The document discusses FPSO layout and turret design. It explains that the key considerations for FPSO layout include cargo capacity, equipment location, hull structure, and integration of marine and topside systems. Internal turrets are suitable for deep water and large numbers of risers, while external turrets eliminate the need for a CALM buoy but risk slamming in large waves. Choosing between internal and external turrets depends on factors like water depth and wave height. An internal turret's position varies along the vessel length depending on its active stationkeeping abilities.

1. Offshore Production Technology
FPSO Layout and Turret
Marine & Offshore Technology

2. Learning Outcomes
1. Explain the key considerations in the FPSO layout and
design
2. Explain the features of an internal and external turret for
a FPSO
3. Explain the considerations for deciding whether to use
internal turret or external turret for a FPSO
4. Explain how the internal turret may be placed along the
length of a FPSO

3. 1. Explain the key considerations in the
FPSO layout and design

4. FPSO Layout / General Arrangement

5. FPSO Layout and GA
Key Issues
 Deadweight
 Cargo (storage) capacity
 Equipment (payload) capacity
 Hull structure - Global and local strength
 Main vessel layout - Deck space - Location of accommodation (NB)
 Location of turret % LBP
Need to be considered
 Hull form, fineness and sea-keeping considerations (NB)
 Bow shape, free board (forecastle & ship side) (NB)
 Green water protection
NB = Issues where scope
for choice exists with new-
builds

6. FPSO layout-aft accommodation
UtilitiesBlast wall Fwd
AccommodationHelideck Process Turret

7. FPSO layout -fwd accommodation
TurretProcess HelideckUtilities
Accommodation
Blast wall
Fwd

8. FPSO Layout - Hull systems and utilities
 Layout of major features (NB)
 Accommodation and Turret
 Main marine systems & utilities
• Cargo & ballast & Pump room
• Main Power, emergency power,
• Fire pumps.
• Heating, Ventilation and Air-Con (HVAC)
• Inert Gas (IG)
 Other spaces and services required for auxiliary equipment and shared systems
 Vessel upper deck piping arrangements (pipe rack integration)
 Integration of hull marine and topsides systems
 Power/fuel
 Control and safety systems
 Emergency power
NB = Issues where scope
for choice exists with new-
builds

9. Interface with Topsides equipment and systems
 There are a number of key issues that need to be considered by the hull design process
 Structural integration of topsides support stools & module support structure into hull structure layout
 Hydrostatics considerations of required maximum topsides weight and Centres of Gravity
 Layout and space considerations in the area of the vessel upper deck
 Systems integration of hull and topsides systems

10. Examples of Layout Considerations
1. Vessel Motions
Minimise the effects of vessel motions
– The process equipment located as close to midship
2. Helicopter Operations
– Accommodation block with the helicopter platform must be located clear of
hazardous zones
– Ideally upwind of the flare stack
3. Metering arrangements
– Export (esp. North Sea) is always likely to be by tandem moored tanker and so
the offloading facilities as well as the metering arrangements will be at the
stern if the turret is near the bow.

11. BUMI ARMARDA CLAIRE
• Layout Considerations

12. 2. Explain the features of an internal and
external turret for a FPSO

13. Turret Technology
 Turret and swivel systems (allow n x 360 degrees rotation) has been the key technology for
the deployment of FPSOs in all met-ocean environments
 Turret allows vessel to weathervane – that is, to take up a position that aligns her heading
towards the dominant forces of wave, wind and current.
 Weathervaning has the effect of minimising environmental loads on the station keeping
system, and minimises the most sensitive vessel motions – generally for a mono-hull – roll.
 This has the effect of minimising disturbance to process equipment and personnel and
maximising the facility uptime.

14. Different Turret Types
 Internal turrets
 External turrets (forward of bow - normally)
 Permanent or disconnectable
 Yoke moored

15. Internal Turret
• An internal turret is convenient when a large number of
risers are to be installed, and therefore a large turret and
swivel assembly are required.
• An internal position also reduces the risk of slamming due to
the reduction of the effect of pitch.
• Internal turrets can be used in deep waters and the most
severe environments
– up to 18 m significant wave height

16. Internal Turret

17. Internal Turret

18. Internal Turrets
Images courtesy of APL

19. Internal Turrets
Images courtesy of APL

20. Internal Turrets
Images courtesy of Bluewater
Turntable Access Structure
(alternative: Deckhouse)
Swivel Stack
Turntable
Turret
Casing / Moonpool
Spider
(bottom ship)
(upper deck)

21. Internal Turrets
Images courtesy of Bluewater
Casing/Moonpool
Mooring Legs
Spider
Lower Radial Bearing
Turret (with riser pipes)
Main Roller Bearing

22. Entry of risers and chains
at bottom of Internal Turret

23. External Turret
• An external turret eliminates the CALM buoy and allows the
turntable and swivels to be directly attached to the vessel
bow or stern.
• Suitable for deep waters and large wave heights
– 12 m significant wave heights
• Can be used up to the point where the combined heave and
pitch motions may cause slamming on the bottom of the
turret (depending on vessel size and length, up to
approximately wave height).

