Introduction and Overview of Condition Assessment. UKSTT Condition Assessment Masterclass

Transcription

1 Introduction and Overview of Condition Assessment UKSTT Condition Assessment Masterclass 21 st September 2017

2 CA Overview Contents 1 Condition Assessment 2 Consequence of Failure 3 Condition Assessment Costs 4 Available Techniques 5 Conclusion

3 1 Overview CA Understanding the condition of an asset to optimize way we intervene

4 Why do Condition Assessment! Mitigation of risk Risk being Likelihood * Consequence

5 Context Background Many water and sewer networks date back >100 years There is a wealth of environmental, historical, and operational information available Various technologies have been developed to inspect/monitor piping systems The Challenge? Intelligently collect and interpret the information available Identify requirements for rehabilitation and repair Develop targeted, cost-effective replacement and rehabilitation strategies

6 Condition Assessment Drivers Assessment of renewal budgets Prioritisation of spending programmes Key condition assessment drivers Determination of appropriate intervention strategy Regulatory requirements

7 What does Condition Assessment tell us? CA assists in providing information about the likelihood of failure Data is only useful if it has a proper context Better processed data generates understanding!

8 Consequence Consequence considerations Diameter/Asset Value Location Activity

9 Consequences of Pipe failure Below Ground Domestic Properties Flooded Above Ground Domestic Flooded Below Ground Commercial/Industrial Properties Flooded Above Ground Commercial/Industrial Flooded Low Pressure Supply interruptions Repair Cost Cost of Water Third Party Costs/Fines Loss of Reputation Shareholder Value Affected

10 Likelihood Mitigation Matrix Consequence Low Medium High Very Good Operational Operational Operational Good Operational Operational Replace / Operational * Average Operational Replace / Operational * Replace Poor Replace / Operational * Replace Replace Very Poor Replace Replace Replace

11 Choosing what to Assess Inspection Likelihood of Failure Prioritisation Priority of pipes Lowfor condition Medium assessment High Based on calculated level of risk Very Low Low Priority Priority Consequence of Failure Low Medium High Low Priority Medium Priority Medium Priority High Priority Medium Priority High Priority Very High Priority

12 Condition Assessment Asset owners under increasing pressure to provide maximum value from existing assets Condition assessment can be used to prioritise rehabilitation and replacement programmes Costs incurred from failure increases with diameter Expenditure on condition assessment must be assessed in the context of failure cost

13 Condition assessment Data sources Inferential information Discreet information Long length information

14 Inferential Approaches Desk top analysis Burst rates Soil types Pipe ages Pipe Materials Historical information

15 Condition Assessment Approaches Discrete Testing High resolution scanning at relatively low cost Excavation may be required to gain access to the pipe Data used in cohort analysis to infer pipe condition in similar areas

16 Condition Assessment Approaches Long Length Scanning Greater distance covered from a single point Generally lower resolution scanning, though very high resolutions are possible Techniques may disturb sediment in pipe, causing water quality issues

17 Summary Overview CA Part 1 CA is done to help analyse Likelihood of failure It is done to protect customers and because of the regulatory environment It can be done as a study, discretely or in long lengths Various data types can be combined

18 2 Pipeline Failure Costs 51,304 bursts (England and Wales) April 2016 to March 2017 At 3000/ burst = 153M

19 Small diameter failure a nuisance but costs can be high if not found 19

20 Small Leaks will grow over time 20

21 And Grow! Small leaks don t get smaller

22 Methodology Risk based inspection strategy based on budget Leakage detection (inferential) External condition assessments method Internal condition assessments method Acceptability Access, live or dry Budget Preparatory work

23 Selection of CA Approach Required coverage Desired resolution Available budget Confidence and quality of data Information to allow appropriate decisions to be made

24 Summary Consequence of Failure Part 2 CA is done to help analyse Likelihood of failure Budget Need to plan and choose methodology Plan for possible problems

25 3 Assessment Costs 1. Desk top Study a few thousands 2. Numerous external measurement a few more thousands 3. Long length internal analysis some tens of thousands

26 Assessment Costs Technology must relate to asset value and risk Small pipes generally are not worthy of high expenditure Most pipelines where not built with a view to later condition assessment New high value pipelines should be built with access points

27 Key Practical Considerations Ease of access can existing appurtenances be used Does the system has insertion points What is the cost of insertion points Will device cause turbidity Can the device get lost or stuck Does the pipeline need to be emptied

28 RESOLUTION & LENGH Cost and Resolution Remote Field Eddy Current High Resolution MFL Internal Ultrasonics JD7 Broadband Electromagnetic SmartBall/Sahara PWA CCTV External Ultrasonic Coupon Sampling The applicable technology generally follows pipeline asset value/replacement cost Desktop Study Only COST

29 Examples of access to larger pipes Thames water insertion points for JD7 or Sahara Scottish water PipeDiver for PCCP

30 Other Industries Gas transmission lines have pig traps Oil lines have pig traps Value of conveyed product and reduction of risk What is a greater problem a city without water or without gas?

31 Intelligent Pig

32 Pig trap Allow insertion and extraction of devices from pipelines should be considered for all water pipe lines >800mm?

