Abstract: Apparatus for use in the completion and workover of a subsea well adapted for coil tubing intervention comprises a surface tree having an upper end on which a coil tubing injection unit may be mounted, a tension joint adapted to be connected to the upper end of a lower riser section extending to a subsea tree and to be suspended from a tensioning system at the surface to enable the lower riser section to be maintained in tension, an upper riser section for connection at its upper end to the surface tree and at its lower end to the tension joint, and a surface joint mounted on and surrounding the riser section in position to extend through the spider at the floor of an offshore rig.

Abstract: There is disclosed well apparatus wherein a so-called "backout sub" connected by right-hand threads at its lower end to a lower well pipe has both left-hand threads thereabout for connection with left-hand threads on the lower end of one upper tubular member to permit it to be released and raised from the lower tubular member, in response to right hand rotation of the upper tubular member, and right-hand threads for connection with right-hand threads on the lower end of another upper tubular member for use in tying the lower tubular member and thus the lower well pipe back to the head of the well in response to right-hand rotation.

Abstract: The present invention relates to an improved subsea wellhead structure which includes a conductor casing having an internal upwardly facing shoulder, and an internal groove above the shoulder, an external groove, a wellhead housing having an external downwardly facing shoulder adapted to seat on the casing shoulder, an external shoulder above the seat shoulder which tapers upwardly and outwardly at a slight angle, such as, for example, five degrees, a split latching and loading ring surrounding said housing and seated on said tapered external shoulder, a cam ring above the split ring, means for releasably retaining the cam ring in its inactive position and actuating means for moving the cam ring into position wedging the split ring outwardly on the tapered shoulder into tight load transmitting position within the internal casing groove and the tapered shoulder.