FPSO Design and Structural Integrity Assessment - Amazon Web

FPSO Design and Structural Integrity Assessment

SNAME TEXASApril 14th 2009

2FPSO Design and Structural Integrity Assessment – SNAME TEXAS – April 14th 2009

Summary

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Background

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Design Aspects

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Condition Assessment (Conversions)

►

Hull Strength Assessment

►

Integrity Management

►

Conclusions


Our Profession : QHSE Compliance

Reference Standard Action Deliverable

Assessment

Full Independencefrom any

Design / Manufacturing / Contracting / Insurance


Bureau Veritas at a Glance

Marine 11%

In-Service Inspection

& Verification 13%

Certification 11%

HSE 10%

Industry 19%

Government Services & International Trade 6%

Consumer Products12%

Construction 18%

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Created in 1828

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A global leader in conformity assessment services in the areas of quality, health and safety, environment and social responsibility (QHSE)

2008 revenue: €2.55bn

2008 adjusted operating profit: €388m

More than 900 offices in 140 countries

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Over 40,000 skilled employees

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Eight global businesses providing a complete set of services

Inspection, testing, audit, certification, risk management, outsourcing, consulting and training services

►

Servicing 370,000 customers across a wide range of end markets

Broad Geographical PresenceRevenue breakdown

Eight Global Businesses

Revenue breakdown

Asia Pacific 23%

EMEA* 35%

France 27%

The Americas15%

* EMEA includes:• Europe –

excluding France• Middle-East• Africa


Extensive Geographic Footprint

Asia-Pacific

205 offices, including 66 laboratories

13,300 staff

37 countries

France


7,400 staff

Americas


8,000 staff

30 countries

EMEA (excluding France)


11,300 staff

77 countries

Global network comprising more than 900 locations across 140 countriesGlobal network comprising more than 900 locations across 140 countries

Note: EMEA = Europe, Middle-East & Africa


A Balanced Portfolio of Activities

Marine ►

Ship classification, ship and marine equipment certification, technical assistance and outsourcing services

Industry►

Conformity assessment of industrial equipment and installations to regulatory or client specifications from feasibility stage to de-commissioning

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Services include design review, shop inspection, site inspection, asset integrity management, product certification and related testing services such as non-destructive testing

In-Service Inspection & Verification (IVS)

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Periodic inspection of equipment and installations to assess conformity with regulations or client-

specific requirements. Services apply to electrical installations, fire safety systems, lifts, pressure equipment, lifting equipment and machinery

Construction►

Conformity assessment of construction projects to local regulations and construction standards, from design stage to completion

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Services include design review, code compliance, technical control, on-site safety coordination, testing of construction materials, asset management and technical due diligence services

Health, Safety and Environment (HSE)

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Inspection, audit, measurement and testing services in the fields of environment / health & safety ►

Technical assistance and consultancy services to help companies define their HSE management strategy and improve their performance

Certification►

Certification of management systems and processes in the areas of quality, health and safety, environment and social responsibility based on public standards

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Second party auditing services based on customer-specific or Bureau Veritas standards

Consumer Products►

Testing, inspection and certification of consumer goods including textile, hardlines, toys, electrical and electronic products

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Factory audits, social responsibility audits and training services

Government Services and International Trade(GSIT)

►

Government Services: Pre-Shipment Inspection, X-Ray Scanning, Verification of Conformity of imported products

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International Trade: Commodity quantity/quality assurance, automotive services

8 global businesses providing strong growth and cross-selling opportunities8 global businesses providing strong growth and cross-selling opportunities


3653 59 62

86106

137

171

204

244268

312

388

0

50

100

150

200

250

300

350

400

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

Adju

sted

Ope

ratin

g Pr

ofit

(€m

)

A Solid Growth Track Record

Adjusted Operating Profit CAGR: 22%

Revenue CAGR: 15%

Revenue Growth since 1996 Adjusted Operating Profit Growth since 1996

13 years of continuous growth and profit improvements Revenue expanded by a multiple of 5.6 and adjusted operating profit by 10.8

13 years of continuous growth and profit improvements Revenue expanded by a multiple of 5.6 and adjusted operating profit by 10.8

