According to the Pipeline Operators Forum (POF), a pinhole is defined as “localized corrosion with surface dimensions smaller than 1t or 10 mm whichever is greater in length and width direction,” whereas t represents the wall thickness of the pipeline. The detection of these small features is often challenging for in-line inspection tools. Especially pinholes of diameters smaller than 4 mm are not detectable by most of the ILI technologies used in the market, such as high-resolution MFL or UT pitting.
MFL-A Ultra technology now enables operators to reliably detect pinholes of diameters down to 1 mm in gas and liquid pipelines. The unrivalled resolution and precision of MFL-A Ultra in-line inspection tools reveal pinholes caused by internal corrosion (e.g. MIC) as well as pinhole leakages caused by external circumstances. If small features remain undetected, they can grow over time and have the potential to cause severe damage to pipelines and result in environmental harm, or even worse, loss of life. This paper focusses on the capabilities of MFL-A Ultra technology to put operators in a position to reliably identify even minuscule critical threats to their pipelines while minimizing field verification cost.
By using data examples from recent inspections, the authors of this paper demonstrate how the RoCorr MFL-A Ultra Service can play an important role in achieving operators’ goals to
• identify locations of product loss through pinhole leakages, especially in liquid lines;
• minimize cost of field verifications and repairs through highly reliable defect identification and sizing; and
• deliver more-conclusive integrity calculations on their pipelines to reduce operational risk.