statoil ppt on fpso design

7/22/2019 Statoil Ppt on Fpso Design

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The Use of Risk Analysis inDesign

Safety Aspects Related to theDesign and Operation of a FPSOLars Tronstad StatoilHydro

SPE-121065


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Asgard FPSO data

Length: 278 mBreadth: 45 m

Displacement: 184.300

tonnesStorage cap.: 910.000 bbl

Process cap.: 200.000 bbl/d

On stream: May 1999

Estimated producing life: 20

yrs


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Norwegian Sea

Outside Mid-

Norway

Location of Asgard

Harstad

Stjrdal

Bergen

Stavanger

Tromsflaket

North Sea

Barents sea

Asgard field


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GullfaksStatfjord

Troll Kollsnes

Krst

Frigg

DraupnerSleipner

St. Fergus

Ekofisk

Etzel

Europipe

NorpipeZeepipe

Zeebrgge

Heidrun

Asgard

Tjeldbergodden

Midgard

Draugen

Heimdal

Emden

Dunkerque

Norfra

UK Germany

Norway

42


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Asgard Field


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Layout - Marine loads


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FPSO - Turret loads Load overview:

Turret weight

Mooring loads

Riser loads

Boyancy load

Dynamic loads Added mass with

vessel motionRiser

BearingsTurretShip

SwivelStigerr oppheng

Ankervinsj

Bunn

Jumper

Fairleads

EV

Anchorline


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FPSO - Load Calculator

Input: Updated light ship condition, loads from anchor lines, risers, variable weights, tank levels,

draught for and aft, wind loads

Output: Stability data, stability margins, hull bending moment and shear loads with limit curves


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Wave impacts - Lessons

High forecastleStrong windowsSolid design fwd


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Green sea protection

Panels

Cargo deck (tank top)


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Protection panels design: prevent green sea damages maintain good ventilation minimize explosion risk CFD analyses

"Green sea"panels


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Gas dispersion and Explosion

modelling- All areas modelled for optimized layout!


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Subsea gas plume

Buoyancy?

355 kg/s subsea riser rupture (5 m/s wind 15 deg. on port side)


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Layout - Segregation


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Fire walls/deck

Fire wall/deck


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Escape tunnel

Escape tunnel


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Turret / Swivel area

Risers

inside guidetubes

Riser ESVfireprotecti

on

2 hrs jet fire Open layout

ESV


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Material handling

Laydown areas

Storage areas

Crane operations

Crash barriers

Lifting restrictions


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Vessel motions

20m high waves Large difference in heave; semi/fpso


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Weather limitations

Helideck: Heave

Pitch

Roll

Night flights


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Sea fastening


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Offloading


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Offloading arrangement

20 hose

8000 m3/h


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Challenges:

Workingenv. issues

Simplerhandling

needed


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Shuttle tanker Collision

risk Flare stack location

Aft arrangement Tandem operation


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Shuttle Tanker Collision aft


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Collision aft Flare stack


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ESD I

ESD II

Alarm zones

Longer offloading hose

Strict requirements to the shuttletankers

FPSO

Collision avoidance

Shuttle tanker


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Strict technical and operative

requirements to the shuttle tankers: All shuttle tankers DP2-class

Several DP reference systems Early warning systems - manual take-

over

At least two DP operators at all times

DP operator competence

requirements Simulator training for tandem loading

Collision avoidance


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Long list of risk/safety

analyses:Concept Risk & Emergency Preparedness AnalysisDesign Accidental Load SpecificationLeaks inside guide tubesFMECA of riser systemGas dispersion study

Explosion evaluation report

Fire risk assessmentRisk related to material handlingQualitative assessment of escape and evac.Safety eval. of essential diesel engines

Safety eval. of compass thrustersSafety review of emergency power systemRisk analysis of pedestal cranesQualitative analysis of ballast systemTank explosion frequency assessment

Quantitative fire and explosion study of oil storage systemsReliabili ty analysis of instrumented overpressure protection for cargo tanksPassive fire protection optimizationDP-operations of tankers offloading AsgardTechnical and operational requirements to shuttle tankers serving Asgard

Environmental Impact AssessmentEmergency Preparedness AnalysisQuanti tative Risk Assessment, QRATotal Risk Assessment, TRA


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Safe Design - Summary

Good segregation between HC areas and safe areas

LQ, evacuation means and HVAC intake upwind

Escape tunnel along the whole ship

Process area segregated from cargo deck by plated

H-0 deck

No high pressure HC equipment on cargo deck


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Safe Design - Summary (contd.)

Water ballast tanks around the cargo tanks, double

barrier (double hull)

Open layout in modules; reduced explosion risk

Design the aft for shuttle tanker collision

Include measures for collision avoidance

Large helideck


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Ship movements must be considered for all materialhandling and storage

Dropped/ swinging load barriers

Lifting above pressurized equipment prohibited

One must expect green sea in bad weather condition;Personnel should not be present at cargo deck insuch conditions

Safe Design Summary

(contd.)

FPSO E i


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FPSO - Experience

transfer Workgroup between the FPSO

operators in Norwegian and UK: Improve FPSO operation and design for

future projects

Web-site: http://fpso.olf.no/lesson

OGP: Guideline for ManagingMarine Risks Associated with

FPSOs


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Conclusions

Assess risk and safety

Early In all phases

Gather experience Identify all hazards

Define safety strategies andstandards

Follow up with control anddocumentation


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Conclusions

There are challenges with

FPSOs, but if properly

designed and operated,a FPSO is a very safe

concept!


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Thank You

for listening!

Questions?

statoil ppt on fpso design

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