LIFE-CYCLE ASSESSMENT OF FLEXIBLE RISERS

The number of flexible pipes in operation is increasing due to new field developments and the desire to extend the lifetime of existing fields. There have been many challenges with respect to long term operation of such pipes, in many cases with the need to replace or repair before the end of the initial design life. The number of identified failure mechanisms and observed failure events is also increasing. The present paper summarizes state of the art technology related to operation of flexible pipes and some recent research and development activities that contribute to resolving these issues. In particular, the following topics are addressed: Fatigue testing of flexible pipes subjected to corrosion damage during operation Development of improved numerical models and methods for assessment of the residual capacity of flexible pipes Integrity assessment of flexible pipes also applying quantified risk and reliability assessment Repair methods for damaged pipe sections In addition, an outline is given of a Handbook (ref. Handbook 2014) which addresses the various topics related to life-cycle design and operation of flexible pipes, see Appendix. Future prioritized research efforts with focus on some of the topical issues given in the list above are finally addressed.