Stuffing box assembly

Abstract

A stuffing box assembly ( 4 ) comprising a primary housing ( 8 ) having a longitudinally oriented hollow bore ( 11 ) extending therethrough, a hanger assembly ( 9 ) within the longitudinally oriented hollow bore of the primary housing, and drive means ( 10 ) received within the hollow bore of the hanger assembly. The hanger assembly has a longitudinally oriented hollow bore extending therethrough. The drive means has means ( 15 ) to releasably secure the drive means to a pump rod such that the pump rod is hung from and supported within the primary housing by the hanger assembly. Rotation of the drive means causes a corresponding rotation of the pump rod. The hanger assembly includes one or more seals ( 17 ) to contain well fluids and to help prevent the flow of well fluids into the bore of the hanger assembly.

1 . A stuffing box assembly comprising:
 a primary housing having a longitudinally oriented hollow bore extending therethrough;   a hanger assembly within said longitudinally oriented hollow bore of said primary housing, said hanger assembly having a longitudinally oriented hollow bore extending therethrough; and,   drive means received within said hollow bore of said hanger assembly, said drive means having means to releasably secure said drive means to a pump rod such that the pump rod is hung from and supported within said primary housing by said hanger assembly and such that rotation of said drive means causes a corresponding rotation of the pump rod, said hanger assembly including one or more seals to contain well fluids and to help prevent the flow of well fluids into said bore of said hanger assembly.   
     
     
         2 . The stuffing box assembly as claimed in  claim 1  wherein said hanger assembly includes bearings to facilitate the rotation of said drive means, said hanger assembly further including one or more seals to prevent the flow of fluid between said hanger assembly and said primary housing. 
     
     
         3 . The stuffing box assembly as claimed in  claim 2  wherein said drive means is a drive rod. 
     
     
         4 . The stuffing box assembly as claimed in  claim 3  further including a pair of radially opposed blowout preventer rams situated in transverse bores extending through said primary housing, said transverse bores in communication with said longitudinal bore through said primary housing such that said blowout preventer rams sealingly engage the exterior surface of said drive rod when said rams are advanced within said transverse bores toward said drive rod. 
     
     
         5 . The stuffing box assembly as claimed in  claim 2  wherein said longitudinally oriented hollow bore through said primary housing includes a first diameter portion and a second reduced diameter portion, said first and said second diameter portions connected by a shoulder portion, said shoulder portion acting as a bearing surface against which said hanger assembly is engaged, said shoulder portion bearing the weight of said hanger assembly, said drive means and a pump rod when attached thereto. 
     
     
         6 . The stuffing box assembly as claimed in  claim 2  wherein said primary housing includes one or more locking mechanisms to retain said hanger assembly within said primary housing. 
     
     
         7 . The stuffing box assembly as claimed in  claim 6  wherein said one or more locking mechanisms comprise one or more lock down screws. 
     
     
         8 . The stuffing box assembly as claimed in  claim 2  wherein said drive means includes torque input means permitting for the transference of rotational torque from a power source to said drive means and to a pump rod attached thereto. 
     
     
         9 . The stuffing box assembly as claimed in  claim 8  wherein said torque input means comprises a recess in the upper end of said drive means and said power source comprises an electric or hydraulic motor, said recess configured and sized to accept the shaft of said electric or hydraulic motor such that the operation of said motor causes a direct rotation of said drive means. 
     
     
         10 . The stuffing box assembly as claimed in  claim 2  wherein said drive means comprises a rotatable mandrel. 
     
     
         11 . The stuffing box assembly claimed in  claim 10  wherein said hanger assembly is hung and supported within the longitudinally oriented hollow bore of said primary housing by a shoulder portion on said primary housing. 
     
     
         12 . The stuffing box assembly is claimed in  claim 11  wherein said rotatable mandrel has a longitudinally oriented hollow bore for receiving a pump rod there through. 
     
     
         13 . The stuffing box assembly as claimed in  claim 12  wherein, the hollow bore through said rotatable mandrel has a reduced diameter portion, said mandrel including slips to engage a pump rod received through said hollow bore in said mandrel, said slips engaging the pump rod at said reduced diameter portion in order to hang the pump rod from said mandrel such that rotation of said mandrel causes a simultaneous rotation of the pump rod. 
     
     
         14 . The stuffing box assembly as claimed in  claim 12  including a rod clamp, said rod clamp operatively securing the pump rod to said rotatable mandrel such that rotation of said mandrel causes a corresponding rotation of the pump rod, said rod clamp further transferring the axial or longitudinal load of the pump rod to said rotating mandrel. 
     
