Composite enhanced metallic drilling riser system

摘要

An offshore composite enhanced metallic drilling riser (20) is equipped to enable preloading of the composite shell (37) and the metallic riser (21). A riser (20) has steel end connectors (22) and a continuous metallic inner liner (21), encased in a composite shell (37). A segmented hyperboloid shaped profile (26, 27) is located near each of the end fittings (22) for preloading of the composite (37) and the metallic riser (21). In one version, both halves of the hyperboloid shape (26, 27) are capable of axial movement by adjusting jack bolts (33) connected to one of the hyperboloid halves (27). One of the halves (26) is limited in axial movement while the other half (27) moves axially away from the restricted half (26), the movement simultaneously generates the composite pre-load and the metallic riser pre-load. The other version uses fluid pressure between mating faces of the segments (47, 49) to push them apart.