Patent Publication Number: US-10329857-B2

Title: Oilfield tubular spin-in and spin-out detection for making-up and breaking-out tubular strings

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/927,656, filed Jun. 26, 2013, now allowed, which is a divisional of U.S. patent application Ser. No. 13/293,742, filed Nov. 10, 2011, now U.S. Pat. No. 8,490,520, which is a divisional of U.S. patent application Ser. No. 11/852,519, filed Sep. 10, 2007, now U.S. Pat. No. 8,074,537, which claims priority to U.S. Provisional Application No. 60/825,067, filed Sep. 8, 2006, now expired, the contents of each of which is hereby incorporated herein by express reference thereto. 
    
    
     FIELD 
     The present invention generally relates to oilfield tubular torque wrench spinners used in make up or breakout of wellbore tubular strings and, in particular, to methods and apparatus for detecting tubular spin-in and spin-out completion. 
     BACKGROUND 
     Torque wrench tongs and spinners have been employed when making up or breaking out tubular strings and, in particular, without limiting the invention: drill pipe joints, drill collars, casing and the like in oil well drilling operations. Such tubular strings are formed by threadedly connecting the tubulars in the string. In operation of a torque wrench, a spinner is utilized to initially rotate a first tubular relative to a second tubular to thread the tubulars together. The spinner rotates the first tubular relative to the second tubular rather rapidly but at a relatively low torque and the tongs serve to finally tighten the tubulars together when making up a tubular string. Conversely, when breaking out a tubular string, the tongs initially break apart the threaded connection between tubulars with the spinner subsequently unthreading the upper most tubular from the rest of the tubular string at a relatively high speed and low torque. 
     SUMMARY 
     In accordance with a first broad aspect of the prevent invention, there is provided methods for making a threaded connection between an upper tubular and a lower tubular using an oilfield tubular spinner and a torque wrench, including holding the lower tubular with the torque wrench, frictionally engaging the upper tubular with the tubular spinner, operating a motor of the tubular spinner to spin-in and shoulder-up a tubular connection between the upper tubular and the lower tubular, establishing a threshold hydraulic system pressure that indicates a shouldered-up condition, monitoring, with a detection system, a hydraulic system pressure of the motor during spin-in and shoulder-up, and maintaining the threshold hydraulic system pressure to operate the motor for a selected period of time after the threshold hydraulic system pressure is reached. 
     In accordance with a second broad aspect of the prevent invention, there is provided an oilfield tubular spinner for an oilfield tubular wrench, the oilfield tubular spinner including a powered spin roller including an axis of rotation; a hydraulic system spin motor operatively connected to, and configured to drive, the powered spin roller to rotate about its axis of rotation; and a make-up detection system configured to detect a make-up condition of an upper tubular being driven by the powered spin roller to threadedly connect the upper tubular to a lower tubular and to initiate spin motor shutdown in response to a make-up condition, wherein the make-up detection system includes: a pressure transducer and controller to monitor operational hydraulic system pressure of the motor, wherein the controller stores a value for a threshold hydraulic system pressure that indicates a shouldered-up condition and the controller maintains the threshold hydraulic system pressure to operate the motor for a selected period of time after the threshold hydraulic system pressure is reached; and a timer to monitor the operational time that the powered spin roller is driven by the motor. 
     In accordance with a third broad aspect of the present invention, there is provided an oilfield tubular spinner for an oilfield tubular torque wrench, the oilfield tubular spinner comprising: a powered spin roller including an axis of rotation; a spin motor operatively connected to, and configured to drive, the powered spin roller to rotate about its axis of rotation; and a shoulder-up system configured to detect a shoulder-up condition of a pair of tubulars being driven to threadedly connect by the powered spin roller and to initiate spin motor shutdown subsequent to the detection of the shoulder-up condition. 
