Abstract: Systems for lifting drilling risers that serve as thrust collars to retain buoyancy modules on the risers and also enable the risers to be lifted using lifting lugs that are attached to the thrust collars. In one embodiment, a lifting device uses two annular ribs at the edges of a cylindrical collar, wherein the ribs have substantially constant height, but varying thickness. The thickness of each rib is greater at the position of the lifting lug, and may also be greater at its base than that its top or outermost edge. The collar may be segmented, where the segments are bolted together to assemble the device around the riser. The segments may be pre-stressed to reduce stresses during lifting. The device may include an elastomeric layer on its inner surface.

Abstract: Lifting devices for use with drilling risers, where the lifting devices have a plurality of segments, some of which are hinged to facilitate handling and provide multiple shear points between the hinged segments. One embodiment comprises a lifting device for a drilling riser, where the device includes a collar and a lifting lug. The collar has a cylindrical ring with one or more annular ribs connected to corresponding circular edges of the ring. The lifting lug is connected to the collar and the ribs. The collar has a plurality of segments, and at least a first one of the segments is pivotally connected to another one of the segments by a hinge. Each rib may taper smoothly from a smaller thickness at a top edge of the rib to a greater thickness at a base of the rib.