Patent ID: 7217067
Filing Date: 2007-05-15
Classification: E21B

Abstract:
1. In a floating offshore structure having a top-tensioned riser arrangement, a compliant riser keel joint assembly, comprising: a. an outer sleeve positioned inside two keel guides in the hull structure; b. an internal riser joint positioned in said sleeve and having a flange attached at the lower end; c. a centralizer mounted inside said outer sleeve adjacent the upper end and sized to receive said internal riser joint; d. a single, tapered riser joint positioned below said internal riser joint; and e. means for connecting the lower end of said internal riser joint to the upper end of said single-tapered riser joint, comprising i. said internal riser joint having a threaded lower end; ii. a flange attached to the upper end of said tapered riser joint; and iii. a machined ring attached to said sleeve, said ring having a threaded bore sized to threadably receive the internal riser joint and providing the attachment point for the flange on the tapered riser joint.