Siemens Energy has received an order for two complete electrical power-generating stations, including Siemens’ ‘closed ring solution’, for supplying offshore drilling rigs with electricity. The seventh-generation semi-submersible drilling rigs of the Frigstad D90 design are under construction at the Chinese shipyard Yantai CIMC Raffles Offshore in Yantai, China. Delivery of the first drilling rig to Frigstad Deepwater is scheduled for December 2015. The second unit is to be delivered six months later. The order also includes an option for equipping a further four drilling rigs with power supply systems over the next four years.
The Siemens systems are to be used on-board the drilling units of the Frigstad D90 design, developed by Frigstad Engineering and tailor-made for safe and efficient exploration and development drilling in ultra-deep waters. The rigs will be capable of operating in water depths up to 12,000 feet and drilling to a total depth of 50,000ft. Siemens’ scope of supply includes the entire power-supply systems, each consisting of medium-voltage switchgear, transformers, drilling-drives, low voltage switchgear, variable frequency drives (VFD) and a power supply system for dynamic positioning (closed ring DP3), which enhances flexibility and streamlines the power management system of the rig.
The ‘heart’ of Siemens’ scope of supply is the closed ring design, which is the only class-approved solution for operating with permanently closed bus-ties in the Norwegian certification body’s (DNV) DYNPOS-AUTRO and DYNPOS-ER class notations. This fuel-efficient design has been verified to allow the dynamic positioning vessels to operate with the lowest environmental footprint available on the market.