J. Ray Mcdermott & Co., Inc.

Clarence W Shaw

An offshore structure adapted to carry a drilling or production platform. The structure has a positive buoyancy and is tied-down to the ocean floor by tensioned cables such that the structure is maintained above the ocean floor and is tiltable. A plurality of anchored guy lines connect to the structure and are coupled to sway control apparatus that prevents excessive tilting of the structure by altering the length of the guy lines between the structure and the anchors. The sway control apparatus comprises first and second winches having a separate reel for each guy line, with each guy line being coupled to a reel through a rigging device mounted on the structure. The winches are operable in response to off-vertical movement of the structure as produced by excessive wind, waves and current.

Anchored offshore structure with sway control apparatus

A marine pipelaying apparatus for supporting pipeline during undersea pipelaying operations from a vessel floating on the surface of a body of water. The apparatus includes a tapering and longitudinally extending pipeline support member secured at one end to the vessel in a cantilevered manner and extending into the water. The pipeline support member includes a plurality of demountable sections decreasing in diameter and having sufficient buoyancy to float. The support member is designed to bend as it supports the pipeline being laid providing a desired profile without exceeding the elastic limit of the pipe. A hydraulic clamp for releasably clamping the pipeline support member is mounted on the vessel to secure the pipeline support member in a fixed relation to the vessel. A plurality of variable buoyancy floats and roller cradle mechanisms for buoyantly and slidably supporting a section of pipeline are attached above the pipeline support member. The apparatus can impart a stabilizing force to the pipeline and create a uniform stress distribution along the pipeline being laid which is within its elastic limit.

Marine pipelaying apparatus

An apparatus for anchoring a structure, such as a drilling platform, to a floor of a body of water has a movable jet nozzle operably disposed in a chamber which is lowered to the floor of a body of water. The jet nozzle is operable to slurry a portion of the floor underlying the chamber, and a pump is provided to evacuate the slurried portion of the floor to provide an excavation into which the apparatus may be lowered. Another pump may depressurize the chamber to provide a pressure differential to hydrostatically urge the apparatus towards the floor of the body of water.

Apparatus for anchoring a structure to the floor of a body of water

An offshore marine terminal for mooring a tanker and transferring fluids between the tanker and an underwater manifold. The offshore marine terminal comprises a buoyant member having a first end extending above the surface of the water and a second end submerged and extending beneath the water, a bathyal service chamber on the second end of the member defining an underwater habitat suitable for maintaining humans in an artificial atmosphere, an upper buoyancy and ballast chamber to selectively change the buoyancy of the member from a first lowered condition which has the bathyal service chamber positioned around the manifold to a second elevated position which has the chamber disposed above the manifold, and flow lines to transport the fluid through the chamber from the manifold to the tanker. The tanker may be moored to the terminal by a swivel mooring connection that is rotatable about the buoyant member. The terminal may be secured to the ocean bottom in a flexible manner such that a fulcrum point is created allowing the terminal to tilt.

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Metairie, LA, United States of America

Clarence W Shaw