Method of and apparatus for dual packing of capillary tubing in a wellhead

Abstract

A body having a bore thereThrough for insertion of capillary tubing. A first means slidably coupled into the bore of the body frictionally restrains movement of the tubing by hydraulically engaging the periphery of the tubing with a compressible elastomeric sealing member. A second means slidably coupled into the bore of the body prevents movement of the tubing in the bore of the body by manually engaging the periphery of the tubing with a compressible elastomeric sealing member. A third means suspends the tubing in the bore of the body by manually engaging a plurality of suspension slips around the periphery of the tubing.

We claim:  
     
         1 . A wellhead pack-off system for controlling the movement of small diameter tubing into and out of a well, comprising: 
 a body having a bore therethrough for insertion of said tubing;    first means slidably coupled into said bore of said body for frictionally restraining movement of said tubing by hydraulicly engaging the periphery of said tubing with an upper compressible elastomeric sealing member; and    second means slidably coupled into said bore of said body for frictionally restraining movement of said tubing by manually engaging the periphery of said tubing with a lower compressible elastomeric sealing member to impart select engagement or disengagement of the periphery of said tubing for its securement therein.    
     
     
         2 . The wellhead pack-off system of  claim 1 , wherein the body further comprises: 
 an upper body portion having a cap portion in threaded engagement with said intermediate portion , and having said bore therethrough, said cap portion having an aperture formed therein and extending therethrough;    an intermediate body portion in threaded engagement to said upper body portion and having said bore therethrough and having an intermediate cap portion; and    a lower body portion;    wherein said first means is operable in said upper body, and said second means is operable in said intermediate body.    
     
     
         3 . The wellhead pack-off system of  claim 2 , wherein said first means comprises: 
 a plunger axially disposed within said cap having a reduced neck portion forming a first cavity between said plunger and said sidewall of said cap, and having a lower end and an upper boss forming a second cavity between the opening of said aperture of said cap and said first cavity;    an upper spring disposed within said first cavity for purposes of the flexing thereof and urging movement against said plunger;    an upper bushing set disposed within the lower end of said plunger, said upper bushing set having a first side abutting the terminal end of said plunger and a second side;    a lower bushing set disposed in and in alignment with said intermediate portion, and having an angulated surface; and    an upper sealing member disposed in axial alignment with said upper bushing and within the walls of said intermediate portion, and having an angulated surface in abutting relationship with the angulated surface of said lower bushing set and an opposite surface in abutting relationship with said second side of said upper bushing set.    
     
     
         4 . The wellhead pack-off system of  claim 3 , wherein said first means is operable to hydraulicly compress said upper sealing member to seal said tubing extending through said bore of said body.  
     
     
         5 . The wellhead pack-off system of  claim 4 , wherein said upper sealing member is compressed by the exertion of an axial force on said surface in abutting relationship with said second side of said upper bushing set by said plunger, whereby said axial force in combination with said angulated surface of said upper sealing member in abutting relationship with the angulated surface of said lower bushing set causes said compressible member to form a seal against said tubing, thereby frictionally restraining the movement of said tubing through said bore.  
     
     
         6 . The wellhead pack-off system of  claim 5 , wherein said second means comprises: 
 a piston axially disposed within said intermediate cap, said piston having an upper reduced neck portion forming a cavity between said piston and said sidewall of said intermediate cap, and having a lower hip portion;    a spring disposed within said cavity for purposes of the flexing thereof and urging movement against said piston;    a lower flat bushing disposed in and in alignment with said intermediate portion and in abutting engagement with the upper terminal end of said plunger, and having a second side;    a conical bushing disposed in and in alignment with said intermediate portion, and having an angulated surface and an opposite surface in abutting engagement with said intermediate portion;    a lower sealing member disposed in axial alignment with and abutting said lower flat bushing and within the walls of said intermediate portion, and having an angulated surface in abutting relationship with said angulated surface of said conical bushing and an opposite surface in abutting relationship with said second side of said lower flat bushing; and    mechanical means for urging said piston upwardly into said flat bushing, thereby compressing said lower sealing member around said tubing and forming a seal therearound.    
     