33 Assessment what to use Lower diameter pipes low cost methods Larger pipes may warrant internal assessment New larger or high consequence pipelines build in pig traps

34 Summary Costs Part 3 CA is done to help analyse Likelihood of failure It is done to protect customers and because of the regulatory environment It can be done discretely or in long lengths Various data types can be combined

35 4 Available CA Techniques Inferential Techniques Discrete External direct Measurement Long length direct Measurement

36 Inferential Techniques DMA monitoring Increased none revenue water Listening for leaks internally or externally These approaches do not describe a pipes condition but give important clues

37 External Leakage Detection Primayer Pros Location of leaks Gives indication of condition Cons Limited survey lengths Limited info on pipe structural condition No visual information

38 Leak Noise Correlators

39 Radio Based Noise Loggers

40 Multi-Point Correlating Loggers

41 Soil Resistivity Checks Pros Low cost Can cover long lengths Cons Possibly no access in urban areas Highly Inferential

42 Discrete External Condition Assessment Techniques

43 External Ultrasonic Thickness Pros Relatively high resolution Low cost for resolution Can provide wall thickness and pit depth Cons Limited survey length Can be difficult on cast iron

44 Magnetic Flux Leakage Detection of anomalies within pipe wall Pipe wall saturated with magnetic flux, leakage of flux detected at defects in the pipe wall

45 Magnetic Flux Leakage Pros Can be very high resolution Complete wall coverage in survey area Can detect internal and external pits Cons Limited survey length Usually used in conjunction with ultrasonics, which can be problematic on cast iron

46 Broadband Electromagnetic Scanning Measures attenuation of electromagnetic signal to determine wall thickness and presence of defects Can be used on pipes >75mm diameter Assessment can be done without coating removal Data is obtained from outside of pipe and gives relative thicknesses

47 Broadband Electromagnetic Scanning Pros Relatively high resolution Complete wall coverage in survey area Can detect wall anomalies Cons Limited survey length Gives overall picture of pipe condition, but not detailed pit depth information

48 Internal Condition Assessment Techniques Numerous systems Numerous types of deployment Some systems require an empty pipe

49 Internal Leakage Detection Pros Long survey lengths Very accurate location of leakage Can provide CCTV Can provide joint counting Cons Qualitative data No information on pipe structural condition CCTV can be of limited use in large pipes

50 SmartBall SmartBall Leak Detection System

51 SmartBall Pros Very long survey lengths Location of leakage Can detect pipe joints Cons Cons Qualitative data Tracking is inferential Ball may not be retrieved Ball could get lost 75mm access point required

52 Robotics platform In-Line Electromagnetic Testing Manned platforms Free-swimming platforms

53 Breivoll Inspection Technology Acoustic Reference Technology

54 Russell See Snake

55 Internal Broadband Electromagnetic Scanning (BEM) Pros Relatively high resolution Complete wall coverage in survey area Can detect wall anomalies Cons Some cleaning required Man access may be required to move sensor array

56 In Line Intelligent Pig 56

57 Defect Width Circumferential Slotting Circumferential Grooving In-Line Inspection Limitations Axial MFL General Corrosion Radial Ultrasonic Pin Hole Pitting Axial Slotting Pipeline Operators Forum Chart Axial Grooving Circumferential MFL Defect Length 57

58 Aqueduct Inspection Tools Out-of-Service Pipeline In-Service Pipeline 58

59 Pre-stressed Concrete Cylinder Pipe Assessment Tend to fail catastrophically, rather than leak wire breaks can be identified in advance 59

60 Prestressed Concrete Cylinder Pipe (PCCP) MORTAR COATING STEEL PRE-STRESSING WIRE OUTER CONCRETE CORE STEEL LINER INNER CONCRETE CORE 60

61 Condition Assessment of PCCP Pipe Electromagnetics Provides a snap-shot of the condition of prestressed pipelines. Identifies badly-damaged pipes for immediate repair. 61

62 In-Line Electromagnetic Testing EM can detect cylinder defects as well as broken bars, individually and in combination.

63 Combining Data Sources The way this is done is primarily dependent on: The available information and the pipe length

64 Likelihood of Failure Results Environmental likelihood scores from desk study Span ID Likelihood Indicators SAPID Pipeline age Wt Pressure Wt Pipe Material Wt Soil Type Wt Burst history Wt Land Use Wt Likelihood (SUMMED) Likelihood (NORMALISED) sections Likelihood of Failure Score

65 Developments in Analysis In this instance we had lots of detailed data and we were able to look at both the detail of the data types and as we will see we were Able to combine the data.

66 Developments in Analysis This pipeline was given a new PE lining

67 Developments in Visualisation

68 Summary Available Techniques Part 4 Very wide range of techniques available Some techniques are inferential, some discreet and others cover long lengths Algorithms for combining all this information exists There are new was of visualizing this information.

69 5 Conclusion Selection of Condition Assessment Tools 1.Available budget 2.Required coverage 3.Desired resolution 4.Ensure that the data processing capacity exists for all data types 5.Information to allow appropriate decisions to be made

70 Make Decision Do Nothing Change operating conditions Rehabilitation Pipe Replacement Minimize costs by treating different lengths of pipeline as required

71 Conclusions 1. Rapid development of Technologies over last 10 years 2. Industry is not always aware of what is available 3. Application of CA technologies is not yet generally part of strategic planning but we are entering a new era of assessment technologies and its processing