Ramin Yasseri

Ramin Yasseri

Mechanical Engineering MEng

Integrity of Subsea Control Umbilicals

This project looks into the application of a methodology termed global-local analysis, for the design of sub-sea control umbilicals. A global model is a less detailed representation of the system which is used to find the global forces and moments. The local models are highly detailed sub-models of the system, to find extremely accurate data about the behaviour at every point in the system. The methodology was tested for two design cases, namely ensuring adequate strength and determining the fatigue lives along the umbilical. For the strength assurance, the response of the umbilical was calculated under extreme wave environment using the global model. The fatigue lives were determined by analysing the global model for ten sea states, and then using local models to determine detailed stress time-histories for all points along the umbilical for all sea states. The work presented as part of this project aims to assist the oil and gas industry to achieve high reliability and availability, and to provide trouble free service during the entire project's life. This work showed that the required computation is within the industry's limitations.