Nexans has been awarded a $15m contract by BP America Production Company to design and manufacture the world’s first subsea service umbilical to integrate a high-voltage cable. The 26km power-umbilical is to be installed in the Gulf of Mexico as part of a project to retrofit two existing subsea wells in BP’s King Complex with multi-phase pumps.
Integration of the power cable and umbilical functions in a single unit will enable an HV (24kV) supply to be provided in deep waters, which has not previously been possible. In addition, it will be more efficient to transport and install one power-umbilical rather than separate umbilical and power cables.
The concept of integrating HV electrical power cables in a subsea umbilical is very challenging from both the mechanical and electrical design aspects, with electrical interference between conductors and inductive losses in the steel tubes of particular concern. An additional challenge is that the cable will operate at depths of over 1,700 metres.