     
         7 . The wellhead pack-off system of  claim 6 , wherein said mechanical means comprises: 
 a nut in threaded engagement with said lower body; and    a plurality of push rods having an upper end bearing against the underneath side of said hip portion of said piston, and a lower end bearing against the upper surface of said nut, and wherein said plurality of push rods extend through apertures extending through the intermediate cap portion.    
     
     
         8 . The wellhead pack-off system of  claim 7 , wherein said second means is operable to mechanically compress said lower sealing member to seal said tubing extending through said bore of said body.  
     
     
         9 . The wellhead pack-off system of  claim 8 , wherein said lower sealing member is compressed by the exertion of an axial force on said surface of said lower sealing member in abutting relationship with said second side of said lower flat bushing by said piston, whereby said axial force in combination with said angulated surface of said lower sealing member in abutting relationship with the angulated surface of said conical bushing forces said lower sealing member to form a seal against said tubing, thereby frictionally restraining the movement of said tubing through said bore.  
     
     
         10 . The wellhead pack-off system of  claim 9 , wherein said nut positions said piston by exerting an axial force against the underside of said plurality of push rods, thereby forcing said piston to impart an axial movement to said flat bushing.  
     
     
         11 . The wellhead pack-off system of  claim 10 , further comprising a jam nut in threaded engagement with said lower body, wherein said jam nut prevents slippage of said nut in threaded engagement with said lower body.  
     
     
         12 . The wellhead pack-off system of  claim 11 , wherein said upper body further comprises a first conical section in communication with said bore extending through said piston.  
     
     
         13 . The wellhead pack-off system of  claim 12 , further comprising a third means for suspending said tubing by engaging a plurality of suspension slips around the periphery of said tubing.  
     
     
         14 . The wellhead pack-off system of  claim 13 , wherein said first conical section comprises a sidewall engaging said plurality of suspension slips is adapted for receiving said plurality of suspension slips.  
     
     
         15 . The wellhead pack-off system of  claim 14 , wherein said third means further comprises a slip cap in threaded engagement with said upper body for engaging said suspension slips with said tubing.  
     
     
         16 . A method for controlling the movement of small diameter tubing into and out of a well, comprising the steps of: 
 inserting said tubing into a body having a bore therethrough;    hydraulically engaging the periphery of said tube with an upper compressible elastomeric sealing member to frictionally restraining movement of said tubing; and    manually engaging the periphery of said tube with a lower compressible elastomeric sealing member frictionally restraining movement of said tubing    
     
     
         17 . The method according to  claim 16 , wherein the step of manually engaging further comprises the step manually engaging a piston so as to compress said lower sealing member, thereby forming a seal around the periphery of said tubing and frictionally restraining movement of said tubing..  
     
     
         17 . The method according to  claim 16 , wherein the step of manually engaging said piston comprises the steps of: 
 placing a plurality of push rods in contact with said piston; and    threadably engaging a nut to the lower end of said body so as to cause contact between said nut and said push rods, wherein axial motion of said nut imparts axial motion to said piston.    
     
     
         18 . The method according to  claim 17 , further comprising the step of preventing slippage of said nut in threaded engagement with the lower end of said body by threadably engaging a jam nut to the lower end of said body, said jam nut abutting the underside of said nut.  
     
     
         19 . The method according to  claim 18 , wherein the step of frictionally restraining movement of said tubing by hydraulically engaging the periphery of said tube with an compressible elastomeric sealing member comprises the step of hydraulically engaging a plunger so as to compress said sealing member, thereby forming a seal around the periphery of said tubing and frictionally restraining movement of said tubing.  
     
     
         20 . The method according to  claim 19 , further comprising the step of suspending said tubing in said bore of said body by manually engaging a plurality of suspension slips around the periphery of said tubing.