Kuparuk, the second largest oilfield in North America, is located on the North Slope of Alaska. The piping and facilities are above ground, and are all insulated to minimize heat loss in the arctic environment. Although technically a desert, the pipelines are subject to external corrosion due to water within the insulation, caused by wind driven snow impacting the pipelines at the seams of the insulation (weld packs). The water accumulates until the pipeline is wetted. Weld packs have previously been inspected by a radiographic technique, with follow up removal of the insulation for visual inspections, if warranted. With over 60,000 weld packs at Kuparuk, a new method was sought to identify locations most
likely to have external corrosion. Accordingly, Kuparuk has been field testing an aircraft-based FLIR (Forward Looking Infrared) camera as one method for rapidly seaming pipelines to identify excessive heat loss, which is an indication of wet insulation and possibly corrosion. Results to date have shown FLIR indeed offers rapid screening of weld packs, and can identify locations for follow up inspections by other techniques. Future work is planned to further determine the usefulness of FLIR as part of a comprehensive inspection program.
Keywords: Arctic, external corrosion, wet insulation, polyurethane insulation, weld packs, infrared, FLIR, aircraft, pipelines