Current in-line inspection technologies (e.g., Caliper/MFL or Combo) for mechanical damage characterization can detect dent with metal loss but with limited ability to discriminate metal loss between corrosion, gouge and crack with certainty. There are also some cases that metal loss signals were detected but not reported by ILI vendors because of either signals below threshold for reporting or other reasons. Practical experience showed that, with assistance of strain based dent analysis and strain limit damage criteria; detailed characterization of MFL tri-axial signals could effectively facilitate to discriminate metal loss features and identify potential risk of cracks or gouges in the dent. In this paper, the newly developed approach is utilized to identify the critical dents in the pipelines and discriminate those dents associated with metal loss reported by combined ILI technologies. A case study was performed with four real dent features, as an example to demonstrate the effectiveness of this approach. The details of the case study, results and findings are summarized in this paper.

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