Pump drive head with stuffing box

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.

1 . A drive head assembly for use to fluid sealingly rotate a rod extending down a well, comprising:
 a rotatable sleeve adapted to concentrically receive a portion of said rod therethrough;   means for drivingly connecting said sleeve to the rod; and   a prime mover drivingly connected to said sleeve for rotation thereof.   
     
     
         2 - 33 . (canceled) 
     
     
         34 . In a stuffing box for sealing the end of a rotatable rod extending from a well bore, the improvement comprising:
 a first fluid passageway disposed concentrically around at least a portion of the rod passing through the stuffing box;   a second fluid passageway disposed concentrically Inside said first passageway, said second passageway being in fluid communication with wellhead pressure during normal operations;   said first and second passageways being in fluid communication with one another and having seal means disposed therebetween to permit the maintenance of a pressure differential between them; and   means to pressurize fluid in said first passageway to a pressure in excess of wellhead pressure to prevent the leakage of well fluids through said stuffing box.   
     
     
         35 - 40 . (canceled) 
     
     
         41 . A drive head for use with a progressing cavity pump in an oil well, comprising:
 a drive head housing; a drive shaft rotatably mounted in said housing for connection to a drive motor;   an annular tubular sleeve rotatably mounted in said housing and drivingly connected to said drive shaft;   a tubular standpipe concentrically mounted within said sleeve in annularly spaced relation thereto defining a first tubular fluid passageway for receiving fluid at a first pressure and operable to receive a polished rod therein in annularly spaced relation defining a second tubular fluid passageway exposed to oil well pressure during normal operation;   seal means disposed in said first fluid passageway;   means for maintaining the fluid pressure within said first fluid passageway greater than the fluid pressure in said second fluid passageway; and   means for releasably drivingly connecting said sleeve to a polished rod mounted in said standpipe.   
     
     
         42 - 65 . (canceled)