Well production by fluid lifting

Abstract

Oil production from formerly producing wells may be restored without removing a preexisting production tube by perforating the production tube above the tubing packer and charging the casing annulus at the surface with a pressurized charging fluid fluid, preferably deoxygenated air, that is lighter than water. The pressurized charging of the casing annulus with charging fluid is continued to purge the production tube flow bore of a static water column and reduce the tubing column head pressure against the formation production zone.

1 . A method of extracting earth formation fluid comprising the steps of: 
 a. drilling a borehole into an earth formation containing formation fluid;    b. positioning a production tube within said borehole, said production tube having a flow bore extending from a formation fluid production zone to a surface discharge zone, said flow bore being confined within a surrounding tube wall;    c. at a point above said formation fluid production zone, sealing a well annulus between an internal wall within said borehole and an external surface of said tube wall;    d. in situ perforating said tube wall above said annulus seal; and,    e. delivering a pressurized charging fluid into said well annulus above said tube wall perforations to drive substantially all fluids present in said flow bore up said flow bore into said surface discharge zone.    
   
   
       2 . A method as described by  claim 1  wherein said borehole is lined with a casing pipe and said internal wall within said borehole is an internal diameter surface of said casing pipe.  
   
   
       3 . A method as described by  claim 1  wherein said tube wall is perforated from within said tube flow bore while positioned within said borehole.  
   
   
       4 . A method as described by  claim 1  wherein said borehole is plugged below said fluid production zone.  
   
   
       5 . A method as described by  claim 1  wherein said charging fluid is non-cryogenic nitrogen.  
   
   
       6 . A method as described by  claim 1  wherein said charging fluid is oxygen depleted air.  
   
   
       7 . A method as described by  claim 1  further comprising the steps of: 
 a. positioning a jet pump within said flow bore above said well annulus seal, said jet pump having a fluid flow passage between a suction end and a discharge end, an aspirating nozzle within said flow passage between said suction and discharge ends and a nozzle supply orifice externally of said flow passage between said suction and discharge ends;    b. sealing said tube flow bore around said jet pump suction end below said tube wall perforation;    c. sealing said tube flow bore around said jet pump discharge end above said tube wall perforation to position said nozzle supply orifice between said jet pump suction and discharge end seals.    
   
   
       8 . A method as described by  claim 7  wherein tube flow bore space around said jet pump between said seals respective to said suction and discharge ends provides a fluid supply plenum for said aspirating nozzle.  
   
   
       9 . A method as described by  claim 7  wherein at least one gas lift valve is positioned in said production tube above said jet pump.  
   
   
       10 . A method of enhancing the fluid production of a petroleum well having a production tube disposed within a wellbore between a formation fluid production zone and a surface discharge zone, said method comprising the following steps: 
 a. sealing a first cross-sectional zone between and inside surface of said wellbore and an outside surface of said production tube at a point above said production zone;    b. in situ perforating said production tube at a point above said first cross-sectional zone;    c. positioning a jet pump within a flow bore of said production tube proximate of said production tube perforation, said pump having a housing around a formation fluid flow channel sealed to an internal flow bore of said production tube above and below said tube perforation to provide an aspirating fluid supply plenum between said above and below seals; and,    d. supplying aspirating fluid to an annulus space between said inside surface of said wellbore and said outside surface of said production tube above said first cross-sectional zone.    
   
   
       11 . A method of enhancing the fluid production of a petroleum well as described by  claim 10  wherein the supply of aspirating fluid opens and closes at least one gas lift valve in said production tube above said jet pump.  
   
   
       12 . A method of enhancing the fluid production of a petroleum well as described by  claim 10  wherein a plurality of gas lift valves are sequentially opened and closed prior to aspirating fluid entering said jet pump.  
   
   
       13 . A method of enhancing the fluid production of a petroleum well as described by  claim 10  wherein said aspirating fluid is non-cryogenic nitrogen.  
   
   
       14 . A method of enhancing the fluid production of a petroleum well as described by  claim 10  wherein said aspirating fluid is oxygen depleted air.  
   
   
       15 . An earthen fluid production well comprising: 
 a borehole penetrating a fluid bearing earth formation;    a fluid production tube comprising a tube wall around a tube flow bore, said production tube disposed within said borehole between a fluid production zone proximate of said formation and a fluid discharge zone proximate of the earth's surface;    a first fluid flow seal between said tube wall and an internal wall surface within said borehole surrounding said tube wall, said fluid seal disposed above said production zone;    perforations of said tube wall above said first fluid flow seal;    a jet pump having a housing, said housing having a suction flow end, a discharge flow end and an aspirating fluid inlet orifice in said housing between said suction and discharge flow ends, said jet pump disposed between a second fluid seal of said tube flow bore around said housing proximate of said suction flow end and a third fluid seal of said tube flow bore around said housing proximate of said discharge flow end whereby said fluid inlet orifice is open to borehole space surrounding said tube wall; and,    at least one gas lift valve in said production tube above said third fluid seal.