Downhole pump with anti-gas lock orifice

Abstract

The present invention relates to a downhole pump for producing volumes of liquids from an oil well, comprising: an extension wall; a barrel that extends vertically to the interior of the extension wall; a gas separating chamber delimited by the barrel and the interior surface of the extension wall; and a piston comprising a travelling valve in its lower portion, wherein the piston is configured to slide vertically in the barrel to the interior of the separating chamber between an upper end of stroke position and a lower end of stroke position; wherein the piston comprises at least one venting orifice, wherein the at least one venting orifice is configured to provide communication between the interior of the piston and the gas separating chamber when the piston reaches the lower end of stroke position, wherein, in the lower end of stroke position, the venting orifice is positioned below the barrel.

1 . Downhole pump comprising:
 an extension wall;   a barrel that extends vertically to the interior of the extension wall; a gas separating chamber delimited by the barrel and the interior surface of the extension wall; and
 a piston comprising a travelling valve in its lower portion, wherein the piston is configured to slide vertically in the barrel to the interior of the separating chamber between an upper end of stroke position and a lower end of stroke position; 
 wherein the piston comprises at least one venting orifice, wherein the at least one venting orifice is configured to provide communication between the interior of the piston and the gas separating chamber when the piston reaches the lower end of stroke position, wherein, in the lower end of stroke position, the venting orifice is positioned below the barrel. 
   
     
     
         2 . Downhole pump according to  claim 1 , wherein the piston comprises a plurality of venting orifices. 
     
     
         3 . Downhole pump according to  claim 2 , wherein the venting orifices are located at the same horizontal position on the piston. 
     
     
         4 . Downhole pump according to  claim 2 , wherein the venting orifices have different dimensions. 
     
     
         5 . Downhole pump according to  claim 1 , wherein the at least one venting orifice provides fluid communication between the interior of the piston and the separating chamber in the uppermost region of the separating chamber. 
     
     
         6 . Downhole pump according to  claim 1 , further comprising a nipple configured to be connected to a lower end of a production pipe between the barrel and the production pipe. 
     
     
         7 . Downhole pump according to  claim 6 , further comprising an end-of-stroke sleeve configured to be connected to a sucker rod, wherein the nipple is adapted to interrupt the descending motion of the end-of-stroke sleeve when the piston reaches the lower end of stroke position. 
     
     
         8 . Downhole pump according to  claim 7 , wherein the end-of-stroke sleeve is configured to be connected at an end of the sucker rod, wherein the pump further comprises a connecting rod which connects the end-of-stroke sleeve to the piston. 
     
     
         9 . Downhole pump according to  claim 7 , wherein the end-of-stroke sleeve is configured to be adjustably connected to the sucker rod. 
     
     
         10 . Downhole pump according to  claim 1 , wherein the extension wall is an extension of the barrel, the interior of the extension wall having a larger diameter than the interior of the barrel. 
     
     
         11 . Downhole pump according to  claim 1 , wherein the gas separating chamber comprises a standing valve. 
     
     
         12 . Downhole pump according to  claim 1 , wherein the piston is configured to be driven by a sucker rod. 
     
     
         13 . Downhole pump according to  claim 1 , wherein the venting orifice is configured not to provide communication between the interior of the piston and the gas separating chamber when the piston is away from the lower end of stroke position.