This paper describes the TRILITE Super Satellite Platform (TRISS), a light 3-legged cost-effective fixed jacket substructure concept supporting a simple topside facility intended for unmanned operation. An overall objective has been to develop a realistic alternative to sub-sea concepts in water depths down to app-rox. 350 meters with the added advantage of having the wellheads located above sea level.
The jacket concept incorporates all known and proven features contributing to weight reductions. Furthermore, additional ideas conforming with this objective has been launched and studied, such as utilizing prestressed conductors and routing caissons inside the legs. Another novel feature is the installation method for cases where the installation weight exceeds the current SSCV lifting capacity, i.e. with use of a special purpose concrete barge-CONRAFT. The approach involves e.g. upending of the jacket jointly with the barge.
The topside facilities studied ranges from the simplest possible sub-sea type arrangement to a more elaborate concept including first stage separation, thereby avoiding multi-phase transportation to the processing facility. Special emphasis has been placed upon developing a layout adapted to a triangular support configuration and minimizing equipment within the frame-work of safety regulations in the Norwegian sector of the North Sea.
Technical merits have been studied and estimates of weight, cost and schedule prepared for a case in 330 m water depth.