Innovative Technologies, Creative Solutions Turret Mooring Design – Some Challenges and Solutions FPSO Forum 2004 NUS, Singapore Arun Duggal FMC SOFEC Floating Systems 31 March 2004

Innovative Technologies, Creative Solutions FPSOs are a Mature & Versatile FPS Technology Over 100 units in operation worldwide FPSO total > than all other FPS combined Water depth range 20 m to > 1,400 meters 1 to 100+ risers 10,000 bbl – 250,000 bbls/day Up to 2,000,000+ bbls storage Benign (West Africa) to Extreme Environments (North Atlantic) Various flavors: Turret-moored Spread-moored Yoke-moored Hawser-moored

Innovative Technologies, Creative Solutions Typical Permanent Internal Turret System Bearing (only upper in this case) Turret Shaft / Riser Guide Tubes Chain Table (Hawse Pipes/Chain Supports) 6 Anchor Legs + 34 Risers Barracuda FPSO: Campos Basin 834m, 34 Risers Swivel Stack (Product/Lift/Controls) Anchor Leg + Riser Pull-In Equipment Manifolds + Pig Launching/Receiving

Innovative Technologies, Creative Solutions Design Considerations Mooring System Anchor Legs Anchors Risers Thrusters & DP Control Environment Water Depth Waves Wind Current Vessel Particulars Storage / Tonnage Topsides Layout Vessel Motions Turret Design Configuration Size Location Loads Turret Mooring of Production Vessels Fluid-Transfer Requirements Well Heads Subsea Manifolding Risers Turret Manifolding Swivels Offloading Pigging

Innovative Technologies, Creative Solutions Some Current Turret Mooring Challenges More Complex Turret Systems –Large number of risers –Increased requirements for turret mounted equipment –High pressures Riser Systems for very Shallow or Deep Water Project Schedule –Short, fast-track schedules –Project Design Basis not well defined –Interfaces and Communication Installation in Deepwater –Installation engineering, equipment, costs

Innovative Technologies, Creative Solutions Example 1: Fast-Track FPSO for Shallow Water Su Tu Den FPSO, Vietnam MODEC, Inc + FMC SOFEC + ConocoPhillips Newbuild FPSO (80,000 bbl oil/day) Schedule: Contact to First Oil – 19 months –Turret Delivery Schedule – 12 months Shallow Water (48m water depth) Harsh Environment (100-yr wave of 8.1m Hs) Large Number of Risers (12)

Innovative Technologies, Creative Solutions Project Milestones 2002 Mar. Contract Award (LOI)(2002/03/21) 2002 Apr. Order Long Lead Items – bearing, forgings, process 2002 Jun. Mooring Design Complete 2002 Aug. Turret Fabrication Begins (MSE) 2002 Oct. Hull Fabrication Begins (Samsung) 2002 Nov. Preliminary Riser Design Complete 2002 Dec. Topside Fabrication Begins 2003 Mar. Drydock – Block Assembly Begins 2003 Apr. Start Topside Module and Turret Installation 2003 May Launching 2003 Jul. Start Shipyard Commissioning 2003 Sep. Tow Out 2003 Oct. Offshore Installation 2003 Oct. 1st Oil (2003/10/29)

Innovative Technologies, Creative Solutions STD Turret Mooring Design & Fabrication Use Standard Components & Design –SOFEC Large External Turret Design Bearing Capacity exceeds anticipated Design Loads –Allows order of main components before final loads derived Design Riser Configuration Flexibility in Chain Table Design/Fabrication Clearly Define all Structural and Fluid transfer Interfaces at Turret Support Structure Parallel Design and Fabrication Effort Easy / Quick Integration with Vessel

Innovative Technologies, Creative Solutions Riser & Mooring Design in Shallow Water

Innovative Technologies, Creative Solutions Mooring and Riser Design 2

Innovative Technologies, Creative Solutions Integration of Turret & Vessel

Innovative Technologies, Creative Solutions First Oil: November 2003

Innovative Technologies, Creative Solutions Application –FPSO weathervaning SPM –Large field (>100,000 bbld) –50 to 100+ risers –Deep to ultra deep water –Worldwide Weathervaning advantages –Mooring tensions –Tandem offloading Simplified turret structure –Allows for simple interface with vessel Robust bearing system Large Decks for Flowline Manifolding, and other Equipment Efficient Mooring & Riser Installation Equipment Example 2: Very Large Turret

Innovative Technologies, Creative Solutions Chain Table I-Tubes Support Columns Chain Supports Main Deck Torque Arm Vertical Bearing Radial Bearing Swivel Stack & Torque Tube Piping / Manifolding Riser Hang-Off Pull-In Deck Anchor LegsRisers & Bend Stiffeners VLT: Deep Water, Large Capacity Internal Turret

Innovative Technologies, Creative Solutions VLT Chain Table 3x3 mooring provides 3 riser corridors Riser quantity defines chain table (and turret) diameter –60 risers - 22 m dia –90 risers - 31 m dia –120 risers - 40 m dia 2 riser rows maximum No shadowing to allow inner row installation and replacement

Innovative Technologies, Creative Solutions VLT Main Deck Supports all loads, including: –Riser hang-off loads –Mooring loads through chain table and support columns –Turret self weight Depth-to-diameter ratio is a key design parameter –Flexibility to move with vessel –Strength to support risers, mooring and turret weight loads –2.5 m depth / 32 m diameter for a 90 riser VLT

Innovative Technologies, Creative Solutions Conclusions Turret Moored FPSOs are a Very Mature Technology –Design for Load Transfer is typically not an issue –Current challenges mostly associated with Fluid Transfer Large Number of Risers High Pressure Manifolding Subsea Intervention & Control Project Parameters also Impact Turret Mooring Design –Schedule Fast-track: 18 – 22 months Complex systems require more commissioning time –Communication & Interfaces – among various contractors / client –Knowledge of others scope of work, issues, etc.