455

619695 722

8501012

11451283

1422

1647

1846

2067

2549

0

500

1 000

1 500

2 000

2 500

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

Reve

nue

(€m

)


Classification & Technical Assistance

More than 80 FSOs & FPSOs studied by BV


•

TOTAL PAZFLOR FPSO (Angola)•

TOTAL USAN FPSO (Nigeria)•

2 FPSOs for Nan Hai in China for CNOOC•

AKPO FPSO in Nigeria for TOTAL•

MOHO BILONDO FPU in Congo for TOTAL•

P53 FPSO in Brazil for PETROBRAS•

CENDOR FSO in Malaysia for MISC / PETROFAC•

FEDERAL 1 FSO for PETROCHINA•

BELANAK LPG FSO for COMPASS ENERGY•

P47 FPSO for PETROBRAS•

ORKID FSO for MISC

Plutonio FPSO (2 mbl) Akpo FPSO

Belanak LPG FSO

Floating Production, Storage & Offloading Systems


Moho FPSO - CongoHyundai

Akpo FPSO - NigeriaHyundai

Classification/Certification Recent References

P-55 - Brazil

P-53 FPU - BrazilKeppel-Fels

Nan Hai FPSO - China


Regulatory Frame

► International rules (IMO and ILO rules…)

► Flag State rules

►Classification Society rules

►Coastal states rules and guidelines

► International maritime standards (OCIMF, ISGOTT…)

►Owner or operating company standards and guidelines

►Offshore industry standards and recommended practices (ISO, API, ASME/ANSI…)

Wide range: Coastal State Regulations and Company Corporate requirement


Project Specification

►Hull type

►Storage capacity

►Cargo and ballast tank layout

►Permanent or disconnectable

►Required FPSO service life

►Service location environmental conditions

► Layout (deck area, cargo tanks and mooring system)

►Materials of construction


New-Built►

Typical of fast-track projects

►

Availability of conversion docks

►

Considered for contained CAPEX

BUT

►

Must know what is being bought

►

Imposes constraintsStorage capacity

Deck space…

►

Age will limit its relocation

►

Purpose-built

►

Take into account latest construction standards and safety margins

►

Can be designed with process versatility

BUT

►

Limited number of shipyards and already packed

►

Usually mean higher CAPEX

►

Longer delivery times

Conversion

New-Built vs. Conversion


General Arrangement - Tank Capacity & Layout

►Provide the specified minimum crude oil storage capacity

►Adequate stability and longitudinal strength (normal and temporary operating conditions)

►Sufficient segregated ballast water tanks to allow adjustment of

heel, trim and draft of the FPSO

►Avoid loading/unloading restrictions

►Ballast piping arrangement (single hull tankers)

► Larger the number of smaller oil storage tanks:

Flexibility for loading and offloading

Reduce free surface effects. Improves vessel stability.

Increase storage capacity during inspections and work in tanks

►Cargo and bunker oil protection


General Arrangement – Deck Area & Accommodation

►Sufficient for layout of topside equipment, accommodations, lay-down areas, etc.

►Separation of hazardous areas from accommodations and lifesaving

►Protect personnel and equipment against green water

► Foundations and supporting structures for the process decks positioned iwo

main deck intersections. Minimize under deck stiffening.

►Spread mooring lines and risers configuration: interface between topsides supports and mooring installation equipment.

►Accommodation module and location of the turret and the main machinery space: natural thrusters assisted weathervaning.


Seakeeping

►Safety and comfort to personnel and maintain high uptime and reliability of production

►Mitigation of excessive roll motion. Weathervaning

turret moored vessels may be aligned beam with swell resulting in production shut downs.

► Freeboard and structural protection to prevent green water onto primary routes of escape and work areas (process, machinery, piping, cabling, equipment, superstructures, etc.)


Single vs. Double Hull Configuration

►Regulatory

Costal State and COMPANY requirements.

MARPOL 73/78 Annex I requirements for FPSOs, as modified by IMO Resolutions MEPC 139(53) and MEPC 142(54).

