Continuous rod pump drive system

Abstract

In a downhole rod-driven pump, continuous rod is used to drive the pump. The continuous rod is connected directly to the drive eliminating the need for a polish rod and an uphole coupling. A coupling is used to connect the continuous rod to the pump reducing restrictions in the production annulus and wear on the production tubing. Further, clean out tubing can be inserted into the production tubing beside the continuous rod and can extend therein to the pump without restriction. When the coupling is a threaded coupling, the continuous rod can be rotated in an appropriate direction to release the continuous rod from the pump when the pump is stuck. When the coupling is a shear coupling, the shear coupling can be sheared for releasing the pump from the continuous rod. When the pump is a progressing cavity pump and the coupling is a shear coupling, the continuous rod can be reverse rotated for changing the direction of pumping and if the rotor thereafter remains stuck, the shear coupling can be sheared.

1 . A method for installing and driving driven component of a rod-driven pump, the pump being fluidly connected at a bottom of a string of production tubing fluidly connected to a wellhead at surface, the method comprising:
 providing a continuous rod;   coupling a downhole end of the continuous rod to an uphole end of the driven component;   running the continuous rod and driven component downhole through a bore of the production tubing;   ensuring the continuous rod is of sufficient length to be operatively connected to the pump in the wellbore and drivingly secured to a drive at surface; and   driveably securing the continuous rod to the drive at surface,   wherein the continuous rod is driven by the drive for pumping produced fluids to surface through the bore of the production tubing.   
     
     
         2 . The method of  claim 1  wherein the pump is a rotary pump having a rotor and a stator, the rotor being the driven component, and the drive is a drive head, the method comprising:
 coupling the downhole end of the continuous rod to an uphole end of the rotor; 
 running the continuous rod and rotor downhole through a bore of the production tubing; 
 landing the rotor in the stator of the rotary pump for operatively engaging the rotor therein; and 
 once the rotor is engaged with the stator, 
 cutting the continuous rod above the drive head for driveably securing the continuous rod thereto, 
 wherein the continuous rod co-rotates with the drive shaft for rotation of the rotor in the stator in a first pumping direction for pumping produced fluids to surface through the bore of the production tubing. 
 
     
     
         3 . The method of  claim 2  further comprising coupling the downhole end of the continuous rod to the uphole end of the rotor using a threaded coupling. 
     
     
         4 . The method of  claim 3 , when the continuous rod is to be disconnected from the rotor without removal of the rotor from the stator, the method further comprising;
 rotating the continuous rod in a reverse direction for unthreading the downhole end of the continuous rod from the rotor.   
     
     
         5 . The method of  claim 2  further comprising driveably coupling the downhole end of the continuous rod to the rotor using a shear coupling. 
     
     
         6 . The method of  claim 5 , when the rotor cannot be rotated in the stator in the first direction, the method further comprising:
 rotating the continuous rod and the rotor in a reverse direction for pumping particulates downhole into the wellbore for freeing the rotor in the stator and thereafter   rotating the continuous rod and the rotor in the first pumping direction for pumping produced fluids to surface.   
     
     
         7 . The method of  claim 6  wherein, after rotating the rotor in the reverse direction, the rotor cannot be reverse-rotated in the stator, further comprising:
 axially shearing the shear coupling for freeing the downhole end of the continuous rod from the rotor. 
 
     
     
         8 . The method of  claim 2  further comprising:
 coupling the downhole end of the continuous rod to the rotor using a length of sucker rod, the sucker rod being welded, at an uphole end, to the downhole end of the continuous rod and having the threaded coupling at the downhole end for threaded connection to the rotor. 
 
     
     
         9 . The method of  claim 1  wherein the pump is a reciprocating pump, the driven component being a plunger, and the drive is a pumpjack, the method further comprising:
 coupling the downhole end of the continuous rod to the uphole end of the plunger using a threaded coupling. 
 
     
     
         10 . The method of  claim 9 , when the continuous rod is to be disconnected from the pump, the method further comprising;
 rotating the continuous rod for unthreading the downhole end of the continuous rod from the plunger.   
     
     
         11 . The method of  claim 1  wherein the pump is a reciprocating pump, the driven component being a plunger, and the drive is a pumpjack, the method further comprising:
 coupling the downhole end of the continuous rod to the plunger using a shear coupling. 
 
     
     
         12 . The method of  claim 11  wherein the continuous rod is to be disconnected from the pump, further comprising:
 axially shearing the shear coupling for freeing the downhole end of the continuous rod from the plunger. 
 
     
     
         13 . The method of  claim 1 , when particulates deposit in the pump, further comprising:
 inserting a cleanout tubing string into the bore of the production tubing in a production annulus formed between the continuous rod and the production tubing;   passing the cleanout tubing string substantially unrestricted through the production annulus to the coupling of the continuous rod to the driven component of the pump; and   providing fluid through the cleanout tubing string for cleaning particulates from the pump.   
     
