Weighttype motion compensation system for a riser moored tanker

摘要

A system for mooring a ship-shape floating production system using a riser tensioned by a weight type motion compensation system. The riser is attached to the ship by a rocking beam that has a weight attached at one end of the beam to balance the vertical load component of the riser attached at the other end of the beam. A rocker arrangement is used whereby the beam support point moves to compensate for the inertial forces of the weight caused by the vertical accelerations of the tanker. Thus the high load fluctuations and hence poor riser fatigue life usually associated with weight type motion compensators is minimized. A gear arrangement is used to transmit horizontal loads. The overall arrangement provides a totally self-contained motion compensation and riser handling system that requires minimal ship modifications and is independent of significant self-induced wave loading.