Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.

During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.

Menu
Search
Filters
Close
Menu

51318-11345-Effectiveness of Shorter Corrosion ILI Re-inspection Interval with varied ILI technologies:Finding the Unexpected High Corrosion Growth Rate of External Corrosion and MIC on Tape Lines.

  • /
  • /
  • /
  • 51318-11345-Effectiveness of Shorter Corrosion ILI Re-inspection Interval with varied ILI technologies:Finding the Unexpected High Corrosion Growth Rate of External Corrosion and MIC on Tape Lines.
Picture for Effectiveness of Shorter Corrosion ILI Re-inspection Interval with varied ILI technologies:Finding the Unexpected High Corrosion Growth Rate of External Corrosion and MIC on Tape Lines.
Available for download

The authors have identified high corrosion growth rate (CGR) features during excavation on one of the polyethylene tape coated lines by running more frequent corrosion in-line inspection tool runs.

Product Number: 51318-11345-SG
Author: Jiajun (Jeff) Liang / Michael Holm / Gordon Fredine / Yanping Li
Publication Date: 2018
Industries: Pipelines, Tanks, and Underground Systems , Corrosion Monitoring and Control
$20.00
$20.00
$20.00

 Most pipeline operators are using back-to-back In-line Inspection (ILI) tool runs to calculate corrosion growth rate (CGR). The CGR is used to predict the remaining life of pipe based on identified corrosion features. This methodology can be problematic as corrosion is a stochastic (non-linear) process. CGR can be higher due to unexpected factors involved with the operation of the pipeline that include, but are not limited to, heavy rain fall, increased operating temperature and changing soil condition due to excavation. Moreover, predicting remaining life on polyethylene (PE) tape coated lines is made more difficult due to potential shielding of the cathodic protection (CP). If CP is not effective enough to prevent the corrosion process, back-to-back or signal-to-signal CGR from the previous inspections can only be representative of past operational conditions and not for the future prediction.

The authors have identified high CGR features during excavation on one of the PE Tape coated lines by running more frequent corrosion ILI tool runs. The previously calculated CGRs were relatively low over the past decade for the pipeline. During the excavation, soil sample collection results showed that the pipeline suffered external corrosion due to general corrosion and microbiologically influenced corrosion (MIC). Identification of MIC as a corrosion threat was not consistent with previous operation and field findings for this pipeline. After confirming these results with several other excavation sites, the integrity program for the pipeline was adjusted and future ILI corrosion runs were selected based on varied corrosion ILI technologies and more frequent ILI tool runs to properly assess and predict the growth rate of these features. This paper summarizes the field findings and the adjustments to the pipeline’s integrity program based on the findings (i.e., MIC) including the methodology for varied ILI tool runs.

KEYWORDS: Corrosion growth rate, CGR, in-line inspection, ILI, metal loss, PE tape, microbiological influenced corrosion (MIC), threat management, re-inspection interval, cathodic prediction

 

 

 Most pipeline operators are using back-to-back In-line Inspection (ILI) tool runs to calculate corrosion growth rate (CGR). The CGR is used to predict the remaining life of pipe based on identified corrosion features. This methodology can be problematic as corrosion is a stochastic (non-linear) process. CGR can be higher due to unexpected factors involved with the operation of the pipeline that include, but are not limited to, heavy rain fall, increased operating temperature and changing soil condition due to excavation. Moreover, predicting remaining life on polyethylene (PE) tape coated lines is made more difficult due to potential shielding of the cathodic protection (CP). If CP is not effective enough to prevent the corrosion process, back-to-back or signal-to-signal CGR from the previous inspections can only be representative of past operational conditions and not for the future prediction.

The authors have identified high CGR features during excavation on one of the PE Tape coated lines by running more frequent corrosion ILI tool runs. The previously calculated CGRs were relatively low over the past decade for the pipeline. During the excavation, soil sample collection results showed that the pipeline suffered external corrosion due to general corrosion and microbiologically influenced corrosion (MIC). Identification of MIC as a corrosion threat was not consistent with previous operation and field findings for this pipeline. After confirming these results with several other excavation sites, the integrity program for the pipeline was adjusted and future ILI corrosion runs were selected based on varied corrosion ILI technologies and more frequent ILI tool runs to properly assess and predict the growth rate of these features. This paper summarizes the field findings and the adjustments to the pipeline’s integrity program based on the findings (i.e., MIC) including the methodology for varied ILI tool runs.

KEYWORDS: Corrosion growth rate, CGR, in-line inspection, ILI, metal loss, PE tape, microbiological influenced corrosion (MIC), threat management, re-inspection interval, cathodic prediction

 

 

Product tags
Also Purchased
Picture for 10069 Finding & Determining Cause of External Corrosion on Coated & Cathodically Protected Pipelines
Available for download

10069 Finding and Determining the Cause of External Corrosion on Coated and Cathodically Protected Pipelines

Product Number: 51300-10069-SG
ISBN: 10069 2010 CP
Author: Richard Norsworthy
Publication Date: 2010
$20.00
Picture for 96198 Case Histories of External Microbiologically
Available for download

96198 Case Histories of External Microbiologically Influenced Corrosion Underneath Disbonded Coatings

Product Number: 51300-96198-SG
ISBN: 96198 1996 CP
Author: Joseph L. Pikas
$20.00
Picture for 00741 PRACTICAL TELLURIC COMPENSATION FOR PIPELINE
Available for download

00741 PRACTICAL TELLURIC COMPENSATION FOR PIPELINE CLOSE INTERVAL SURVEY

Product Number: 51300-00741-SG
ISBN: 00741 2000 CP
Author: T.D. Place, T.O. Sneath
$20.00
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support