Detection of Corrosion Under Insulation Using Infrared Thermography

Corrosion Under Insulation (CUI) is one of the most common issues in oil and gas industry. CUI remains as the main threat due to its obscure condition, which resulted in undetected corrosion, leads to eventually pipe leakages. The challenge is to detect the CUI cases before any failure occurs. A preferred method of detection of CUI is by non-contact and non-intrusive technique, such as infrared thermography. The objective of this project is to detect and predict the degree of CUI damage in a pipeline using infrared thermography technique. Using a pipe with fabricated metal loss of 10%, 25% and 50% of its original thickness, an infrared (IR) camera was used to detect the effect of percentage of material loss, temperature of the oil inside of the pipe and the pattern of the heat map captured by the IR camera. The experiment setup was based on ASTM Standard G189. Results obtained show that section with higher percentage of metal loss projected a more obvious pattern on the thermal image obtained from the camera. Higher degree of metal loss will results in higher temperature difference between the inner region of the pipe and the outermost layer of the insulation, where on the thermal images, areas with higher temperature are marked with brighter and more outstanding color compared to region with lower temperature. Section with 10% of metal loss doesn’t indicate much obvious pattern on the thermal image, while section with 20% metal loss started to show some. Meanwhile, section with 50% metal loss projected a clear temperature difference pattern on the thermal image. Based on the findings, infrared thermography technique is promising to detect a significant metal loss due CUI and thus preventing failure.