Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a production tree (10) with a top block (mandrel) (12) of the tree provided with a cone-shaped male connector member (14) which also functions as a manifold, and called a cone seal manifold, by having a plurality of shuttle valves (66) which, in the production mode connect umbilical hydraulic control lines (44) to valve actuator control lines (42). In the workover mode, a running tool (132) having a mating bell-shaped female connector member (134) engages the cone seal manifold (14) and moves the shuttle valves (66) to disconnect the umbilical control lines (44) from the valve actuator control lines (42) and to open the valve actuator control lines (42) to rig hydraulic control lines in the running tool (132) through the mating cone seal surfaces (134,56). Normally closed passageways (112) in the cone (56) of the cone seal manifold (14) are opened by fluid pressure from the rig control lines.