Gas well liquid recovery

Abstract

A gas operated, submersible pumping system, is disclosed as being capable of recovering well fluids below ground surface from a natural gas production well and is adapted to be coupled to flexible continuous metal conveyance conduits. The system includes a housing constructed of a corrosion resistant material; gas inlet and output ports for accommodating respectively higher and lower pressures; well fluids inlet and outlet ports; an internal gas logic switching valve to control pumping action; and a pneumatic mechanical amplifier piston, which isolates gas from liquids, and transfers lower pressure gas into higher pressure liquid discharge pressure, wherein the submersible pumping system is operable between a refill and discharge mode so as to recycle inlet well gas back into the production well without substantially reconstituting the well gas.

1 . An apparatus comprising a low pressure pneumatic means, down a well and driven by gas from the well, for driving a high pressure hydraulic means, also down the well, for expelling liquid from the well.  
   
   
       2 . The apparatus as defined in  claim 1 , wherein at least one said means is in fluid communication with the surface of the well through flexible tubing.  
   
   
       3 . The apparatus as defined in  claim 2 , wherein the flexible tubing is selected from the group consisting of: room-temperature flexible tubing, tubing that is spooled prior to use and unspoiled for use, stainless steel tubing.  
   
   
       4 . The apparatus as defined in  claim 1 , further comprising a container for both the pneumatic means and the hydraulic means.  
   
   
       5 . The apparatus as defined in  claim 1 , further comprising: 
 means for removing gas from the well; and compressor means, fired by the gas removed from the well, for compressing the gas from the well, wherein the gas from the well that drives the pneumatic means is the compressed gas that is compressed by the compressor means.    
   
   
       6 . Any pneumatic pump in a well, driven by gas from the well, and driving any hydraulic pump in the well to pump liquid from the well.  
   
   
       7 . The apparatus as defined in  claim 6 , wherein at least one of the pneumitic and hydraulic pumps is in fluid communication with the surface of the well through flexible tubing.  
   
   
       8 . The apparatus as defined in  claim 7 , wherein the flexible tubing is selected from the group consisting of tubing that is flexible at room-temperature, tubing that is spooled prior to use and is unspoiled for use, and stainless steel tubing.  
   
   
       9 . The apparatus as defined in  claim 6 , further comprising a compressor to compress the gas removed from the well, wherein the gas driving the pneumatic pump in the well is the compressed gas.  
   
   
       10 . The apparatus as defined in  claim 6 , further comprising a container for both the pneumatic pump and the hydraulic pump.  
   
   
       11 . The apparatus as defined in  claim 6 , wherein: 
 each of the pneumatic pump and the hydraulic pump have a piston; and the piston of the pneumatic pump is separated by a fixed distance from the piston of the hydraulic pump by a rigid member.    
   
   
       12 . The apparatus as defined in  claim 11 , wherein the piston of the pneumatic pump has a greater pumping surface area than that of the hydraulic pump.  
   
   
       13 . A method comprising: 
 driving a pneumatic pump in a well with gas from a well to output gas there from;    driving a hydraulic pump in the well with the gas output from the pneumatic to thereby pump liquid from the well.    
   
   
       14 . The method as defined in  claim 13 , further comprising removing the gas from the well prior to driving the pneumatic pump with the gas from the well.  
   
   
       15 . The method as defined in  claim 14 , further comprising compressing the gas removed from the well, wherein the gas driving the pneumatic pump in the well is the compressed gas.  
   
   
       16 . The method as defined in  claim 13 , wherein at least one of the pneumatic pump and the hydraulic pump is in fluid communication with the surface of the well through flexible tubing.  
   
   
       17 . The method as defined in  claim 16 , wherein the flexible tubing is selected from the group consisting of: room-temperature flexible tubing, tubing that is spooled prior to use and unspoiled for use, stainless steel tubing.  
   
   
       18 . A method comprising: 
 removing gas from a well;    compressing the gas removed from a well by a compressor fired by a portion of the gas removed from the well;    driving a pneumatic pump in the well by inputting thereto the compressed gas;    driving a hydraulic pump in the well by inputting thereto the gas output of the pneumatic pump; and    removing liquid from the well with the driven hydraulic pump.    
   
   
       19 . The method as defined in  claim 18 , wherein the pneumatic and hydraulic pumps are in fluid communication with respective containers on the surface of the well through respective flexible tubing.  
   
   
       20 . The method as defined in  claim 19 , wherein the flexible tubing is selected from the group consisting of room-temperature flexible tubing, tubing that is spooled prior to use and unspoiled for use, and stainless steel tubing.  
   
   
       21 . The method as defined in  claim 18 , wherein the portion of the gas removed to fire the gas fired compressor so as to compress the gas is substantially less than the gas removed from the well.  
   
   
       22 . A gas operated, submersible pumping system, for recovering well fluids below ground surface from a natural gas production well and adapted to be coupled to a flexible continuous metal conveyance conduits thereto, comprising: 
 a housing constructed of a corrosion resistant material;    gas inlet and output ports for accommodating respectively higher and lower pressures;    well fluids inlet and outlet ports;    an internal gas logic switching valve to control pumping action; and    a pneumatic mechanical amplifier piston, which isolates gas from liquids, and transfers lower pressure gas into higher pressure liquid discharge pressure, wherein the submersible pumping system is operable between a refill and discharge mode so as to recycle inlet well gas back into the production well without substantially reconstituting the well gas.