     In accordance with a fourth broad aspect of the present invention, there is provided a method for threadedly connecting an upper tubular and a lower tubular using an oilfield tubular spinner and a torque wrench, the method comprising: holding the lower tubular with the torque wrench; aligning the upper tubular with the lower tubular with their threaded intervals arranged for threaded connection therebetween; frictionally engaging the upper tubular with the tubular spinner; operating a hydraulic motor of the tubular spinner to rotate the upper tubular relative to the lower tubular; monitoring hydraulic fluid pressure of the hydraulic motor to detect a pressure condition of interest during rotation of the upper tubular relative to the lower tubular; and shutting down the hydraulic motor after a pressure condition of interest is detected. 
     In accordance with a further broad aspect of the present invention, there is provided an oilfield tubular spinner for an oilfield tubular torque wrench, the oilfield tubular spinner comprising: a powered spin roller including an axis of rotation; a spin motor operatively connected to, and configured to drive, the powered spin roller to rotate about its axis of rotation; and a spin-out detection system configured to detect a spun-out condition of an upper tubular being driven by the powered spin roller to threadedly disconnect from a lower tubular and to initiate spin motor shutdown in response to the detection of the spun-out condition. 
     In accordance with a fifth broad aspect of the present invention, there is provided a method for breaking out a threaded connection between an upper tubular and a lower tubular using an oilfield tubular spinner and a torque wrench, the method comprising: holding the lower tubular with the torque wrench; frictionally engaging the upper tubular with the tubular spinner; operating a motor of the tubular spinner to rotate the upper tubular relative to the lower tubular; monitoring a condition of the upper tubular to detect a condition of interest during rotation of the upper tubular relative to the lower tubular; and shutting down the motor after a condition of interest is detected. 
     It is to be understood that other aspects of the present invention will become readily apparent to those of ordinary skill in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings wherein like reference numerals indicate similar parts throughout the several views, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein: 
         FIG. 1  is a perspective view of a torque wrench and spinner mounted on a mounting structure; 
         FIG. 2  is a top plan of a torque wrench and spinner according to one embodiment of the invention; 
         FIG. 3  is a top plan view of a spinner assembly according to one aspect of the present invention; 
         FIG. 4  is a front elevation view of the spinner assembly of  FIG. 3 ; 
         FIG. 5  is a left side elevation view of the spinner assembly of  FIG. 3 ; 
         FIG. 6  is a perspective view of the spinner assembly of  FIG. 3 ; 
         FIG. 7  is an enlarged view of a spinner roller assembly of the spinner assembly of  FIG. 3 ; 
         FIG. 8  is a schematic sectional view of a typical threaded connection between drill pipe; 
         FIG. 9  is a graphical illustration of typical hydraulic system pressure vs. time during operation of a tubular spinner; and 
         FIG. 10  is a chart of a system according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention. However, it will be apparent to those of ordinary skill in the art that the present invention may be practiced without these specific details. 
     The present invention generally relates to tubular spinners used in making up or breaking apart oilfield tubular strings. Such strings are made up of threadedly connected tubulars such as, for example, drill pipe joints, drill collars, casing and the like in oil well drilling operations. The following description may refer to drill pipe and drill pipe joints, but it is to be understood that a torque wrench and tubular spinner may also be useful for the manipulation of other oilfield tubulars. 
     A tubular spinner is often used with a torque wrench, also known as an iron rough neck. Commonly, a torque wrench includes tongs that grip and rotate tubulars being handled and a tubular spinner includes rollers that frictionally engage and rotate a tubular being handled. In operation of a torque wrench and tubular spinner, the tubular spinner is utilized to initially rotate an upper drill pipe when making up the drill pipe, with the spinner rotating the pipe rapidly but at a relatively low torque and the tongs of the torque wrench serving to finally tighten the drill pipe joints when making up a tubular string. Conversely, when breaking out a tubular string, the tongs initially torque the connection to “break” it and begin the unthreading process, with the tubular spinner subsequently unthreading the upper most tubular from the rest of the tubular string at a relatively high speed and low torque. 
