The Low Motion FPSO (LM-FPSO) The SCR and TTR Friendly Floater in Harsh Environment

Transcription

1 The Low Motion FPSO (LM-FPSO) The SCR and TTR Friendly Floater in Harsh Environment Alaa Mansour, Ph.D Marine Engineering Manager

2 Outlines Slide 2 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

3 Outlines Slide 3 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

4 Heave (m/m) Roll (deg/m) Field Development Challenges Lack of Infrastructures/Remoteness Requirement for DVA to wells Water depth Persistent swells Harsh environment Large number/diameter risers Inherently high dynamic floater FPSO or FPU+FSO/FPSO TTR feasibility or Separate DTU Riser feasibility Slide FPSO Heave FPSO Roll Period (s) Period (s)

5 Field Development Challenges Slide 5 Question?. Can we develop FPSO that offers: High oil storage capacity and deck payloads Superior motion response - TTR/SCR/mooring friendly No turret or swivel Large number/ large diameter risers Fast deployment & decommissioning Quayside integration Simple and efficient hull form Maintain simple topside layout Commercially attractive (CAPEX & OPEX) Low risk and minimum or no schedule impact

6 Outlines Slide 6 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

7 The LM-FPSO Design Slide 7 Conventional Topside Tendon Top Connector Short Tendon Pipe No couplings Conventional hull construction Conventional Mooring System Solid Ballast tank (SBT) SCRs / Umbilicals Tendon Bottom receptacle

8 The LM-FPSO Constructability Slide 8 Simple hull form Stiffened plate structure Simple fabrication SBT fabricated independently Solid ballast is added in SBT Hull modules are integrated above SBT Topside integrated Mooring chains are used to connect SBT to hull Dry dock is flooded

9 The LM-FPSO Install-ability Slide 9 Wet-tow

10 The LM-FPSO Install-ability Slide 10 Positioning and Ballasting

11 The LM-FPSO Install-ability Slide 11 Tendon Installation

12 The LM-FPSO Performance Slide 12 The mass of the SBT: Maintains positive tendon tension in all design conditions Ensures full coupling in heave, roll and pitch Ensures full coupling in the slow motion surge/sway & yaw Provides high stability (high GM) less compartments SBT mass and added mass Long heave, roll and pitch natural periods Significantly low heave roll/pitch motions The relative motion in surge, sway and yaw Limited to first order Much less than TLP hull-to-foundation relative motions

13 The LM-FPSO Performance Slide 13 Typical Heave Response Typical Roll Response Very long Heave Natural period Significantly reduced heave response in WF Very long Roll Natural period Significantly reduced Roll response in WF & LF

14 RY [deg] Z [m] RX [deg] The LM-FPSO Performance Slide DM-FPSO Hull vs. SBT, Heave Motion Typical Heave FPSO Z w/o Mean SBT Z w/o Mean DM-FPSO Hull vs. SBT, Roll Motion Typical Roll FPSO RX SBT RX Time [s] Time [s] DM-FPSO Hull vs. SBT, Pitch Motion FPSO RY SBT RY Typical Pitch Full coupling in heave, roll and pitch modes Very low heave roll/pitch motions, less than a third that of Spar, almost TLP like Time [s]

15 RZ [deg] X [m] Y [m] The LM-FPSO Performance Slide DM-FPSO Hull vs. SBT, Surge Motion 35 DM-FPSO Hull vs. SBT, Sway Motion 30 Typical Surge FPSO X SBT X 30 Typical Sway FPSO Y SBT Y Time [s] Time [s] DM-FPSO Hull vs. SBT, Yaw Motion Typical Yaw FPSO RZ SBT RZ Time [s] Full coupling in Surge, Sway and yaw modes Relative motion is quite small

16 Bottom Tension [kn] The LM-FPSO Performance Slide Critical Tendon Bottom Tension Critical Tendon Bottom Tension Tendon Tension Time [s] TLP vs LM-FPSO Dry Tree & Harsh Environment 1000 yr condition Tendon tension is positive even in survival conditions LM-FPSO to SBT Relative motion is less than that of TLPto-Foundation.

