Mechanical pump spacing adjustment system

Abstract

A well string positioner capable of actuation during the vertical reciprocal movement of a well string will, upon actuation, increase or decrease the length of the well string within the tubular. The vertical reciprocal stroke of the power unit of the well is not changed when the well string length within the tubular is changed, and the well string can be adjusted in operation of the well without the need to disassemble the well string. A system for retrofit to a pre-existing pump jack is disclosed, as well as a conventional pump jack with the well string positioner and capability of the system incorporated as manufactured.

1 . A system for use in the adjustment of the well string length within a well tubular of a well comprising:
 a) a well tubular extending downwards from a wellhead at the earth surface to the bottom of the well in a subterranean fluid-producing formation;   b) a well string having a lower end and a top end and extending downward inside the well tubular through a seal at the wellhead to at least a position within the tubular within the fluid-producing formation;   c) a downhole plunger-style pump located within the tubular and attached at the lower end of the well string which will be actuated by vertical reciprocating movement of the well string to pump oil from the formation up the well tubular to the wellhead; and   d) a vertical reciprocating power unit capable of applying vertical reciprocating motion of the desired stroke length for the pump to the well string;   said system comprising:   a) a well string positioner capable of powered actuation and connecting the top end of the well string to the reciprocating power unit and which, upon actuation, will raise or lower the well string below the well string positioner through the seal on the wellhead, resulting in the decrease or increase of the length of the well string within the tubular; and   b) a controller capable of actuation of the well string positioner by an operator;   
       whereby during operation of the vertical reciprocating power unit, an operator can use the controller to actuate the well string positioner to modify the length of the well string within the tubular; and
 wherein the length of the well string within the tubular can be adjusted during operation of the vertical reciprocating power unit without the need to disassemble the well string, and the stroke of the reciprocal movement does not change when the length of the well string within the tubular is changed. 
 
     
     
         2 . The system of  claim 1  wherein the top end of the well string is threaded, and the well string positioner comprises a rotary power source capable of engaging the threaded top end of the well string and altering the length of the well string within the tubular by rotary power applied to the threaded end resulting in the raising or lowering of the well string in relation to the wellhead seal. 
     
     
         3 . The system of  claim 2  wherein the well string positioner comprises:
 a. a carrier bar with a bar aperture therethrough through which the threaded portion of the top end of the well string extends, said carrier bar being attached to the reciprocating movement; 
 b. load-bearing means engaging the threaded portion of the top end of the well string to the carrier bar, such that the vertical motion of the carrier bar will be translated upon the well string; and 
 c. a bi-directional rotary power means capable of actuation while the reciprocating movement is in operation, whereby on actuation of the rotary power means the threaded portion of the top end of the well string can be moved up or down through the bar aperture, resulting in the raising or lowering of the well string below the carrier bar and the decrease or increase of the length of the well string within the tubular. 
 
     
     
         4 . The system of  claim 3  wherein the rotary power means comprises a hydraulic motor. 
     
     
         5 . The system of  claim 3  wherein the rotary power means comprises an electric motor. 
     
     
         6 . The system of  claim 1  wherein the well string positioner can rotate the length of the well string within the tubular, and the controller can be used to rotate the well string. 
     
     
         7 . The system of  claim 6  wherein the controller automatically periodically and incrementally rotates the well string. 
     
     
         8 . The system of  claim 1  wherein the well string positioner is a linear actuator configured to apply a linear contraction or extension of the length of the well string within the tubular. 
     
     
         9 . The system of  claim 1  wherein the vertical reciprocating power unit is a conventional oilfield pump jack. 
     
     
         10 . A vertical reciprocating pump jack for use in oilfield extraction being adapted to allow for adjustment of the well string length within a well tubular of a well comprising:
 a) a well tubular extending downwards from a wellhead at the earth surface to the bottom of the well in a subterranean fluid-producing formation;   b) a well string having a lower end and a top end and extending downward inside the well tubular through a seal at the wellhead to at least a position within the tubular within the fluid-producing formation; and   c) a downhole plunger-style pump located within the tubular and attached at the lower end of the well string, which will be actuated by vertical reciprocating movement of the well string to pump oil from the formation up the well tubular to the wellhead;   said pump jack comprising:   a) a vertical reciprocating power unit capable of applying vertical reciprocating motion of the desired stroke length for the pump to the well string;   b) a well string positioner capable of powered actuation and connecting the top end of the well string to the reciprocating power unit and which, upon actuation, will raise or lower the well string below the well string positioner through the seal on the wellhead, resulting in the decrease or increase of the length of the well string within the tubular; and   c) a controller capable of actuation of the well string positioner by an operator;   whereby during operation of the vertical reciprocating power unit, an operator can use the controller to actuate the well string positioner to modify the length of the well string within the tubular; and   wherein the length of the well string within the tubular can be adjusted during operation of the vertical reciprocating power unit without the need to disassemble the well string, and the stroke of the reciprocal movement does not change when the length of the well string within the tubular is changed.   
     
