Gas Powered Subsurface Pump Drive System

Abstract

A gas powered subsurface pump drive system for use in driving a subsurface pump positioned downhole a well and connected to completion tubing includes a pressure connected to the wellhead of the well in fluidic communication with the completion tubing. A pneumatic cylinder is supported above the pressure vessel and has a vertically positioned and reciprocal piston rod extending into the pressure vessel and is connected to an intermediate drive member extends through the production tubing and is connected to a piston rod the subsurface pump for conjoint reciprocation. A pneumatic drive system alternately provides pressurized gas to an instroke port of the pneumatic cylinder and to the pressure vessel to vertically reciprocate the piston rod, the intermediate drive member and the piston rod of the subsurface pump to pump formation fluid upwardly through the tubing.

1 . A gas powered subsurface pump drive system for use with a well having a wellhead located at the ground surface, a length of completion tubing extending downwardly from the wellhead and a subsurface pump connected to a lower end of the completion tubing by which formation fluid can be pumped upward through the tubing to the wellhead, the system comprising:
 a pressure vessel supported above the wellhead and sealing connected to said wellhead establishing a fluidic connection between the internal space of said pressure vessel and the completion tubing extending downwardly from the wellhead;   a pneumatic cylinder supported above said pressure vessel, said pneumatic cylinder having a vertically positioned and reciprocal piston rod sealing extending into said internal space of said pressure vessel;   an intermediate drive member extending through the production tubing and coupling said piston rod of said pneumatic cylinder and a piston rod of the subsurface pump for conjoint reciprocation; and   a pneumatic drive system alternately providing pressurized gas to an instroke port of said pneumatic cylinder and to said pressure vessel to vertically reciprocate said piston rod, said intermediate drive member and the piston rod of the subsurface pump to pump formation fluid upwardly through the tubing.   
     
     
         2 . The system of  claim 1 , wherein said pressurized gas is gas from a sales gas pipeline from a production plant located remotely from the well. 
     
     
         3 . The system of  claim 2 , wherein said pneumatic system further alternately discharges said pressurized gas from said instroke port of said pneumatic cylinder and said pressurized vessel into a crude formation fluid pipeline to said production plant. 
     
     
         4 . The system of  claim 3 , wherein an outstroke port of said pneumatic cylinder is vented to atmosphere. 
     
     
         5 . The system of  claim 3 , wherein an outstroke port of said pneumatic cylinder is connected to said crude formation fluid pipeline. 
     
     
         6 . The system of  claim 1 , wherein the production tubing is coiled tubing. 
     
     
         7 . The system of  claim 1 , wherein said intermediate drive member is a flexible cable. 
     
     
         8 . The system of  claim 1 , wherein the wellhead is connected to a crude formation fluid pipeline to receive pumped formation fluid at a position vertically lower elevation than connection between said pressure vessel and said wellhead. 
     
     
         9 . The system of  claim 1 , wherein said pneumatic drive system operates to measure gas pressure at said instroke port and to measure gas pressure at said pressure vessel, and as a function of said measured gas pressures alternately provides said pressurized gas to said instroke port and to said pressure vessel.