Submersible pump

Abstract

A submersible pump includes a fluid-end section, a power-end section, a top connection sub and an umbilical. The fluid-end section includes a tubular fluid-end barrel, an upper piston disposed within the fluid-end barrel bore, and a traveling valve disposed at the upper piston upper end. The power-end section includes a tubular hydraulic cylinder. A lower piston disposed within the hydraulic cylinder bore is connected to the upper piston. The top connection sub connected to the fluid-end barrel upper end has a discharge port and a standing valve disposed below the discharge port. The umbilical includes first and second tubing strings providing fluid communications between a prime mover and the hydraulic cylinder bore below and above the lower piston face, respectively. A third tubing string provides fluid communications between a wellhead and the top connection sub discharge port.

What is claimed is: 
     
         1 . A submersible pump adapted for use with a downhole well having a wellhead, a prime mover providing wellbore fluid, and a wellbore extending from the wellhead, the pump comprising:
 an umbilical including
 a first tubing string adapted to provide fluid communications with the prime mover, 
 a second tubing string adapted to provide fluid communications with the prime mover, and 
 a third tubing string adapted to provide fluid communications with the wellhead; 
   an upper, fluid-end section including
 a tubular fluid-end barrel extending from an upper end to a lower end and having an inner surface that defines an axially extending bore, and 
 an upper piston disposed within the fluid-end barrel bore and axially, slidably movable therein, the upper piston extending from an upper end to a lower end and having
 an inner surface defining a bore extending axially from the upper end, 
 a ported piston rod adaptor disposed at the lower end defining a fluid passage for flow of wellbore fluid into the upper piston bore, and 
 a traveling valve disposed at the upper piston upper end, the traveling valve having open and closed positions wherein the upper piston bore is in fluid communication with a space above the upper piston when the traveling valve is in the open position and no fluid can flow between the upper piston bore and the space above the upper piston when the traveling valve is in the closed position; 
 
   a lower, power-end section including
 a tubular hydraulic cylinder extending from an upper end to a lower end and having an inner surface defining an axially extending bore, and 
 a lower piston disposed within the hydraulic cylinder bore and axially, slidably movable therein, the lower piston having
 an upper piston face, 
 a connecting rod extending upwardly from the upper piston face to an upper end connected to upper piston lower end, and 
 a lower piston face; 
 
   a top connection sub connected to the fluid-end barrel upper end having
 a discharge port connectable with the third tubing string, and 
 a standing valve disposed below the discharge port, the standing valve having open and closed positions wherein the space above the upper piston is in fluid communication with the discharge port when the standing valve is in the open position and no fluid can flow between the space above the upper piston and the discharge port when the standing valve is in the closed position; 
   a bottom connection sub connected to the hydraulic cylinder lower end, the bottom connection sub having a port connectable to first tubing string providing fluid communication with the hydraulic cylinder bore below the lower piston face;   an intermediate connection sub having
 a lower end connected to the hydraulic cylinder upper end, 
 a port connectable to second tubing string providing fluid communication with the hydraulic cylinder bore above the upper piston face, and 
 an inner surface defining an axially extending bore; and 
   a ported suction strainer having
 a lower end connected to the intermediate connection sub, 
 an upper end connected to the fluid-end barrel lower end, and 
 an inner surface defining an axially extending bore. 
   
     
     
         2 . The submersible pump of  claim 1  wherein the intermediate connection sub also has an upper end connected to the ported suction strainer lower end, the intermediate connection sub upper end comprising a seal section. 
     
     
         3 . The submersible pump of  claim 2  wherein the seal section has an inner surface defining an axially extending bore. 
     
     
         4 . The submersible pump of  claim 1  wherein the lower piston connecting rod defines an axially extending bore for directing a portion of the wellbore fluid from the lower piston into the fluid-end barrel whereby the upper piston is lubricated. 
     
     
         5 . The submersible pump of  claim 1  wherein the lower piston has an outer surface that engages the hydraulic cylinder inner surface defining a fluid seal between the hydraulic cylinder bore below the lower piston face and the hydraulic cylinder bore above the upper piston face. 
     
     
         6 . The submersible pump of  claim 1  further comprising a pressure sensor disposed in the hydraulic cylinder, the pressure sensor being adapted to send pressure signals to a controller of the prime mover. 
     
     
         7 . The submersible pump of  claim 1  wherein the standing valve and the traveling valve each include a spring, a stem guide, a valve body and a seat, the spring and the stem guide directing the valve body to engage the seat. 
     
     
         8 . A pumping system adapted for use with a downhole well having a wellhead and a wellbore extending from the wellhead, the pumping system comprising:
 a prime mover providing a high pressure wellbore fluid;   a submersible pump comprising
 an upper, fluid-end section including
 a tubular fluid-end barrel extending from an upper end to a lower end and having an inner surface that defines an axially extending bore, 
 an upper piston disposed within the fluid-end barrel bore and axially, slidably movable therein, the upper piston extending from an upper end to a lower end and defining a bore extending axially from the upper end, and 
 a traveling valve disposed at the upper piston upper end, the traveling valve having open and closed positions wherein the upper piston bore is in fluid communication with a space above the upper piston when the traveling valve is in the open position and no fluid can flow between the upper piston bore and the space above the upper piston when the traveling valve is in the closed position, 
 
 a lower, power-end section including
 a tubular hydraulic cylinder extending from an upper end to a lower end and having an inner surface defining an axially extending bore, and 
 a lower piston disposed within the hydraulic cylinder bore and axially, slidably movable therein, the lower piston being connected to the upper piston lower end and having
 an upper piston face, and 
 a lower piston face, 
 
 
 a top connection sub connected to the fluid-end barrel upper end having
 a discharge port, and 
 a standing valve disposed below the discharge port, the standing valve having open and closed positions wherein the space above the upper piston is in fluid communication with the discharge port when the standing valve is in the open position and no fluid can flow between the space above the upper piston and the discharge port when the standing valve is in the closed position, and 
 
 a ported suction strainer disposed intermediate the fluid-end section and the power-end section, the strainer defining an axially extending bore; and 
   an umbilical including
 a first tubing string providing fluid communications between the prime mover and the hydraulic cylinder bore below the lower piston face, 
 a second tubing string providing fluid communications between the prime mover and the hydraulic cylinder bore above the upper piston face, and 
 a third tubing string providing fluid communications between the wellhead and the top connection sub discharge port. 
   