     
         11 . The pump jack of  claim 10  wherein the top end of the well string is threaded, and the well string positioner comprises a rotary power source capable of engaging the threaded top end of the well string and altering the length of the well string within the tubular by rotary power applied to the threaded end resulting in the raising or lowering of the well string in relation to the wellhead seal. 
     
     
         12 . The pump jack of  claim 11  wherein the well string positioner comprises:
 a. a carrier bar with a bar aperture therethrough through which the threaded portion of the top end of the well string extends, said carrier bar being attached to the reciprocating movement; 
 b. load-bearing means engaging the threaded portion of the top end of the well string to the carrier bar, such that the vertical motion of the carrier bar will be translated upon the well string; and 
 c. a bi-directional rotary power means capable of actuation while the reciprocating movement is in operation, whereby on actuation of the rotary power means the threaded portion of the top end of the well string can be moved up or down through the bar aperture, resulting in the raising or lowering of the well string below the carrier bar and the decrease or increase of the length of the well string within the tubular. 
 
     
     
         13 . The pump jack of  claim 12  wherein the rotary power means comprises a hydraulic motor. 
     
     
         14 . The pump jack of  claim 12  wherein the rotary power means comprises an electric motor. 
     
     
         15 . The pump jack of  claim 10  wherein the well string positioner can rotate the length of the well string within the tubular, and the controller can be used to rotate the well string. 
     
     
         16 . The pump jack of  claim 15  wherein the controller automatically periodically and incrementally rotates the well string. 
     
     
         17 . The pump jack of  claim 10  wherein the well string positioner is a linear actuator configured to apply a linear contraction or extension of the length of the well string within the tubular. 
     
     
         18 . A method of adjustment of the well string length within a well tubular of a well wherein the well comprises:
 a) a well tubular extending downwards from a wellhead at the earth surface to the bottom of the well in a subterranean fluid-producing formation;   b) a well string having a lower end and a top end and extending downward inside the well tubular through a seal at the wellhead to at least a position within the tubular within the fluid-producing formation; and   c) a downhole plunger-style pump located within the tubular and attached at the lower end of the well string, which will be actuated by vertical reciprocating movement of the well string to pump oil from the formation up the well tubular to the wellhead;   wherein the method comprises:
 a. attaching a vertical reciprocating pump jack to the top end of the well string, comprising:
 i. a vertical reciprocating power unit capable of applying vertical reciprocating motion of the desired stroke length for the pump to the well string; 
 ii. a well string positioner capable of powered actuation and connecting the top end of the well string to the reciprocating power unit and which, upon actuation, will raise or lower the well string below the well string positioner through the seal on the wellhead, resulting in the decrease or increase of the length of the well string within the tubular; and 
 iii. a controller capable of actuation of the well string positioner by an operator; 
 
 b. during the operation of the vertical reciprocating power unit when it is desired to adjust the length of the well string within the tubular, an operator using the controller to actuate the well string positioner to modify the length of the well string within the tubular to a desired length; 
   whereby the well string positioner can be actuated and operated during the operation of the vertical reciprocating power unit without the need to disassemble the well string; and   wherein the stroke of the vertical reciprocating power unit does not change when the positioning of the length of the well string within the tubular is changed.   
     
     
         19 . The method of  claim 18  wherein the top end of the well string is threaded, and the well string positioner comprises a rotary power source capable of engaging the threaded top end of the well string and altering the position of the length of the well string within the tubular by rotary power applied to the threaded end. 
     
     
         20 . The method of  claim 19  wherein the well string positioner comprises:
 a. a carrier bar with a bar aperture therethrough through which the threaded portion of the top end of the well string extends, said carrier bar being attached to the reciprocating movement; 
 b. load-bearing means engaging the threaded portion of the top end of the well string to the carrier bar, such that the vertical movement of the carrier bar will be translated upon the well string; and 
 c. a bi-directional rotary power means capable of actuation while the reciprocating movement is in operation, whereby on actuation of the rotary power means the threaded portion of the top end of the well string can be moved up or down through the bar aperture, resulting in the raising or lowering of the well string below the carrier bar and the decrease or increase of the length of the well string within the tubular. 
 
     
     
         21 . The method of  claim 20  wherein the rotary power means comprises a hydraulic motor. 
     
     
         22 . The method of  claim 20  wherein the rotary power means comprises an electric motor. 
     
     
         23 . The method of  claim 19  wherein the well string positioner can rotate the length of the well string within the tubular, and the controller will periodically and incrementally rotate the well string. 
     
     
         24 . The method of  claim 19  wherein the well string positioner comprises a linear actuator configured to apply a linear contraction or extension of the length of the well string within the tubular resulting in the adjustment of the length of the well string within the tubular. 
     
     
         25 . The method of  claim 19  wherein the vertical reciprocating power unit is a conventional oilfield pump jack.