Method and apparatus for injecting packing into stuffing boxes for reciprocating rods

Abstract

A stuffing box for a polished rod used with a downhole pump uses injectable packing to provide a seal around the polished rod. The stuffing box has a chamber for receiving the packing. The chamber has an opening to allow the addition of packing to the chamber. The packing is maintained in a compacted condition by either injecting additional packing through the opening or adjusting the volume of the chamber.

1 . An apparatus for use on wellhead equipment having a reciprocating polished rod, comprising: 
 a) a stuffing box having a wall defining a stuffing chamber with two ends, the ends having openings for receiving the polished rod, the polished rod reciprocating relative to the stuffing box wall;    b) at least one opening through the wall communicating with the stuffing chamber;    c) a reservoir structured and arranged to contain injectable packing material, the reservoir communicating with the opening to the stuffing chamber;    d) a pressure source applying pressure to the packing material and the reservoir so as to inject the packing material from the reservoir into the stuffing chamber.    
     
     
         2 . The apparatus of  claim 1  further comprising: 
 a) the at least one opening through the wall communicating with the stuffing chamber further comprises a plurality of openings circumferentially spaced about the stuffing box chamber;  
 b) a collar coupled to the stuffing box wall, the collar having a circumferential passage therein, which passage communicates with the openings through the stuffing box wall, the reservoir communicating with the collar passage.  
 
     
     
         3 . The apparatus of  claim 2  wherein the reservoir is mounted to the collar.  
     
     
         4 . The apparatus of  claim 3  wherein the collar rotates about the circumference of the stuffing box.  
     
     
         5 . The apparatus of  claim 1  further comprising the reservoir communicating with the stuffing box chamber opening by a passage, the passage having a check valve therein to prevent packing from flowing from the stuffing box chamber to the reservoir.  
     
     
         6 . The apparatus of  claim 1  further comprising a piston inside of the reservoir, the pressure source acting on the piston.  
     
     
         7 . The apparatus of  claim 6  wherein said pressure source comprises fluid acting on said piston.  
     
     
         8 . The apparatus of  claim 6  wherein said pressure source comprises a spring acting on said piston.  
     
     
         9 . The apparatus of  claim 6  further comprising a shaft coupled to the piston, the shaft extending out of the reservoir and providing a visual indication of the amount of packing in the reservoir.  
     
     
         10 . The apparatus of  claim 9  wherein the shaft has a fill passage therethrough that communicates with the reservoir.  
     
     
         11 . The apparatus of  claim 1  further comprising an indicator of the amount of packing material contained in the reservoir.  
     
     
         12 . The apparatus of  claim 1  wherein the stuffing box is mounted to the wellhead by bearings, wherein the stuffing box maintains alignment with an axis of reciprocation of the polished rod.  
     
     
         13 . A method of sealing a stuffing box on wellhead equipment having a reciprocating polished rod, comprising the steps of: 
 a) providing a supply of packing;    b) providing a connection between the supply of packing to the stuffing box;    c) pressurizing the supply of packing and injecting the packing into the stuffing box.    
     
     
         14 . The method of  claim 13  wherein the step of injecting the packing into the stuffing box occurs while the polished rod reciprocates.  
     
     
         15 . The method of  claim 14  further comprising the step of reciprocating the polished rod in and out of wellhead fluids.  
     
     
         16 . The method of  claim 13  wherein the step of injecting the packing into the stuffing box further comprises the step of injecting the packing into circumferentially spaced locations about the polished rod.  
     
     
         17 . The method of  claim 13  further comprising the step of providing an indication of the supply of packing in the stuffing box.  
     
     
         18 . The method of  claim 13  further comprising the step of allowing the stuffing box to move so that the stuffing box maintains alignment with an axis of reciprocation of the polished rod.  
     
     
         19 . A stuffing box for use with a downhole pump, a reciprocating polished rod and sucker rods connecting the polished rod to the pump, comprising: 
 a) a housing forming a closed chamber therein, the chamber having first and second ends, each of the first and second ends having an opening for receiving the polished rod, with one of the first or second ends being structured and arranged to couple to wellhead equipment;    b) a valved port in the housing allowing selective communication between an exterior of the housing and the chamber;    c) injectable packing located in the chamber.    
     
     
         20 . The stuffing box of  claim 19  further comprising a pressure application member in contact with a portion of the injectable packing and applying pressure to the packing in the chamber.  
     
     
         21 . The stuffing box of  claim 20  wherein the pressure application member is located inside of the housing.  
     
     
         22 . The stuffing box of  claim 21  wherein the pressure application member forms a bushing in the chamber.  
     
     
         23 . The stuffing box of  claim 22  wherein the pressure application member is structured and arranged to contact the fluid pumped uphole by the downhole pump.  
     
     
         24 . The stuffing box of  claim 22  wherein the pressure application member is exposed to a pressure source.  
     
