LESSONS LEARNT FROM CORROSION UNDER INSULATION AT ESSO AUSTRALIA

摘要

Corrosion Under Insulation (CUI) is an industry wide problem. The decision to fully strip equipment of insulation and inspect is costly and the consequence of failure can be high. This paper presents and discusses actual field data obtained from the oilfield industry particularly onshore plants, one coastal and the other inland and concentrates on pressure vessels rather than piping found at Esso Australia's onshore facilities. CUI data gathered includes; the size of corrosion (both depth and extent) found, the effect of temperature and the effect of CUI geography with respect to pressure vessel fitness for service. Location of the corrosion has been mapped and data is presented indicating whether corrosion has a higher probability of occurring at certain locations and whether these locations are predictable. In service engineering assessment methodology is discussed as well as relevance to CUI corrosion patterns. The paper also describes an execution plan to mitigate the risk of CUI.