Apparatus and method

Abstract

The present invention includes methods and apparatuses to pump fluids from a well bore using a hydraulically actuated reciprocating pump to pump fluids from a well to the surface. In one embodiment the weight of the pumped fluid is utilised to return the piston in one direction and preferably the pressure within the well is utilised to urge the piston in the opposite direction thus reducing the amount of force required to reciprocate the piston and consequently reducing the amount of power required to operate the pump.

1 . A hydraulically powered pump, adapted to be placed in a well and pump fluids from the well to the surface.  
   
   
       2 . A pump as claimed in  claim 1 , comprising a reciprocating piston and a cylinder, the cylinder having a bore, wherein the piston is adapted to move within at least a portion of the bore of the cylinder.  
   
   
       3 . A pump as claimed in  claim 2 , wherein the pump is adapted to allow fluid within the well to bias the piston in a first direction.  
   
   
       4 . A pump as claimed in  claim 3 , wherein the piston, in use, is biased towards an upper direction.  
   
   
       5 . A pump as claimed in  claim 3 , wherein fluid in a separate part of the well is adapted to urge the pump in a second direction, preferably opposite the first direction.  
   
   
       6 . A pump as claimed in  claim 1 , comprising a resilient seal adapted to seal the pump within a tube, such as a portion of production tubing.  
   
   
       7 . An apparatus for recovering fluids from a well comprising a hydraulically powered pump and a hydraulic conduit.  
   
   
       8 . Apparatus as claimed in  claim 7 , wherein the hydraulic conduit is a flexible conduit.  
   
   
       9 . Apparatus as claimed in  claim 7 , comprising a hydraulic power source which is adapted to pressurise the hydraulic conduit and in turn the pump.  
   
   
       10 . A method for removing fluid from a well, the method comprising the steps of: 
 lowering a hydraulically powered pump into a well;    the pump being connected to the surface via a hydraulic conduit; and    hydraulically activating the pump to pump fluid from the well to the surface.    
   
   
       11 . A method as claimed in  claim 10 , wherein a portion of the pump is secured in production tubing within the well.  
   
   
       12 . A method as claimed in  claim 11 , wherein fluid within the production tubing biases the piston of the pump in a first direction.  
   
   
       13 . A method as claimed in  claim 10 , wherein pressure within the well, outside the production tubing, urges the piston of the pump in a second, preferably opposite, direction.  
   
   
       14 . A method as claimed in  claim 10 , wherein the hydraulic line is repeatedly pressurised and depressurised in order to reciprocate a piston of the pump.  
   
   
       15 . A method as claimed in  claim 10 , wherein the fluid includes water and the method includes the step of recovering gaseous hydrocarbons from a formation proximate to the well.  
   
   
       16 . A method as claimed in  claim 10 , wherein pressure is applied to the production tubing at the surface in order to increase the pressure therein.  
   
   
       17 . A method as claimed in  claim 10 , wherein the pump is operated from a point below where hydrocarbons may enter the well.  
   
   
       18 . A downhole pump to remove fluids from a wellbore, the pump comprising: 
 a first power transmission line and a second power transmission line;    a piston, said piston configured to be displaced within a cylinder from a first upward position to a second downward position;    said piston within said housing defining a first fluid chamber and a second fluid chamber    said piston urged into said first downward position when pressure within said first power transmission line is increased;    said piston urged into said second upward position when pressure within said second power transmission line is increased; and    a fluid return line connected to outlets of said first and second fluid chambers.    
   
   
       19 . The downhole pump of  claim 18  wherein pressure within said first and said second power transmission lines are controlled by a surface pump.