Pipeline Condition Assessment - Trenchless Asia

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TRENCHLESS ASIA 2018

Pipeline Condition Assessment

Peter Henley WRc Infrastructure

7-8 May 2018

Organised by Platinum SponsorsEvent Partner

wrc-infrastructure.co.ukwrc-infrastructure.co.uk

What’s going on down there? Condition Assessment Investment

Strategy

Cost of Cost of Cost of Cost of

InspectionInspectionInspectionInspection

Capital CommitmentCapital CommitmentCapital CommitmentCapital Commitment

Capital EfficiencyCapital EfficiencyCapital EfficiencyCapital Efficiency

Lower ResolutionLower ResolutionLower ResolutionLower Resolution

High ResolutionHigh ResolutionHigh ResolutionHigh Resolution

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External - NDT Inspection

• Traditional methods

• Exposing the pipe and

measuring the remaining

pipe wall thickness

• Typical techniques used are

ultrasonics and electro

magnetics

• Limited to a snapshot of the

pipe at that location

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• Small and medium leaks are hard to find with external tools

• Inline technologies bring the sensor to the leak

• Both type of inspection can offer Pipe Wall Assessment (PWA) in

live mains

‘Free-

Swimming’

‘Tethered’

Internal Pipeline Inspection

Techniques


• Acoustic sensor hears leaks

• Other sensors can be added

• Detects 0.1 Ml/d per km

Tethered Inspection - Sahara


Acoustic Leak Detection & CCTV

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Free Swimming Inspection Systems

Pure SmartBall Aquam Bullet

Free Swimming High Resolution

Inspection

• Systems such as Pure PipeDiver & Aquam Pipescan

• Provide high resolution data on pipe condition

Detailed Pipeline Assessment Results Condition Assessment Gravity Sewers

CCTV Inspection

• CCTV Inspection CCTV Inspection CCTV Inspection CCTV Inspection ---- defect observationdefect observationdefect observationdefect observation

• Well established technique for assessing the condition of sewerWell established technique for assessing the condition of sewerWell established technique for assessing the condition of sewerWell established technique for assessing the condition of sewer

• Depends on the skill of the surveyor for accuracy Depends on the skill of the surveyor for accuracy Depends on the skill of the surveyor for accuracy Depends on the skill of the surveyor for accuracy

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Gravity Sewers - Electro Scan

• Identifies infiltration sources that CCTV doesn’t seeIdentifies infiltration sources that CCTV doesn’t seeIdentifies infiltration sources that CCTV doesn’t seeIdentifies infiltration sources that CCTV doesn’t see

• Quantifies the amount of infiltrationQuantifies the amount of infiltrationQuantifies the amount of infiltrationQuantifies the amount of infiltration

• Allowing rehabilitation to be better targetedAllowing rehabilitation to be better targetedAllowing rehabilitation to be better targetedAllowing rehabilitation to be better targeted

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Typical Electro Scan Survey Plot


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Electro Scan & CCTV Comparisons

B

A

A

B

C

Joint

C

Joint

Case Study – Southern Water

Romsey Rising Main - SmartBall Survey 1. Provided operational confidence in the technology

2. Confirmed the outputs available from the technology

3. Understand the context in which the results would form part of the capital

maintenance targeting process and decision tree - Capital Maintenance

Efficiency Strategy

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Case Study Findings

• 2.4km Ductile Iron Wastewater

• Pressure Main

• No leaks presenting

• No stationary, trapped pockets of gas

• 3 vertical blanked Ts discovered

– during planning

• Several pockets of entrained air

• No significant deviation between the recorded pipeline route and that

detected using SmartBall

Condition Assessment Results –

Suggested Actions

Leak location using in-pipe survey Leak type Suggested action

Small leak, cast/spun iron joint Stable Monitor through regular data review

Large leak, cast/spun iron joint Stable Plan in repair at time of lower reactive maintenance

Leak on cast/spun iron pipe barrel Critical Urgent repair

Small leak, ductile iron or steel UnstableFrequent monitoring through data review. Consider regular

in-pipe surveys

Large leak, ductile iron or steel Unstable Urgent repair

Multiple leaks observed in

single surveyMixed

Planned regular in-pipe inspections; determine sections

which may benefit from rehabilitation rather than repair


Survey Decision Tree - Examples

What do we need to know? How do you find that out? What did we find out?

How much of a 15km pipeline needs

replacement?

Leak and wire break detection using untethered

inspection device on 30" pipeline

Only one pipe length requiring intervention

0.04% of total length.

The condition and location of a brick

sewer before nearby construction

project starts?

Laser/sonar profile and deep tracing Mapped position of localised damage to

brickwork and informed construction company of

exact route of 150m sewer

How much of a 2.8km 800mm steel

pipeline is corroded, and requires

intervention?

Acoustic and pipe wall loss assessment tool

required

4 pipes with corrosion spots > 60% through wall

corrosion. 2%

Is there a large diameter leak not picked

up by correlation?

Acoustic leak detection Leak located

How much of a 10km 400mm rising

main requires replacement?

Free rolling leak detection and magnetic data

inspection on a CI and AC pipeline.

The line of the main and pipe materials were

very different from GIS. A significant length of

replacement was de-scoped as the pipe was

found to be new.

Are trunk mains leaking? Upstream loss analysis followed by targeted in-

pipe leak detection

Real loss of 2MLD estimated from analysis. Leak

found and repaired. 2 MLD saved.

Survey Decision Tree - Examples

What do we need to know? How do you find that out? What did we find out?

Which damaged sewer pipes are causing a

waste water pumping station to be

overwhelmed?

Electro Scan of 600m section 63 infiltrations but 80% of infiltration restricted to just 3

sections 3%

How to minimise excavation locating and

repairing 10m deep suspected leak?

Sahara deep location and acoustic

detection

5 M/ld leak location pinpointed.

What is the route cause of corrosion and

high number of historic bursts, and likely

locations requiring intervention?

Acoustic and conductivity survey

on 300m 250mm main

Gas pockets identified and new gas relief valves installed as

well as providing new information on the route and material

of the main.

To what extent are dead zebra mussels

affecting treatment works?

Sonar profile scan using Sahara The location and quantification of mussels enabled planned

maintenance

Can we increase pressure on the pipeline? 6km Untethered acoustic survey Leaks found at one previous repair and 2 scour points, the

rest of the pipeline has not leaked in 40 years so pressure

was successfully increased.

The extent to which joints are leaking on a

1500mm PCCP pipeline?

Untethered 6km acoustic survey “The survey was an extremely worthwhile exercise that has

identified an unexpected leak. Critical trunk mains should be

subject to such inspections routinely to reduce risk to supply

and allow for the repair of pipes in a planned manner.” –

John Slattery (Senior Executive Engineer)

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wrc-infrastructure.co.ukwrc-infrastructure.co.uk

PETER HENLEY – WRC INFRASTRUCTURE

Thank you for your attention

See me on JBP Stand 119 for further information

[email protected]

Pipeline Condition Assessment - Trenchless Asia

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