Rotating lock ring bottom tendon connector

A subsea connector assembly for anchoring a buoyant structure, comprising:

• a receptacle for securing to a piling embedded in a sea floor, the receptacle having an axial bore defined by an inner wall surface;
• a plurality of receptacle segments spaced circumferentially around the inner wall surface of the receptacle, each of the receptacle segments being separated from adjacent ones of the receptacle segments by axially extending receptacle slots, each of the receptacle segments having an inward-facing locking profile;
• a shaft for connection to the buoyant structure;
• a housing carried by the shaft, the housing having a cylindrical outer surface that inserts the bore;
• a flex joint assembly joining the shaft to the housing to enable the shaft to incline relative to the housing;
• the housing and the receptacle having mating anti-rotation elements to prevent rotation of the housing relative to the receptacle;
• a lock ring mounted to the outer surface of the housing, the lock ring having a plurality of lock ring segments spaced circumferentially around the lock ring, each of the lock ring segments of the lock ring being separated from adjacent ones of the lock ring segments by axially extending lock ring slots, each of the lock ring segments having an outward-facing locking profile;
• and
• the lock ring having an installation position wherein the lock ring segments are axially aligned with the receptacle slots to enable the housing to be inserted into the receptacle, the lock ring being rotatable relative to the housing from the installation position to a locked position wherein the lock ring segments slide into mating engagement with the receptacle segments.

A subsea connector assembly for anchoring a buoyant structure, comprising:

• a receptacle adapted to be secured to a piling embedded in a sea floor, the receptacle having an axial bore and an open upper end;
• a shaft for connection to a lower end of the buoyant structure;
• an inner body having a passage into which a lower portion of the shaft slidingly extends;
• a housing surrounding the shaft;
• a flex joint assembly joining the inner body to the housing to enable the shaft and the inner body to incline relative to the housing;
• a lock member carried by the housing for locking the housing in the axial bore of the receptacle;
• a flange on the lower portion of the shaft that is located below the inner body to provide a limit for upward movement of the shaft relative to the inner body when tension is applied to the shaft;
• and
• a downward facing shoulder on the shaft above the inner body to provide a limit for downward movement of the shaft relative to the inner body, the axial distance between the flange and the downward facing shoulder being greater than an axial length of the passage in the inner body so as to allow the shaft to move downward relative to the inner body and the receptacle in the event tension on the shaft ceases.

A connector assembly, comprising:

• an outer member having a bore containing an annular locking profile divided into segments by a plurality of axially extending slots;
• an inner member that inserts into the outer member;
• a lock ring carried by the inner member and having an outer surface with an annular locking profile divided into segments by a plurality of axially extending slots;
• the lock ring having an unlocked position wherein the segments of the lock ring axially align with the slots of the outer member to enable the inner member to be inserted into the outer member, the lock ring being rotatable from the unlocked position to a locked position wherein the segments of the lock ring engage the segments of the outer member;
• a split ring mounted around the inner member and having a natural outer diameter that is greater than an inner diameter of the outer member at the segments of the outer member, causing the split ring to contract when the split ring contacts the segments of the outer member;
• the natural outer diameter of the split ring being no greater than an inner diameter of the outer member immediately past the segments of the outer member, causing the split ring to expand when moving past the segments of the outer member;
• and
• one end of the split ring being attached to the inner member and the other to the lock ring, so that the contraction of the split ring causes an increment of rotation of the lock ring to the unlocked position, and the expansion of the split ring causes an increment of rotation of the lock ring to the locked position.

A method of connecting a subsea shaft of a buoyant structure to a receptacle secured to a sea floor, the receptacle having a bore, the shaft being connected by a flex joint to a connector housing that inserts into the bore, the method comprising:

• (a) providing an annular locking profile in the bore of the receptacle, the annular locking profile being divided into segments by a plurality of axially extending slots;
• (b) providing a lock ring with an outer surface having an annular locking profile divided into segments by a plurality of axially extending slots, and mounting the lock ring on the housing;
• (c) aligning the segments of the lock ring with the slots of the housing and inserting the housing into the bore of the receptacle;
• then
• (d) rotating the lock ring relative to the housing and the receptacle to a locking position with the segments of the lock ring engaging the segments of the receptacle.