     To facilitate understanding of tubular torque wrench tongs and spinners, reference may be made to  FIGS. 1 and 2  for a brief description of one embodiment thereof. One embodiment of a power actuated tubular torque wrench is generally designated by numeral  10  and illustrated in association with a drill rig floor  12 , a supporting member including, in this embodiment, an arm  16  which includes a laterally extending support member  18  for the wrench. The wrench is associated with a spinner generally designated by numeral  20 , which is located above the wrench for spinning tubulars. Spinner  20  in this illustrated embodiment is mounted on the wrench and supported over floor  12  by the supporting members  16 ,  18 . 
     While the invention is hereafter described utilizing hydraulically actuated power cylinders and a hydraulic circuit therefor, it will be readily appreciated and understood by those of ordinary skill in the art that any one or all of the power cylinders of this invention can alternately be pneumatic and a conventional pneumatic circuit may be used in conjunction therewith. Alternately, screw drives or other drivers may be used. 
     Wrench  10  includes drill pipe tongs including an upper tong  22  and a lower tong  24  each of which may be substantially identical and which each include a body  26  with a generally U-shaped recess  28  in an edge thereof to receive oilfield tubulars to be handled thereby including for example joints of drill pipe, drill collars, casing, wellbore liners and the like. Recesses  28  are formed to accommodate tubulars extending generally along an axis x through the recess. Axis x is substantially vertically oriented. 
     In the illustrated embodiment, tubulars  30  and  31  are positioned to be acted upon by the wrench tongs and the spinner. In operation, upper tong  22  and spinner  20  generally act on an upper tubular  30  and lower tong  24  generally acts on a lower tubular  31 . Considering a normal oilfield string and its manipulation by a torque wrench, tubular  30  is the upper most or last tubular and tubular  31  is the penultimate tubular of the string. The tubulars  30 ,  31  are shown in phantom to facilitate illustration. With the upper tong  22  gripping an upper tubular and the lower tong gripping a lower tubular, tongs  22 ,  24  may be swiveled relative to each other, which often includes holding one of the tongs stationary, while the other tong swivels relative thereto, to either torque up or break out a threaded connection between the tubulars. 
     The tongs may include various devices to permit tubulars to be gripped. For example, in one embodiment, a plurality of dies  34  having pipe gripping teeth thereon are mounted in each recess  28 . In the illustrated embodiment, dies  34  are mounted on die heads  38  that are moveable, as by hydraulics  39 , pneumatics, screw drives, etc., toward and away from axis x. As such, dies  34  may be moved into a gripping position or pulled back from a gripping position, as desired. The die heads may be positioned in recess  28 , as shown, to act substantially diametrically opposite each other to grip a tubular therebetween. 
     Each die head  38  may have an angular or curved surface on which its dies  34  are mounted in spaced apart relation so that the dies are arranged along an arcuate path to generally follow the outer surface of a tubular  30  to be gripped, which is also generally acuate. The spaced, angular positioning may enable the dies  34  to engage spaced points on the circumference of the drill pipe or tool joint. 
     The upper tong  22  may swivel in relation to the lower tong  24  to move the tongs from a neutral position shown in  FIG. 1  to one of the make up or break out torqueing positions. To permit the swiveling action, in this embodiment, a double acting hydraulic piston and cylinder assembly  96  may be provided adjacent the end of the tong bodies  26  remote from the die heads  38  which interconnects the upper and lower tongs  22  and  24  so that by extending and retracting the torqueing piston and cylinder assembly  96  in timed relation to extension and retraction of the die heads, the upper and lower tubulars  30  and  31  may be gripped and torqued in a manner to make-up or break apart a threaded connection therebetween. 
     Extension and retraction of the piston and cylinder assembly  96 , in this embodiment, causes the upper and lower tongs  22  and  24  to move toward and away from the torqueing position and into or through the neutral position shown in  FIG. 1 . That is, with the upper tong  22  either in alignment with the lower tong  24  or the upper tong  22  moved into angular position with respect to the lower tong  24 , the tongs  22  and  24  are moved in a swivelling manner and after each tong respectively grips by use of dies one of a pair of tubulars positioned along axis x, the tubulars are rotated in opposite directions along axis x, for example, one in relation to the other. 