17 The LM-FPSO Performance Slide 17 Current speed = 1.1 m/sec Vr = 3.7 A/D = 0.07 VIM Response

18 The LM-FPSO Performance Slide 18 SBT Structural Analysis

19 The LM-FPSO Performance Slide 19 SBT Structural Analysis

20 The LM-FPSO Economics Slide 20 Compared to the corresponding conventional FPSO: Dry Tree Harsh Environment Wet-Tree Persistent Swell Hull Steel 10-15% Increase - SBT Steel (% of hull steel) 14% 5% Solid Ballast (% of Displacement) 25% 15% Tendon system TIC/tendon $4.1MM $4.1MM Offloading Buoy cost $100MM Increase Mooring system $15MM Increase $25MM Reduction SLWR to SCR (per riser) $15MM Reduction $15MM Reduction Turret $250MM Reduction - Eliminate DTU (CAPEX) - Each $500MM Reduction - Topside cost $50MM Reduction - OPEX $100MM Reduction? - Decommissioning $100MM Reduction -

21 Outlines Slide 21 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

22 Dry Tree LM-FPSO in South China Sea Slide 22 Water depth = 500 m Topside payload = 25,000 MT 1.0 MMBBL Storage 15 TTRs 1 Multiphase production SCR Environment:. 1,000 Yr 100 yr Hs (m) Tp (sec) Ws (m/s) surface (m/sec)

23 Slide 23 Dry Tree LM-FPSO in South China Sea The Hull L x w x H (m) x x 51.5 Corner radius (m) 10.5 Draft / Freeboard (m) 33.5 x 22.0 Center Well (L x W) (m) 60.7 x 60.7 Hull Lightship Wt (Mt) 44,330 Displacement (Mt) 227,768 The SBT L x W x H (m) x x 3.7 Center Opening L x W (m) 24.4 x 14.6 SBT steel Weight (Mt) 6,076 Solid ballast weight (Mt) 49,556 The Mooring System Mooring (-) 16 Chain-PE-Chain Platform Chain Dia x L (mm x m) 162 mm R4S x 100 m Polyester Dia x L (mm x m) Platform Chain Dia x L (mm x m) 305 mm x 750 m 162 mm R4S x 150 m Tendons (-) 44"OD x 1.7" Length (m) 88.0 Wt weight (Mt) 12.0 System Natural periods Heave Np (sec) 25.0 Roll/Pitch Np (sec) 46.0 GM (m) 31.9 Pre-service Key Figures Integrated Platform Lightship weight (Mt) 71,134 Hull+SBT Draft (inc. SB) (m) 12.3 Solid ballast is added in dry dock (-) YES Lightship Draft (no solid ballast) (m) 4.9

24 Dry Tree LM-FPSO in South China Sea Slide 24 Heave RAO Roll Response

25 Dry Tree LM-FPSO in South China Sea Slide 25 Variable Unit 1,000-yr 100-yr Max offset % 11.7% 8.7% Max SCR Porch Velocity (m/s) Max heave (SA) (m) Max combined Roll/pitch (SA) (deg) Max Yaw (deg) Max Hull-SBT rel. horizontal motion (m) Minimum tendon tension (Mt) Max Tendon Tension (Mt) 6,411 5,178 TTR dynamic Stroke (m) Max Keel Joint Reaction (Mt) Max Von Mises Stresses (MPa)

