Qualified Assessment for Lifetime Extension of Flexible Risers

There have been many challenges with respect to long term operation of flexible pipes, in many cases with the need to replace or repair them before the end of the initial design life. The number of identified failure mechanisms and observed failure events is also increasing. In the present paper, some typical issues that arise during the process of integrity assessment and qualification for lifetime extension are outlined. More detailed considerations are illustrated in relation to a particular case study. This involves elaboration of the different steps which are required in order to be able to extend the lifetime of a flexible riser for the case of corrosive annulus environments. The particular case of an outer sheath damage is applied for the purpose of illustration.