Patent ID: 6129149
Filing Date: 2000-10-10
Classification: E21B

Abstract:
A connector device for connecting a wellhead christmas tree assembly to a wellhead, said device comprising:a cylindrical body member having a circular transverse cross section and an internal bore with a diameter conforming to the external diameter of the wellhead such that said body member can be sleeved about the wellhead,said cylindrical body member having a plurality of circular lateral openings extending transversely from the external surface of the cylindrical body member to the interior thereof, said openings being in equiangular spacing about the central axis of the cylindrical body member;a locking sleeve having an annular cross section and an inner surface comprising a first surface portion of circular cylinder configuration extending from one end of the locking sleeve and having an internal diameter conforming to the external diameter of said cylindrical body member such that said locking sleeve can be sleeved about said body member, a second inner surface portion of circular cylinder configuration extending from the other end of the locking sleeve and having a greater diameter than said first inner surface portion, and an inwardly facing frusto-conical camming surface of a tapered configuration extending and tapering outwardly from the first inner surface portion towards the second inner surface portion of said locking sleeve;a plurality of locking dogs equal in number to the circular lateral openings in said body member, each said locking dog having a transverse cross section sized and configured to conform to the shape of said circular lateral openings whereby each said locking dog can be inserted into a different one of said circular lateral openings, each said locking dog having an inner front face, a side wall and an outer rear face with the inner face having a plurality of projecting teeth providing a toothed surface conforming in configuration to the external surface of the wellhead and said outer face of the locking dog having an outward facing tapered surface which conforms to inwardly facing frusto-conical camming surface of the locking sleeve and is adapted to cooperably engageable therewith when the locking dog is inserted into one of said circular lateral openings with its inner toothed surface disposed to engage the external surface of the wellhead, and each said locking dog having in its side surface an arcuate shaped groove which provides an inward facing tapered camming surface which faces inwardly and is divergent outwardly;piston means provided on said connector device for driving said locking sleeve in a selected axial direction comprising at least one piston and cylinder assembly having a piston and piston rod wherein the piston rod is fixed to the locking sleeve in parallel relation to the cylindrical axis of the locking sleeve and is movable in a vertically axial direction whereby when the piston means is actuated to drive the locking sleeve in a first axial direction, the camming surface of the locking sleeve engages the outer camming surfaces of the plurality of locking dogs to drive the locking dogs inwardly into locking engagement with the external surface of the wellhead;an unlocking sleeve disposed in sleeved relationship about the lower external surface of the connector body member and fastened to the bottom end of the locking sleeve in coaxial relation therewith, said unlocking sleeve having an outwardly facing external camming surface portion of frusto-conical configuration convergent in the upward direction and adapted to cooperably engage with the inward facing camming surfaces of the plurality of locking dogs when said piston means is operated to drive the locking sleeve and unlocking sleeve in the axial direction to reverse to said first axial direction to thereby force the locking dogs outwardly from the wellhead and thereby unlock the connector from the wellhead; andmeans for fixedly securing a wellhead christmas tree assembly to the upper end of said cylindrical body.