Imodco, Inc.

Peter Lunde

Jack Pollack

Rene Perratone

An offshore system is described, of the type that includes a turret (20) anchored to the sea floor and connected by at least an upper bearing assembly (34) to the vessel hull (14) so the hull can weathervane about the turret, wherein the upper bearing assembly is of moderate cost and high reliability, is easily maintained, and accommodates vessel hull deformation. The upper bearing assembly includes a circle of bearing devices(202) wherein each device includes a cylinder (224) and piston (226). A source (260) of pressured fluid is applied to the devices to push apart the cylinder and piston to support an upper bearing part (204) of the turret on a lower bearing part (210) of the hull.

Offshore turret with circle of bearing devices

An offshore system is described, of the type that includes a turret (20) anchored to the sea floor and connected by at least an upper bearing assembly (34) to the vessel hull (14) so the hull can weathervane about the turret, wherein the upper bearing assembly is of moderate cost and high reliability. In one construction, the upper bearing assembly includes upper and lower slider bearing rings (40, 42) that lie facewise adjacent at an interface (44), with the upper bearing ring fixed to the turret and the lower bearing ring supported on the hull through quantities of elastomeric material (102). The elastomeric material permits slight tilt of the turret upper portion without opening a gap at one side of the interface. The lower bearing ring is divided into segments (112A, 112B), and large turret tilt allows pressured lubricant to escape from only one or a few segments that begins to lift up during turret tilt. In another construction, a circle of bearing devices (202) is provided, wherein each device includes a cylinder (224) and piston (226) and a source of pressured fluid that is applied to the device.

Offshore turret upper bearing

A turret that is rotatably mounted on a vessel and connected to risers extending down to sea floor wells, is constructed so the turret is of moderate diameter to enable the use of a moderate size bearing and moderate weight turret, while providing room around the terminations of the upper ends of the risers. The risers (46A, 46G, FIG. 3 ) extend through tubes (62, 70, 72) which are oriented at an angle to the turret axis (22), so the lower ends of the tubes lie on large diameter circles to be considerably spaced apart, while the upper ends of the tubes are closer together to fit within the inside of the moderate sized bearing (60). The upper ends of the risers may be terminated at a plurality of different levels (90, 92, 94) within the turret to provide room around each termination.

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Westlake Village, CA, United States of America

Peter Lunde