Rational Design of FPSO Hulls

Singapore, 28 September 2010

NAUTILUS MARINE CONSULTANTS PTE. LTD.20 Cecil Street, #14-01, Equity Plaza, Singapore 049705

RATIONAL DESIGN OF FPSO HULLSAdvances in new-build FPSO hull design

Alexandre DURAN

2 11th Annual FPSO Congress, Singapore, 28 September, 2010 A.DURAN

Introduction

2 -


SHIP-SHAPED OFFSHORE UNITS

F

P

S

O

FLOATING

PRODUCTION

STORAGE

OFFLOADING OPERATIONS

Rational design of FPSO Hulls


MODERN FPSO HULL CONCEPTS

NEW BUILD HULL DESIGN PARAMETERSThe RATIONAL RATIONAL FPSO Hull Concept

FFUNCTIONAL FLOATER

PPRODUCTION REQUIREMENTS

SSTORAGE OPTIMIZATION

OOPERATIONAL CHARATERISTICS


Floater Concept

5 -


SPECIFIC HULL LINES

Functional hull design for an FPSO:

Balanced hull shape

minimal TPC variation between min and max drafts

Smaller volumes Fore and Aft

effectively reduce bare hull weight

Reduced Fore and Aft volumes

act to minimize Still Water Bending Moments

Aft end is specifically shaped

for optimal on-site environment directionality


BALANCED FLOATER

Hydrostatic Stability

Evolution of LCF vs. LCBfor trim = 1% (by the bow)

169.00

169.50

170.00

170.50

171.00

171.50

172.00

172.50

173.00

15.000 16.000 17.000 18.000 19.000 20.000 21.000 22.000 23.000 24.000 25.000

Draft (m)

Cen

ter

(m)

Longitudinalcenter ofbuoyancy

Longitudinalcenter ofwaterlinerLCF

LCB


Production Requirements

8 -


HULL PROCESS TANKS

Include Process Functions in the Hull


PRODUCTION CHEMICALS

Self-Supporting Tanks

Inside Hull

Stainless Steel

Non-Structural

Flush Interior

Segregated


Storage Optimization

11 -


2M bbls storageProcess Deck

HULL VOLUME UTILIZATION

Optimizing Hull Volumetric Parameters:

Minimum water Ballasting

Only FWD and AFT ballast tanks for static balancing of FPSO

“Oil Ballasting” Philosophy

CO quasi-static balancing between loading and offloading sequences

“Parcel” storage capacity

Full load for an FPSO ≠ Full load for a Tanker

“Dry Belt” Concept

Cargo Hold Zone is free of ballast tanks


82 h 28 h 114 h

Minimum volume needed:

1,732,000 bbl

4 h

CARGO CAPACITY

Offloading philosophyDictates Storage RequirementsTypical example for a 2Mbbl Storage Capacity FPSO


Operational Characteristics

14 -


“OIL BALLASTING” PHILOSOPHY

“Dry Belt” benefits

Reduced ballast deadweight = More cargo capacity

Void spaces only

Corrosion resistance Dry belt


CORROSION ISSUES

Problem:Corrosion in Ballast tanks BHD next to Cargo Tanks

Reason:Higher temperature in seawater environment stimulates corrosive attack by increasing the rate of electrochemical reactions and diffusion processes

Corrosion witnessed after 5 years on new build FPSO


Corrosion Solutions

“Dry Belt” SolutionNo ballast = non-corrosive environment in void spaces

Wing tank is highly susceptible to corrosion

Wing tank is protected against corrosion

high temperature gradient at BHD


Other Innovations

18 -


MOORING DESIGN

Mooring pattern of FPSO is fixed


SIMPLIFIED DESIGN

Design innovations

Rational

Functional

Simplified

Example:

Mooring Fairleads


FUNCTIONAL DESIGN

Multi-purpose riser porch

May be used for:

Pulling OOL

Pulling Risers

Pulling Umbilicals

Material Handling

Hydrate Remediation


RATIONAL DESIGN

Multi-function riser porch


PRACTICAL DESIGN

On-board Coiled Tubing Intervention


Conclusion

24 -


RE-SHAPED OFFSHORE UNITS

F

P

S

O

Rational design of FPSO Hulls

FLOATING

PRODUCTION

STORAGE

OPERATIONS


Future Challenges

26 -


DESIGN FOR THE FUTURE

Rational Design of / for:

Hull Shape / Size

More Stringent Specifications

Technical Challenges

Deeper Waters

Harsh Environments

New Technology

Operational Requirements

Etc.

Constructability

Safety

Ecology / Carbon Footprint

Economy

Operational Efficiency

Fast Track Projects

Scale of Projects


Thanks

28 -

Singapore, 28 September 2010

NAUTILUS MARINE CONSULTANTS PTE. LTD.20 Cecil Street, #14-01, Equity Plaza, Singapore 049705

Questions?

Alexandre DURAN

[email protected] +65 9115 1830

Business

Rational Design of FPSO Hulls