Design of the World’s 1^st Gravity Actuated Pipe (GAP) for Murphy’s Kikeh Deepwater Development, East Malaysia

MURPHY Sabah Oil Co. Ltd. has developed the Kikeh Field located offshore Malaysia in the South China Sea in a water depth of 1325m. This field development is based on a Floating Production Storage and Offloading unit (FPSO) and a Spar Dry Tree Unit (DTU). Fluids are transported in fluid transfer lines (FTL) using SBM’s newly developed and patented Gravity Actuated Pipe (GAP) system. The GAP principle is based on a large diameter carrier pipe supporting a number of flow lines and a power/control umbilical. The carrier pipe serves as a structural support for the flow lines and umbilical. The flow lines are attached to the carrier pipe by supports allowing movement in the axial direction. The carrier pipe terminates at each end with a towhead, which channels the forces into the carrier pipe and supports flexible jumpers between the flowlines and the floating facilities. Tether chains are suspended from the floaters to support each end of the carrier pipe. Clump weights and buoyancy are mounted at the ends of the carrier pipe to generate vertical load. The action of the clump weights and buoyancy on the angled chains keeps the carrier pipe under tension. This tension minimizes the hog/sag deflections of the pipe bundle and keeps the system within acceptable limits. This paper presents a technical overview of the Kikeh FTL GAP system. Several challenging engineering and design aspects and their solutions are presented. Design of the GAP sub-components is highly interactive requiring significant hydrodynamic and structural analysis by experienced personnel. The Kikeh FTL GAP project commenced fabrication in 1st quarter 2006, and completed installation and achieved first oil in August 2007.