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 riser tensioner for an offshore floating platform has a frame stationarily mounted to the upper portion of the riser. Pistons and cylinders are spaced circumferentially around the riser and connected between the frame and the floating platform. A tubular guide member is mounted to the floating platform for movement in unison in response to waves and currents. The riser extends through the guide member. A guide roller support is mounted to and extends downward from the frame around the guide member. At least one set of guide rollers is mounted to the guide roller support in rolling engagement with the guide member as the guide member moves in unison with the platform.
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 self-inserting seal assembly that sets a seal at a well component to allow for pressure testing of the well component. The seal assembly can be landed on a well component with an ROV. A seal is located on the lower portion of a lower body in the assembly. A set of outer dogs lock with a grooved mating profile formed on the well component to lock the outer housing to provide a reaction point for setting the seal, which may require several thousand pounds of force. A set of inner dogs lock with a grooved mating profile formed on the inner diameter of the outer housing. This locks the lower body to the outer housing to ensure the seal remains set in place. After the well component is pressure tested, the seal assembly can be unlocked and retrieved from the well via an ROV.
Abstract:
A connector for connecting sections of drilling riser pipe wherein a first riser contains a pin assembly with an external first grooved profile and a second riser contains a housing assembly. An internal split pivoting latch segment assembly carried by the housing assembly contains a second grooved profile adapted to mate to the first grooved profile and a split actuation ring movably carried by the housing assembly forces the second grooved profile of the latch segment assembly into engagement with the first grooved profile of the pin assembly. A plurality of retraction links engage an upper edge of the latch segment assembly to disengage the second grooved profile of the latch segment assembly from the first grooved profile of the pin assembly if the risers are to be disconnected.
Abstract:
A riser connector uses a box and upset pin connector threadform design having S-shaped load flanks that provide a variable load angles depending on the radial position along the engaged teeth. This design promotes a load path that changes with position along the axial length of the engaged thread, as well as increasing or decreasing external loads on the connector. The connector also varies radial distention of the pin from the box in a manner that is different from one thread to the next. The threadform uses a combination of thread cuts that vary in shape, pitch, and/or thread cone angle to provide load and stab flanks, as well as a load path, that vary from one axial end of the engaged thread to the other.
Abstract:
A connector for tying back a riser from a subsea wellhead to a platform, wherein the wellhead has an internal wellhead housing with external grooves thereon. The connector having a plurality of dog members carried within a cavity which engage the external grooves. The dog members are actuated by axial movement of a piston linked to a cam ring. The connector has a plurality of transfer members located within the cavity to support the dog members and transfer upward loading to the wellhead housing during tension on one side due to bending. Further, the connector has a release ring which forces the dog members out of engagement with the external grooves when the connector is released.
Abstract:
A connector for tying back a riser from a subsea wellhead to a platform, wherein the wellhead has an internal wellhead housing with external grooves thereon. The connector having a plurality of dog members carried within a cavity which engage the external grooves. The dog members are actuated by axial movement of a piston linked to a cam ring. The connector has a plurality of transfer members located within the cavity to support the dog members and transfer upward loading to the wellhead housing during tension on one side due to bending. Further, the connector has a release ring which forces the dog members out of engagement with the external grooves when the connector is released.
Abstract:
A bottom connector for the tendon of a tension leg platform uses a latch ring with an outer profile to engage a mating profile in a receptacle on the sea floor. The latch ring moves radially within a housing, relative to the receptacle, between an engaged position and a retracted position. The latch ring engages the receptacle by lowering the connector into the receptacle below the mating profile and then lifting it until the latch ring locks into the receptacle. The latch ring disengages the receptacle by lowering the connector beyond a recess located below the mating profile and then lifting the connector out of the receptacle. As the connector is lifted above the recess, a retaining ring is actuated by the recess to retain the latch ring in its retracted position.
Abstract:
A subsea wellhead system is used in areas which have shallow water producing sands. A first string of casing extends from the sea floor through a section of conductor pipe and below the conductor pipe to a point above the water sand. An external wellhead housing having flow ports is supported at the upper end of the conductor pipe. A valve sleeve is located on the exterior of the external wellhead housing. The valve sleeve is movable to a closed position, closing the flow ports. A second string of casing is installed to a point below the water producing formation. An internal wellhead housing is secured to the upper end of the second string of casing, which lands within the external wellhead housing. During cementing of the second string of casing the flow ports are open. After cementing, the valve sleeve is moved to the closed position.