EAST SPAR DEVELOPMENT - NCC BUOY - THE VERTICAL SUBMARINE

The remote East Spar gas/condensate field has been developed using a s ubsea production system operated by an unmanned navigation, communicat ion, and control (NCC) buoy. The use of this type of system allows con trol of the field from any convenient location, with the command-respo nse time and the cost of the facility almost completely independent of the distance to the shore or host facility. Successes during the proj ect (such as using model tests to prove the concept and using a tensio n-leg mooring system to reduce the motion response of the buoy) are di scussed and compared to failures, like the weight and size growth of t he structure, caused as the design requirements were finalized and ext ernal factors changed. The operation and layout of this facility is su mmarized, showing why it was described as a vertical submarine. Conclu sions are drawn about the use of an NCC buoy to develop this field, sh owing that the main objectives have been achieved. The limited operati ng experience to date is also considered in the review of the design o bjectives. The paper concludes with the possibilities for the future o f this type of concept.