The development of the cell spar Platform for the Kerr-McGee Red Hawk Field in the Gulf of Mexico represents the first application of this deepwater concept. The Red Hawk cell spar Platform was installed in about 5300 feet of water at Garden Banks Block 876 in early 2004 and achieved full production within 15 days of start-up.
This paper describes the design of the integrated spar hull and topside, with particular emphasis on the hull and related hull systems, due to their novelty. It provides a general description of the hull structure as well as the various hull and marine systems, riser support systems, and main structural appurtenances, including strakes.
The operation of the ballast system using compressed air is compared to a conventional ballast pump design. The inspection philosophy for the ballast tanks is described along with regulatory issues related to the ballast system. The operation of the mooring line winch and the handling of the chain at the top of the spar is also described. Vortex Induced Motion (VIM) performance, the upending of the spar, and initial impressions of the spar motion by field personnel are also discussed.
Red Hawk is the first application of the cell spar hull form. Building on several years of development, this new technology offers a more cost-effective solution than previous spar designs for small topsides payloads and low riser counts. The engineering of the cell spar demanded solutions to several challenging new problems. These solutions are now ready for implementation on future projects.
The Red Hawk field is a deepwater gas field located in the Gulf of Mexico approximately 210 miles southeast of Sabine Pass, Texas in Garden Banks 877. The field development spans both the GB877 and GB876 blocks, as shown in Reference [1]. The field development consists of a cell spar moored in approximately 5300 feet water depth, and one or more subsea systems that are tied back to the spar. Kerr-McGee Oil and Gas Corporation (the Operator) is the operator and Devon Energy (Devon) is a 50% partner. The discovery well at Red Hawk was drilled in August 2001.
After a review of potential development options, including a number of novel proposed systems, the Operator opted to develop the field through the use of the cell spar, which is the third generation of spar technology. Conventional wisdom for a field of this type dictates the use of a subsea tieback to a host. Economic comparisons demonstrated clear value to development of a 'dry spot' in this area for the purposes of developing the Red Hawk field, as well as potential future production which may be located within the 'area-wide' development for Kerr-McGee. A more complete description of the selection process and rationale are provided in Reference [1].
The cell spar has many of the characteristics of its predecessors, the classic and truss spars. The in-place response of all of these spars is similar.
