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 7th generation semi-submersible drilling rigs of the Frigstad D90™ design are under construction at the Chinese shipyard Yantai CIMC Raffles Offshore Ltd in Yantai, China. Delivery of the first drilling rig to Frigstad Deepwater Ltd. 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 onboard 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 50,000 feet. 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.
“There is increasing market demand for advanced and highly efficient power supply systems for rigs equipped with dynamic positioning. Compared to older design concepts, our systems enable ships to operate at a high level of performance with a smaller ecological footprint”, stated Mario Azar, CEO of the Oil & Gas Solutions Business Unit of Siemens’ Energy Sector. “Several years were devoted to developing these systems. They were designed in line with our customer’s needs and fulfill the requirements and regulations prescribed by the classification authorities.”
This fuel efficient design has been verified to allow the dynamic positioning vessels to operate with the lowest environmental footprint available on the market. The rig owner Frigstad Deepwater Ltd. has stipulated that the rig’s power plant must be able to operate with closed ring in the various DP modes in order to enhance operating flexibility, increase fuel efficiency and reduce emissions, and has worked together with Siemens and the rig designer Frigstad Engineering to achieve this goal.