Rapid Deployment System f i i l i ifor monitoring slugging in 

subsea pipelines

AgendaAgenda

IssueDesign criteriaDesign processDesign processOperating principlesQualification strategySystem descriptiony pFuture applications

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Pulse ServicesPulse Services

Structural Data Delivery Services

What and where does Pulse monitor?What and where does Pulse monitor?

Offshore wind farms

Vessels / platformsTidal generators

Flexible risers

Drilling risers

Free‐standing risers

Drilling risers

Top‐tensioned risers

Steel catenary risers

Mooring lines

Pipelines

Mooring lines

An ACTEON companyAn ACTEON company

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ProblemProblem

Installed deepwater pipeline offshore Australia

After installation the client became concerned about 

fatigue life

Potential for VIV and slugging impact at buckle initiation 

sleepersp

Wanted to measure movement in order to calculate the 

fatigue life

Types of spansTypes of spansFree spans

d f b lUnsupported section of subsea pipelineCaused by:

local sea bed movementlocal sea bed movementPipeline profile does not conform to seabed geometry

Pipeline sleepersPipeline sleepersMethod of preventing lateral buckling on pipelineHowever can cause issues due to slugginggg g

Potential fatigue damage to pipeline Onset of scour Tunnel erosion Lee-wake erosion Equilibrium stage Vortex induced 

D

U

D e

U

D

U

D

U

Onset of scour Tunnel erosion Lee wake erosion Equilibrium stage

vibration (VIV)Flow induced b ( ) e

eS

W1 W2

e Soil

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vibration (FIV)

Typical System LayoutTypical System Layout

Current Meter

INTEGRIpod‐SM

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Free span monitoring system:Data loggerData logger

Standalone data logger monitoring systemTri axial accelerationTri plane angular rateExternal hydrostatic pressure sensor (for direct changes in water depth)The following parameters can be derived:

Linear displacementA l ti d t tiAcceleration due to motionAverage InclinationHarmonics

Typical battery life of 3 months at 10hz intermittent sampling

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Free span monitoring system:Current meter

Current Meter

Current meter

Measures the speed and direction of ocean currents

Horizontal

direction of ocean currents using the principle of “Doppler shift”.

Upper

Battery Operated20‐30min recording per hour

Lower

2D                                                       3D10

Mechanical InterfaceMechanical Interface

C ‐ ROV deployable on structures

A‐ Diver deployable on chains

B ‐ Diver deployable on risers

D ‐ ROV deployable on structures

E ‐ ROV deployable on pipelines/risers

F ‐ Diver deployable on risers

Free span monitoringRelevant ExperienceRelevant Experience

Humber estuary pipeline (UK) –2005y p p ( )

N th S i li ib ti 2009North Sea pipeline span vibration‐ 2009

Pipeline bundle tow out & span monitoring (Malaysia) ‐ 20092009

Gas pipeline  span monitoring (Trinidad) – 2010

Gas pipeline span monitoring (Australia) – 2012‐13 12

Design criteriaDesign criteriaClient required a system to be:

Completely ROV deployableEasy to useQuick to install‐ reducing ROV time/cost Cost effective‐ time and manufactureDeployable at multiple locations

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Design criteriaDesign criteriaDesign Parameter Value

Clamp design life 1 year

Installation depth >1,000m

Buoyant weight <50Kg

Flowline diameter 635mm

Flowline insulation material PolypropyleneFlowline insulation material Polypropylene

Outer pipe finish Smooth

Max pipe inclination 5Degp p g

Max pipe rotation/roll 10Deg

ROV gripper opening distance 97mm

ROV closing force 4092N

Design processDesign process

Conceptual design Client review Constructability 

review Prototype testing Qualification

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Clamp / logger holderClamp / logger holder

Clamp / logger holderClamp / logger holder

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Qualification strategy

Axial load test

Qualification strategy

Tortional load test Conformation force within capacity of ROVs manipulatorConformation force within capacity of ROVs manipulatorTested on different pipeline diameters and ovality to h k f t d t lcheck range of expected tolerancesDeflection and structural tests to ensure rugged construction

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Qualification strategyQualification strategy

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Operating principlesOperating principles

Single point ROV grab bars to operate clampAdapter developed to suit a range of ROVs ensuring any ROV can install clampTakes responsibility off the ROV in terms of resulting clamping force

Springs with adjustable pre load Stroke limit plates which effect the closed clamp stroke

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Operating principlesOperating principles

Material‐ no corrosion issues‐ no additional cathodic protection requiredTough plastic‐ structural part of clamp Softer grade of rubber at contact points to give a higher coefficient of frictionAll materials 25 years life span subsea without additional protection and degradation 

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Thank YouThank Youwww.pulse‐monitoring.com