Abstract: A stuffing box for sealing the end of a rotatable rod is disclosed. The stuffing box includes a sleeve adapted to concentrically receive a portion of the rod therethrough and a tubular pipe concentrically arranged within the sleeve, the rod passing generally concentrically through the pipe, the pipe being in annular spaced relation to the sleeve and the rod. One or more ring seals are arranged between the pipe and the sleeve to prevent the flow of well fluids into the annulus between the sleeve and the pipe. An annular fluid chamber is defined between the sleeve and the pipe below the ring seals. During normal operation, the fluid chamber is pressurized to apply a pressure to the one or more ring seals. One or more uni-directional seals are arranged below the fluid chamber and configured to permit fluid flow into the fluid chamber.

Abstract: A rod lock out clamp includes a housing having a central bore for receiving a rod in spaced relation therethrough and clamp members in the housing for grippingly and frictionally engaging the rod in the bore. At least one of the clamp members has an inner end and a recess in the inner end, the recess having a profile with an arcuate portion having a radius of curvature that reduces from a maximum radius to a minimum radius. Manipulating means are coupled to the housing and the clamp members for moving the clamp members between a rod gripping position and a retracted position.

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 pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for the stuffing box. To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only in the backspin direction and a gear drive between the input shaft and output shaft are provided.

Abstract: A pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for the stuffing box. To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only in the backspin direction and a gear drive between the input shaft and output shaft are provided.

Abstract: A pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for the stuffing box. To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only in the backspin direction and a gear drive between the input shaft and output shaft are provided.

Abstract: Embodiments of a safety guard, fit concentrically over a rotating member, such as a rod assembly, which extends outwardly from apparatus, such as a drive head. The guard may be restrained during normal operation for preventing entanglement of personnel or other apparatus with the rod assembly which continues to rotate within the tubular guard, or may be unrestrained during normal operation. When unrestrained, the guard is free to co-rotate with the rod assembly, but has a low moment of inertia such that the guard decelerates rapidly when restrained so as to prevent entanglement. An anti-friction interface between the guard and the rod assembly is formed by the material of manufacture of the guard itself or by bearings or bushings supported in an annulus between the guard and the rod assembly.

Abstract: A cam assisted centrifugal brake or clutch system provides increased mechanical advantage to improve the output torque relative to prior art devices such as leading brake shoes. The brake or clutch engagement is cammed radially outwardly to engage a brake housing in one direction and guided to a disengaged position in the other direction. Centrifugal forces retain the brake in the disengaged position. Embodiments of the present invention are applied as a backspin braking system that is incorporated into a drive head for a progressing cavity pump drive system.

Abstract: A pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for the stuffing box. To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only in the backspin direction and a gear drive between the input shaft and output shaft are provided.

Abstract: Embodiments of a safety guard, fit concentrically over a rotating member, such as a rod assembly, which extends outwardly from apparatus, such as a drive head. The guard may be restrained during normal operation for preventing entanglement of personnel or other apparatus with the rod assembly which continues to rotate within the tubular guard, or may be unrestrained during normal operation. When unrestrained, the guard is free to co-rotate with the rod assembly, but has a low moment of inertia such that the guard decelerates rapidly when restrained so as to prevent entanglement. An anti-friction interface between the guard and the rod assembly is formed by the material of manufacture of the guard itself or by bearings or bushings supported in an annulus between the guard and the rod assembly.

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.

Abstract: In a downhole rod-driven pump, continuous rod is used to drive the pump. The continuous rod is connected directly to the drive eliminating the need for a polish rod and an uphole coupling. A coupling is used to connect the continuous rod to the pump reducing restrictions in the production annulus and wear on the production tubing. Further, clean out tubing can be inserted into the production tubing beside the continuous rod and can extend therein to the pump without restriction. When the coupling is a threaded coupling, the continuous rod can be rotated in an appropriate direction to release the continuous rod from the pump when the pump is stuck. When the coupling is a shear coupling, the shear coupling can be sheared for releasing the pump from the continuous rod. When the pump is a progressing cavity pump and the coupling is a shear coupling, the continuous rod can be reverse rotated for changing the direction of pumping and if the rotor thereafter remains stuck, the shear coupling can be sheared.

Abstract: A cam assisted centrifugal brake or clutch system provides increased mechanical advantage to improve the output torque relative to prior art devices such as leading brake shoes. The brake or clutch engagement is cammed radially outwardly to engage a brake housing in one direction and guided to a disengaged position in the other direction. Centrifugal forces retain the brake in the disengaged position. Embodiments of the present invention are applied as a backspin braking system that is incorporated into a drive head for a progressing cavity pump drive system.

Abstract: Progressive cavity (PC) pump drive heads require a stuffing box to seal crude oil from leaking onto the ground where the polish rod passes from the crude oil passage in the wellhead to the drive head. Because crude oil typically contains fine sand particles, alignment between the stuffing box and the polished rod is imperfect, and PC drive heads run continuously, it is very difficult make stuffing boxes that last as long as desirable by oil production companies. By using a flexibly mounted standpipe in various configurations, around which is a bearing supported shaft carrying the sealing means, long term durability of the stuffing box can be achieved. By using a pressurization system such that the pressure output exceeds the pressure at the wellhead, stuffing box seal life can be extended and external leakage from the stuffing box can be eliminated. A double wall standpipe may be provided in some applications as part of the pressurization system.

Abstract: A pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for the stuffing box. To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only in the backspin direction and a gear drive between the input shaft and output shaft are provided.

Abstract: Progressive cavity (PC) pump drive heads require a stuffing box to seal crude oil from leaking onto the ground where the polish rod passes from the crude oil passage in the wellhead to the drive head. Because crude oil typically contains fine sand particles, alignment between the stuffing box and the polished rod is imperfect, and PC drive heads run continuously, it is very difficult make stuffing boxes that last as long as desirable by oil production companies. By using a flexibly mounted standpipe in various configurations, around which is a bearing supported shaft carrying the sealing means, long term durability of the stuffing box can be achieved. By using a pressurization system such that the pressure output exceeds the pressure at the wellhead, stuffing box seal life can be extended and external leakage from the stuffing box can be eliminated. A double wall standpipe may be provided in some applications as part of the pressurization system.

Abstract: A pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for the stuffing box. To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only in the backspin direction and a gear drive between the input shaft and output shaft are provided.

Abstract: A pump drive head for a progressing cavity pump comprises a top mounted stuffing box rotatably disposed around a compliantly mounted standpipe with a self or manually adjusting pressurization system for said stuffing box, To prevent rotary and vertical motion of the polish rod while servicing the stuffing box, a polished rod lock-out clamp is provided with the pump drive head integral with or adjacent to a blow-out-preventer which can be integrated with the pump drive head to save space and cost. A centrifugal backspin braking system located on the input shaft and actuated only In the backspin direction and a gear drive between the input shaft and output shaft are provided.