     
         25 . The stuffing box of  claim 20  wherein the pressure application member is located exteriorly of the housing.  
     
     
         26 . The stuffing box of  claim 19  further comprising an indicator of the amount of packing located in the chamber.  
     
     
         27 . A stuffing box for use with a polished rod of a downhole pump, comprising: 
 a) a housing having a chamber therein, the chamber is structured and arranged for receiving the polished rod and allowing the polished rod to reciprocate therein, the chamber having two ends;    b) a first bushing located at one end of the chamber;    c) a second bushing located at the other end of the chamber, the second bushing being movable with respect to the first bushing;    d) a valved port in the housing allowing selective communication between an exterior of the housing and the chamber;    e) malleable packing located in the chamber between the first and second bushings.    
     
     
         28 . The stuffing box of  claim 27  wherein the second bushing has a first end located in contact with the packing and a second end located out of contact with the packing; the second bushing first end having a first surface area, the second bushing second end having a second surface area, the first surface area being different than the second surface area.  
     
     
         29 . The stuffing box of  claim 28  wherein the first surface area is smaller than the second surface area.  
     
     
         30 . The stuffing box of  claim 28  wherein the second bushing second end is structured and arranged to be in contact with fluid produced by the pump.  
     
     
         31 . The stuffing box of  claim 28  further comprising an indicator coupled to the second bushing, with at least a portion of the indicator located exteriorly of the housing at selected positions of the second bushing in the chamber.  
     
     
         32 . A method of providing a seal around a polished rod for a downhole pump, comprising the steps of: 
 a) providing a closed chamber having first and second openings therethrough for receiving the polished rod;    b) injecting packing into the chamber.    
     
     
         33 . The method of  claim 32  wherein the step of injecting packing into the chamber further comprises the step of injecting packing while the polished rod is reciprocating.  
     
     
         34 . A method of providing a seal around a polished rod for a downhole pump, comprising the steps of: 
 a) providing a closed chamber having first and second openings therethrough for receiving the polished rod;    b) filling the chamber with a malleable packing;    c) compressing the packing.    
     
     
         35 . The method of  claim 34  wherein the step of compressing the packing further comprises the step of diminishing the volume of the chamber.  
     
     
         36 . The method of  claim 34  wherein the step of diminishing the volume of the chamber further comprises the step of pressurizing the chamber with fluid produced by the pump.  
     
     
         37 . A method of providing a seal around a polished rod for a downhole pump, comprising the steps of: 
 a) providing a closed chamber having first and second openings therethrough for receiving the polished rod;    b) inserting packing into the chamber;    c) indicating the amount of packing during the reciprocation of the polished rod.    
     
     
         38 . A stuffing box for use with a downhole pump, a reciprocating polished rod and sucker rods connecting the polished rod to the pump, comprising: 
 a) a chamber structured and arranged to receive the reciprocating polished rod, the chamber comprising an annulus around the polished rod when the polished rod is received in the chamber;    b) malleable packing located in the annulus;    c) the annulus comprising a first member that exerts pressure on the malleable packing, the annulus changing volume according to the quantity of packing located therein;    d) an indicator of the quantity of packing located in the annulus, the indicator being visible from the exterior of the stuffing box.    
     
     
         39 . The stuffing box of  claim 38  wherein the indicator comprises a second member coupled to the first member.  
     
     
         40 . The stuffing box of  claim 39  wherein: 
 a) the annulus is sealed;  
 b) the second member is coupled to the first member outside of the sealed annulus.  
 
     
     
         41 . An apparatus for use in a well having a downhole pump, the reciprocating polished rod and sucker rods connecting the polished rod to the pump, comprising: 
 a) a stuffing box comprising a housing having a chamber therein, the chamber being structured and arranged to receive the reciprocating polished rod, the chamber having an annulus around the polished rod when the polished rod is received within the chamber;    b) a piston located at one end of the chamber, the piston being annular so as to receive the polished rod, one end of the piston being located within the chamber annulus with another end of the piston being structured and arranged so as to be exposed to well fluids;    c) malleable packing located in the chamber annulus and in contact with the piston, the packing being pressurized by the piston.    
     
     
         42 . The apparatus of  claim 41  wherein the housing further comprises an inlet port that communicates with the chamber so that packing can be added to the chamber.  
     
     
         43 . The apparatus of  claim 41  further comprising an indicator member coupled to the piston and visible from an exterior of the housing.  
     
     
         44 . The apparatus of  claim 41  wherein the other end of the piston that is exposed to well fluids is sized according to the pressure of the well fluids.  
     
     
         45 . The apparatus of  claim 41  further comprising: 
 a) upper and lower sacrificial bushings for receiving the polished rod;  
 b) a bearing arrangement to maintain the alignment of the polished rod with the stuffing box, the bearing arrangement coupled to the stuffing box.