Abstract
Corrosion under insulation (CUI) has been a recognised issue in the North Sea for a number of years, resulting in considerable cost to operators in terms of safety and lost production implications. Several strategies and a variety of non-intrusive methods have been proposed and utilised with mixed success. The increasing number of mature assets operating beyond their original intended operating or design lives has necessitated the requirement for greater understanding in this area of corrosion management. This paper focuses on a series of case studies identifying the key contributory factors within each example and discusses the limitations of the first pass desktop approach. Experience in employing these differing techniques has verified that intimate knowledge of the system in question can greatly increase the probability of success and reduce the associated risks. This was found to include consideration of pipework wall thickness, degree of exposure and other less obvious factors. This practical approach employed in executing CUI strategies has produced greater success in identifying areas of concern. The inherent limitations of an abstract strategy are discussed, while highlighting some of the lessons learnt and the importance of applied local knowledge.