     When the tongs are properly aligned with oilfield tubulars  30 ,  31  to be handled, a threaded connection therebetween is positioned between the dies  34  of upper tong  22  and the dies of lower tong  24  with the tubulars extending generally along axis x. In that position, die heads  38  of lower tong  24  may be actuated to grip therebetween lower tubular  31 . Then, depending upon whether the threaded connection is being made up or broken apart, the torque piston and cylinder assembly  96  is extended or retracted. During the extension or retraction of the torque cylinder, the die heads  38  on the upper tong  22  will be in their retracted positions so that the upper tong  22  can rotate in relation to the upper tubular  40 . Thus, with the upper tong  22  released and the torque piston and cylinder assembly  96  either extended or retracted to an initial position depending upon whether the drill pipe is being made up or broken out, the upper tong  22  may then be brought into gripping engagement with the upper tubular  30  by moving the die heads out to place the dies carried thereon into gripping relation with the tubular. After this has occurred, both the upper tubular  30  and the lower tubular  31  are securely gripped by the respective tongs. Then, the piston and cylinder assembly  96  is actuated for moving the upper and lower tongs  22  and  24  pivotally in relation to each other thus torqueing the tubulars  30  and  31  either in a clockwise manner or a counterclockwise manner depending upon whether the drill pipe is being made up or broken out. 
     In operation of the torque wrench, spinner  20  is utilized to quickly rotate one of the pair of tubulars being handled while the other is held against rotation by one of the tongs of the torque wrench. For example, when making up a drill string, spinner  20  is utilized to initially rotate drill pipe  30 , which is the drill pipe being added to the remainder of the string, into threaded engagement with tubular  31 , which is held steady. When making up the drill string, the spinner rotates the pipe to be added rather rapidly but at a relatively low torque while the upper tong  22  is disengaged and the lower tong  24  grips, for example, bites into, tubular  31  to hold it steady. The tongs  22  and  24  serve to finally tighten the threaded connection between drill pipe joints  30 ,  31  when making up a drill pipe string. Conversely, when breaking out a drill pipe, the tongs  22  and  24  initially torque the connection at low speed and high torque to initiate an unthreading operation of the connection with the spinner  20  subsequently frictionally engaging and unthreading the upper tubular  30  from the lower tubular  31  at a relatively high speed and low torque. 
     Making reference to the Figures, spinner  20  frictionally engages and rotates a tubular being handled. Thus, a tubular spinner often has an overall clamp configuration. For example in the illustrated embodiment, spinner  20  includes a pair of clamp arms  300 , pivotally connected by pivot pins  302  to a frame for clamping about a tubular to be added to the tubular string during make up, or about the upper most tubular, which is that tubular to be removed from the tubular string, during break out. Of course, the invention is not limited to a clamp shaped spinner; a variety of other spinner configurations may be used. 
     Engagement between spinner clamp arms  300  and the tubular to be spun is through spinner rollers  310  and  312 . Spinner rollers  310 ,  312  rotate about an axis of rotation substantially parallel to axis x. Without limiting the invention, the spinner rollers include one or more powered rollers  312  and, optionally, idler rollers  310 . While  FIGS. 1 to 6  show paired powered rollers  312  and idlers  310 , the invention is not limited thereto. For example, any number of powered rollers may be used. In one embodiment, for example, four powered rollers are used without any idlers. 
     The implementation shown in the Figures includes a powered roller  312  and an idler  310  on each clamp arm  300 . In the illustrated embodiment, the rollers are mounted on a clamp arm extension  304 , which has some provision for pivotal movement relative to its clamp arm  300 , as through pivot pin  308 . In accordance with the implementation, the rollers  312  and idlers  310  are moved from a neutral position towards axis x to a spinning position for engaging tubular  30  via clamping action of the clamp arms  300 . Clamp arms  300  may be driven, for example, by a hydraulic or pneumatic cylinder  306  to open or close relative to axis x. The pivotal movement of clamp arm extensions  304  may allow the rollers  312  and idlers  310  to engage and accommodate tubulars of various different diameters and to provide for a variance in grip pressure and positioning the spinner  20  about a tubular  30 . Each extension  304  may be limited in its pivotal motion relative to its arm to prevent the extension from moving out of a useful position during operation. Alternately or in addition, the two extensions  304  may be connected by a linkage to maintain their relative alignment during movement of clamp arms  300  between the neutral and the spinning positions. 
