Coatings for corrosion under insulation (CUI) protection—accelerated testing methodology

Abstract

Corrosion under insulation (CUI) is a serious issue in the oil and gas industry, with failures often occurring without warning and having devastating effect. When expensive redesign is not possible or practical, operators have a number of options open to them to mitigate the risk of CUI; these include the use of various protective coatings or thermally sprayed metals. Despite a number of technologies presently available, the industry is yet to establish an accepted laboratory test method for the performance benchmarking of products. This has, in the past, damaged confidence in some solutions and hampered the selection and further development of CUI coatings. As a result, the subject of accelerated laboratory testing for CUI coatings is now receiving significant attention across the industry with joint industry programs proposed in both Europe and North America. This paper will examine state-of-the-art accelerated CUI testing, evaluating the advantages and disadvantages of the existing methods available. It will then offer a detailed description of a test method that has been in use since 2004, testing more than 300 specimens and assessing a wide range of coating technologies. The reproducibility of the test program will be established by the presentation of a range of data including results obtained from a third-party test house. The third-party results will then be correlated with a seven-year case study from an end user perspective provided by Santos, a major Australian oil and gas exploration and production company, from experiences at their Port Bonython facility in SA.