NDT Global provided an accurate and detailed baseline survey of Statoil's new Polarled gas pipeline. Polarled is the first pipeline on the Norwegian continental shelf that crosses the Arctic Circle, which brings both operational and environmental challenges. Statoil utilized NDT Global's ultrasonic technology (UT), a solution that offers highly accurate results for feature depth sizing of their Polarled gas pipeline, a pipeline with varied wall thickness.
Due to the absence of a liquid coupling medium, magnetic flux leakage (MFL) is typically chosen for corrosion identification. On this run, a UT inspection was feasible as prior to operation, the pipeline was filled with treated seawater.
The inspection was completed using high-resolution pinhole and pitting (UMp) metal loss inspection technology. This configuration features an optimized sensor carrier design and a high-resolution grid that is unmatched in the industry. The ultrasound measurement is ideal for thick walled pipes used in deep sea operations with depth sizing accuracy of 0.4 mm (0.02 in).
NDT Global provided tool customisation to overcome operational and environmental challenges associated with this line.
An exacting dataset to accurately monitor future corrosion was delivered. Not only is the pipeline ready for operation but Statoil now has the inputs required to improve integrity management over the lifetime of this strategic asset. The baseline manufacturing defects are now identified and corrosion growth can be monitored.
Edited from press release by Angharad Lock
Read the article online at: https://www.worldpipelines.com/equipment-and-safety/13072016/ndt-globals-custom-solution-for-an-extreme-subsea-pipeline-322/