     
         14 . A method for installing and driving a rotor in a stator of a rod-driven rotary pump, the pump being fluidly connected at a bottom of a string of production tubing fluidly connected to a wellhead at surface, the method comprising:
 providing a continuous rod;   coupling a downhole end of the continuous rod to an uphole end of the rotor;   running the continuous rod and rotor through a bore of the production tubing;   landing the rotor in the stator of the rotary pump for operatively engaging the rotor therein; and   once the rotor is engaged with the stator,
 locking the continuous rod in the wellhead; 
 cutting the continuous rod at a length calculated to extend above a drive head when installed on the wellhead; 
 installing the drive head to the wellhead, the continuous rod passing through a hollow drive shaft in the drive head; and 
 driveably securing the continuous rod thereto above the drive head, 
   wherein the continuous rod co-rotates with the drive shaft for rotation of the rotor in the stator in a first pumping direction for pumping produced fluids to surface through the bore of the production tubing.   
     
     
         15 . The method of  claim 14  further comprising coupling the downhole end of the continuous rod to the uphole end of the rotor using a threaded coupling. 
     
     
         16 . The method of  claim 15 , when the continuous rod is to be disconnected from the rotor without removal of the rotor from the stator, the method further comprising;
 rotating the continuous rod in a reverse direction for unthreading the downhole end of the continuous rod from the rotor.   
     
     
         17 . The method of  claim 14  further comprising coupling the downhole end of the continuous rod to the rotor using a shear coupling. 
     
     
         18 . The method of  claim 17 , when the rotor cannot be rotated in the stator in the first direction, the method further comprising:
 co-rotating the continuous rod and the rotor in a reverse direction for pumping particulates downhole into the well for freeing the rotor in the stator and thereafter   co-rotating the continuous rod and the rotor in the first pumping direction for pumping produced fluids to surface.   
     
     
         19 . The method of  claim 18  wherein after co-rotating the continuous rod and the rotor in the reverse direction, the rotor cannot thereafter be co-rotated in the stator in the first pumping direction, further comprising:
 axially shearing the shear coupling for freeing the downhole end of the continuous rod from the rotor. 
 
     
     
         20 . The method of  claim 14  further comprising:
 coupling the continuous rod to the rotor using a length of sucker rod welded, at an uphole end, to the downhole end of the continuous rod and having a threaded end at the downhole end for threaded connection to the rotor. 
 
     
     
         21 . The method of  claim 14 , when particulates deposit in the stator inhibiting co-rotation of the rotor, further comprising:
 inserting a cleanout tubing string into the bore of the production tubing in a production annulus formed between the continuous rod and the production tubing;   passing the cleanout tubing string substantially unrestricted through the production annulus to the coupling of the continuous rod to the rotor; and   providing fluid through the cleanout tubing string for cleaning particulates from the pump.   
     
     
         22 . A method for servicing a rod-driven pump fluidly connected to a bore of a production tubing in a wellbore comprising:
 driveably connecting an uphole end of a continuous rod to a drive at surface, the continuous rod extending through the bore of the production tubing from the drive to the pump;   providing a coupling for driveably connecting between a downhole end of the continuous rod and the pump;   inserting a cleanout tubing string into the bore of the production tubing in a production annulus formed between the continuous rod and the production tubing, the cleanout tubing string passing within the production annulus, substantially unrestricted by the continuous rod therein, to the coupling at the downhole end of the continuous rod; and   circulating cleanout fluids through the cleanout tubing string.   
     
     
         23 . The method of  claim 22  further comprising:
 providing a threaded coupling for connecting between the downhole end of the continuous rod and the pump. 
 
     
     
         24 . The method of  claim 22  further comprising:
 providing a shear coupling for connecting between the downhole end of the continuous rod and the pump. 
 
     
     
         25 . A rod-driven pumping system comprising:
 a drive positioned at surface;   a continuous rod driveably connected to the drive and extending downhole through a bore of a production tubing to a pump, forming a production annulus therebetween; and   a coupling connecting between the continuous rod and the pump, the production annulus having a maximized pass-by clearance along a length of the continuous rod from the wellhead to the coupling at the pump and being sufficient to permit a cleanout tubing to pass substantially unrestricted therethrough.   
     
     
         26 . The rod-driven pumping system of  claim 25  wherein the coupling is a threaded coupling. 
     
     
         27 . The rod-driven pumping system of  claim 25  wherein the coupling is a shear coupling. 
     
     
         28 . The rod-driven pumping system of  claim 25  wherein the system further comprises a length of sucker rod welded at an uphole end to a downhole end of the continuous rod and having threads at a downhole end for connection to the coupling. 
     
     
         29 . The rod-driven pumping system of  claim 25  wherein the pump is a rod-driven progressing cavity pump having a stator and a rotor operatively engaged within the stator for rotation therein and wherein,
 the drive comprises a drive head having a hollow drive shaft supported on a wellhead at surface, the continuous rod being driveably connected through the hollow drive shaft of the drive head; and 
 the coupling connects between the continuous rod and the rotor. 
 
     
     
         30 . A rod string for driving a pump in a wellbore, the rod string comprising:
 a continuous rod having an uphole end for drivingly connecting to a drive at surface and a downhole end for connection to the pump; and   a coupling for connecting between the downhole end of the continuous rod and the pump.   
     
     
         31 . The rod string of  claim 30  further comprising
 a length of sucker rod having an uphole end welded to the downhole end of the continuous rod and having a downhole end for connection to the coupling. 
 
     
     
         32 . The rod string of  claim 30  wherein the coupling is a threaded coupling. 
     
     
         33 . The rod string of  claim 31  wherein the coupling is a threaded coupling and wherein the downhole end of the length of sucker rod is threaded for connection to the coupling. 
     
     
         34 . The rod string of  claim 30  wherein the coupling is a shear coupling.