INTERNAL TURRETS
Unit type: FPSO
Mooring: Internal turret
Client: Samsung Heavy Industries (SHI)
Field: Development project for North Sea fields
WD: Up to 400 metres
No of risers:18
The project was a joint turret development program together with SHI and Promor’s scope included the conceptual and detail design of the internal turret including detail design of the main shaft and caisson structures and components such as the main bearing system, swivel stack arrangement, chain stopper assemblies, piping PFD’s and P&ID’s.
The mooring arrangement utilized a 3 x 5 arrangement to allow for two line failure conditions. Mooring lines would typically be comprised of all chain and with the chains sized to suit the environment loads. For initial design the more stringent metocean data was used.
The riser system was multi-functional with slots for production, water injection, gas and umbilicals. Riser manifolding was provided on the turret shaft decks.
Unit Type: FPSO
Mooring: Internal turret
Client: Teekay Petrojarl
Field: Van Gough, offshore Australia
WD: 350 metres
No of risers: 5
The Project scope included the conceptual and detail design for the modification of the existing internal turret mooring into a dis-connectable internal turret mooring.
The scope included the shaft modifications, design of a compact structural connection system for locking onto the mooring buoy, piping system connections and routing through the swivel stack, turret winch and hydraulic power unit, buoy recovery system and umbilical connection system. All the turret systems were required to be accommodated in the existing design and arrangement of the internal turret on the FPSO.
When completed the turret mooring would connect to the DTM buoy and provide connections and flow paths for production, water injection, gas lift and umbilical risers.
EXTERNAL TURRETS
Unit type: FLNG
Mooring: External Turret
Client: SHI/Petronas
Field: East Malaysia
WD: 1300 metres
No pf risers: 8
Promor’s scope included the conceptual and detail design for an external turret to be used on an FLNG unit moored in deep water.
The scope included the design of the main structural sections of the shaft and turret head, swivel stack detail design, chain stopper details, winch and rigging arrangements for handling the mooring lines and risers, piping systems and E&I components. Turret design was coordinated with the production department at SHI for fabrication and assembly.
The mooring system utilized a 3 X 3 arrangement with polyester mooring lines terminating in suction piles. The chain stoppers were of a Promor dual axis type to allow for out of plane bending of the top chain and chain pull through during hook up and re-tensioning.
Complete turret system was designed as a single lift assembly for integration with the rigid arm structure on the FLNG unit.
Unit type: FPSO
Mooring: External Turret
Client: Sabah International Petroleum
Field: Limbayong, East Malaysia
WD: 1500 metres
No of risers: 18
Promor’s scope included the complete detail design of the external turret including the turret head, shaft, rigid arm, piping systems, swivel stack, bearing system, mooring lines and suction piles, material handling including mooring line tensioning and riser handling systems.
The mooring system utilized a 3 x 3 arrangement with polyester mooring lines terminating in suction piles.
The turret bearing system utilized a Promor proprietary multi-roller system for axial and radial loads to allow for increased space for moorings and risers and associated piping.