Low Cost Flexible Production System for Remote Ultra-Deepwater Gulf of Mexico Field Development

Transcription

1 Low Cost Flexible Production System for Remote Ultra-Deepwater Gulf of Mexico Field Development Jelena Vidic-Perunovic, Doris, Inc. Lars Ødeskaug, Sevan Marine ASA RPSEA Ultra-Deepwater Technology Conference October 29-30, 2013 Lone Star College Conference Center The Woodlands, Texas 1 rpsea.org

2 2 Project Schedule

3 3 Project Spending vs Budget

4 Agenda o Project background o Basis of Design o Field Layout and FPSO Orientation o Hull Motions o Riser Analysis o Hull Design o Mooring System o Topside Layout o Moonpool Arr t o Offloading System 4

5 Context o FPSO o Group of challenges related to Lower Tertiary o o Field anticipated far from existing infrastructure Local storage Fig. 1: Existing Oil and Gas Pipelines in GoM and Outlined Lower Tertiary Reservoirs (Image Credit: Wood Mackenzie, taken from [19]) o Oil export to shuttle tankers o Gulf enviroment o These solutions may provide increased flexibility and reduced investment risk 5 o Innovative solutions may result in cost reduction Fig. 3: Tracks for Ivan, Denis, Katrina and Rita [16]

6 Design Basis o Field: Generic, Gulf of Mexico o Water depth: 2,500m o Storage capacity: 1,000,000 bbls o Oil production: 60,000 bopd (+50% future) o Water production: 60,000 bopd o Gas processing: 60 mmscfd o Motions: Acceptable for Steel Catenary Risers o No. of risers: 11 (not critical for Sevan design) The floating facilities shall have direct production and offloading capabilities and shall be capable of producing, processing and offloading crude oil from two separate drilling centers. 6

7 Hull Selection indicated as possible concepts are o Ship-shaped FPSO o Non ship-shaped cylindrical FPSO (represented by SEVAN 1000) o Non ship-shaped hemispherical FPSO (represented by SSP 320 Plus) o Deep draft semi-submersible FPSO (represented by Octabuoy 1 MMbbls) SEVAN 1000 selected for further study! 7

8 Scope of Work o Preliminary design and analysis of hulls, risers, moorings and topside o Evaluate whether hurricane abandonment is acceptable with hydrocarbons in storage o Regulatory evaluations o Risk analysis o Establish a complete shuttle tanker oil export concept o Provide cost and schedule for the concept, including an export solution 8

9 9 Hull and Risers

10 Sevan FPSO Motions Natural periods are obtained: Ballast Loaded Heave 23.2 s 23.6 s Roll/Pitch 32.1 s 42.1 s Hydrodynamic models of the Sevan FPSO, Left: Panel model of hull without moonpool Right: Panel model with moonpool (only used to quantify simplification effect) 10

11 Motions Heave accelerations The most probable maximum vertical acceleration amplitude at the FPSO bow (towards the waves) in the 1000-year condition is limited to 0.15g. Vertical Acceleration Process Deck Bow Wave condition Hs [m] Tp [s] Sign Amp [m/s2] Loaded draft MPM Amp [m/s2] Sign Amp [m/s2] Ballast draft MPM Amp [m/s2] 1y Operating Condition y Operating Condition y Operating Condition y Hurricane Condition y Hurricane Condition Furthermore, motion sickness evaluation is based on a Motion Sickness Dose Value (MSDV) of 15. Based on the results it can be concluded that sea sickness should not be a major issue even in the worst hurricane conditions.

12 Global Strength Analysis The analysis is based on a load case matrix considering operation, extreme, survival, and hydrotest conditions, with parameters: o OD=10.75 o WT=1.61 o 3 insulation coating o Fully straked, C d =1.4 o Dynamic analysis o Airy wave theory o Titanium TSJ at riser hang-off 12

13 Stress Utilization of Standard Pipe Joints Load Case Load Category Vessel Offset (% WD) Vessel Offset Direction Environment C f Max Stress Utilization on Standard Pipe Joints Operation Extreme Extreme Survival Installation Hydrotest Near yr Hurricane 1.0 Far 0.71 Near yr Hurricane 1.2 Far 0.79 Near yr Hurricane 1.2 Far 0.70 Near yr Hurricane 1.5 Far 0.60 Near yr Winter Storm 1.35 Far 0.48 Near yr Winter Storm 1.35 Far

14 Tension Along SCR 6000 RPSEA SCR for SEVAN Floater Tension Along SCR Arc 1000 yr Hurricane, Vessel Near Offset 5000 Tension (kn) SCR Arc Length (m) Min Tension Max Tension 14

15 Future Riser Assessment o The strength responses indicate that the designed SCR meets the strength requirements of API-RP-2RD, based on the preliminary Ballast RAOs. o Hull hydrodynamics to be validated o The way-forward is to perform a fatigue assessment on the riser s fatigue responses. 15

16 Hull Design Main Particulars Based on the design basis and design philosophy, the resulting main dimensions are: Description Hull Diameter (m) Bilge box Diameter (m) Bilge box plate Diameter (m) Main Deck Diameter (m) Process Deck Diameter (m) Main Deck El. (Hull depth) (m) Process Deck El. (m) Draft, Ballast (m) Draft, Loaded (m) Freeboard to MD, Ballast (m) Freeboard to MD, Loaded (m)

17 Hull Design Capacity Based on the main dimension in the previous slide, the key capacities are: Item Description Topside carrying capacity (t) Cargo Oil Storage (Net. at 92% fill ratio) (m3) (bbls) Slop tanks (m3) (bbls) Water Ballast (fill ratio = 95%) (m3) Marine Diesel Oil (m3) Potable Water (m3) 300 Service Water (m3) 800 Other tanks (m3)

18 18 Hull Design Tank Arrangement

19 Mooring System - Layout As only omnidirectional environmental conditions have been given in the design basis, an omnidirectional mooring system with 15 lines in three clusters has been proposed. o Anchor o 158 mm R4S bottom chain o 270 mm lower polyester rope o Connection element o 270 mm Upper polyester rope o 158 mm R4S Top chain 19

20 20 Topside Layout

21 21 Moonpool Arrangement

22 Field Layout and FPSO Orientation The field layout and FPSO orientation will be developed as a trade-off between several parameters: Governing directions of wind and waves Routing of risers and umbilicals Location of offloading station and offloading sector Location and orientation of accommodation & life boats Location of flare Other surface units or subsea structures 22

23 Offloading - Principles 23 An elongated sector is proposed to allow for near 360 degrees operation. Shuttle tanker DP2 Normal operating distance between the shuttle tanker bow and the FPSO is m Green Sector 30m wide Yellow Sector 10m wide Minimum distances between the outer side of yellow sector and the nearest mooring line is in the range of 25 m

24 Offloading - Reel o Typical diameter: 10-11m o Length: 10m o Hose length: m o Hose diameter: 20 o Offloading rate: m 3 /h o Offloading bbls in 20 hours 24

25 Contacts FPSO Sevan 1000 for the ENI operated Goliat Contract type: Technology license field Location: Norwegian Barents Sea Water depth: 400m (Harsh and sub arctic) Yard: Hyundai Heavy Industries Hull size: Sevan1000 Oil processing: bod Water injection: bwd Gas compression: 140 Mill Scfd Oil storage: bbls Power feed from shore 60 MW 25

26 Contacts PI: Jelena Vidic-Perunovic Doris, Inc RPSEA PM: Bill Head Presenter: Lars Ødeskaug SEVAN Marine ASA 26