Smart Cathodic Protection RetrofitSmart Cathodic ... - Jim Britton.pdf · Smart Cathodic Protection RetrofitSmart Cathodic Protection Retrofit ... and offshore transportationand offshore

Smart Cathodic Protection RetrofitSmart Cathodic Protection RetrofitSmart Cathodic Protection Retrofit Smart Cathodic Protection Retrofit Methods for ROV InstallationMethods for ROV Installation

Jim BrittonDeepwater Corrosion Services Inc.

Houston, TX.,

UTC 2008 Bergen © Deepwater Corrosion Services Inc. 2008

Presentation OutlinePresentation OutlinePresentation OutlinePresentation Outline

IntroductionKey Factors to Consider

Anode SystemTie-Back SystemMonitoring & VerificationMonitoring & Verification

Project Case History OutlinesNorthern North Sea PipelinesNorthern North Sea PipelinesGulf of Mexico Subsea Field DevelopmentGulf of Mexico SPAR Risers & Wellheads


IntroductionIntroductionIntroductionIntroductionROV friendly methods

d l d fwere developed out of necessity to fix GOM gaffs – water depth.

ROV usage is on the increase irrespective ofincrease irrespective of water depth.

Sacrificial systems presented, but ROV’s have successfullyhave successfully retrofitted ICCP


Anode System Design ConsiderationsAnode System Design ConsiderationsAnode System Design ConsiderationsAnode System Design Considerations

ConstraintsSize suitable for onshore and offshore transportationand offshore transportationWeight to be deployed by RSVCan or cannot protrude above seabed


Anode System OptimizationAnode System OptimizationAnode System OptimizationAnode System Optimization

Anode Design GoalsWork within physical constraintsOptimize current availabilityOptimize current availability

Minimize number of installationsFulfill design life requirementg qMinimize mutual interference between anodes in an arrayProvide stability at installation siteProvide stability at installation siteMinimize installation time


HowHow NOTNOT to do itto do itHow How NOTNOT to do itto do it

Mutual interference Mutual interference maximized, low current maximized, low current 200 yr life!200 yr life!


Seabed DeploymentSeabed DeploymentSeabed Deployment Seabed Deployment

Allows rapid deployment of large amount of anode materialmaterialSimplifies ROV interventionKeep anodes in water ifKeep anodes in water if possibleLarge long parallelLarge long parallel geometries for sub bottom arraysy


Typical subTypical sub--bottom deployed rigid sled bottom deployed rigid sled used for pipeline retrofitused for pipeline retrofit


TieTie Back SystemsBack SystemsTieTie--Back SystemsBack SystemsThe electro-mechanical connection between the anode array and the structure is critical

Connect fails ! CP system fails!Must be ROV friendly

OptionsMechanical clamp

Generally favored by most operators based on cost andGenerally favored by most operators based on cost and reliability

Friction WeldingExpensive and tough to controlExpensive and tough to control

Explosive StudsDifficult for ROV, not suited to pipelines

Wet WeldingOperators tend to shy away – very difficult for ROV


The RetroClamp familyThe RetroClamp familyThe RetroClamp familyThe RetroClamp family


Clamp OptionsClamp OptionsClamp OptionsClamp Options

Can carry anode payload directlyU ll t d ithUsually connected with flexible cables


Tieback Clamp Design FeaturesTieback Clamp Design FeaturesTieback Clamp Design FeaturesTieback Clamp Design Features

Range of configurations have been used they all have common features.

Single action easy location onto targetSingle action easy location onto targetHolding mechanism to hold position while torque is appliedContact element held with constant tensionVariety of contact tips for connection to

StructuralPi li / PPipeline / ProcessPipelines with coating variables


Variety of types used in project examplesVariety of types used in project examplesVariety of types used in project examplesVariety of types used in project examples

StructuralTubular / Square Tubing

Pi liPipelineThin film FBE

Pipe FlangePipe FlangeBolt circle engagement


Different geometriesDifferent geometriesDifferent geometriesDifferent geometries

B lt Ci l E t S T biBolt Circle Engagement Square Tubing


Verification / MonitoringVerification / MonitoringVerification / MonitoringVerification / Monitoring

Temporary installation readerIndicates clamp contact

P t itPermanent monitorsShow anode current or potential shift

Portable ProbesPortable ProbesBefore / after measurement


The temporary reader systemThe temporary reader systemThe temporary reader systemThe temporary reader system

S f i ll dSurface installedMonitors artificially ydepressed clamp potentialROV recover andROV recover and re-use


Permanent electrodes with ROV light Permanent electrodes with ROV light powered readoutspowered readouts


Conventional CP ProbesConventional CP ProbesConventional CP ProbesConventional CP Probes


Project AProject A N North Sea 2007N North Sea 2007Project A Project A –– N. North Sea 2007N. North Sea 2007

150 MetersReason for Retrofit

Pipelines showing advanced anode depletion, draining CP to platform jackets. Pipeline boost required.

Scale of RetrofitScale of Retrofit17 Anode arrays – 34 tiebacks10 Pods 7 Sleds4 locations CWC removal

ROV’s 2 x Triton WC / 1 Seaeye Tiger ICOffshore Retrofit Duration 238 HrsAverage / Array 14 Hrs.


Project A GalleryProject A Gallery








Project BProject B Subsea FieldSubsea Field GOMGOM 20082008Project B Project B –– Subsea Field Subsea Field –– GOM GOM -- 20082008


New wells, flowline anodes consumed, life extension required.

Scale of Retrofit19 Pods 38 Tiebacks19 Pods 38 Tiebacks4 Flowlines – 5-15 Km each, 2nd ROV excavating several areas.8 Subsea Hardware Pieces8 Subsea Hardware Pieces

ROV’s 2 x WCOffshore Retrofit Duration 72 HrsOffshore Retrofit Duration 72 HrsAverage / Array 4 Hrs.


Project B GalleryProject B Gallery








Project CProject C SPAR SubseaSPAR Subsea GOMGOMProject C Project C –– SPAR Subsea SPAR Subsea -- GOMGOM


TSA consumption of production risers draining to well casing (dry tree system). Low potentials deep and need to preserve TSA.

Scale of Retrofit6 Risers / 6 Wells 3 SmartPods 2 wells / pod.

ROV’s 1 x WCOffshore Retrofit Duration 24 HrsAverage / Array 8 Hrs.


Project C GalleryProject C Gallery










Summary & ConclusionsSummary & ConclusionsSummary & ConclusionsSummary & Conclusions

ROV can be very efficient at anode retrofitProject planning criticalUse proven hardware solutionsUse proven hardware solutions

As this type of maintenance becomes second nature new equipment can go safely to post installed CPnew equipment can go safely to post installed CP.


EndeEndeEndeEnde


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Smart Cathodic Protection RetrofitSmart Cathodic ... - Jim Britton.pdf · Smart Cathodic Protection RetrofitSmart Cathodic Protection Retrofit ... and offshore transportationand offshore