Since the installation of the Neptune Spar, the Spar type platform has increasingly become the preferred concept for many deepwater applications. Due to the inherent shape of the Spar, its design must consider the various pre-service conditions that a Spar has to experience prior to its in-place operation, and the many requirements and constraints imposed no the Spar design. The additional requirements and constraints associated with a Spar in these conditions impact, and sometimes govern, the design of Spars, and need to be identified and covered in the configuration and detail engineering phases.
This paper presents an overview of the key pre-service conditions that are to be covered in the design of Spars, the major design considerations, and how the design, fabrication and installation can be impacted by these considerations. The need for the design of more pre-service friendly Spar configurations is discussed.