1837aa3901aa94f940c8486e735a6c8b 2013 subsea im summit interpretation of subsea inspection data

8/10/2019 1837aa3901aa94f940c8486e735a6c8b 2013 Subsea IM Summit Interpretation of Subsea Inspection Data

1/18


2/18

Interpretation of SubseaInspection Data

Subsea Integrity Management Summit

Dharmik Vadel

10 September 2013


3/18

of 18

Agenda

3

Objectives of inspection

Inspection planning

Data interpretation examples

Marine growth observations

Cathodic protection data

UT wall thickness data

Considerations for future inspections

Conclusions


4/18

of 18

Objectives of Inspection

4

GovernmentRegulations

Organizational Goals

Industry Best Practices

Design Requirements


5/18

of 18

Objectives of Inspection

5

Determine Fitness for Service

Confirm effectiveness of barrier(s)

Increase knowledge of operationalcondition(s)


6/18

of 18

Inspection Planning

6

Compliance

Fitness for ServiceWhy

Equipment (Object/Defect/Extent)What Internal/External

Fatigue critical locations

Anomalous locationsWhere Risk based

Prescriptive

Event basedWhen

GVI, CVI, UT, CP, Pigging

How Operators, Inspectors, Engineers

Certification/TrainingWho


7/18

of 18

Inspection Data Types

7

Pictures Videos

Report Tables


8/18

of 18

Data Quality and Relevance

8

Subsea field Equipment(s)Scope

Inspection tool calibration Post processingQuality

Failure mechanism Trends analysis

Barriers/Mitigation effectivenessRelevance


9/18

of 18

Data Interpretation Process

9

Way Forward Way Forward Engineering

Assessment

Engineering

Assessment

Potential Risks Potential Risks Observations Observations


10/18

of 18

Data Interpretation

Marine Growth

10

www.iev-group.com

www.seatrepid.com

www.seatrepid.comwww.seatrepid.com

www.offshore-technology.com


11/18

of 18

Data Interpretation

Marine Growth

Observations

Levels of marine growth

Interference with visual condition assessment

PotentialRisks

Reduction in VIV suppression effectiveness

Clashing risk from increased drag

EngineeringAssessment

Trend analysis baseline/historic MG levels

VIV fatigue analysis

Clashing analysis

Way

Forward

Marine growth cleaning intervals

Visual inspections

www.iev-group.com

www.seatrepid.com


12/18

of 18

Data Interpretation

Cathodic Protection Data

12

www.diveworks.com.au www.mackayunderwater.co.ukwww.red7marine.co.ukwww.stoprust.com


13/18

of 18

Data Interpretation

Cathodic Protection Data

Observations

Cathodic potential measurements

Anode wastage levels

Potential

Risks

Inadequate cathodic protection

Increased external corrosion risk

Engineering

Assessment

CP system design review

Trend analysis Baseline/Historic CP results

Determination of remaining life of anodes

Way

Forward

CP inspection intervals

Retrofit anode sled

www.iev-group.com

Keel joint

Mudline

Hard Tank

Riser

-1100mV -700mV-mV(Ag/AgCl)


14/18

of 18

Data Interpretation

UT Inspection Data

Observations

Wall thickness measurements

Visual corrosion/coating damage

PotentialRisks

Potential for leak

Excessive wall loss derate system

EngineeringAssessment

Fitness for service assessments

Trend analysis baseline/historic UT data

Determination of remaining life

Way

Forward

UT inspection intervals

Wall thickness loss rate

Permanent mitigation

www.iev-group.comwww.iev-group.com


15/18

of 18

Considerations for Future

Inspections

Risk Assessment is a tool todefine inspection intervals

Inspection work scopes

Define specific requirements

Provide historic information

Inspection data sheetsversus data logs

Video quality and displayrequirements

HD versus SD

ROV overlay

Inspection tools

Repair kit, Cleaning, CP, UT

15


16/18

of 18

Effective Work Scope - Examples

CP measurement

locations

Flange and boltcorrosion

16

www.diveworks.com.au

CP Location1

West Side

AB

CD

www.storktechnicalservices.com

NorthFlange 21


17/18

of 18

Conclusion

Interpretation of subsea inspection data depends upon

Relevant and quality inspection data Baseline and historic inspection data

Knowledge of equipment design

Awareness of potential risks to your equipment

A successful inspection campaign depends upon

Inspection planning

Detailed work scopes

Communication - pre and post inspection meetings

Right people for the right job

Review and update your inspection cycle periodically

based on documented operational history 17


18/18

of 18

1837aa3901aa94f940c8486e735a6c8b 2013 subsea im summit interpretation of subsea inspection data

Documents