Waved steel production riser, offshore hydrocarbon production system, and method of producing a hydrocarbon stream

摘要

A waved steel production riser (100), which in addition to a primary buoyancy section (103) wherein the waved steel production riser is provided with a first set of external buoyancy modules (130) and an upward buoyancy force in the body of water is greater than a downward gravity force, further comprises an auxiliary buoyancy section (106) in the hanging section (102) in which the waved steel production riser is provided with a second set of external buoyancy modules and wherein the upward buoyancy force in the body of water is smaller than the downward gravity force. The sag point (125) is located within the auxiliary buoyancy section. The waved steel production riser may be used in a method for producing a hydrocarbon stream, whereby mineral hydrocarbon fluids produced from a subsea hydrocarbon reservoir are conveyed to a floating structure via the waved steel production riser.