Abstract:
An offshore composite enhanced metallic drilling riser is equipped to enable preloading of the composite shell and the metallic riser. A riser has steel end connectors and a continuous metallic inner liner, encased in a composite shell. A segmented hyperboloid shaped profile is located near each of the end fittings for preloading of the composite and the metallic riser. In one version, both halves of the hyperboloid shape are capable of axial movement by adjusting jack bolts connected to one of the hyperboloid halves. One of the halves is limited in axial movement while the other half moves axially away from the restricted half, 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 to push them apart.
Abstract:
A pipe is wrapped with a composite to form a pre-stressed interface to facilitate load sharing between the materials. Prior to being wrapped, the pipe is placed in tension via hydraulic devices or the like. Alternatively, a combination of cured and uncured composite wraps is used in proximity to each other to apply compressive stress to the pipe. In addition, the pipe may be subjected to cold temperatures to change its dimensions prior to being wrapped with a composite material.
Abstract:
A surface assembly that communicates with subsea structures and includes a working deck on a floating structure. The working deck has an aperture extending axially therethrough. A riser extends from a subsea location to the working deck and through the aperture. The surface assembly includes a frame extending circumferentially around the riser so that the frame moves axially with the riser. The assembly also includes a tensioner assembly connected between the working deck and the frame. The tensioner assembly includes a piston slidably carried in a piston chamber, a piston rod extending from the piston and away from the piston chamber, and a shroud enclosing the piston rod. The shroud has a plurality of segments with at least one of the shroud segments being movable in unison with the piston rod.
Abstract:
An offshore composite enhanced metallic drilling riser is equipped to enable preloading of the composite shell and the metallic riser. A riser has steel end connectors and a continuous metallic inner liner, encased in a composite shell. A segmented hyperboloid shaped profile is located near each of the end fittings for preloading of the composite and the metallic riser. In one version, both halves of the hyperboloid shape are capable of axial movement by adjusting jack bolts connected to one of the hyperboloid halves. One of the halves is limited in axial movement while the other half moves axially away from the restricted half, 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 to push them apart.
Abstract:
A tieback connector connects a tieback conduit from an offshore platform to a subsea wellhead assembly. The tieback connector has a mandrel that is connected to a string of tieback conduit and a sleeve and load ring that are carried by the mandrel. The load ring is radially expansible and has a conical portion with internal threads. The load ring has an external grooved profile that engages an internal grooved profile in the subsea assembly. The mandrel is rotatable relative to the sleeve while in its lower position, causing the load ring to further expand outward into engagement with the internal profile. A locking member is carried below the load ring on an exterior cam surface of the mandrel. The cam surface moves the locking member outward when the mandrel moves downward into engagement with an internal profile in the subsea assembly.
Abstract:
A tensioner anti-rotation device and method that transfers rotational force from an offshore platform deck to a riser in response to waves and currents. The device includes a bracket mounted on the deck, and a rib that transfers force from the deck through the bracket, to the rib, and into the riser such that the tensioners on the riser are not subjected to torque.
Abstract:
A tendon bottom connector assembly has a receptacle with a bore having an annular locking profile divided into segments by axially extending slots. The connector has a housing that inserts into and locks in the receptacle. The housing and receptacle have mating an anti-rotation elements. The lock ring has an outer surface with an annular locking profile divided into segments by axially extending slots. The lock ring is carried by the housing initially in the installation position with its segments aligned with the slots of the receptacle. This position allows the housing to be fully inserted into the receptacle. An ROV then rotates the ring from the installation position to a locked position, with the segments of the lock ring engaging the segments of the receptacle. Alternately, a split ring with one end fixed rotates the lock ring.
Abstract:
A pipe is wrapped with a composite to form a pre-stressed interface to facilitate load sharing between the materials. Prior to being wrapped, the pipe is placed in tension via hydraulic devices or the like. Alternatively, a combination of cured and uncured composite wraps is used in proximity to each other to apply compressive stress to the pipe. In addition, the pipe may be subjected to cold temperatures to change its dimensions prior to being wrapped with a composite material.
Abstract:
A subsea production system and method includes a wellhead field having multiple wellheads and utilizes a stackable guide funnel system for sequential tying back of those wellheads. A storage frame retains several guide funnels that are nestably stacked one upon the other. The frame is made up of a plurality of guide members that are secured to the exposed tubular conductor of a wellhead. A pair of annular rings surrounds portions of each of the guide members. A riser having a riser connector is lowered to the central location. The riser connector latches onto the uppermost guide funnel within the frame. The riser, together with the affixed funnel, is then lifted upwardly, removing the affixed funnel from the frame. The riser is then moved laterally through the sea until the funnel and riser are proximate a second wellhead within the wellhead field.