Handling systems specialist, Caley Ocean Systems has been awarded a contract by Subsea 7 to design, manufacture and supply a deepwater lowering system (DLS). The DLS will initially be deployed by Subsea 7 on the Chevron-operated Gorgon project, located off the northwest coast of Western Australia, to lower subsea structures weighing up to 950Te in water depths in excess of 1,300m.
The DLS comprises two double drum traction and storage winches and fully redundant controls, all mounted on an integrated grillage structure for rapid mobilization onto the pipelay and heavy lift vessel Sapura 3000. The system will connect to a deepwater lowering beam (DLB) and connector. Each set of winches has its own dedicated hydraulic power unit for optimum control.
The range of equipment to be handled by the DLS in the Gorgon and Jansz-Io fields will include subsea structures and foundations and heavy lift spools.
"The lifting requirements for oceanographic and offshore are very different", said Gregor McPherson, sales director, Caley Ocean Systems. "For oceanographic systems, great depths are involved up to 10,000m but the payload is small - often amounting to only a few tons, compared with the offshore industry where the depths are less but the payloads much higher. The dual winch DLS system is designed to provide optimum load handling and speed of deployment. It will also feature our modular control systems methodology to ensure safe operation offshore."
The Gorgon Project is operated by an Australian subsidiary of Chevron and is a joint venture of the Australian subsidiaries of Chevron (47.3%), ExxonMobil (25%), Shell (25%), Osaka Gas (1.25%), Tokyo Gas (1%) and Chubu Electric Power (0.417%).