NDT Global, a leading service provider of ultrasonic pipeline inspection and data analysis, has conducted a detailed and accurate baseline survey of Statoil’s Polarled gas pipeline. NDT Global used its ultrasonic technology to get highly accurate results for Polarled pipeline, a pipeline with varied wall thickness.

This new pipeline of Statoil brings both environmental and operational challenges, as it is the first project on the Norwegian continental shelf crossing the Arctic Circle.

Due to the absence of a liquid coupling medium, magnetic flux leakage (MFL) is typically chosen for corrosion identification in a gas pipeline. On this run, a UT inspection was feasible prior to operation and the pipeline was filled with treated seawater.

NDT Global used high-resolution pinhole and pitting (UMp) metal loss inspection technology to complete the inspection. This technology with 0.4 mm (0.02 in) depth sizing accuracy is the best for thick walled pipes used in deep sea operations. Tool customization was provided by NDT Global for overcoming the environmental and operational challenges involved with this pipeline.

NDT Global has identified all the manufacturing baseline defects and delivered a thorough dataset to monitor the future corrosion thoroughly. Statoil now has the inputs required to improve integrity management over the lifetime of this strategic asset. The Polarled pipeline is now ready for operation.