FSO Aisla Permanent Internal Turret
Scope of Work
SOFEC designed, constructed, fabricated and installed a permanent internal turret for the FSO Ailsa (Maersk Culzean).
The Culzean project development is an ultra-high pressure high temperature (UHP/HT) gas condensate development located some 145 miles (233 km) East of Aberdeen in the UK sector of the Central North Sea.
The Culzean discovery is located on Block 22/25a (License P111) in a water depth of some 90m (295 ft). MOUK as operator holds a 49.99% interest in Culzean, with partners JX Nippon UK and BP. Condensate is exported to an FSO where it is stored and periodically offloaded
to shuttle tankers. The FSO location is 3 km away from the WHP in straight distance. The riser base position is at a water depth of 85m.
The SOFEC internal turret mooring system will be DNV GL classed.
General Description
| Client Name: | Maersk Offshore UK (MOUK) |
| FPSO Contractor: | MODEC Offshore Production Systems (MOPS) Singapore |
| Contract Award: | September 2015 |
| Installation Date: | June 2018 |
| First Condensate: | June 2019 |
| Vessel Size: | 70,000 dwt |
| Storage Capacity: | 350,000 bbls |
| Water Depth: | 85m (279ft) |
| Fabrication: | Turret - Keppel Shipyard Topsides - Dyna-Mac Vessel - SembCorp Marine |
Design Environmental Criteria
100-year storm
| Sig. Wave Height: | 13.2m (43.3ft) |
| Wind Velocity: | 33.5m/s (65.11 kts) |
| Current: | 0.77m/s (1.49 kts) |
Fluid Swivel Assembly
In Phase 1, the assembly includes from top to bottom:
• One (1) LVESR (Low Voltage Electrical Slip Ring)
• One (1) Utility Swivel
• One (1) Condensate Toroidal Swivel Spare
• One (1) Condensate Toroidal Swivel
• One (1) Fuel Gas Toroidal Swivel Spare
• One (1) Fuel Gas Toroidal Swivel
Future Phase, the assembly includes from top to bottom:
• One (1) LVESR (Low Voltage Electrical Slip Ring)
• One (1) Utility Swivel
• One (1) Crude Oil Toroidal Swivel
• One (1) Crude Oil Toroidal Swivel
• One (1) Crude Oil Toroidal Swivel
• One (1) Condensate Toroidal Swivel Spare
• One (1) Condensate Toroidal Swivel
• One (1) Fuel Gas Toroidal Swivel Spare
• One (1) Fuel Gas Toroidal Swivel
Riser System
Phase 1:
1 x 4-in. Flexible Riser (Fuel Gas Import)
1 x 6-in. Flexible Riser (Condensate Import)
Future Phase:
2 x 8-in, Flexible Risers (Condensate/Crude Oil) 1 x 10-in, Flexible Riser (Condensate/Crude Oil)
Comments
The turret mooring system complies with the mandatory EU directives and UK HSE requirements.