System and method for monitoring and adjustment of the well string positioning within a well tubular

Abstract

A well string positioner capable of actuation during the vertical reciprocal movement of a well string will, upon detection of a string positioning condition within the tubular by a controller, be actuated to increase or decrease the length of the well string. The vertical reciprocal stroke of the power unit of the well is not changed when the well string position or 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.

1 . A method of automatic adjustment of the well string positioning and length within an oil well tubular 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 through a seal on the wellhead inside the well tubular to at least a position within the tubular within the fluid-producing formation; and   c) a downhole plunger-style pump located within the tubular 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;   d) a vertical reciprocating power unit capable of applying vertical reciprocating motion of a desired stroke length to the well string;   e) a well string positioner 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   f) a controller capable of capable of monitoring at least one well condition sensor to determine the existence of a string positioning condition within the tubular, and of actuating the well string adjuster;   
       wherein the method comprises, during the operation of the vertical reciprocating power unit, using the controller:
 a) monitoring the at least one well condition sensor to detect the existence of a string positioning condition within the tubular; and 
 b) upon detection of a string positioning condition within the tubular, actuating the well string positioner to modify the length of the well string within the tubular to eliminate the string positioning condition; 
 
       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. 
     
     
         2 . The method 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 position of the length of the well string within the tubular by rotary power applied to the threaded end. 
     
     
         3 . The method 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 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. 
 
     
     
         4 . The method of  claim 3  wherein the rotary power means comprises a hydraulic motor. 
     
     
         5 . The method of  claim 3  wherein the rotary power means comprises an electric motor. 
     
     
         6 . The method of  claim 1  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. 
     
     
         7 . The method of  claim 1  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. 
     
     
         8 . The method of  claim 1  wherein the string positioning conditions sought to be detected within the tubular are selected from the following:
 a) a travelling valve assembly of the pump not being optimally positioned, such that the length of the length of the well string within the tubular needs to be increased or decreased; or 
 b) a manual control input from operators wishing to manually adjust the length of the well string within the tubular. 
 
     
     
         9 . The method of  claim 1  wherein the vertical reciprocating power unit is a conventional oilfield pump jack. 
     
     
         10 . A system for use in the automatic adjustment of the well string positioning and length within an oil well tubular 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 through a seal on the wellhead inside the well tubular to at least a position within the tubular within the fluid-producing formation;   c) a downhole plunger-style pump located within the tubular 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:
 e) a well string positioner 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 
 f) a controller capable of capable of monitoring at least one well condition sensor to determine the existence of a string positioning condition within the tubular, and of actuating the well string adjuster; 
 
       whereby during operation of the vertical reciprocating power unit, the controller will monitor the at least one well condition sensor to detect the existence of a string positioning condition within the tubular; and upon detection of a string positioning condition within the tubular, actuate the well string positioner to modify the length of the well string within the tubular to eliminate the string positioning condition; 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 system 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 position of the length of the well string within the tubular by rotary power applied to the threaded end. 
     
     
         12 . The system 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 system of  claim 12  wherein the rotary power means comprises a hydraulic motor. 
     
     
         14 . The system of  claim 12  wherein the rotary power means comprises an electric motor. 
     
     
         15 . The system of  claim 10  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. 
     
     
         16 . The system 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 resulting in the adjustment of the length of the well string within the tubular. 
     
     
         17 . The system of  claim 10  wherein the string positioning conditions sought to be detected within the tubular are selected from the following:
 a) a travelling valve assembly of the pump not being optimally positioned in the downhole plunger-style pump, such that the length of the length of the well string within the tubular needs to be increased or decreased; or 
 b) a manual control input from operators wishing to manually adjust the length of the well string within the tubular. 
 
     
     
         18 . The system of  claim 10  wherein the vertical reciprocating power unit is a conventional oilfield pump jack. 
     
     
         19 . A controller for use in the automatic adjustment of the well string length and positioning within an oil well tubular comprising:
 g) a well tubular extending downwards from a wellhead at the earth surface to the bottom of the well in a subterranean fluid-producing formation;   h) a well string having a lower end and a top end and extending downward through a seal on the wellhead inside the well tubular to at least a position within the tubular within the fluid-producing formation; and   e) a downhole plunger-style pump located within the tubular 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   i) a vertical reciprocating power unit capable of applying vertical reciprocating motion of a desired stroke length for the pump to the well string; and
 c) a well string positioner 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; 
   
       said controller comprising an electronic controller capable of monitoring at least one well condition sensor to determine the existence of a string positioning condition within the tubular, and of actuating the well string positioner to modify the length of the length of the well string within the tubular; 
       whereby during operation of the vertical reciprocating power unit, the controller will monitor the at least one well condition sensor to detect the existence of a string positioning condition within the tubular; and upon detection of a string positioning condition within the tubular, actuate the well string positioner to modify the length of the well string within the tubular to eliminate the string positioning condition. 
     
     
         20 . The controller of  claim 19  wherein the stroke of the vertical reciprocating pump does not change when the length of the well string within the tubular is changed. 
     
     
         21 . The controller of  claim 19  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. 
     
     
         22 . The controller of  claim 21  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 attac 
 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. 
 
     
     
         23 . The controller of  claim 21  wherein the rotary power means comprises a hydraulic motor. 
     
     
         24 . The controller of  claim 21  wherein the rotary power means comprises an electric motor. 
     
     
         25 . The controller 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. 
     
     
         26 . The controller of  claim 19  wherein the well string positioner is a linear actuator configured to, on actuation, 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. 
     
     
         27 . The controller of  claim 19  wherein the string positioning conditions sought to be detected within the tubular are selected from the following:
 a) a travelling valve assembly of the pump not being optimally positioned, such that the length of the length of the well string within the tubular needs to be increased or decreased; or 
 b) a manual control input from operators wishing to manually adjust the length of the well string within the tubular. 
 
     
     
         28 . The controller of  claim 27  further comprising a human interface through which an operator can create a manual control input to trigger a string positioning condition.