The Challenges of Extending the Life of UK Offshore Installations

The majority of the oil and gas production infrastructure in the UK sector of the North Sea was installed in the 1980’s and 1990’s. Typically these installations were designed with a lifespan of 15-25 years, and many of them are now at or beyond their original design life. With higher prevailing oil prices, and continued development via subsea field tie-backs, the economic lifespan of these installations look set to exceed design lives by a considerable margin. In addition, many installations are now processing very different fluids and rates as they enter the mature phases of production. This paper describes in more detail how the life extension challenge is being managed in Shell UK. It covers the overall process being adopted for managing facilities beyond their design life, as well as describing some of the methods and techniques being used to make key decisions. The key learning’s that can be applied in other mature fields includes: