Patent Publication Number: US-10767425-B2

Title: Wrench assembly with eccentricity sensing circuit

Description:
BACKGROUND 
     Field 
     Embodiments disclosed herein relate to a wrench tool assembly for coupling or de-coupling tubulars in a drilling or workover operation utilized in the oil and gas industry. 
     Description of the Related Art 
     A spinner and wrench tool (also known as a “spinner and tong”) is commonly used in the oil and gas industry to rotate a tubular when making up or breaking out a threaded connection. The spinner and wrench tool rotates a tubular relative to another tubular to thread the tubulars together during a make-up operation, and rotates the tubular in an opposite direction to unthread the tubulars from each other during a break-out operation. The spinner is a relatively low torque, high speed device used for the initial makeup of a threaded connection, while the wrench is a relatively high torque, low speed device that is coupled to the spinner and subsequently used to provide a greater amount of torque to complete the threaded connection. 
     The wrench (also known as a “power tong”) may be composed of upper and lower torque bodies having a plurality of grippers that are moved into contact with the tubulars. The upper torque body is configured to rotate one of the tubulars relative to the other tubular, which is held stationary by the lower torque body, to couple or decouple the tubulars. One problem that often occurs is the grippers grip the tubular in a position such that the center axis of the tubular is offset from the center axis of the wrench. This is caused when some of the grippers contact the tubular prior to the other grippers, which results in a misalignment of the wrench with the center axis of the tubular. The improper alignment between the wrench and the center axis of the tubular often results in a misapplication of the appropriate amount of torque to a threaded connection, thereby potentially resulting in a leak in the threaded connection. 
     Therefore, there exists a need for new and/or improved wrench tools. 
     SUMMARY 
     In one embodiment, a wrench assembly is provided that includes an upper clamp assembly, a lower clamp assembly coupled to the upper clamp assembly, an alignment device disposed between the upper and lower clamp assemblies to allow the upper clamp assembly to move laterally relative to the lower clamp assembly when rotated relative to the lower clamp assembly, and an eccentricity sensing mechanism coupled between the upper clamp assembly and the lower clamp assembly. 
     In another embodiment, a wrench assembly is provided that includes an upper clamp assembly, a lower clamp assembly coupled to the upper clamp assembly, an alignment device disposed between the upper and lower clamp assemblies, wherein the alignment device is configured to adjust an axis about which the wrench assembly applies torque by allowing the upper clamp assembly to move laterally relative to the lower clamp assembly, and an eccentricity sensing mechanism coupled between the upper clamp assembly and the lower clamp assembly and configured to stop the lower or upper clamp assembly from applying torque to a tubular connection. 
     In another embodiment, a wrench assembly is provided that includes an upper clamp assembly, a lower clamp assembly coupled to the upper clamp assembly, an alignment device disposed between the upper and lower clamp assemblies, wherein the alignment device is configured to adjust an axis about which the wrench assembly applies torque by allowing the upper clamp assembly to move laterally relative to the lower clamp assembly, wherein the alignment device includes a wedge that engages a groove, the wedge being movable relative to a plate member of the lower clamp assembly, and an eccentricity sensing mechanism coupled between the upper clamp assembly and the lower clamp assembly and configured to stop the lower or upper clamp assembly from applying torque to a tubular connection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a wrench tool according to one embodiment. 
         FIG. 2  is a side view of the wrench tool of  FIG. 1 . 
         FIG. 3  is a front view of the wrench tool of  FIG. 1 . 
         FIG. 4  is a top plan view of the wrench tool of  FIG. 1 . 
         FIG. 5  is a sectional view of the wrench tool along lines  5 - 5  of  FIG. 4 . 
         FIG. 6  is an isometric exploded view of the wrench tool. 
         FIG. 7  is an isometric bottom view of a portion of the wrench assembly. 
         FIG. 8  is a sectional view of a portion of the wrench assembly along lines  8 - 8  of  FIG. 7 . 
         FIG. 9  is a sectional view of a portion of the wrench assembly rotated about 90 degrees from the sectional view shown in  FIG. 8 . 
         FIG. 10  is a sectional view of the portion of the wrench assembly shown in  FIG. 9  in a position different than the position shown in  FIG. 9 . 
         FIGS. 11A-11C  are schematic representations of an eccentricity sensing circuit according to one embodiment. 
         FIGS. 12A-12C  are schematic representations of an eccentricity sensing circuit according to another embodiment. 
         FIGS. 13A and 13B  are schematic representations of the wrench tool in a pre-torque position and a torque application position, respectively. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized with other embodiments without specific recitation. 
     DETAILED DESCRIPTION 
     Embodiments of the disclosure include a wrench tool for making up and breaking out a threaded connection between two tubulars. The wrench tool may be used with a spinner tool. While the spinner tool is a relatively low torque, high speed device used for the initial makeup of the threaded connection, the wrench tool is a relatively high torque, low speed device that is coupled to the spinner tool and is subsequently used to provide a greater amount of torque to complete the threaded connection. 
     The wrench assembly includes an upper clamp assembly and a lower clamp assembly. During a make-up or break-out operation, the upper clamp assembly grips and rotates one tubular relative to another tubular, which is gripped and held stationary by the lower clamp assembly. The wrench assembly is used to apply a specified torque value to a threaded connection between two tubulars. The upper and lower clamp assemblies are at least partially laterally movable relative to each other by a torque alignment device comprising a wedge and groove engagement to account for any eccentricity between a center axis of the tubulars and a center axis of the wrench assembly. The wedge and groove engagement allows the upper clamp assembly to move laterally out of alignment with the lower clamp assembly when applying torque, and forces the upper clamp assembly body back into alignment with the lower clamp assembly after applying torque. 
     When the wrench assembly is applying torque to the tubulars, the torque applied is at a maximum when the center axis of the tubulars is aligned with the center axis of the wrench assembly, which is the axis about which the maximum amount of torque can be applied by the wrench assembly. Any eccentricity between the center axis of the tubulars and the axis about which torque is applied may adversely affect the actual amount of torque that is applied to the threaded connection between the tubulars. To compensate for any eccentricity between the center axis of the tubulars and the axis about which torque is applied, the upper and lower clamp assemblies of the wrench assembly are configured to move laterally relative to each other to enable the torque to be applied about the center axis of the tubulars and not the center axis of the wrench assembly, thereby applying maximum torque to the threaded connection. 
       FIGS. 1-5  are various views of one embodiment of a wrench tool  100 .  FIG. 1  is an isometric view of the wrench tool  100 .  FIG. 2  is a side view of the wrench tool  100 .  FIG. 3  is a front view of the wrench tool  100 .  FIG. 4  is a top view of the wrench tool  100 .  FIG. 5  is a sectional view of the wrench tool along lines  5 - 5  of  FIG. 4 . 
     The wrench tool  100  includes a wrench assembly  105  coupled to a support structure  115 . The support structure  115  may include hangers  120  for suspending the wrench tool  100 . A space  110  may be provided between the hangers  120  for a spinner tool (not shown). 
     The wrench assembly  105  includes an upper clamp assembly  135  and a lower clamp assembly  140 . The wrench assembly  105  also includes hydraulic cylinders  125  that move the upper clamp assembly  135  relative to the lower clamp assembly  140  along a tool axis TA (shown  FIG. 5 ). The upper clamp assembly  135  and the lower clamp assembly  140  include a plurality of grip assemblies  145  and  150 , respectively (some are shown in  FIGS. 1 and 3 ). The grip assemblies  150  of the lower clamp assembly  140  may be used to grip a box end of a first tubular, and the grip assemblies  145  of the upper clamp assembly  135  may be used to grip a pin end of a second tubular. 
     In a make-up operation, the wrench tool  100  is brought into proximity with a first tubular that is held by a rotary spider on a rig floor for example. The grip assemblies  150  of the lower clamp assembly  140  are actuated to grip the box end of the first tubular. A pin end of a second tubular is positioned on top of the box end of the first tubular, for example by an elevator or top drive (not shown). 
     The second tubular is rotated by a spinner tool (not shown) to initially make up the threaded connection between the tubulars. After the initial make up, the grip assemblies  145  of the upper clamp assembly  135  are actuated into contact with the pin end of the second tubular, while the box end of the first tubular remains gripped by the lower clamp assembly  140 . The upper clamp assembly  135  then is rotated relative to the lower clamp assembly  140  to further tighten the threads between the first and second tubulars. 