26 Dry Tree LM-FPSO in South China Sea Slide 26 1,000-yr Critical Event 100-yr Critical Event The System Performance

27 Dry Tree LM-FPSO in South China Sea Slide 27 LM-FPSO + ONE TLP Cost Delta Fabrication cost delta (Hull + SBT) $50MM Transportation & Installation Solid Ballast TIC (at quayside) Mooring system delta Tendon cost including Installation (TIC) Offloading buoy TIC Additional Tensioner costs Eliminate one TLP (Hull& Mooring T&I) $10MM $5MM $15MM $65MM $100MM $24MM -$500MM Compared to a Turret- Moored FPSO + TLP in SCS Topside saving No turret No FTL from One TLPs Decommissioning saving of 1 TLPs OPEX delta Total Delta -$50MM -$250MM -$30MM -$100MM -$100MM?? -$761 MM

28 Outlines Slide 28 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

29 The Semisubmersible Version - TLS Slide 29 Similar technology is applicable to conventional semisubmersibles designs to significantly improve their motions Tension Leg Semisubmersible (TLS) Tendon Porch Tendon bottom receptacle The TLS Semi In-place

30 The Semisubmersible Version - TLS Slide 30 The TLS Semi Pre-service

31 Heave RAO (ft/ft) Wave Energy Spectrum (ft^2-sec/rad) The Semisubmersible Version - TLS Slide Wave Energy H1000 Conventional Semi Spar FHS Semi Period (sec) 0

32 Outlines Slide 32 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

33 The Business Case Slide 33 FPSO market share is greater than the combined FPU market Potentially replace the common development scheme in west Africa (TLP+FPSO) big market share (Example Maersek Chissonga, Hess Ghana) Attractive solution for Liuhua development in SCS Attractive solution for Talisman development in Vietnam No feasible riser solution on FPSO for ultra-deepwater (Example Petrobras Pre-salt) Industry is developing FPSO with SCRs for the GoM Enable dry tree Semi with potential application (Mad Dog 2, Shenandoah,..etc) Improved semisubmersible response in wet tree application (CVX Jansz Io, Equus, etc)

34 Outlines Slide 34 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

35 Scope and Required Funding Slide 35 Develop a basis of design Develop a LM-FPSO design that meets the BOD. Perform compartmentations and stability analysis Perform hydrodynamic and mooring analysis Perform TTR analysis Prepare model test specs (wind tunnel test, wave basin test, and towing tank test) Perform Tendon top and bottom connector fatigue (ongoing) Perform structural analysis (ongoing) Perform model tests Perform model test calibration Verify the design based on model test to ensure it still meets the BOD 3D rendering Presentation and marketing material

36 Scope and Required Funding Slide 36 RDC contribution of $178K (55%) with WP/INTECSEA covering: * $55,000 USD in cash * $55,000 USD in-kind Potentially RDC can contribute $200K (62%) with WP/INTECSEA covering the $121,810 (38%): * $33,000 USD in cash * $55,000 USD in-kind

37 Outlines Slide 37 Field Development Challenges The Low Motion FPSO (LM-FPSO) The Design The Constructability The Install-ability The Performance The Economics Case Study: Dry Tree LM-FPSO in South China Sea The Semisubmersible Version - TLS The Business Case Scope and Required Funding Concluding Remarks

38 Concluding Remarks Slide 38 The LM-FPSO is an enabling solution for TTR and SCR on FPSOs in harsh environment It avoids the need for a separate DTUs. Compared to FPSO+TLP a $760 MM saving is estimated The LM-FPSO offers High oil storage capacity and deck payloads Superior motion response - TTR/SCR/mooring friendly No turret or swivel Large number/ large diameter SCRs Fast deployment & decommissioning Quayside integration Simple and efficient hull form

39 Concluding Remarks Slide 39 The LM-FPSO offers (cont.) Maintain simple topside layout Low risk and minimum or no schedule Impact Flexible ballast compensation capacity The LM-FPSO & TLP when project ready will be a game changer to the industry Required funding is about $55K USD in Cash and $55K USD in-kind contribution based on funding of $178K USD from RDC

40 Contact Information INTECSEA Floating Systems Alaa M. Mansour, Ph.D. Marine Engineering Manager 575 North Dairy Ashford Rd. Houston, TX77079 USA (O) alaa.mansour@intecsea.com