Abstract
The Stones Field FPSO design provided many challenges in the design of the disconnectable Buoy Turret Mooring (BTM), including the 2900m (9500ft) water depth (the world's deepest floating production system), the first use of steel lazy wave risers from a BTM system, the local environment which included Rossby Topographic Wave currents along the Sigsbee Escarpment, and especially the efficient and safe mating and un-mating of two large floating bodies at sea without use of support vessels.
The paper covers the overall philosophy of the disconnect/reconnect operation of the turret/buoy, and then describes the major design challenges encountered. The major system components will be described. The functional aspects of the disconnection and reconnection will be discussed, with discussion of how the particular challenges of the project drove the design.
A sequence of increasingly complex model tests was used to guide the design. These initially included forced motion and drop tests to define the hydrodynamic properties of the buoy and the hydrodynamic near-field interaction of the buoy and a fixed FPSO turret. Later tests modeled the full system in waves while disconnecting and reconnecting. The model test results were then used to calibrate a numerical simulation which was used to refine and validate the design. A follow-on paper by Carrico and Leverette (2017) describes the test programs in detail.
