AOG- Pulse- Mooring Line Monitoring to Reduce the Risk of ...Case study: FPSO in South ChinaCase...

Mooring Line Monitoring to Reduce the Risk ofReduce the Risk of Line Failure20th February 2014

www.pulse-monitoring.com

AgendaAgenda

• Introduction – Facts & Figures

• Mooring monitoring• Case study• Conclusion


Mooring Line Integrity ManagementMooring Line Integrity Management

Number of FPUs

Introduction

• Number of FPUs increasing

• Deeper water harsher• Deeper water-harsher environments-climate changeg

• 20+ mooring incidents since 2001



Mooring failures versus installed FPUs5400

4300

acili

ties

3

200

ng fa

ilure

s

rodu

ctio

n Fa

1

2

100

Moo

ri

Floa

ting

Pr

002000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011


Floating Production Facilities Mooring Failures Linear (Mooring Failures)


Wear: Damage

Mechanisms contributing to failure

• Wear:– Component rubbing

• Fatigue:

• Damage• Strength

E i T i• Fatigue:– Axial and bending stress

• Abrasion:

• Excessive Tension:– Severe environmental

conditionsAbrasion:– Contact with sediment

• Corrosion:

conditions• Operational:

Various i eCo os o– Common in splash zone

– Various, i.eDisconnect failure



Fairlead/ hawse pipe

Typical failure locations

• Fairlead/ hawse pipe• Shackles/ H-links

B l i ht t i l t• Buoys, clump weights, tri-plates• Thrash zone

Wh li d d i t• Where line descends into seabed 2006- Noble Denton Europe Limited- “FPS Mooring

Integrity”



Location of mooring integrity incidents

5%5%

Chain

C t ( h kl H

47%19%

Connector(shackle, H-link, Triplate etc)Wire Rope

24%

Polyester Rope

Yoke Column24%

www.pulse-monitoring.com2013- Kai-Tung Ma et al- “Historical Review on Integrity Issues of Permanent Mooring Systems”


Vessel drift

Consequences of mooring failure

• Vessel drift• Riser rupture

P d ti h td• Production shutdown• Hydrocarbon release

C t f i i• Cost of repairing damaged lines

2006- Noble Denton Europe Limited- “FPS Mooring Integrity”


Mooring Line Integrity ManagementMooring Line Integrity ManagementRecent mooring failures in APAC

HYSY 113

Liuhua

Rubicon VantageNan Hai Fa Xian

Rubicon Vantage

FPSO Kikeh


SO e

Cyclones in AustraliaCyclones in Australia


FPSOs in AustraliaFPSOs in AustraliaGlas Dowr

Northern Endeavour

Montara Venture

Ichthys

Prelude

Maersk Ngujima-Yin

Modec Venture 11

Armada ClaireNganhurraOhka

StybarrowMaersk Ngujima Yin

NingalooVision

Pyrenees Venture


InspectionInspection

Main focus is on inspection and

Overview

• Main focus is on inspection and maintenance

• Visual ROV & 3D camera• Visual, ROV & 3D camera inspection– Marine growth, Missing stud, Mud g , g ,

line– Change in Geometry, Line

length Damagelength, Damage


InspectionInspection

Pros:

Pros & cons

• Pros: – Immediate Results– Non-Invasive– Non-Invasive – Limited Interruption to

Production

• Cons:– Not Quantitative– Hidden Defects – Not Instant Warning

N d f T i Hi t


– No record of Tension History

Mooring Line MonitoringMooring Line Monitoring

Benefits



• Instrumented chain stopper (load cell)

Monitoring Options

• Instrumented chain stopper (load cell)• In-line tension (strain gauge on chain link)• Line inclination• Line inclination• Sonar • GPS Position Monitoring• GPS Position Monitoring



• Fewer design requirements

Inclination monitoring

• Fewer design requirements• Inclinometers• Measure angle• Measure angle• Calculate tension using look-

up tablesup tables• Acoustic communication• RetrofittableRetrofittable


Case study: FPSO in South ChinaCase study: FPSO in South China Sea

• Region of frequent typhoons-

Overview

• Region of frequent typhoons-number of recent failures

• STP buoySTP buoy• 9 mooring lines (3 sets of 3)• Retrofitted to FPSO inRetrofitted to FPSO in

operation• First ever diver installable

inclination system



Magnetic holderSystem overview Magnetic holder for acoustic DAU

Acoustic receiverMagnetic clamps attach cable to vessel



• 9 Acoustic loggers

Data loggers

• 9 Acoustic loggers• Attached using diver

installable holdersinstallable holders• Typically 5 years battery

life



• 2 DAUs mounted on

Data acquisition units

• 2 DAUs mounted on underside of hull

• Specially designedSpecially designed magnetic holders

• Ensure constant communication with loggers

• No cables along mooring line



• Cables required to transfer

Cable

• Cables required to transfer data from DAU to control room

• Magnetic clamps attach cable to vessel hull

• On vessel- 2 x cables from turret to control room



Diver team and support vessel

Installation

• Diver team and support vessel• Mooring lines/ hull cleaned of

marine growthmarine growth • System has been installed 1

year resisting currents andyear resisting currents and typhoons


Case study: FPSO in South ChinaCase study: FPSO in South China SeaSoftware

• Adjustable loggingAdjustable logging frequency

• Angle/Tension Conversion• Historical Tension Data• Alarm if over tension or

failure



• Indirect tension

Limitations of inclination monitoring

• Indirect tension measurement

• Tension must be inferredTension must be inferred from angle

• Some accuracy losty• Slight delay with acoustic

communication



• Mooring failures are a real

Conclusion

threat with significant cost implications if not dealt with

i klquickly• Mooring line monitoring

provides reliable data onprovides reliable data on mooring integrity– Warning of line failureWarning of line failure– Record of tension history

• Allows informed decisions to


be made


D ’t it f f il t h it i

Conclusion

• Don’t wait for a failure to happen; monitoring systems can be installed without affecting

tioperations


Thank You

AnyAnyQuestions ?Questions ?


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