Pipeline Pigging & Integrity Management
Houston - February 2008

Clarion Technical Conferences


Optimizing ILI Inspection Scheduling

February 12, 2008

Course objective

This new one-day course presents methods for dealing with inherent uncertainties about corrosion growth rates as well as ILI tool measurements, with the object of improving the reliability of ILI inspections, and the interpretation of the inspection results into maintenance decisions. It examines methods of determining corrosion rates, timing of inspections, and deterministic-, reliability-, and risk-based approaches to dealing with uncertainties and establishing failure criteria. The course is intended for those with basic familiarity with ILI tools and their capabilities.

Course Notes

 All delegates will receive a detailed set of lecture notes providing an invaluable reference document.

Continuing Education Units

Upon completion of the course, participants will be eligible to receive .4 Continuing Education Units (CEUs).

Who should attend

The course is especially designed for pipeline integrity engineers and inspection specialists, ILI data analysts, and technical personnel responsible for pipeline integrity assurance and corrosion control.


Guy Desjardins is president of Desjardins Integrity, a consulting firm in Calgary, AB. He has more than 25 years experience in the oil and gas industry and 12 years with pipelines. In 1997, he became a principal co-owner of Morrison Scientific and became Morrison’s president in 1998. He has been an independent consultant since 2005, offering services of data analysis, research, and software development.

Course Program

  • Introduction
    • Goals of the course
    • ILI inspections scheduling
    • Repairs
    • Reliability
    • Risk
    • Cost
  • Corrosion rates
    • Location dependence
      • Variation of corrosion rate with location
    • Time dependence
      • Corrosion rate from season to season
      • Year to year
      • Historical rates versus future rate
    • Distance scale
      • Gross scale corrosion rate
      • Microscopic
    • Time scale
  • Introduction to Inspection timing
    • General problem
    • Goals of the solution
  • Deterministic approach
    • General approach
    • Dealing with ILI uncertainty
    • Dealing with corrosion rate uncertainty
    • Setting a failure criteria
  • Reliability approach
    • General approach
    • Dealing with ILI uncertainty
      • Assessing ILI accuracy
    • Dealing with corrosion rate uncertainty
    • Setting a failure criteria
      • Probability of failure (POF)
      • Probability of rupture (POR)
      • Probability of leak (POL)
      • Probability of exceedance (POE)
      • Individual POE versus aggregate POE
        • Pros and cons of the aggregate POE
      • Calibrating POF/POE failure criteria to conventional maintenance methods
  • Risk approach
    • Similarity to Reliability approach
    • Setting a failure criteria
  • Assessing ILI uncertainty
  • Methods of assessing corrosion rates
    • Industry standards
    • NACE standard
    • API 570 long term rate
    • Correlation of anomalies from two (or more) ILI runs
    • Environmental correlations
    • LPR measurements
    • Coupons
    • Reducing uncertainty in corrosion rate assessment
  • Assessment of failure pressure
    • B31G
    • Rstreng .85dl
    • Rstreng effective area
    • Other better methods
  • Miscellaneous Topics
    • Conservativeness versus accuracy
    • Unknown factors
  • OPIS Software Tutorial

Organized by:      
Clarion Technical Conferences Global Pipeline Monthly    
Supported by:      
ASME Internationalthe In Line Inspection Association Pigging Products & Services AssociationPipeline & Gas Journal   Gold Sponsor
Gold SponsorRosen
the Journal of Pipeline Engineering PIPE  

Silver Sponsors
Silver Sponsorship Synergy Services

Tuboscope Pipeline Services

Oil & Gas Journal PRCI   Business Center Sponsor
Bronze SponsorshipApplus RTD
Pipeline and Gas Technology      


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