Apparatus and method for preventing particle interference of downhole devices

Abstract

A device and method for inhibiting particle (e.g., sand) accumulation on down hole equipment, such as an ESP, particularly when the equipment is not in use. The device and methods permit the equipment to start and stop with fewer break downs and at greater efficiency. The device includes a central tubular section connecting the equipment to the production tubing string. The tubular section is surrounded by an annulus and a number of ports in the tubular section angled to allow fluid communication between the tubular section and the annulus during operation, but prevent particles from flowing from the annulus into the tubular section when not in use. A check valve between the tube and ESP assists in isolating the ESP from sand.

1 . A device for preventing particle interference with downhole lifting equipment in a well bore having a production tubing string, comprising:
 a tube positioned between the downhole lifting equipment and the surface and in fluid communication with the downhole lifting equipment and the production tubing string;   a housing positioned around the tube defining an annulus portion between the tube and the housing;   an upper check valve connected to a proximal end of the tube nearest the surface that is biased into a closed position to prevent flow into the tube through the proximal end;   a lower check valve connected to a distal end of the tube that is biased into a closed position to prevent flow out of the tube through the distal end; and   a plurality of ports disposed through the tube that are configured to permit flow from the tube into the annulus, wherein the ports are spaced along the tube and oriented at a downward angle relative to the longitudinal axis of the tube.   
     
     
         2 . The device of  claim 1 , wherein the downward angle of the ports is between 30 degrees and 60 degrees relative to the longitudinal axis of the tube. 
     
     
         3 . The device of  claim 1 , wherein the largest number of ports are positioned nearest the distal end. 
     
     
         4 . The device of  claim 3 , wherein the fewest number of ports are positioned nearest the proximal end. 
     
     
         5 . The device of  claim 1 , wherein the upper check valve is movable into an open position to permit flow out of the tube through the proximal end. 
     
     
         6 . The device of  claim 1 , wherein the lower check valve is movable into an open position to permit flow into the tube through the distal end. 
     
     
         7 . A system for preventing particle interference with downhole lifting equipment in a well bore having a production tubing string, comprising:
 downhole lifting equipment;   a tube positioned between the downhole lifting equipment and the surface and in fluid communication with the downhole lifting equipment and the production tubing string;   a housing positioned around the tube defining an annulus portion between the tube and the housing;   an upper check valve connected to a proximal end of the tube nearest the surface that is biased into a closed position to prevent flow into the tube through the proximal end;   a lower check valve connected to a distal end of the tube that is biased into a closed position to prevent flow out of the tube through the distal end; and   a plurality of ports disposed through the tube that are configured to permit flow from the tube into the annulus, wherein the ports are spaced along the tube and oriented at a downward angle relative to the longitudinal axis of the tube.   
     
     
         8 . The system of  claim 7 , wherein the downward angle of the ports is between 30 degrees and 60 degrees relative to the longitudinal axis of the tube. 
     
     
         9 . The system of  claim 7 , wherein the largest number of ports are positioned nearest the distal end. 
     
     
         10 . The system of  claim 9 , wherein the fewest number of ports are positioned nearest the proximal end. 
     
     
         11 . The system of  claim 7 , wherein the upper check valve is movable into an open position to permit flow out of the tube through the proximal end. 
     
     
         12 . The system of  claim 7 , wherein the lower check valve is movable into an open position to permit flow into the tube through the distal end. 
     
     
         13 . The system of  claim 7 , wherein the downhole lifting equipment comprises an electric submersible pump.