Cranked rod pump apparatus and method

Abstract

An improved apparatus and method are provided, for pumping fluids, such as water and/or hydrocarbons, from a subterranean formation or reservoir, through use of a cranked rod pumping (cranked rod pumping) apparatus for imparting reciprocating substantially vertical motion to a rod of a sucker-rod pump having a pump stroke. The cranked rod pumping apparatus includes a motor driven cranked mechanical actuator arrangement. The cranked mechanical actuator arrangement includes a cable coupled to a substantially vertically moveable member which is attached to the rod of the sucker-rod pump for imparting and controlling vertical motion of the rod of the sucker-rod pump.

What is claimed is: 
     
         1 . A cranked rod pumping apparatus, for imparting reciprocating substantially vertical motion to a rod of a sucker-rod pump having a pump stroke, the apparatus comprising:
 a cranked mechanical actuator arrangement, having a substantially vertically movable member attached to the rod of the sucker-rod pump for imparting and controlling vertical motion of the rod of the sucker-rod pump;   a motor coupled to a crank arm, the crank arm configured to rotate about a pivot bearing coaxial aligned with the motor axis of rotation at one end of the motor; and   an actuator member coupled to the substantially vertically movable member at one end and pivotally coupled to the crank arm at another end in a manner establishing a fixed relationship between the rotational position of the crank arm and the reciprocal vertical movement of the vertically movable member.   
     
     
         2 . The cranked rod pumping apparatus of  claim 1 , further comprising, the actuator member is a cable, with one end of the cable fixedly coupled to the substantially vertically movable member and another end pivotally coupled to the crank arm. 
     
     
         3 . The cranked rod pumping apparatus of  claim 1 , further comprising, the actuator member is a rigid rod, with one end of the rigid rod pivotally coupled to the substantially vertically movable member and another end pivotally coupled to the crank arm. 
     
     
         4 . The cranked rod pumping apparatus of  claim 1 , further comprising, a motor drive and controller for operating the motor in a substantially constant input power operational mode. 
     
     
         5 . The cranked rod pumping apparatus of  claim 4 , wherein, the cranked rod pumping apparatus includes substantially no electrical power storage elements. 
     
     
         6 . The cranked rod pumping apparatus of  claim 4 , wherein, the cranked rod pumping apparatus includes substantially no power storage elements. 
     
     
         7 . The cranked rod pumping apparatus of  claim 1 , wherein, the cranked rod pumping apparatus includes a solar energy power source operatively attached for providing some or all of the power for driving the motor. 
     
     
         8 . The cranked rod pumping apparatus of  claim 7 , wherein, the cranked rod pumping apparatus solar energy power source is the sole source of power for driving the motor, such that the cranked rod pumping apparatus only pumps when the solar energy power source is producing sufficient power to drive the motor. 
     
     
         9 . The cranked rod pumping apparatus of  claim 2 , wherein, the cranked mechanical actuator arrangement further comprises, a frame having a base thereof adapted for attachment to the wellhead of a well, and at least one support column extending vertically upwardly from the base and the cable is slidably mounted on a pulley rotatably coupled to the support column and constrained by the pulley for substantially linear reciprocating movement. 
     
     
         10 . The cranked rod pumping apparatus of  claim 1 , wherein, cranked rod mechanical actuator further comprises a pneumatic counterbalance arrangement operatively connected between the base and the vertically movable member. 
     
     
         11 . The cranked rod pumping apparatus of  claim 10 , wherein, the pneumatic counterbalance arrangement comprises, at least one pneumatic cylinder operatively connected to the base and the vertically movable member for storing energy during a portion of the downward stroke of the vertically movable member, and for releasing the stored energy during a portion of a subsequent upward stroke of the vertically movable member. 
     
     
         12 . The cranked rod pumping apparatus of  claim 11 , wherein, the at least one pneumatic cylinder is disposed between the vertically movable member and the base. 
     
     
         13 . The cranked rod pumping apparatus of  claim 2 , wherein the cable and crank arm are configured to substantially align the cable with a line of force exerted by the vertically movable element on the rod. 
     
     
         14 . The cranked rod pumping apparatus of  claim 1 , wherein, the cranked rod mechanical actuator further comprises an additional crank arm coupled to the motor with a second pivot bearing coaxial aligned with the motor axis of rotation on another end of the motor;
 a second actuator member coupled to the substantially vertically movable member at one end and pivotally coupled to the additional crank arm at another end for substantially linear reciprocating movement in unison with the other cable.   
     
