In ultra deepwater, riser systems become a technical challenge and a major part of the field development costs. Large external pressures in these great depths cause flexible solutions to run into weight and cost problems. These same depths however enable steel pipe configurations to maintain curvatures that cause little bending and thus make them suitable for deepwater SCR use.
The FPSO with its large displacement is ideally suited to carry a large number of these deepwater SCRs. SCR bending fatigue concerns in this use have been addressed and shown not to be a problem in mild to moderate environments.
Further internal R&D studies are underway to reduce the SCR installation costs by placing the installation means on the FPSO thus enabling SCR use without lay barge mobilization for remote offshore areas. Major equipment and interfaces for this installation operation, which uses an SCR pull-out method have been identified. Further studies are being progressed to improve the laying operation, fatigue life and riser strength.
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