Abstract: The present invention provides a riser protection structure being suitable to be employed in a Jackup rig. The riser protection structure comprises a plurality of piles, an upper module, wherein the upper module comprises a main protection tubing for receiving a riser, a plurality of sleeves to be installed over the plurality of piles, and a connecting network; wherein the plurality of sleeves are disposed around the main protection tubing; and wherein the main protection tubing and the plurality of sleeves are connected together by the connecting network, and a lower module, wherein the lower module comprises a plurality of tubular guides for guiding and later fixing the piles and a connecting structure, wherein the plurality of piles are securely disposed into the seabed for providing the requisite support for the upper and lower modules when they are assembled.

Abstract: Pre-assembled self installing platforms with improved performance due to additional rotational restraint to supporting legs and methods of installation. The platform includes a hull, legs movable relative to the hull, at least one brace frame movably connected to at least two of the legs. Upon installation, the brace frame may be positioned at a desired elevation and rigidly secured to the legs, providing rotational restraint to significantly reduce leg stress and increase rigidity of the legs. With the increased rigidity, it becomes possible to install platforms in relatively deep waters and harsh environments, and yet preventing large overall platform sway induced by adverse weather or sea conditions. As the brace frame is securable to the legs after the legs or footings are penetrated into or supported on the sea bed, differential penetration of legs or footings into the seabed becomes possible without risking large structural loads in the brace frame.

Abstract: A leg guide for use in a leg of a jack up unit adapted to provide sliding guidance of the leg during vertical movement of the leg. The leg guide has a first portion contacting an edge of a leg chord and a second portion contacting a face of the leg chord along a longitudinal plane opposite the contact plane of the first portion. The edge contacting guide has a deflecting guide unit, which uses a compressible member sandwiched between two rigid plates. As the leg moves, the teeth of the leg chord contact the edge guide unit, with the compressible member absorbing compressible loads acting on the leg chord. The second portion provides for a face plate mounted transversely to the edge contacting guide for reducing the build-up of horizontal moment acting on the leg chord during the vertical movement of the leg and for reducing bending moments acting on the leg.

Abstract: A leg guide for use in a leg of a jack up unit adapted to provide sliding guidance of the leg during vertical movement of the leg. The leg guide has a first portion contacting an edge of a leg chord and a second portion contacting a face of the leg chord along a longitudinal plane opposite the contact plane of the first portion. The edge contacting guide has a deflecting guide unit, which uses a compressible member sandwiched between two rigid plates. As the leg moves, the teeth of the leg chord contact the edge guide unit, with the compressible member absorbing compressible loads acting on the leg chord. The second portion provides for a face plate mounted transversely to the edge contacting guide for reducing the build-up of horizontal moment acting on the leg chord during the vertical movement of the leg and for reducing bending moments acting on the leg.

Abstract: A leg guide for use in a leg of a jack up unit adapted to provide sliding guidance of the leg during vertical movement of the leg. The leg guide has a first portion contacting an edge of a leg chord and a second portion contacting a face of the leg chord along a longitudinal plane opposite the contact plane of the first portion. The edge contacting guide has a deflecting guide unit, which uses a compressible member sandwiched between two rigid plates. As the leg moves, the teeth of the leg chord contact the edge guide unit, with the compressible member absorbing compressible loads acting on the leg chord. The second portion provides for a face plate mounted transversely to the edge contacting guide for reducing the build-up of horizontal moment acting on the leg chord during the vertical movement of the leg and for reducing bending moments acting on the leg.