Abstract: A tank is secured under the keel of a floating structure for offshore energy development. The tank is filled with ballast material that supplements or replaces the ballast already present on the floating structure, thereby gaining larger topsides payload capacity for the floating structure or increasing stability and motion performance of the floating structure.

Abstract: A subsea removable flex joint laydown tool is described herein. The tool can include a body having a first portion and a second portion hingedly coupled to the first portion. The tool can also include a flex joint coupling feature disposed on an inner surface of the first portion and the second portion toward a proximal end of the body, where the flex joint coupling feature is configured to couple with a first laydown tool coupling feature of a flex joint. The tool can further include a riser coupling feature disposed on the inner surface of the first portion and the second portion toward a distal end of the body, where the riser coupling feature is configured to couple with a second laydown tool coupling feature of a riser. The tool can also include at least one laydown tool coupling feature movably coupled to the first portion.

Abstract: A subsea removable flex joint laydown tool is described herein. The tool can include a body having a first portion and a second portion hingedly coupled to the first portion. The tool can also include a flex joint coupling feature disposed on an inner surface of the first portion and the second portion toward a proximal end of the body, where the flex joint coupling feature is configured to couple with a first laydown tool coupling feature of a flex joint. The tool can further include a riser coupling feature disposed on the inner surface of the first portion and the second portion toward a distal end of the body, where the riser coupling feature is configured to couple with a second laydown tool coupling feature of a riser. The tool can also include at least one laydown tool coupling feature movably coupled to the first portion.

Abstract: A method of mating of a buoyant hull with a truss structure while at the installation site of the completed offshore structure. The buoyant hull is moored in place. The truss structure is placed in the water, self upends, and maneuvered near the buoyant hull. The buoyant hull and truss structure are rigged with lines to allow the truss structure to be pulled into engagement with the buoyant hull. The truss structure is lowered to a predetermined depth below the water surface but above the sea floor and the weight is transferred to the lines from the buoyant hull. The truss structure is aligned with the buoyant hull and lines from the buoyant hull are used to pull the truss structure into engagement with the buoyant hull. The truss structure and buoyant hull are rigidly attached together as is customary using grouting and welding.

Abstract: A method of mating of a buoyant hull with a truss structure while at the installation site of the completed offshore structure. The buoyant hull is moored in place. The truss structure is placed in the water, self upends, and maneuvered near the buoyant hull. The buoyant hull and truss structure are rigged with lines to allow the truss structure to be pulled into engagement with the buoyant hull. The truss structure is lowered to a predetermined depth below the water surface but above the sea floor and the weight is transferred to the lines from the buoyant hull. The truss structure is aligned with the buoyant hull and lines from the buoyant hull are used to pull the truss structure into engagement with the buoyant hull. The truss structure and buoyant hull are rigidly attached together as is customary using grouting and welding.

Abstract: A mechanically releasable shackle pin arrangement that is readily operated by an ROV and is not affected by the hydrostatic pressures encountered at depth. A shackle body having two ends has a shackle pin received through bores at one end of the shackle body. A shackle nut threaded on the shackle pin secures the shackle pin in an installed position through the bores in the shackle body. An anti-rotation link plate is attached to the shackle body. The anti-rotation link plate extends to one end of the side plate. The shackle pin extends through bores at one end of the shackle body and the anti-rotation link plate and is secured in its installed position by a shackle nut threaded on the shackle pin. Means for preventing rotation of the shackle nut and loss of the shackle nut is provided on the anti-rotation link plate such that the shackle pin can be removed by a remotely operated tool on an ROV at depth to release a load without the need for hydraulics on the shackle assembly.