Abstract:
A device for torquing a tubular connection. The device comprises an upper assembly having an upper jaw member, a lower assembly having a lower jaw member, an upper gear for advancing the upper jaw member, and a lower gear for advancing the lower jaw member. The upper jaw member includes a first jaw operatively associated with a first rack, a second jaw operatively associated with a second rack, and a third jaw operatively associated with a third rack. The lower jaw member includes a fourth jaw operatively associated with a fourth rack, a fifth jaw operatively associated with a fifth rack, and a sixth jaw operatively associated with a sixth rack. A method of torquing a first tubular with a second tubular is also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus for handling tubulars. More particularly, but not by way of limitation, this invention relates to an apparatus for centering tubular connections, applying torque to the tubular connections as well as breaking the tubular connection. 
     In the course of drilling wells, operators will find it necessary to threadedly connect and disconnect tubular strings. For instance, tubulars that are run into well bores will be required to be made up on the rig floor. As readily appreciated by those of ordinary skill in the art, operators will use specialized tools in order to create the necessary torque required to properly connect the tubulars. 
     Many problems have been experienced with prior art torque tools. For instance, in order to make up the box end to the pin end, the two tubulars must be properly aligned. Prior art tools have experienced significant problems with proper alignment. Also as appreciated by those of ordinary skill in the art, during the course of drilling, completing, or producing, an operator may use many different size tubulars. Hence, the jaws of the torque tools would have to be replaced, which is a time consuming and expensive operation due to high day rates charged by rigs. 
     Therefore, there is a need to have an apparatus for handling tubulars that can properly align a box end and pin end. There is also a need for an apparatus that can be used on tubulars that have varying outer diameters. There is also a need for an apparatus that is economical to manufacture and undemanding to maintain. 
     SUMMARY OF THE INVENTION 
     An apparatus for making up a tubular connection is disclosed. The apparatus comprises a first assembly having first jaw means, wherein the first jaw means includes a first driving jaw operatively associated with a first driving rack, a first driven jaw operatively associated with a first driven rack, and a second driven jaw operatively associated with a second driven rack. The apparatus further includes a second assembly having second jaw means, wherein the second jaw means includes a second driving jaw operatively associated with a second driving rack, a third driven jaw operatively associated with a third driven rack, and a fourth driven jaw operatively associated with a fourth driven rack. A first gear means, operatively associated with the first assembly, for advancing said first jaw means, and a second gear means, operatively associated with the second assembly, for advancing the second jaw means is included. The apparatus may further comprise a driver cylinder for driving the first and second driving jaw. 
     In one preferred embodiment, the first gear means includes a primary idler gear and a secondary idler gear, wherein the primary idler gear is engaged with the first driving jaw so that movement of the first driving jaw effects movement of the first driven jaw. Also in one preferred embodiment, the second gear means includes a primary idler gear and a secondary idler gear, wherein the primary idler gear is engaged with the first driving jaw so that movement of the first driving jaw effects movement of the second driven jaw. 
     The apparatus may further include a first load cylinder operatively attached to the first assembly for imparting a rotational force to the first assembly and to the second assembly. A second load cylinder may be included that is operatively attached to the second assembly for imparting a rotational force to the second assembly relative to the first assembly. 
     A method of torquing a first tubular with a second tubular is also disclosed. The method comprises providing a first apparatus and second apparatus, wherein the first apparatus comprises: a first driving jaw having a first and second driving rack, a first driven jaw having a first driven rack, a second driven jaw having a second driven rack, first gear means engaging the first driven rack and the first driving rack, and a second gear means engaging the second driving rack and the second driven rack; and wherein the second apparatus comprises: a second driving jaw having a third and fourth driving rack, a third driven jaw having a third driven rack, a fourth driven jaw having a fourth driven rack, third gear means engaging the third driving rack and the third driven rack, and a fourth gear means engaging the fourth driving rack and the fourth driven rack. The method further includes advancing the first driving jaw, engaging the first driving rack with teeth of the first gear means, and engaging the second driving rack with teeth of the second gear means. The method includes simultaneously advancing the first driving jaw, the first driven jaw and the second driven jaw, and simultaneously contacting the first driving jaw, the first driven jaw and the second driven jaw with the first tubular so that the first tubular is centered within the first apparatus. 
     Next, the second driving jaw is advanced and the third driving rack with teeth of the third gear means is engaged. The method further includes engaging the fourth driving rack with teeth of the fourth gear means, simultaneously advancing the second driving jaw, the third driven jaw and the fourth driven jaw, and simultaneously contacting the second driving jaw, the third driven jaw and the fourth driven jaw with the second tubular so that the second tubular is centered with the second apparatus. The first and second tubular can then be threadedly torqued together. 
     In one preferred embodiment, the step of advancing the first driving jaw device includes extending a piston from a driver cylinder so that the first driving rack and the second driving rack is advanced. 
     An advantage of the present invention is a gear-driven gripping method will be implemented in order to increase the accuracy of jaws between the upper and lower assembly. The gear-driven gripping method will eliminate the need for the operator to change jaws due to a change in tool size. Another advantage is that the jaw system will contain three jaws per tool that will be drawn together uniformly via gearing in order to ensure centering of the tubular consistently. 
     Yet another advantage is that the action as well as the geometry of the tool and jaws allows for equal velocity between the three (3) jaws as they approach the center of rotation. Another advantage is that the equiangular geometry of the jaw channels allows for constant equiangular geometry of the jaws themselves. This equiangular contact between the jaw face and the surface of the tubular creates equal forces at three points all equidistant from each other. Still yet another advantage is that the equal velocity paired with the geometry of the jaw travel allows for centering of the tubular with the center of rotation of the tool repeatable constantly. 
     A feature of the present invention is that each assembly will implement a single gripping cylinder used in the actuation of all three (3) jaws. Another feature is that the four (4) gears and racks will be used per assembly. Yet another feature is that two (2) torque cylinders will be used between the required two (2) assemblies per torque tool. Another feature is that the two (2) torque cylinders being used in series will allow for torques to be created that meet and/or exceed the requirements for this tool during operation. Still yet another feature is that the upper and lower assemblies are interchangeable in the preferred embodiment. Another feature includes the use of hydraulic or electronic remote control of the activation means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross-sectional view of the preferred embodiment of the self-centering apparatus with the jaws in the expanded position. 
         FIG. 2A  is the partial cross-sectional view of the self-centering apparatus seen in  FIG. 1  with the jaws in the partially contracted position. 
         FIG. 2B  is the partial cross-sectional view of the self-centering apparatus seen in  FIG. 2A  with the jaws in the fully contracted position. 
         FIG. 3  is an exploded, perspective view of the self-centering apparatus seen in  FIG. 1 . 
         FIG. 4  is a perspective view of a first and second self-centering apparatus positioned about a first and second tubular. 
         FIG. 5  is a top view of the first and second self-centering apparatus seen in  FIG. 4 . 
         FIG. 6  is a perspective view of the self-centering apparatus on a rig floor. 
         FIG. 7  is an exploded, perspective view of the first and second self-centering apparatus that depicts the load cylinders. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIG. 1 , a partial cross-sectional view of the preferred embodiment of the self-centering apparatus  2  with the jaws in the expanded position will now be described. In this preferred embodiment, the driving jaw device  4  is shown having a rack device, and in particular, the first rack  6  and the second rack  8 . The driving jaw device  4  further includes the jaw die inserts  10 , and wherein the jaw die inserts  10  will engage the tubular as will be more fully described later in the application.  FIG. 1  shows the hydraulic cylinder  12  which is operatively attached to the driving jaw device  4 . The hydraulic cylinder  12  acts as the driving cylinder for the driving jaw device  4 . 
