Umbilicals are used to control hydraulic valves, transmit electricity to electrical subsea systems, transmit signals for surveillance/monitoring, inject fluids into the production stream in order to optimise production, inject methanol to counteract plug formation, and operate electric pumps (power umbilical) in order to increase recovery from reservoirs.
A steel tube umbilical will typically consist of steel tubes, electrical elements and fibre cable for monitoring and surveillance. In addition to fill material around elements, it is covered by steel reinforcement and protective layers. In principle, a power umbilical is identical to a steel tube umbilical, except that it also has power phases.
Nexans has delivered over 90 umbilical projects worldwide and manufactured over 3,000 kilometres of umbilicals. We work to ISO 13628-5 Umbilical Specification, which contains testing requirements, third party requirements and information requirements. In addition, there will be client-specific requirements concerning welding, for example.