     
     
         9 . The submersible pump of  claim 8  wherein
 the submersible pump further comprises a pressure sensor disposed in the hydraulic cylinder, and 
 the prime mover includes a directional controller in communication with the submersible pump pressure sensor, the directional controller being adapted to sense pressure spikes of the wellbore fluid. 
 
     
     
         10 . The submersible pump of  claim 9  wherein the directional controller shifts the high pressure wellbore fluid to another of the first or second tubing strings when a pressure spike of the wellbore fluid is sensed. 
     
     
         11 . The submersible pump of  claim 9  wherein the submersible pump has a speed of operation, the wellbore fluid has a flow volume, and the directional controller controls the submersible pump speed of operation by adjusting the wellbore flow volume. 
     
     
         12 . A submersible pump adapted for use with a downhole well having a wellhead, a prime mover providing wellbore fluid, and a wellbore extending from the wellhead, the pump comprising:
 an upper, fluid-end section including
 a tubular fluid-end barrel extending from an upper end to a lower end and having an inner surface that defines an axially extending bore, 
 an upper piston disposed within the fluid-end barrel bore and axially, slidably movable therein, the upper piston extending from an upper end to a lower end and defining a bore extending axially from the upper end, and 
 a traveling valve disposed at the upper piston upper end, the traveling valve having open and closed positions wherein the upper piston bore is in fluid communication with a space above the upper piston when the traveling valve is in the open position and no fluid can flow between the upper piston bore and the space above the upper piston when the traveling valve is in the closed position, a lower, power-end section including 
 a tubular hydraulic cylinder extending from an upper end to a lower end and having an inner surface defining an axially extending bore, and 
 a lower piston disposed within the hydraulic cylinder bore and axially, slidably movable therein, the lower piston being connected to the upper piston lower end and having
 an upper piston face, and 
 a lower piston face, 
 
   a top connection sub connected to the fluid-end barrel upper end having
 a discharge port, and 
 a standing valve disposed below the discharge port, the standing valve having open and closed positions wherein the space above the upper piston is in fluid communication with the discharge port when the standing valve is in the open position and no fluid can flow between the space above the upper piston and the discharge port when the standing valve is in the closed position; 
   a ported suction strainer disposed intermediate the fluid-end section and the power-end section, the strainer defining an axially extending bore; and   an umbilical including
 a first tubing string adapted to provide fluid communications between the prime mover and the hydraulic cylinder bore below the lower piston face, 
 a second tubing string adapted to provide fluid communications between the prime mover and the hydraulic cylinder bore above the upper piston face, and 
 a third tubing string adapted to provide fluid communications between the wellhead and the top connection sub discharge port. 
   
     
     
         13 . The submersible pump of  claim 12  wherein the upper piston bore extends axially from the upper end and the upper piston also includes a ported piston rod adaptor disposed at the lower end, the piston rod adaptor defining a fluid passage for flow of wellbore fluid into the upper piston bore. 
     
     
         14 . The submersible pump of  claim 12  wherein the lower piston is connected to the upper piston lower end by a connecting rod, the connecting rod extending upwardly from the upper piston face to an upper end connected to upper piston lower end. 
     
     
         15 . The submersible pump of  claim 12  further comprising a bottom connection sub connected to the hydraulic cylinder lower end, the bottom connection sub having a port connectable to first tubing string. 
     
     
         16 . The submersible pump of  claim 12  further comprising an intermediate connection sub disposed intermediate the suction strainer and the power-end section, the intermediate connection sub including
 a lower end connected to the hydraulic cylinder upper end, 
 a port connectable to the second tubing string, and 
 an inner surface defining an axially extending bore. 
 
     
     
         17 . The submersible pump of  claim 16  wherein the suction strainer includes
 a lower end connected to the intermediate connection sub, and 
 an upper end connected to the fluid-end barrel lower end. 
 
     
     
         18 . The submersible pump of  claim 12  wherein the intermediate connection sub also has an upper end connected to the suction strainer lower end, the intermediate connection sub upper end comprising a seal section. 
     
     
         19 . The submersible pump of  claim 18  wherein the seal section has an inner surface defining an axially extending bore. 
     
     
         20 . The submersible pump of  claim 12  wherein the lower piston connecting rod defines an axially extending bore for directing a portion of the wellbore fluid from the lower piston into the fluid-end barrel whereby the upper piston is lubricated. 
     
     
         21 . The submersible pump of  claim 12  wherein the lower piston has an outer surface that engages the hydraulic cylinder inner surface defining a fluid seal between the hydraulic cylinder bore below the lower piston face and the hydraulic cylinder bore above the upper piston face. 
     
     
         22 . The submersible pump of  claim 12  further comprising a pressure sensor disposed in the hydraulic cylinder, the pressure sensor being adapted to send pressure signals to a controller of the prime mover. 
     
     
         23 . The submersible pump of  claim 12  wherein the standing valve and the traveling valve each include a spring, a stem guide, a valve body and a seat, the spring and the stem guide directing the valve body to engage the seat.