►Single hull FPSOs

deployed worldwide

►Double hull main advantages:

External structural protection to crude oil and bunkers

No ballast piping through cargo tanks

Means of inspection while in service

Smooth tank bottom


High Tensile Steel Construction


Structural Detail Design

►Hard toed structural details shall be avoided

►Cutout radius

►Snipe angles

► Longitudinal Web Frame Penetrations and Lugs

► Longitudinal stiffener end connections (soft toe brackets)

► Transverse Bulkhead Penetration. Soft toe brackets fitted on both sides


Hull Condition Assessment (Conversion)

► Following information should be reviewed: Structural drawings

Trading history

Previous thickness measurements

Condition and extent of protective coatings

Classification status including any outstanding conditions of class

Previous repairs

Typical load conditions and purpose of tanks (i.e. cargo, clean ballast, dirty ballast, segregated ballast)

► Typical defects:Corrosion

Buckling

Cracks


Areas of Special Concern - Cracks

► Longitudinal stiffeners end-connections

►Web frame penetrations

►Bilge keels

►Hoppers

►Horizontal stringer terminations

►Vertical bulkhead stiffener terminations


Areas of Special Concern - Corrosion

►Areas exposed to corrosion:

Horizontal stringers

Longitudinals on longitudinal bulkhead

Longitudinal bulkhead plating

Web frames upper part and close to Longitudinal bulkheads

Cross ties

Transverse bulkhead plating, upper part

►Areas exposed to pitting:

Horizontal surface of stringers

Bottom plating

Bottom longitudinal face plates/flanges


Hull Strength Assessment – Environmental Loads

►Design environmental condition equivalent to a 100-year rp

based on site specific metocean

data

►Metocean

data for transit route to the FPSO final station

► Tank inspection, maintenance and repair conditions combined with

the 1-year rp

site-specific wave loading

►Results:Ship’s motions and accelerations

Relative wave elevation (RWE)

Global hydrodynamic loads (VWBM and VWSF)

►Application:Heading and mooring analysis

Structural strength

Fatigue calculations


Design Load Assessment

Hydrodynamic analysis

3D global analysis

Dynamic loads

Site Specific

Data

3D local analysis


Hull Strength Assessment – Stability & Hull Girder

►

Intact & Damage Stability checked for all operational and maintenance loading conditions

Classification Society production system rules.

IMO intact stability requirements (static and dynamic).

MARPOL 73/78

IMO Mobile Offshore Drilling Units Code.

1966 International Load Line Convention and amendments.

►

Hull girder and hull girder ultimate strength checks


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Multi-step analysis procedure:

2D analysis

3D Coarse Mesh analysis

3D Fine Mesh analysis

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Limit state check:Corrosion

Fatigue

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Hull life assessment:Stress levels

Remaining fatigue life

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Hot Spot map

Yielding Buckling Ultimate Strength Fatigue

Hull Girder

Plating

Ordinary stiffeners

Primary supporting

Structural details

Limit state checks


Hull Monitoring for each InspectionB V

ThicknessUnit History recordedUnit History recorded

Crack on Bracket

Hull Condition Assessment


FPSO at ConversionFPSO at Conversion FPSO + 15 yearsFPSO + 15 years

AsAs--built Tankerbuilt Tanker

30.0

25.0

20.0

15.0

10.0

5.0

0.0

Corrosion (%)

30.0

25.0

20.0

15.0

10.0

5.0

0.0

Corrosion (%)

Hull Condition Assessment


►

Hull Structure

►

Turret Integration

►

Flare Tower

►

Topsides

►

…

Detailed stress analysis


►Deterministic fatigue analysis

Based on site conditions (modification of Rules parameter to take into account hydrodynamic results) – Previously calibrated with SFA

►Spectral fatigue analysis (SFA)

Site conditions

Direct input of loads coming from hydrodynamic analysis and use of scatter diagram

Fatigue Analysis for Offshore Units


Fatigue Strength Assessment

►

Locations -

selection criteria:

