Product transfer between floating systems in deep and ultra deep water is often more efficient if handled at minimal depth by mid-water pipe systems. Two such systems having distinct uses are being developed. These are the Trelline for large diameter flexible lines used in the transfer of stabilized crude from FPSOs to export buoys and the Gravity Actuated Pipe (GAP) for the transfer of multiple live produced fluids between gathering satellites and an FPSO used for processing of the hydrocarbon production.
Oil Offloading Line (OOL): Trelline
- The Trelline is a remote export system for deep water projects comprising a large diameter reinforced bonded rubber hose that issuspended in a simple wave of about 2km, between an FPSO and a deep water buoy.
- The Trelline concept has been developed to provide high flexibility, low weight, long fatigue life and big diameter for large low pressure throughput.
- This application is a field proven technology as it is a natural extension of the existing KlelineTM technology for longer lengths and higher static and dynamic loads.
- The Trelline has been certified according the API 17 K for a design life of 25 years.
- The flanges are fully protected and are reinforced using integrated bending stiffeners.
- Steel reinforcement rings in the hose handle collapse pressure.
Connection at Buoy and FPSO through a Gimbal:
For the end connections of the proposed design, use is made of an existing solution developed and tested by SBM that relies on a gimbal joint. The gimbal joint forms a structure around the last piece of Trelline hose. This structure bends to any angle and transmits the mid-water pipe tension to the buoy. The last Trelline gimbal hose joint therefore is subject to bending only, which it has been specifically designed to do. This gimbal hose is fully inspectable and can be easily replaced.
Trellian Brocure (PDF)
Gravity Actuated Pipe (GAP)
The GAP consists of a neutrally buoyant bundle of steel pipes supported and tensioned at a near surface depth by chains and weights attached to floating systems. The floating systems transfer production fluids through the pipe bundle via flexible lines. This near surface transfer greatly reduces flow assurance problems of hydrates and waxing that would occur with a sea bottom-based SCR piping system. The GAP's neutrally buoyant bundle also greatly reduces the load placed on the floater when compared to SCR use, which is quite important when designing TLP tie-ins. Studies of tie-ins from two to thirty km have shown the GAP to be applicable in any deepwater production area of the world.
GAP Brochure (PDF)