Launching elongate subsea structures
AssigneeSubsea 7 Limited
InventorsPhilip Derek Brown, Eric Fletcher McEwan
Life of this patent
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Abstract
A method of launching an elongate subsea structure such as a pipeline bundle unit into water provides buoyant support to the structure by displacing water with a hollow buoyancy unit that applies buoyant upthrust to the structure. By lowering the buoyancy unit in the water to bring a permanently open aperture of the buoyancy unit beneath a surface level of the water, the buoyancy unit is flooded with water through the or each permanently open aperture to reduce the buoyant upthrust applied to the structure. A corresponding elongate subsea structure is also claimed.
Claims19
A method of launching an elongate subsea structure into water, the method comprising:
- providing buoyant support to the structure by displacing water with a hollow buoyancy unit that applies buoyant upthrust to the structure;
- and
- by lowering the buoyancy unit in the water to bring at least one permanently open aperture of the buoyancy unit beneath a surface level of the water, flooding the buoyancy unit with water through the or each permanently open aperture to reduce the buoyant upthrust applied to the structure;
- wherein the method further comprises dragging at least part of the structure along a seabed while launching the structure.
Dependencies are inferred from the claim text.