Vetco Gray Inc.

Abb Vetco Gray Incorporated

Stephen A Cromar

Ian D Calder

Garry R Stephen

Eric R Schwelm

Norman Brammer

Gavin T Reilly

A wellhead housing a supports a string of casing in tension by using a load ring. The load ring mounts to the exterior of a casing hanger which secures to the upper end of the string of casing. The load ring is split, resilient and outwardly biased. The load ring is retained during the running of the casing. The running tool then releases the load ring to spring outward to support the load. The load ring has wickers on its exterior that mate with wickers in the interior of the bore.

Casing tension retainer

A mechanism mounts to a casing hanger for supporting the casing in tension. The mechanism includes a plurality of dogs mounted around the exterior of the casing hanger. Each of the dogs has wickers on its exterior which engage wickers formed in the bore of a wellhead housing. The dogs are carried within a recess. The recess has upper and lower parallel conical shoulders. A sleeve retains the dogs in a retracted position until tension has been applied. The sleeve releases the dogs by rotational movement of the running tool which runs the casing hanger.

Casing tensioning mechanism for a casing hanger

A torque tool and mating profile allow large diameter conductor pipe to easily be retrieved from a subsea well. The profile will be located near the sea floor immediately above a left-hand threaded connector joint. The profile has a lifting shoulder and a torque key. The torque tool lowers through the conductor pipe from the drill rig on drill pipe. It has spring biased dogs that spring outward into the profile. The dogs have lifting surfaces for lifting the conductor string at the lifting shoulder at the profile. Rotating the torque tool causes it to engage the torque key to break out the connector joint.

Release apparatus and method for threaded conductor pipe

A connector for tying back a wellhead (10) to a floating platform rigidly attaches to the wellhead housing (12). It is engaged with the casing hanger (14) through a bellows (86) arrangement. Strain cycling of the connection is reduced while thermal expansion and manufacturing tolerance are readily tolerated.

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Aberdeen, United Kingdom

Stephen A Cromar