A general overview of design aspects related to metal catenary risers is first given. Response characteristics of these types of riser configurations are considered. It is subsequently focused on models for soil-pipe interaction, which have a strong influence on computed riser stresses in the touch-down region. The so-called CARISIMA models for riser-soil interaction in relation to horizontal and vertical motion (i.e.horizontal resistance and suction) are presented. Inherent limitations of the models are summarised. Basic input parameters are described, considerations relevant for establishment of initial trench profile are given, and examples of riser response analysis are presented. Typical behaviour of the numerical models which is observed in the example analyses is also reported.
Statoil have experienced failures in a number of flexible risers due to collapse, overload, tearing and unspiraling of the carcass in pipe structures with multi-layer PVDF pressure barrier. The paper will discuss the carcass failure modes that are characteristic for multilayer flexible pipes with particular focus on the failures due to carcass tearing. The nature of the carcass tearing problem is explained and suggestions for load model and operational policy for mitigation risk of new failures is presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.