Comparison of Integrity Management Assessment Techniques for Natural Gas Transmission Pipelines

This report was prepared in order to provide a high level view of the integrity assessment process for pipelines operating under an integrity management program. Specifically, this report looks at the tools and processes used during the integrity assessment or inspection and the results of these efforts.

The pipeline industry has performed the necessary research to establish the technical basis for each of the integrity assessment techniques and tools. The research has been used to develop new consensus standards that address the use of the techniques and tools and provide industry-wide consistency in approach including acceptance criteria. These standards are briefly addressed in the body of the paper and more fully discussed in the appendices.

The techniques and tools address the assessment of all the identified threats to pipeline integrity including time-dependent, time-independent and stable threats. When considering all the threats discussed, the time-dependent threats of external and internal corrosion are the primary targets of the assessment tools prescribed in the legislation and regulations for integrity management programs.