Abstract: The present invention provides a system and method that keeps a barge and grillage system on the barge in compression with a topsides supported by the grillage system during the transport, while providing a quick release system between the barge, grillage system, and topsides during an installation procedure that transfers the topsides to an offshore platform. The quick release system can be in tension to apply a compressive force between the grillage system and the topsides until the quick release system is released.

Abstract: A spar hull for a floating vessel can include a hard tank having a belly portion, a fixed strake coupled to the outer surface of the tank and a folding strake coupled to the belly portion of the tank, the folding strake having one or more strake panels and one or more support frames. A method for installing folding belly strakes on a spar hull may include providing a floating spar hull having a hard tank with a belly side, rotating the spar so that the belly side is in a first workable position, coupling at least one folding strake to the belly side of the spar, and coupling the strake in a folded position for transport. The method may include positioning the spar hull offshore in a transport position, upending the spar hull, unfolding the strake, fixing the strake in the unfolded position and installing the spar hull.

Abstract: The disclosure provides a system and method for locking and unlocking an extendable column to a deck. A deck-to-column connection assembly includes a pawl and shim used in a sequential de-ballasting and ballasting of the column to the deck that can easily lock and unlock the column with the deck. Generally, the locking method includes ballasting the column to insert a pawl between the column and the deck, de-ballasting the column to raise the column relative to the deck and create a vertical gap between the column and the deck, inserting a shim to fill the gap and secure the pawl in a deployed position, and further de-ballasting the column to raise the deck connected to the column. Generally, the unlocking method lowering the deck to float on water, de-ballasting the column to remove compressive stress on the shim, removing the shim, ballasting the column, and retracting the pawl.

Abstract: The present disclosure provides an improved design for a multi-sectional truss spar hull platform having a truss and a spar hull. One or more sections can be transported to a designated location and off-loaded into water from an available transport vessel. The truss includes a skirt tank at the upper end of truss that can be coupled to the lower end of the hull. The skirt tank can provide buoyancy during float-off and mating operations to the hull. The skirt tank is designed to allow the portion above the water to be coupled to the hull in a first orientation, the truss with the skirt tank rotated with the hull in the water to a second orientation to expose the previously underwater portion, and then the previously underwater portion can be coupled together above the water. The integral skirt tank will be flooded after the spar hull is up-ended.

Abstract: The disclosure provides a tension leg platform (“TLP”) with a plurality of buoyant pontoons suitable for highly disturbed seas that can expand the stability of the tension leg platform by extending at least one buoyant pontoon beyond an intersection of two pontoons. In at least one embodiment, the location of the column can be decoupled from the customary end of the pontoon. The tendons can be located at the ends of the pontoons extending beyond the intersection. In some embodiments, such as four-column TLPs, the pontoons can be extended orthogonally relative to an adjacent pontoon. The extending pontoon increases a buoyancy of the pontoon, increases a pitch stability of the TLP, and increases quayside stability. The extended pontoon can be structurally intersected with the adjacent pontoon to strengthen the extended pontoon and reduce the failure mode of such structure.

Abstract: The present disclosure provides an improved design for a pull tube sleeved stress joint and associated pull tube for managing stresses on a catenary riser for a floating offshore structure. The pull tube sleeve stress joint includes at least one sleeve surrounding a length of the pull tube with an annular gap between the sleeve and pull tube and a link ring therebetween. For embodiments having a plurality of sleeves, a first sleeve can be spaced by an annular first gap from the pull tube and coupled thereto with a first ring between the pull tube and the first sleeve, and a second sleeve can be spaced by an annular second gap from the first sleeve and coupled thereto with a second ring between the first sleeve and the second sleeve. Both pull tube and sleeves can be made with regular pipe segments welded together with regular girth welds.

Abstract: The present invention provides an improved method and system for load-out of a topsides onto at least two float-over barges without requiring an intermediate transportation barge. The topsides and float-over barges create a catamaran system that can be used to install the topsides to an offshore structure, such as a Spar hull, using a float-over method. The load-out process offers several advantages and can be less time-consuming and less expensive than a typical procedure using the intermediate transportation barge.

Abstract: The present invention reduces loads and saves steel on topsides and grillage of a catamaran system by creating a counteracting moment to offset a sagging bending moment of its self-weight on the topsides during transportation. The present invention can reduce the span of the supports on the topsides on the catamaran float-over barges and move the reaction forces toward inner edges of the float-over barges. The counteracting moment can cause a reduction of stress on the topsides' and grillage's members caused during the topside offloading and transportation. The stress reduction can result in the members withstanding the additional dynamic load caused by a catamaran system without increasing member sizes adequate for an offloading operation. The reduction results in a significant savings, given the size of a typical topsides for a Spar hull.

Abstract: The present invention reduces loads and saves steel on topsides and grillage of a catamaran system by creating a lifting force from a barge to the topsides to offset a sagging bending moment of the self-weight on the topsides during transportation. The present invention can reduce the span of the supports on the topsides on the catamaran float-over barges and move the reaction forces toward inner edges of the float-over barges. The lifting force can cause a reduction of stress on the topsides' and grillage's members caused during the topside offloading and transportation. The stress reduction can result in the members withstanding the additional dynamic load caused by a catamaran system without increasing member sizes adequate for an offloading operation. The reduction results in a significant savings, given the size of a typical topsides for a Spar hull or other offshore structure.