     In the event that the center axis of the tubulars when gripped by the grip assemblies  145 ,  150  is offset from the center axis of the wrench assembly  100  (identified by axis TA of the wrench tool  100  shown in  FIG. 5 ), which is the axis about which torque is normally applied, the upper clamp assembly  135  is configured to move laterally relative to the lower clamp assembly  140  so that the torque can be applied about the center axis of the tubulars as further described below. 
     The wrench assembly  105  shown in  FIGS. 1-5  also includes a switch mechanism  155  which is part of an eccentricity sensing circuit according to one embodiment. The switch mechanism  155  is coupled to the wrench assembly  105  at opposing sides thereof as shown in  FIG. 4 . The switch mechanisms  155  are utilized to sense misalignment between the upper clamp assembly  135  and the lower clamp assembly  140  such as when the center axis of the tubulars is offset from the axis TA as will be further described below. The switch mechanism  155  and corresponding eccentricity sensing circuit will be described in more detail with respect to  FIGS. 12A-12C . 
     The wrench tool  100  also includes an alignment device  500  as a portion of another embodiment of an eccentricity sensing circuit. The alignment device  500  is configured to adjust the axis about which the wrench assembly  105  applies torque by allowing the upper clamp assembly  135  to move laterally relative to the lower clamp assembly  140 . The alignment device  500  enables the upper clamp assembly  135  to move to a position out of alignment with the lower clamp assembly  140  to apply torque about an axis that is aligned with the center axis of the tubulars, which may not be along the axis TA of the wrench tool  100  but instead is offset from the axis TA of the wrench tool  100 . After the torque is applied, the alignment device  500  forces the upper clamp assembly  135  back into alignment with the lower clamp assembly  140 . 
     As shown in  FIGS. 5 and 6 , the alignment device  500  includes one or more wedges  505  formed on the lower clamp assembly  140  that contact a groove  510  formed on the upper clamp assembly  135 . The wedges  505  are disposed through an upper plate member  605  of the lower clamp assembly  140 . The groove  510  is formed in a lower plate member  515  of the upper clamp assembly  135 . 
     The tapered surfaces of the wedges  505  engage the tapered surfaces of the groove  510  such that the upper clamp assembly  135  can move laterally in the X and/or Y directions into and out of alignment with the lower clamp assembly  140 . When torque is applied by the wrench assembly  105 , the upper clamp assembly  135  (which is gripping the upper tubular) is rotated relative to the lower clamp assembly  140  (which is gripping the lower tubular). As the upper clamp assembly  135  rotates relative to the lower clamp assembly  140 , if the center axis of the tubular is offset from the center axis of the wrench assembly  105 , then the tapered surfaces of the groove  510  forces the wedges  505  downwardly (in at least the Z direction) to allow the upper clamp assembly  135  to move laterally (in at least the X and/or Y directions) relative to the lower clamp assembly  140  to apply torque about the center axis of the tubulars. After the torque is applied, the wedges  505  are biased upward so that the tapered surfaces of the wedges  505  force the upper clamp assembly  135  back into alignment with the lower clamp assembly  140 . 
       FIG. 6  is an isometric exploded view of the wrench assembly  105  that clearly shows the wedges  505  and the groove  510 . Each of the wedges  505  extend up through an opening  600  formed in the upper plate member  605  of the lower clamp assembly  140 . Each of the wedges  505  are biased toward the upper clamp assembly  135  by a biasing member, such as a spring  805  shown in  FIG. 8 . The groove  510  is formed as a recess in a surface  610  of the lower plate member  515  of the upper clamp assembly  135 . Each of the groove  510  and the wedges  505  are curved and shaped as an arc. The groove  510  may include an arc length  615  that is greater than an arc length  620  of each of the wedges  505 . The curved shape of the groove  510  and the wedges  505  allows relative rotation between the lower clamp assembly  140  and the upper clamp assembly  135 . In an alternative embodiment, the wedges  505  can be disposed through the upper clamp assembly  135  and the groove  510  can be located on the lower clamp assembly  140 . 