       FIG. 1  further depicts the first driven jaw  14  that will have the third rack  16 , as well the second driven jaw  18  that contains the fourth rack  20 . The self-centering apparatus  2  will contain the first gear means  22  that contains the primary idler gear  24  with associated teeth  26  and the secondary idler gear  28  with associated teeth  30 . The self-centering apparatus  2  will contain the second gear means  32  that contains the primary idler gear  34  with associated teeth  36  and the secondary idler gear  38  with associated teeth  40 . 
     As seen in  FIG. 1 , the driving jaw device  4 , the driven jaws  14 ,  18 , and associated gear means are contained within the body  44 , wherein the body  44  is generally cylindrical and has the opening  46  for insertion and removal of the tubular member, as is well understood by those of ordinary skill in the art. The body  44  will have fixedly attached the rear cylinder body mount  48  for a first torque cylinder (not shown in this figure), for torquing a tubular connection, as well as the forward cylinder body mount  50  which will be attached to a second torque cylinder (not shown in this figure), for torquing the tubular connection, as will be more fully explained later in the application. Mounting locations  52 ,  54  are included for different types of support systems. These support systems include, but are not limited to a hanger style system as depicted in  FIG. 6  as well as a floor mounted support and positioning system. These mounting locations will also be used for mounting accessories to the tool, as understood by those of ordinary skill in the art. The first driven jaw  14  will have the jaw die insert  56  for engaging the tubular, and the second driven jaw  18  will have the jaw die insert  58  for engaging the tubular. The die inserts  10 ,  56  and  58  will contain a frictional outer surface in order to engage and capture the tubular thereby preventing the tubular from rotating and moving longitudinally, as well understood by those of ordinary skill in the art. The frictional outer surface maybe of a jagged, tooth like outer surface. In one embodiment, the die inserts have several rows of teeth. 
     The operation of the apparatus will now be described with reference to  FIGS. 2A and 2B , which depicts the partial cross-sectional view of the self-centering apparatus seen in  FIG. 1  with the sequential view of the jaws being moved to the contracted position. It should be noted that like numbers appearing in the various figures refer to like components. Hence, the operator will activate the hydraulic cylinder  12  which will cause the driving jaw device  4  to expand (extend) which in turn causes the primary idler gear  24  and primary idler gear  34  to rotate. The teeth  26  will then transfer its motion to teeth  30  on the secondary idler gear  28 , and the teeth  36  will transfer its motion to teeth  40  on the secondary idler gear  38 . As shown in  FIG. 2A , the rotation of teeth  30  will be transferred to the rack  16  thereby causing movement of the driven jaw  14  and the rotation of teeth  40  will be transferred to the rack  20  thereby causing movement of the driven jaw  18 . The movement to the center of the driving jaw  4 , the driven jaw  14 , and the driven jaw  18  will occur simultaneously so that the radial force on the tubular will be exerted equally, according to one preferred embodiment. In other words, simultaneous movement of the three jaws has to do with the effect of concentricity of the tubular with the tool itself consequently causing equiangular contact on the tubular. Equiangular radial force applied to the tubular is related to this same phenomenon but the radial force itself is due to the distribution of force caused by the geartrain.  FIG. 2B  depicts the partial cross-sectional view of the self-centering apparatus seen in  FIG. 2A  with the jaws in the fully contracted position. 
