Session: 03-04-01 Inline Inspection Performance Session 1.2

Paper Number: 133132

133132 - Evaluating the Performance of EMAT ILI Technology for Managing Stress Corrosion Cracking on Natural Gas Pipelines 

Abstract: 

This paper is based on an INGAA Foundation EMAT Performance research project completed in Q4 2023.  As EMAT (Electro Magnetic Acoustic Transducer) technology improves, so does its measurement performance. Seven years ago, a PRCI study evaluating ILI performance included some EMAT measurements for crack-like features.  Since then, EMAT technology has improved and application has flourished throughout industry.  With a plethora of new data sets documenting measurement results with the newest generation of tools, the INGAA Foundation and member decided to initiate a study on EMAT measurement performance.  In this effort, a consortium of operators compiled a robust dataset encompassing EMAT and field measurements, with a focus on pipe body stress corrosion cracking features. 

Measurement performance is evaluated using two approaches.  The first, using API 1163 validation procedures, the study characterizes EMAT's performance in reporting depth and crack length, comparing various combinations of field and In-Line Inspection (ILI) measurement reporting techniques.

The second, assesses the safety factor, a critical ratio of calculated burst pressure to the maximum operating pressure, by comparing EMAT and field Non-Destructive Testing (NDT) estimates of burst pressure using CorLAS. When ILI measurements yield a lower safety factor than the field estimate, a conservative result is obtained.  Results from real-wold data sets are characterized as probability distributions to express the degree of conservatism and non-conservatism in the EMAT estimate, allowing the safety factor to be adjusted to meet a desired level of performance.

This paper summarizes the measurement techniques and processes used to assess the field and EMAT measurements and ranks them to support best practices that reduce conservatism and error in the safety factor calcuations, offering valuable insights for operators. The findings not only contribute to understanding the measurement performance of EMAT for stress corrosion cracking on natural gas pipelines, but also compare the efficiency and effectiveness for different measurement methods and implied safety factors used in deterministic assessments.

Presenting Author: Jason Skow Integral Engineering

Presenting Author Biography: Jason has a proven track record in a variety of engineering and leadership positions. He has 23 years of experience in the oil & gas industry with a focus on asset integrity, measurement performance, risk & reliability, and data analytics.

Authors:

Jason Skow Integral Engineering
Ryan Stewart Jason Skow
Oleg Shabarchin Enbridge
Sean Moran Williams