Seahorse Equipment Corporation

Abb Vetco Gray Incorporated

Single Buoy Moorings Inc.

Jeffrey Douglas Otten

Peimin Cao

Travis Randall Jordan

Thomas Prichard

David Trent

Kent B Davies

Chenteh Alan Yu

Yung-sen Chou

Michael E Capesius

Sammy R Moore

A top interface for subsea riser on offshore, floating vessel has an upper funnel and a co-axial lower funnel in spaced-apart relation. Tension loads on the riser are reacted at the upper funnel while lateral and bending loads are reacted at the lower funnel. The riser top interface may be used with flexible risers or steel catenary risers.

Steel catenary riser top interface

A top-tensioned riser system comprises a substantially vertical riser extending upward from the seafloor; a conductor surrounding an upper portion of the riser in spaced-apart relation; a coaxial keel guide surrounding a lower portion of the conductor; a tensioner attached to the conductor and the riser; a keel guide support structure attached to the keel guide and connected to the keel of a dry-tree, semi-submersible vessel; and, a keel joint centralizer attached to the riser proximate the keel guide and sized to prevent radial movement of the riser relative to the conductor. Side loads on the riser (such as those arising from displacement of the vessel from its nominal position or currents acting on the riser) are reacted from the riser to the conductor via the keel joint centralizer and then to the keel of the vessel via the keel guide.

Riser tensioner conductor for dry-tree semisubmersible

A top-tensioned riser (TTR) is supported by a tensioning system on the deck of a floating platform. The tension ring may include an elastomeric layer which permits small angular and lateral displacements of the tension joint. The tension joint comprises a tapered section to resist the bending moment and shear imposed by the vessel's motion. The riser tension joint may be supported laterally by rollers below the tension ring. The rollers react on the tapered section when the riser strokes up and down. The tapered section may be engineered to maximize the use of the tension joint, and to reduce bending moment and shear loads imposed on the tensioning system. In certain embodiments, there may be a small gap between the rollers and the tapered section. In certain other embodiments, the rollers may be spring-loaded to increase the stability of surface equipment on the upper terminus of the riser.

Top-tensioned riser system

A top tensioned riser extends substantially vertically from a platform hull to the seabottom. The riser includes length adjustment at its upper end and is detachably connected to an anchor pile at its lower end. Riser tension is monitored via load cells incorporated in the riser porch. The riser is connected to one or more import/export flowlines or pipelines.

Top tensioned riser

A riser centralizer for transferring lateral loads from the riser to a platform hull includes a keel centralizer mounted on a keel joint. The keel centralizer is received within a keel guide sleeve secured in a support mounted at the lower end of the platform hull. The keel centralizer includes a nonmetallic composite bearing ring having a radiused peripheral profile for minimizing contact stresses between the keel centralizer and the keel guide sleeve in extremes of riser and platform motion. The internal surface of the keel guide sleeve is clad with a corrosion resistant alloy and coated with a wear resistant ceramic rich coating.

Keel joint centralizer

A tensioning device is provided for applying tension to a riser from a surface deck of an offshore oil or gas well. The tensioning device is used with a riser of the type having threads formed on an exterior surface thereof. A tension ring of the tensioning device is formed from first and second ring halves that are clamped together about the riser. The first and second halves have inner threads for engaging the threads of the riser. A clearance exists between the first and second ring halves when the ring halves are clamped together about the riser to allow the first and second ring halves to be tightened against the exterior surface of the riser so that the tension ring is securely fastened to the riser. Fastening means are used for clamping the first and second ring halves together about the riser. Tensioning members that couple at one end to the tension ring and at the other end to the surface deck are used to apply tension to the riser from the surface deck.

Tension ring for riser

A centralizing device is provided for a riser of an offshore well platform having a frame that defines an opening through which the riser passes from the platform to a subsea wellhead. The centralizing device has a centralizing ring with an inner diameter greater than the outer diameter of the riser so that the riser can be passed longitudinally therethrough. The centralizing ring is positioned within the opening of the frame. Adjustable mounting means are used for mounting the centralizing ring to the frame at different positions within the opening. A roller assembly of the centralizing device is carried upon the riser as the riser is lowered through the centralizing ring. The roller assembly is configured to engage the centralizing ring as the riser is lowered through the centralizing ring so that the centralizing ring stops further carriage of the roller assembly by the riser. The roller assembly has rollers mounted thereon that bear against an exterior of the riser to limit lateral movement of the riser but that allow longitudinal movement of the riser when the roller assembly is engaged with the centralizing ring.

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Cypress, TX, United States of America

Jeffrey Douglas Otten