Goliat

The Goliat FPSO is the largest of SEVAN’s rigs – featuring a unique circular hull capable of storing up to 1 million barrels of oil.
Located 50 km west of Hammerfest, the Goliat oil field faces extremely harsh weather conditions. To ensure safety and operational reliability during the cold and dark season, all handrails and walkways are heated to prevent ice buildup. The mooring system is engineered to withstand a once-in-10,000-year storm – a testament to the rig’s robust design and resilience.

Image credit: National Geographic

SEMAR was engaged alongside DOF Subsea to execute the Tow & Hook-up operations in the Arctic offshore region near Hammerfest, located at Norway’s northernmost edge. The end client was ENI Norge – now part of Vår Energi.

The hull was constructed in South Korea, where SEMAR conducted several site visits to test the onboard mooring equipment. A major part of SEMAR’s contribution was the engineering and planning of the overall mooring operation. This included key subtasks such as pre-rigging for dry tow transport from Korea to Hammerfest, temporary inshore mooring in Hammerfest, and preparations for the offshore tow.

The project presented several challenges along the way, which SEMAR worked diligently to resolve. During the engineering phase, SEMAR provided up to 15 specialists, contributing between 200 and 450 work hours per week.

Scope of work summary

• Audit and selection of suction anchor fabricator
• Follow-up on fabrication of suction anchors
• Supervision of installation and testing of mooring systems onboard the FPSO
• Analysis for temporary inshore mooring in Rypefjord, Hammerfest
• Analysis for offshore tow and hook-up operations
• Operation of the offshore base, including receipt of mooring system components (as freeport)
• Pre-installation of suction anchors and bottom chains
• Engineering for installation vessel modifications and installation aids
• Pre-installation of fiber-rope segments, midline buoys, and top chains
• Engineering of midline buoy upending and overboarding systems
• Fabrication follow-up and testing of the buoy handling system
• Engineering of clump weights for seabed storage of mooring lines

Key figures

Client: ENI Norge (Vår Energi)

Operator: ENI Norge (Vår Energi)

Project duration: 2011-2015

Project characteristics: Tow & Hook-up of FPSO with several variation orders.

Construction site: Hunday Heavy Industries, Ulsan, South Korea

Successful offshore installation campaigns in 2013 (anchors), 2014 (lines) and 2015 (FPSO)

All activities and operations were planned by experienced personnel, supported by use of 3D models. The fabricated installation aids fitted well to the designated positions and worked as intended.