Abstract: A floating offshore structure for use in oil or gas drilling or production operations, having apertures in its sides in order to reduce the movement of the structure as a result of undersea currents is disclosed herein. The structure contains a production platform extending above the ocean's surface, a series of buoyancy tanks providing the structure with the ability to float, apertures, surrounded by coamings, located around the structure such that ocean currents are allowed to flow laterally through the center of the structure and such that oil and gas can dissipate from the center of the structure if a rupture occurs, a fluid retention tank and ballast in order to lower the center of gravity of the structure and make it more stable, and a centerwell running through the longitudinal center of the structure which allows one or more risers to run from the ocean floor to the operating platform. The structure can then be moored to the sea floor through the use of a catenary or other mooring system.

Abstract: A polygon shaped floating offshore structure for use in oil or gas drilling or production operations, having apertures in its sides in order to reduce the movement of the structure as a result of undersea currents. The structure contains a production platform extending above the ocean's surface, a series of buoyancy tanks providing the structure with the ability to float, apertures, surrounded by coamings, located on each side of the structure such that ocean currents are allowed to flow laterally through the center of the structure and such that oil and gas can dissipate from the center of the structure if a rupture occurs, a fluid retention tank and ballast in order to lower the center of gravity of the structure and make it more stable, and a centerwell running through the longitudinal center of the structure which allows one or more risers to run from the ocean floor to the operating platform. The structure can then be moored to the sea floor through the use of a catenary mooring system.

Abstract: A semi-submersible pipelaying vessel has an improved configuration and structure for laying pipe wherein the pipeline path extends along a port or starboard side of the vessel. The pipeline path passes through the upper deck member of the vessel and then through a supporting column member of the vessel. A cantilevered overhang or deck member extension is not required. The pipe is supported along the pipeline path by a plurality of pipeline supports for providing the pipe at the stern of the vessel with the correct inclination with respect to the water surface. The slotted column advantageously provides protection for the pipeline below the deck level with respect to lateral wave action forces and added vessel stability and/or work area efficiency.