       FIG. 7  is an isometric bottom view of a portion of the lower clamp assembly  140  showing a bottom surface  700  of one of the wedges  505 . A biasing assembly  705  is coupled between the bottom surface  700  of the wedge  505  and a lower plate member  710  of the lower clamp assembly  140 . The biasing assembly  705  biases the wedges  505  upward toward the upper clamp assembly  135 . 
     In some embodiments, the alignment device  500  includes a switch mechanism  715  (as shown in  FIG. 8 ) configured to shut off the wrench assembly  105 . The switch mechanism  715  may be utilized as a limit switch. Extreme lateral movement of the upper clamp assembly  135  relative to the lower clamp assembly  140  forces the wedges  505  downwardly into contact with the switch mechanism  715  and causes the wrench assembly  105  to stop applying torque. If the wedges  505  move toward the lower plate member  710  of the lower clamp assembly  140  a predetermined distance, the bottom surface  700  of the wedges  505  contacts a button  820  (shown in  FIGS. 8-10 ) coupled to a bracket  720  of the switch mechanism  715 , which controls the opening or closing of a valve that controls power fluid flow to operate the wrench assembly  105 . 
       FIG. 8  is a sectional view of a portion of the alignment device  500  along lines  8 - 8  of  FIG. 7 . As shown in  FIG. 8 , the wedge  505  is biased upwardly into contact with the groove  510  by two biasing assemblies  705 , each of which includes a pin  800  and a spring  805 . The spring  805  may be supported by a support member  810  (e.g. such as another pin) that is coupled to the lower plate member  710 . A cylindrical cover  815  may at least partially enclose the pin  800  and the spring  805 . The biasing assembly  705  allows the wedge  505  to be moved downward relative to the upper plate member  605  of the lower clamp assembly  140  in the Z direction, thereby compressing the spring  805 . If the wedge  505  is moved in the Z direction beyond a predetermined distance, the bottom surface  700  contacts the button  820  which actuates (opens or closes) a valve  900  as shown in  FIGS. 9 and 10 , which controls power fluid flow (such as hydraulic fluid) to the wrench assembly  105 . 
     During operation, the valve  900  is normally maintained in a closed position. However, when the bottom surface  700  of the wedge  505  contacts the button  820 , the power fluid is allowed to flow through the valve  900  to a hydraulic control circuit  825  (or an eccentricity sensing circuit  1100  described below in  FIGS. 11A-11C ). The circuit  825  stops torque application by the wrench assembly  105  by depressurizing the hydraulic cylinders  125  (shown in  FIG. 1 ). If torque application is stopped by the circuit  825 , an operator may release the tubulars from the wrench assembly  105 , and then re-actuate the wrench assembly  105  to re-grip the tubulars to position the center axis of the tubular closer to or in alignment with the axis TA of the wrench tool  100 . While only one switch mechanism  715  is shown, another switch mechanism may be used in conjunction with the wrench tool  100 . However, as the upper plate member  605  of the lower clamp assembly  140  is maintained in a parallel or substantially parallel relationship with the lower plate member  515  of the upper clamp assembly  135  during torque application, only a single switch mechanism  715  is needed. 
       FIG. 9  is a sectional view of a portion of the alignment device  500  in a first position where the upper clamp assembly  135  is in alignment with the lower clamp assembly  140  such that the wedges  505  are centrally positioned within the groove  510 .  FIG. 10  is a sectional view of the same portion of the alignment device  500  as shown in  FIG. 9  but in a second position where the upper clamp assembly  135  has moved laterally relative to the lower clamp assembly  140  such that the tapered surface of the groove  510  has forced the wedges  505  downwardly (against the pin  800  to compress the springs  805  shown in  FIG. 8 ) and into contact with the button  820  of the switch mechanism  715 . After release of the tubulars by the upper clamp assembly  135 , the springs  805  and the pins  800  force the tapered surface of the wedges  505  up against the tapered surface of the groove  510  to force the upper clamp assembly  135  back into alignment with the lower clamp assembly  140 . 