24. External Turret

25. External turrets - Baobab Ivoirien FPSO,
Baobab Oilfield (Ivory Coast)
Images courtesy of Modec/Sofec
 970 m water depth
 8-leg polyester
mooring
 357,000 dwt tanker
conversion
 2.0 million bbls storage

26. External turrets- FPSO Fluminense Brazil
Images courtesy of Modec/Sofec
 800 m water depth
 357,000 dwt tanker conversion
 1.2 million bbls storage

27. External turrets - Cuulong MV9 FPSO,
Su Tu Den Field (Vietnam)
Images courtesy of Modec/Sofec

28. Turntable- Typical Lay-out
Includes for example:
 Subsea Control Skids
 Pipe headers
 Control valves
 Pig receivers
 Pig launchers
 Installation Winch

Images courtesy of Bluewater

29. Yoke Mooring
CNOOC Bohai Bay QHD32-6 FPSO (China)
Kome Kribi FSO
w/ Tower Yoke Mooring System
Images courtesy of Modec/Sofec
 66 ft water depth
 New-build vessel
 1.0 million bbls storage

30. Disconnectable systems
SBM’s External and Internal solutions
External or Riser Turret Mooring Internal turret with disconnectable buoy
Images courtesy of SBM

31. The Riser Turret Mooring (RTM)
 Cossack Pioneer
 Location NW Shelf
Australia
 Vessel size: 152,000 Dwt
 Topsides
 115,000 bopd
Images courtesy of SBM

32. Disconnectable internal turret system
APL’s STP system (Submerged Turret Point)
Images courtesy of APL

33. Disconnectable systems –Terra Nova
Images courtesy of Modec/Sofec
Turret Access
Structure
Upper Turret
Lower Turret
Spider Buoy
Fluid Swivel
Manifold System
Upper Bearing
Connector System
Quick Connect/Disconnect
(QC/DC) Connectors
Lower Bearing

34. Swivel systems

35. Swivel systems
 Swivel systems allow the transfer of:
 Production fluids from the subsea equipment to the vessel
 Export fluids from the vessel to the sub-sea infrastructure
 Well/subsea management/control fluids e.g. methanol
 Electrical signals for control and monitoring
 Electrical power for driving subsea/down-hole equipment
 Swivel systems allow n x 360 degrees rotation
 Swivel manufacturers are pushing back the boundaries of pressure and temperature to:
 ~400+ bar
 ~120 ⁰C

36. Various Deck Levels of Turret

37. Swivel stack located on top of the turret
Swivel stack (Anasuria)

38. Swivel stack modules
Images courtesy of Bluewater

39. P37 Swivel stack
Images courtesy of Bluewater

40. Leadon FPSO stack
Images courtesy of Framo
Leadon power slip ring to be
installed later when required
(4 x 1 MW)
Fluid paths
Utilities

41. Swivel stack located
on top of the turret

42. What is going on inside a swivel?
Images courtesy of Bluewater

43. What is going on inside a swivel?
Images courtesy of Framo

44. 45
What is going on inside a swivel?
Stator Rotor
Roller Bearing
(3-race)
Wiper Seal
Dust/Grease Seal
Outer Seal
Backup
Sliding
Bearings
Stator Rotor
Roller Bearing
(3-race)
Wiper Seal
Dust/Grease Seal
Outer Seal
Backup
Sliding
Bearings
Images courtesy of Bluewater

45. 3. Explain the considerations for deciding
whether to use internal turret or external
turret for a FPSO

46. Internal Turret
• An internal turret is convenient when a
large number of risers are to be installed,
and therefore a large turret and swivel
assembly are required.
• Internal turrets can be used in deep
waters and the most severe environments
– up to 18 m significant wave height
• An internal position also reduces the risk
of slamming due to the reduction of the
effect of pitch.
External Turret
• An external turret eliminates the CALM
buoy and allows the turntable and
swivels to be directly attached to the
vessel bow or stern.
• Suitable for deep waters and large
wave heights
– 12 m significant wave heights
• Can be used up to the point where the
combined heave and pitch motions may
cause slamming on the bottom of the
turret (depending on vessel size and
length, up to approximately wave
height).

47. 4. Explain how the internal turret may be
placed along the length of a FPSO

48. 4. Explain how the internal turret may be placed
along the length of a FPSO
Pg 5-10:
• if the vessel is passive i.e. no Dynamic-Position (DP) thrusters or has
a minimum thruster capacity, the internal turret is positioned within
the first 25% of the vessel length from the bow in severe
environments
• if the vessel is active i.e. sufficient Dynamic-Position (DP) thruster
capacity, the internal turret is positioned just forward of midships

49. Key Questions
1. Explain the key considerations in the FPSO layout and design
2. Explain the features of an internal and external turret for a FPSO
3. Explain the considerations for deciding whether to use internal turret or
external turret for a FPSO
4. Explain how the internal turret may be placed along the length of a FPSO