Abstract: Embodiments of a wellhead assembly have a tubular body with a removable bottom cap to house a tubing rotator comprising a multi-enveloping worm gear assembly which provides sufficient torque to rotate tubing strings in deep and/or deviated wellbores. The bottom cap is supported on a wellhead having a dognut for supporting a production string therefrom in a wellbore. The bottom cap rotatably supports a mandrel and multi-enveloping worm wheel thereon, the mandrel being connected to the dognut and tubing string for co-rotation therewith. The tubular body supports a multi-enveloping worm for engagement with the worm wheel when the tubular body is lowered axially onto the bottom cap. When the tubular body and worm are lifted axially from the bottom cap, the worm wheel and mandrel are exposed for repair or replacement without need to pull the production string from the wellbore.

Abstract: Embodiments of a wellhead assembly have a tubular body with a removable bottom cap to house a tubing rotator comprising a multi-enveloping worm gear assembly which provides sufficient torque to rotate tubing strings in deep and/or deviated wellbores. The bottom cap is supported on a wellhead having a dognut for supporting a production string therefrom in a wellbore. The bottom cap rotatably supports a mandrel and multi-enveloping worm wheel thereon, the mandrel being connected to the dognut and tubing string for co-rotation therewith. The tubular body supports a multi-enveloping worm for engagement with the worm wheel when the tubular body is lowered axially onto the bottom cap. When the tubular body and worm are lifted axially from the bottom cap, the worm wheel and mandrel are exposed for repair or replacement without need to pull the production string from the wellbore.

Abstract: A pulling clamp is provided for releasable connection to a blunt, uphole string end of a continuous string. A main clamp body has clamp bore therethrough and having a string-receiving opening at the pulling end for receiving the string end, an actuating bore at the pulled end and a tapered bore therebetween. A taper insert having a radially compressible gripping bore is locatable in the tapered bore and axially actuable between a passive first receiving position, for receiving the string end, and the active second gripping position for radially compressing the taper insert about the string end for actively gripping the string end therein. The taper insert can be axially actuated using a threaded main body and threaded top cap for sandwiching the taper insert therebetween, the top cap being threaded axially into and out of the pulled end of the main body between the passive and active positions.