Dexon was called on to perform an offline inspection of a 6” riser on an offshore platform. Visual inspection confirmed that severe corrosion was likely at the position of the hanging riser clamp and that external ultrasonic inspection was not possible due to the location and extent of the corrosion.

Using a tethered Ultrasonic Intelligent Pig system it was possible to inspect the line over a length of 50 meters and provide a highly accurate assessment of the extent of the corrosion at the position of the hanging riser clamp which had external corrosion down to 3.58 mm, representing 79.5% metal loss.

This critical wall loss was identified and reported to the customer within 30 minutes of tool retrieval and our API qualified inspection personnel recommended that the pipeline be shut down and repaired. A comprehensive dig sheet was provided highlighting all areas of concern with recommendations.