     
         15 . The stuffing box assembly as claimed in  claim 9  wherein said shaft of said motor includes a longitudinal hollow bore extending therethrough, when said shaft of said motor is received within said recess in the upper end of said drive means said longitudinal bore in said motor shaft is in fluid communication with a longitudinally oriented hollow bore extending through at least the upper end of said drive means, said bore in said drive means having at least one transverse oriented exit port in communication with the exterior surface of said drive means, said bore extending through said shaft of said motor being at least partially filled with lubricant and having associated therewith pressurization means to pressurize said lubricant, said pressurization means forcing said lubricant through said shaft of said motor into said bore within the upper end of said drive means and through said transverse exit port, said lubricant assisting in the lubrication of said seals and pressurizing the interior of said stuffing box. 
     
     
         16 . The stuffing box assembly as claimed in  claim 15  wherein said pressurization means pressurizes said lubricant to a level such that the lubricant pressure within said stuffing box exceeds the pressure of fluids within a well upon which said stuffing box is mounted to help prevent the flow of well fluids into said stuffing box. 
     
     
         17 . The stuffing box assembly as claimed in  claim 16  wherein the upper end of said longitudinal bore extending through said shaft of said electric or hydraulic motor is sealed, said pressurization means situated within said longitudinal bore in said motor shaft. 
     
     
         18 . The stuffing box assembly as claimed in  claim 17  wherein said pressurization means comprises a spring or gas actuated piston. 
     
     
         19 . The stuffing box assembly as claimed in  claim 2  including an external source of pressurized lubricant connected to the interior of said hanger assembly, said pressurized lubricant lubricating said one or more seals and pressurizing said hanger assembly to a higher pressure than the pressure of a wellbore upon which said stuffing box is mounted to help prevent the flow of well, fluids into said hanger assembly. 
     
     
         20 . The stuffing box assembly as claimed in  claim 1  in combination with a casing head, said casing head including one or more side entry passageways to permit the introduction of coiled tubing or other tubular or elongate member into the wellbore of a wellhead onto which said stuffing box assembly is mounted, said introduction of said coiled tubing or other tubular or elongate member occurring at a point below said stuffing box assembly and without the removal of said stuffing box assembly from the wellhead. 
     
     
         21 . A casing head for securing to the upper end of the casing of a well extending into an underground formation, the casing head including one or more side entry passageways to permit the introduction of coiled tubing or other tubular or elongate member into the wellbore of the casing without the removal of wellhead equipment positioned above said casing head. 
     
     
         22 . The casing head as claimed in  claim 21  including removable plugs in said one or more side entry passageways to help prevent the ingress of debris into the wellbore and the escape of fluids from the wellbore. 
     
     
         23 . The casing head as claimed in  claim 22  wherein said one or more side entry passageways are arranged with their longitudinal axes at a shallow angle relative to the centerline of the wellhead to permit the coiled tubing or other tubular or elongate member to be inserted at a shallow angle of approach relative to the casing and any tubing string that may be received therein. 
     
     
         24 . A stuffing box assembly comprising:
 a primary housing;   a removable hanger assembly releasably and sealingly receivable within a longitudinally oriented hollow bore extending through said primary housing, said hanger assembly having a longitudinally oriented hollow bore extending therethrough; and,   drive means sealingly receivable within said hanger assembly and extending through said hollow bore within said primary housing when said hanger assembly is received therein, said drive means including torque input means permitting for the transference of rotational torque from a power source to said drive means, said drive means having means to releasably secure said drive means to a pump rod such that rotation of said drive means causes a corresponding rotation of the pump rod when secured thereto, said drive means including one or more seals between said drive means and the pump rod,   when said hanger assembly is received within said primary housing said hanger assembly hanging said drive means, and a pump rod when attached thereto, from said primary housing, said hanger assembly including bearings to facilitate the rotation of said drive means, said hanger assembly including one or more seals to seal against the exterior surface of said drive means to help prevent the flow of fluid between said drive means and said hanger assembly.   
     
     
         25 . A stuffing box assembly comprising;
 a primary housing;   a hanger assembly within a longitudinally oriented bore extending through said primary housing, said hanger assembly having a longitudinally oriented bore extending therethrough; and,   drive means sealingly received within said hollow bore of said hanger assembly, said drive means including torque input means permitting for the transference of rotational torque from a power source to said drive means, said drive means having means to releasably secure said drive means to a pump rod such that rotation of said drive means causes a corresponding rotation of the pump rod when secured thereto,   said hanger assembly hanging said drive means, and a pump rod when attached thereto, from said primary housing, said hanger assembly including bearings to facilitate the rotation of said drive means, said hanger assembly including one or more seals to contain well fluids and to help prevent the flow of well fluid into said bore in said hanger assembly.   
     
     
         26 . The stuffing box assembly as claimed in  claim 25  wherein said drive means is a rotating mandrel, said rotating mandrel having a longitudinally oriented hollow bore for securedly receiving the pump rod therein such that rotation of the rotating mandrel causes a corresponding rotation of the pump rod.