BV Rules

Detailed stress analysis

Feedback from experience

Survey records

►

Fatigue Screening

2D analysis

Simplified 3D analysis


Stress Concentration

Before After

Lower Stresses

Detail Design Improvement


2D Analysis Limitations

Side shell longitudinal stiffeners end connections

Flexural mode Shear mode


Hull + Topsides Integrated ModelHull + Topsides Integrated Model

Adding Topsides on the Deck: Coupling with Hull to be checked

Hull and Topside integrated model


►

Spectral Fatigue Analysis

Specific Environmental Conditions

A 5 steps analysis interfacing Hydrodynamic and Structural Analysis

BV methodology calibrated with experience

Methodology

HydrodynamicCalculation

StructuralMesh

Coarse MeshCalculation

Fine MeshCalculation

SpectralCalculation

Spectral Fatigue Analysis for Offshore Units


►

1 –

Structural Mesh

VeriSTAR CSM

Complete ship model

Side shell refined near free surface

StructuralMesh


Global ModelCalculation


SpectralCalculation



►

2 –

Hydrodynamic calculation

Extraction of the Hydrodynamic mesh and Mechanical properties

3D diffraction radiation analysis

StructuralMesh




SpectralCalculation



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3 –

Coarse Mesh Calculation

Complete ship model

Equilibrium between inertia loads and wave pressure checked

Intermittent wetting correction implemented

StructuralMesh




SpectralCalculation

25 frequencies

7 headings (180 to 360° each 30°)

4 loading conditions

Real and Imaginary part

2 cases for intermittent wetting correction

1402 loadings cases



►

4 –

Fine Mesh Calculation

Local stress for each loading

Localization of fine mesh based on Hydrodynamic results for acceleration

1402 calculations

Interpolation of stress at weld toe

RAO of stress for wave headings from portside to starboard

StructuralMesh




SpectralCalculation



►

5 –

Spectral calculation

Based on given environmental conditions

Long term distribution of stress

StructuralMesh




SpectralCalculation



►

5 –

Spectral calculation

Damage calculation based on Miner law

Fatigue Life / Safety Factors

StructuralMesh




SpectralCalculation



Stress Range due to the L/U cycle higher than the Stress Range due to Waves.

stress ranges

0

100

200

300

400

500

600

9.6 12.12 13.12 14.66 15.17 15.66 16.92 18 18.4 19.5 L/U

0

100

200

300

400

500

600

700

9.6 12.12 13.12 14.66 15.17 15.66 16.92 18 18.4 19.5

Draft (m)

Stre

ss (M

Pa)

CrestTroughstress range

L/U Cycle plays a main role in the crack propagation, being the main driving effect

in those locations where stress ranges due to waves are low.

Relevance of the L/U Cycles


►

Parameters:

Critical connection details (stress level and fatigue)

Areas corroded or prone to corrosion

Hot Spots (structural analysis results)

0.975

0.950

0.925

0.900

0.800

0.500

0.000

Stress Ratio

0.975

0.950

0.925

0.900

0.800

0.500

0.000

Stress Ratio

0.975

0.950

0.925

0.900

0.800

0.500

0.000

Stress Ratio 310

290270250230210190170150130110908070605040302010

Stress ComponentAll Load CaseGD/Shell SVMM

310290270250230210190170150130110908070605040302010


310290270250230210190170150130110908070605040302010


Hull Structural Strength


Continuous Survey Program (Hot Spot Map)

Full Ship model (as-built)

Hull Structure Database

►

Hull structure models and results

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Material properties

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Coating condition

►

Corrosion condition

Hull Structure Database


Risk-Based Inspection studies covering hull, topsides and

mooring system

Dalia FPSO (2 mbl) for Total

Floating Production, Storage & Offloading Systems


Conclusions & Discussions

►

Regulatory frame impact the engineering work level and Operator effort for regulatory compliance.

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Hull structure should not have no restrictions on individual cargo tanks (i.e., all combinations of tank usage and tank filling levels shall be possible).

►

Design also to performance (availability of cargo tanks):Facilitate access to tanks and internal compartments

Rational IRM planning

Designed to life time (corrosion and fatigue)

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Extensive analyses required to address FPSO structural adequacy in during transit and normal operation onsite

►

Short schedule requires use efficiently resources to perform design and engineering verification. Adequate tools and methodologies. Not necessarily the most sophisticated. New developments required.

►

Conversion requires additional verification effort. Source of corrosion and fatigue uncertainties.

Documents

FPSO Design and Structural Integrity Assessment - Amazon Web