     
         15 . The cranked rod pumping apparatus of  claim 1 , wherein, the motor is a hydraulic motor directly coupled to the crank arm without a gearbox. 
     
     
         16 . A method for extending the operating life of a hydrocarbon well having a walking beam apparatus operatively connected thereto for imparting reciprocating substantially vertical motion to a rod of a sucker-rod pump having a pump stroke disposed in the well, the method comprising:
 disconnecting the rod from the walking beam apparatus, and operatively connecting the rod to a cranked rod pumping apparatus, with the cranked rod pumping apparatus comprising:
 a cranked mechanical actuator arrangement, having a substantially vertically movable member attached to the rod of the sucker-rod pump for imparting and controlling vertical motion of the rod of the sucker-rod pump; a motor coupled to a crank arm, the crank arm configured to rotate about a pivot bearing coaxial aligned with the motor axis of rotation at one end of the motor; and 
   an actuator member coupled to the substantially vertically movable member at one end and pivotally coupled to the crank arm at another end in a manner establishing a fixed relationship between the rotational position of the crank arm and the reciprocal vertical movement of the vertically movable member, wherein the actuator member is one of a cable having one end fixedly coupled to the substantially vertically movable member and a rigid rod having one end pivotally coupled to the substantially vertically movable member.   
     
     
         17 . The method of  claim 16 , further comprising, operating the cranked rod pumping apparatus at a lower production rate than the production rate of the walking beam pump prior to its replacement by the cranked rod pumping apparatus. 
     
     
         18 . The method of  claim 16 , further comprising, mounting the cranked rod pumping apparatus directly on a wellhead of the well. 
     
     
         19 . The method of  claim 16 , further comprising, leaving the walking beam apparatus in place adjacent the well. 
     
     
         20 . The method of  claim 16 , wherein the motor is a hydraulic motor directly coupled to the crank arm without a gearbox. 
     
     
         21 . A method for pumping fluid from a source of fluid located in a remote location, comprising: operatively attaching a cranked rod pumping apparatus to the source of fluid, with the cranked rod pumping apparatus including:
 a cranked mechanical actuator arrangement, having a substantially vertically movable member attached to the rod of the sucker-rod pump for imparting and controlling vertical motion of the rod of the sucker-rod pump;   a motor coupled to a crank arm, the crank arm configured to rotate about a pivot bearing coaxial aligned with the motor axis of rotation at one end of the motor; and   a cable fixedly coupled to the substantially vertically movable member at one end and pivotally coupled to the crank arm at another end in a manner establishing a fixed relationship between the rotational position of the crank arm and the reciprocal vertical movement of the vertically movable member.   
     
     
         22 . The method of  claim 21 , further comprising, attaching the cranked rod pumping apparatus to a stand-alone source of power. 
     
     
         23 . The method of  claim 22 , wherein, the stand-alone source of power comprises a solar energy power source. 
     
     
         24 . A method for starting a cranked rod pumping apparatus driven by a motor having an output shaft, comprising the steps of:
 rotating the motor to impart a rotational speed and direction of rotation to the output shaft;   if the rotational speed slows below a threshold speed, reversing the direction of rotation of the motor; and   continuing to reverse the direction of rotation according to the second step until the rotational speed no longer slows below the threshold speed.   
     
     
         25 . The method for starting a cranked rod pumping apparatus of  claim 24 , wherein, the cranked rod pumping apparatus comprises:
 a cranked mechanical actuator arrangement, having a substantially vertically movable member attached to the rod of the sucker-rod pump for imparting and controlling vertical motion of the rod of the sucker-rod pump;   a motor coupled to a crank arm, the crank arm configured to rotate about a pivot bearing coaxial aligned with the motor axis of rotation at one end of the motor; and   an actuator member coupled to the substantially vertically movable member at one end and pivotally coupled to the crank arm at another end in a manner establishing a fixed relationship between the rotational position of the crank arm and the reciprocal vertical movement of the vertically movable member, wherein the actuator member is one of a cable having one end fixedly coupled to the substantially vertically movable member and a rigid rod having one end pivotally coupled to the substantially vertically movable member.   
     
     
         26 . The method of  claim 25 , wherein the motor is a hydraulic motor directly coupled to the crank arm without a gearbox.