     To prevent damage to the switch mechanism  715  and/or the valve  900 , for example from the wedge  505  moving after contact with the button  820 , one or more biasing assemblies  1000  may be coupled between a body  1005  of the valve  900  and the upper plate member  605  of the lower clamp assembly  140 . Each of the biasing assemblies  1000  may include a spring  1010  and a fastener  1015  coupled to the upper plate member  605  of the lower clamp assembly  140 . The biasing assemblies may be configured to allow the body  1005  of the valve  900  to compress the springs  1010  to compensation for any excessive force applied to the valve  900  by the wedges  505 . 
       FIGS. 11A-11C  are schematic representations of an eccentricity sensing circuit according to one embodiment.  FIGS. 11A-11C  show an eccentricity sensing circuit  1100  that may be utilized with the switch mechanism  715  shown in  FIGS. 7-10 . In the eccentricity sensing circuit  1100 , the letter “P” represents pressure and the letter “R” represents return. 
     The eccentricity sensing circuit  1100  is part of a hydraulic control system that controls the flow of the control fluid supplied to the hydraulic cylinders  125  to control the torque applied by the wrench tool  100  when making up or breaking out a tubular connection. The eccentricity sensing circuit  1100  includes a pressure control valve  1105  that controls the actuation of a main spool valve  1110 , which is configured to control the supply of fluid to the hydraulic cylinders  125  to conduct either a make-up operation or a break out operation. 
     In  FIG. 11A , the pressure control valve  1105  is in a neutral position such that all the fluid in the eccentricity sensing circuit  1100  is directed to a return R 1  and no force is applied to the main spool valve  1110 . When no force is applied to the main spool valve  1100 , it is biased into a neutral position such that no fluid can be supplied to either of the hydraulic cylinders  125  and the wrench tool  100  cannot apply any torque. 
     In  FIG. 11B , in a make-up operation for example, the pressure control valve  1105  is actuated into an operating position such that pressurized fluid from P 1  flows along flow path  1115  to actuate the main spool valve  1110 . The main spool valve  1110  is actuated by the pressurized fluid in the flow path  1115  into an operating position such that pressurized fluid from P 2  is supplied to the hydraulic cylinders  125  via flow paths  1117  to actuate the wrench tool  100 . Fluid in flow path  1125  is returned to a return R 2 . Fluid in flow path  1120  is returned to the return R 1 . 
     The wrench tool  100  is actuated to apply torque to a tubular connection as described above. The switch mechanism  715  and the valve  900  remain in a closed position such that there is no fluid communication between the flow paths  1115  and  1120 . The valve  900  is biased into the closed position. However, if extreme lateral movement of the upper clamp assembly  135  relative to the lower clamp assembly  140  is experienced during torque application, the bottom surface  700  of one of the wedges  505  of the alignment device  500  contacts the button  820  which actuates the valve  900  into an open position. 
     In  FIG. 11C , the valve  900  opens fluid communication between the flow paths  1115  and  1120  via a flow path  1130  such that any pressurized fluid from P 1  in flow path  1115  flows through flow path  1130  into flow path  1120  and back to the return R 1 . When the valve  900  is actuated into the open position, a portion of the flow path  1115  is short circuited and halts fluid flow to the main spool valve  1110  such that the main spool valve  1110  is biased back into the neutral position to stop fluid flow to the hydraulic cylinders  125 . Stopping fluid flow to the hydraulic cylinders  125  tolls torque application by the wrench tool  100 , and when torque application is stopped, an operator may release the tubular from the upper clamp assembly  135 , and then re-grip the tubular to position the center axis of the tubular closer to or in alignment with the axis TA of the wrench tool  100 . A reverse of fluid flow through the flow paths  1115 ,  1120 ,  1130 ,  1117 , and  1125  would occur in a break-out operation. 
       FIGS. 12A-12C  are schematic representations of an eccentricity sensing circuit according to another embodiment.  FIGS. 12A-12C  show an eccentricity sensing circuit  1200  utilizing the switch mechanism  155  shown in  FIGS. 1, 2, and 4 . The eccentricity sensing circuit  1200  is part of a hydraulic control system that controls the flow of the control fluid supplied to the hydraulic cylinders  125  to control the torque applied by the wrench tool  100  when making up or breaking out a tubular connection. In the eccentricity sensing circuit  1200 , the letter “P” represents pressure and the letter “R” represents return. 