     Referring now to  FIG. 3 , an exploded, perspective view of the self-centering apparatus seen in  FIG. 1  will now be described. The driving jaw device  4  is seen with the rack  8 . The gear means  32  is shown, and wherein the teeth  36  engage the rack  8 , and the teeth  40  engage the teeth  36 . The second driven jaw  18  is shown with rack  20 , and wherein the rack  20  engages the teeth  40 .  FIG. 3  further depicts the gear means  22 , and wherein the teeth  26  engage the teeth  30 . The first driven jaw  14  is illustrated with the rack  16 , and wherein the rack  16  engage teeth  30 . The hydraulic cylinder  12  is shown, and wherein the body  44  has the opening  62  through which a piston rod “R” from the hydraulic cylinder  12  will be disposed.  FIG. 3  depicts where the driving jaw device  4 , and the driven jaws  14 ,  18  are in the general configuration of a rectangular block, and at one end will be situated the jaw die inserts  10 ,  56 ,  58 . The jaw die inserts  10 ,  56 ,  58  are to engage and grasp the tubular, as well understood in the art. 
     As shown in  FIG. 3 , the body  44  contains side walls that serve as compartments and tracks  4  for the driving jaw device  4 , and the driven jaws  14 ,  18 ; more particularly, the body  44  contains the side walls  64 ,  66 ,  68 .  FIG. 3  illustrates that primary idler gear  24  has the gear shaft  70 , the secondary idler gear  28  has the gear shaft  72 , the primary idler gear  34  has the gear shaft  73 , and the secondary idler gear  38  has the gear shaft  74 . Additionally, the body  44  contains the internal bearing caps  76 ,  78  and the internal bearing caps  80 ,  82  for cooperation with the gear shafts. 
       FIG. 3  also contains the bearing caps  84 ,  86 ,  88 ,  90 , and wherein bearing cap  84  is operatively associated with the gear shaft  70 , bearing cap  86  is operatively associated with gear shaft  72 , bearing cap  88  is operatively associated with gear shaft  72  and bearing cap  90  is operatively associated with gear shaft  74 . The top cover plate  92  is disposed on top and will be connected to the body  44  using conventional means such as nuts and bolts. 
     Referring now to  FIG. 4 , a perspective view of a first and second self-centering apparatus positioned about a first and second tubular will now be described. More specifically, the first self- 18  centering apparatus  2  is shown, along with a tandem second self-centering apparatus  94 . The second self-centering apparatus  94  will be of essentially identical construction as the first self-centering apparatus  94  and apparatus  94  is simply rotated 180 degrees i.e. a mirror image. The first self-centering apparatus  2  and the second self-centering apparatus  94  may be collectively known as the self-centering device  95 .  FIG. 4  depicts the hydraulic cylinder  12  of the first apparatus  2  as well as the hydraulic cylinder  96  of the second self-centering apparatus  94 . 
     A first tubular member  98  is disposed within the opening  46  of the first self-centering apparatus  2 . As shown in  FIG. 4 , the jaws have been drawn to the center to engage the tubular member  98  according to the teachings of the present invention. As those of ordinary skill in the art will recognize, the second self-centering apparatus  94  surrounds a second tubular member  100  so that the first and second tubular can be threadedly torqued together, or alternatively, to be disconnected. As shown in  FIG. 4 , the outer diameter of the second tubular member  100  is larger than the outer diameter of the first tubular member  98 . The jaws of the second self-centering apparatus  94  will close and engage the second tubular member  100  as previously described, despite the larger outer diameter.  FIG. 4  illustrates that concentricity of the upper and lower tubulars will be maintained regardless of differences, large or small, in the diameter of one tubular relative to the other. 
     A load cylinder  102  is shown attached to the forward cylinder body mount  104  at one end and attached to the rear cylinder body mount  48  at the other end. Body mount  104  is attached to the apparatus  94 . Also, the load cylinder  106  is shown attached to the forward cylinder body mount  50  at one end and attached to the rear cylinder body mount  110  at the end. Body mount  50  is attached to apparatus  2  and body mount  110  is attached to apparatus  94 . As those of ordinary skill in the art will recognize, activation of load cylinder  102  will extend a piston rod thereby creating a rotational force in a first direction (as denoted by the arrow “A”). The activation of load cylinder  106  will extend a piston rod thereby creating a rotational force in a second direction (as denoted by the arrow “B”). In most instances, the tubular  100  is being held stationary within the rotary table, as is well understood by those of ordinary skill in the art. Hence, the activation of load cylinders  102  and  106  imparts a rotational force such that self-centering apparatus  2  is rotated relative to self-centering apparatus  94  which in turn torques the tubulars  98  and  100  together. By activation of both cylinders  102  and  106 , the tubular members  98  and  100  can be threadedly coupled with the proper amount of torque in this manner. 
