Marine pipeline installation method and apparatus

摘要

A marine pipeline installation technique that allows the required length of pipeline (11) to be welded and assembled onshore, with the full pipeline length then being towed for installation. A series of buoyancy balls (18) or cylindrical tanks are attached to the pipeline (11) at selected intervals. The skin of the balls (18) or tanks is fabricated from a soft, strong material. A flexible hose (20) in fluid communication with each buoyancy ball (18) or tank is in fluid communication at each end with a storage tank that contains a buoyancy agent. The buoyancy agent, a light incompressible liquid, is directed into the balls (18) or tanks to cause the pipeline (11) to float a short distance above the seafloor (32). Chains (24) attached to the pipeline (11) at selected intervals maintain contact with the seafloor (32) to stabilize the pipeline (11). Lines (16A,16B) attached to each end of the pipeline (11) are respectively attached to a tow vessel (12) and a service vessel (14) for towing the pipeline (11) to the installation site. <IMAGE>