Taking Care of Pipelines

Pipeline companies, companies that use tanks and pressure vessels, and inspection companies spend extensive effort and resources in finding where corrosion hides. They are dedicated to preventing leaks and failures.

They train on identifying corrosion (see https://www.nace.org/about), on predicting where corrosion can happen, and on developing technologies looking for corrosion. Why go to these lengths? All the training and effort are necessary since detecting corrosion is challenging.

To illustrate the effort needed to identify corrosion, a pipeline owner had extensive ultrasound thickness surveys done on the 6.625-inch diameter pipeline example shown (top image) to track the equipment condition. Earlier in 2019, deep pits were identified on the pipe bottom. When the pipe was cut open, the losses could not be seen (middle image). However, once the pipe was sectioned, it was clear that only 7% of the original cross-section was left (bottom image).

Under deposit corrosion was occurring (see Jose R Vera, Danny Daniels, Mohsen H. Achour, “Under Deposit Corrosion (UDC) in the Oil and Gas Industry: a Review of Mechanisms Testing and Mitigation,” C2012- 0001379, NACE Corrosion 2012). Based on these findings, the pipeline owner is continuing the periodic UT inspections and other mitigation strategies. All challenging, but part of the day to day quest.