore for the operation, including project and crew personnel on a 24/7 setup.

Selected buoyancy modules were successfully removed and subsequently replaced, completely reinstating the effectiveness of the original setup. The teams offshore from MOUK, SubC Partner, DOF and GC Rieber worked together very closely and completed the project in about 3 weeks without any incident, accident or LTI. 

See how it works here: Repair of buoyancy module on live riser
Hear how SubC Partner helped Maersk UK save millions: Maersk UK -Bouyancy repair innovation saves millions!
Read more about the succes here: Oil & Gas UK success stories


Lars Wigant, Director Subsea Engineering, This email address is being protected from spambots. You need JavaScript enabled to view it. , +45 28782377


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