Session: 03-04-02 Inline Inspection Performance I

Paper Number: 133504

133504 - Optimized ILI-based Corrosion Management Program Towards a High Reliability
Industry 

Abstract: 

This paper presents the critical areas for optimizing an in-line inspection (ILI) based corrosion management program (referred to as “ILI based program” hereafter) identified by TC Energy (TCE).  The ILI based program is the most successful path to manage time-dependent threats that are prevalent on majority of the existing pipeline systems.  It has proven to reduce industry wide failure rates but has not always prevented all post ILI failures.

However, ILI based programs can give very different failure performance and mitigation results depending on the ILI tools, assessment models, safety factors, and assessment methodologies.  Historical evidence and data analytics show the differences in ILI based programs in both performance and mitigation results.

Effective process improvement strategies require the essential steps to define, measure, analyze, improve, and control. The objective of an optimized ILI based program is to reduce failures and maintain the pipeline system to an acceptable reliability level while minimizing unnecessary actions.  Improvement and control are obtained by identifying the areas in which reliability is most sensitive to (i.e., significant areas) and then improving these areas to achieve the necessary reliability. TCE’s research has identified the most significant areas to optimize an ILI based program:

1.How do the many uncertain variables such as ILI measurements, material properties, growth rate, and assessment models come together to provide safety?  TCE has demonstrated that the use of both probabilistic (or Reliability-based) and deterministic assessment methods is able to portray safety, which will be discussed together with target reliability levels or safety factors.  Reliability-based assessment method has enabled TCE to identify critical anomalies that would be missed by deterministic assessment method. Understanding the correlation between deterministic methods and probabilistic methods and consequently the correlation between safety factors and reliability target has enabled reduction in failure rates. 

2.ILI tool sizing, and corrosion growth are significant variables which need to be characterized appropriately.  ILI sizing is morphology dependent and sometimes run specific.  Growth rates are time and location dependent.  Accounting for these uncertainties without broad brushing error margins allows mitigation actions to avoid failures while reducing unnecessary actions.

3.An assessment model that quantifies the burst pressure based on feature sizing is critical to optimizing integrity decisions.  The Psqr model development and expert review to achieve industry vetting examined the role of model error and its impacts, improvement and benefits. This model will enable cost efficiency in corrosion management programs.

4.Continuous monitoring, learning, improving, and optimization based on post ILI failures, excavations, and failure rates is key to this program.  Understanding failure behavior and failure prevention and appropriately incorporating them into the program to improve performance, best practices in meaningful data analytics to improve corrosion management will be presented.

As accuracy and precision are key to developing optimized ILI based programs, the above areas were focus areas of improvement through R&D and investigation.  The implementation of these critical areas to achieve operational excellence will be described in the paper.

A prudently optimized ILI based program reduces failure rates while reducing unnecessary mitigation actions.  This kind of optimized ILI based program enables the pipeline industry to become a high reliability industry while staying economically viable.  It provides the social license essential for the industry and allocates resources to prevent failures while minimizing unnecessary actions. These objectives were achieved by focused research to improve key areas, data analytics to portray reality, and continuous learning from incidents, which are all steps that operators can use to improve and optimize ILI based programs to demonstrate the “Zero is Real” aspiration.

Presenting Author: Shenwei Zhang TC Energy

Presenting Author Biography: Shenwei Zhang obtained his PhD degree in Structural Engineering from the University of Western Ontario before joining TC Energy in 2014. He is a senior pipeline integrity engineer particularly focusing on the technology development associated with pipeline integrity and risk assessment. He developed TC Energy’s ILI-based decision optimization tools and procedures for corrosion, crack and dent assessment as well as surface loading stress analysis for pipeline under road crossing. He is the inventor of a more accurate and precise corrosion assessment model considering multiple plausible profiles, called Psqr model. Psqr model was granted the US Patent and won the ASME Global Pipeline Award, CEPA Quality and Innovation Award, and TC Energy CEO Safety Leadership Award. This model was adopted by CSA Z662-2023 and the new edition of ASME B31G and will be included in API 579-1/ASME FFS-1 and PDAM. All his work has been well recognized by industry peers and disseminated through numerous presentations, Workshops, Webinars, PRCI report and approximately 50 peer-reviewed conference and journal papers.

Authors:

Shenwei Zhang TC Energy
Zijian (Jason) Yan TC Energy
Vincent Tse TC Energy
Elvis Sanjuan Riverol TC Energy