     The eccentricity sensing circuit  1200  is part of a hydraulic control system that controls the flow of the control fluid supplied to the hydraulic cylinders  125  to control the torque applied by the wrench tool  100  when making up or breaking out a tubular connection. The eccentricity sensing circuit  1200  includes a pressure control valve  1105  that controls the actuation of a main spool valve  1110 , which is configured to control the supply of fluid to the hydraulic cylinders  125  to conduct either a make-up operation or a break out operation. 
     In  FIG. 12A , the pressure control valve  1105  is in a neutral position such that all the fluid in the eccentricity sensing circuit  1200  is directed to a return R 1  and no force is applied to the main spool valve  1110 . When no force is applied to the main spool valve  1100 , it is biased into a neutral position such that no fluid can be supplied to either of the hydraulic cylinders  125  and the wrench tool  100  cannot apply any torque. 
     In  FIG. 12B , in a make-up operation for example, the pressure control valve  1105  is actuated into an operating position such that pressurized fluid from P 1  flows along flow path  1205  to actuate the main spool valve  1110 . The main spool valve  1110  is actuated by the pressurized fluid in the flow path  1205  into an operating position such that pressurized fluid from P 2  is supplied to the hydraulic cylinders  125  via flow paths  1210  to actuate the wrench tool  100 . Fluid in flow path  1215  is returned to a return R 2 . Fluid in flow path  1220  is returned to the return R 1 . 
     The wrench tool  100  is actuated to apply torque to a tubular connection as described above. The switch mechanisms  155  and the valves  900  remain in a closed position such that there is no fluid communication between the flow paths  1205  and  1220 . The valves  900  are biased into the closed position. However, if extreme lateral movement of the upper clamp assembly  135  relative to the lower clamp assembly  140  is experienced during torque application, a portion of the wrench tool  100  contacts buttons  820  of the switch mechanisms  155  which actuate the valves  900  into an open position. 
     In  FIG. 12C , the valves  900  open fluid communication between the flow paths  1205  and  1220  via a flow path  1225  such that any pressurized fluid from P 1  in flow path  1205  flows through flow path  1225  into flow path  1220  and back to the return R 1 . When the valves  900  are actuated into the open position, a portion of the flow path  1205  is short circuited and halts fluid flow to the main spool valve  1110  such that the main spool valve  1110  is biased back into the neutral position to stop fluid flow to the hydraulic cylinders  125 . Stopping fluid flow to the hydraulic cylinders  125  tolls torque application by the wrench tool  100 , and when torque application is stopped, an operator may release the tubular from the upper clamp assembly  135 , and then re-grip the tubular to position the center axis of the tubular closer to or in alignment with the axis TA of the wrench tool  100 . A reverse of fluid flow through the flow paths  1205 ,  1220 ,  1225 ,  1210 , and  1215  would occur in a break-out operation. 
       FIGS. 13A and 13B  are schematic representations of the wrench tool  100  in a pre-torque position and a torque application position, respectively, when the center axis PA of a tubular is offset from the center axis TA of the wrench tool  100 . As shown in  FIG. 13A  and  FIG. 13B , the axis PA is not aligned with the axis TA, and the axis PA is more misaligned relative to the axis TA in  FIG. 13B . The misalignment of the center axis PA of the tubular relative to the center axis TA of the wrench tool  100  may occur by, for example, grip assemblies  150 , depicted in  FIGS. 1-3 , that push the tubular out of alignment with the axis TA during initial gripping of the tubular. 
     While the misalignment of the center axis TA and the center axis PA is exaggerated in  FIGS. 13A and 13B , the wrench tool  100  as disclosed herein may adjust for this misalignment. For example, as shown in  FIG. 13B , the alignment device  500 , consisting of the groove  510  and one or more wedges  505  biased by springs  805 , allows the wrench assembly  110  to shift laterally and rotate about the center axis PA during torque application as described above. The torque alignment includes lateral movement of the upper clamp assembly  135  relative to the lower clamp assembly  140  in the X and/or Y directions, as well as movement of the wedges  505  forced downward in the Z direction against the bias of and compressing the springs  805 . Upon release of the tubular, the springs  805  force the wedges  505  back up against the groove  510  to re-center the upper clamp assembly  135  with the lower clamp assembly  140  as shown in  FIG. 13A . 
     While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure thus may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.