Marine riser
OwnerVincent Alliotinventor
Life of this patent
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Abstract
The invention relates to a production riser system wherein the riser (1), at the touchdown point (5), has a bottom flexjoint (8) so that the dynamic motion of the riser (1) is absorbed by angular excursion (9) of the flexjoint (8) and not by the interaction of the sag bend (10) with the seabed (6). The surface end of the riser may be fixed, or coupled by a second flexjoint to a production and storage vessel.
Claims16
A riser system comprising a continuous metallic riser conduit (1) extending substantially from seabed to surface, to connect a surface installation (3) to a seabed installation wherein, where the riser reaches the seabed (6), there is incorporated at least a joint which allows relative angular rotation between the riser conduit and conduit supported by the seabed, so as to fix the point at which the riser reaches the seabed during expected excursions of the surface support position.
A riser system as claimed in any preceding claim, wherein said surface support is controlled so as to maintain a minimum horizontal displacement from the relative to the touchdown point.
A riser system as claimed in any preceding claim, wherein the surface support comprises a dynamically positioned vessel.
A riser system as claimed in any preceding claim, wherein the surface support comprises a moored vessel.
A riser system as claimed in any preceding claim, wherein said first joint provides at least two angular degrees of freedom.
A method of controlling the touchdown point of a substantially continuous catenary riser conduit, wherein a joint is incorporated which allows relative angular rotation between the riser and a conduit supported on the seabed.
Dependencies are inferred from the claim text.