       FIG. 5  is a top view of the first self-centering apparatus  2  and the second self-centering apparatus  94  seen in  FIG. 4 . More specifically,  FIG. 5  depicts the apparatus  2  and  94  in the open throat position. 
     In  FIG. 6 , which is the most preferred embodiment, the self-centering apparatus  2  and self-centering apparatus  94  will be used on a rig floor  116 , and hence, the apparatuses  2 ,  94  will be operatively connected to the derrick using conventional, and well known means such as a hoist  118 . On the rig floor  116 , the tubular member  100  will be disposed within the rotary table, while the tubular member  98  will be suspended from the derrick. Operators will find it desirable to use a tubing spinner  120 , and wherein the tubing spinner will be positioned on top of the self-centering apparatus  2 . Tubing spinners are well known and commercially available from Grey EOT Corporation under the name  4  D R Spinner. After the self-centering apparatus  2  and the self-centering apparatus  94  has centered the tubular  98  relative to tubular  100 , the tubing spinner  120  will spin the tubular member  98  which will threadedly engage the tubular member  98  with the tubular member  100 . According to the teachings of this invention, after the spinner has threadedly made-up the connection, the self-centering apparatus  2  and the self-centering apparatus  94  can then be utilized to provide the proper amount of torque to the connection. 
     It should be noted that the self-centering apparatus  2  and self-centering apparatus  94  can be utilized on horizontal applications. In other words, the self-centering device can be rotated 90 degrees, and therefore, the self-centering device can be used on the surface in the industry for a lay-down service, bucking application, horizontal service, or multi-angular applications. 
     Referring now to  FIG. 7 , an exploded, perspective view of the first and second self-centering apparatus will now be described.  FIG. 7  shows, among other things, the load cylinders  102 ,  106  connections. The self-centering apparatus  2  is shown, and wherein the forward cylinder body mount  50  and the rear cylinder body mount  48  is attached to the apparatus  2  as shown. The bearing caps  84 – 90  are shown, along with the hydraulic cylinder  12  that will extend the piston rod, as previously described. The second self-centering apparatus  94  is shown, and wherein the apparatus  94  includes the forward cylinder body mount  104  and the rear cylinder body mount  110 . The hydraulic cylinder  96  that will extend a piston rod, as previously described, is also shown.  FIG. 7  further depicts the flange rim  124  that is attached to the apparatus  94 , as well as the reciprocal flange rims  126   a ,  126   b ,  126   c  that will allow slidable attachment with the apparatus  2  i.e. apparatus  2  and apparatus  94  can rotate independently of each other. 
     The load cylinder  102  will be attached at a first eyelet end  128  to the rear cylinder body mount  48  via the pin  130 . The second eyelet end  132  will be attached to the body mount  104  via pin  134 .  FIG. 7  also depicts the load cylinder  106  that will have a first eyelet end  136  attach to the forward cylinder body mount  50  via pin  138  and a second eyelet end  140  connected to the rear cylinder body mount  110  via pin  142 . As previously described, the activation of cylinders  102  and  106  will impart a rotational force on apparatus  2  and apparatus  94  since each load cylinder is attached to both apparatuses  2 ,  94 . Each apparatus will experience a rotational force in a different direction thereby allowing the tubulars to be torqued. It should be noted that the load cylinders  102  and  106  described herein are also used to disconnect a made-up joint i.e. the load cylinders  102  and  106  can also be used for disconnecting threadedly connected tubulars. 
     While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the features and providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.