     Powered rollers  312  are formed to frictionally engage a tubular to be handled. In one embodiment, rollers  312  are formed of durable materials such as steel. Rollers  312  may include surface treatments such as spiral grooving, roughening, etc. to enhance engagement of the tubular. During spin-in and spin-out, spinning motion is imparted to the tubular  30  via rollers  312  as powered by motors  314 . In particular, motors  314  drive rollers  312  to rotate about their axis of rotation and in turn rollers engage and drive rotation of the tubular. In accordance with a paired spin drive implementation, such as shown in  FIGS. 1 to 6 , or in a multiple spin drive implementation (not shown), each powered spin roller  312  imparts spinning torque to the tubular  30 , the spinning torque necessary to spin tubular  30  about axis x being divided over the multiple motors  314  and rollers  312  associated therewith reducing individual load and tear thereon. In one embodiment, motor redundancy is provided should one of the motors  312  fail. 
     It could be said that tubular connection make-up may be divided into three steps: spin-in, shouldering up, and tightening, and conversely that the tubular connection break-out may be divided into loosening and spin-out. Shouldering up is achieved when the entire tapered thread of a pin end of the tubular being added to a tubular string is inserted in the box end of the last tubular of the tubular string. With reference to  FIG. 8 , in some embodiments, the tubulars each include at one end a shoulder  413  adjacent the base of their pin threaded intervals  415  and at their opposite ends a threaded box end  417 . The tubulars are formed such that the pin threaded interval  415  threads into the box end  417  of a next tubular. Shouldering up is achieved when an end face  419  of the box end butts against shoulder  413  of the pin end being threaded into the box. It will be appreciated that the illustration of  FIG. 8  represents a standard oilfield drill pipe connection. Often, many hundreds of identical type tubulars are used in series to form an oilfield string. Thus, during string handling the same connection type will be acted upon repeatedly by the torque wrench. 
     The tightening and loosening of tubular connections may be performed as described hereinabove using tongs  22  and  24  of the torque wrench, wherein relatively high torques are imparted to tubulars at relatively low rotational speeds. In contrast, the spin-in and spin-out steps are desirably performed at comparatively high rotational speeds by the spinner  20  while employing comparatively much reduced torque. Relatively high spin-in and spin-out speeds are desired as tubular strings include large numbers of tubulars and as the minimization of make-up and break-out time overheads is desired. 
     It is desirable that the process of spinning-in a tubular be rapid to reduce the overall time for drill string handling. A person of ordinary skill in the art would appreciate that high-speed spin-in imparts a large angular momentum to the tubular  30 . If the spinner roller(s)  312  slip while being driven, the tubular being handled may be marred and both the tubular and the spinner rollers may potentially be damaged. Thus, roller slipping should be avoided as much as possible. 
     Other variables require consideration when spinning-in and shouldering-up tubular  30 . The thread on the pin end of tubular  30  is tapered, as is the thread on the box end of tubular  31 . The same tubulars  30  and  31  are used and reused in making-up and breaking-out a number of tubular strings, which may result in cumulative wear of the tapered threads. As it may be appreciated, doping may be used to grease the threads. The pipe dope has different viscosity under different environmental conditions (i.e. temperature, humidity, etc.) and depending on the type of pipe dope being used. 
     With reference to  FIG. 9 , in a tubular spinner applied torque substantially corresponds to the fluid pressure of the hydraulic system driving motors  314 . Since system pressure may be monitored by a pressure transducer and/or other means, the applied torque may conveniently be monitored and understood by observing the hydraulic system pressure response. During a spin in operation hydraulic system pressure is originally at a starting level Pstart. When the driven rollers  312  are brought into contact with a tubular and motors  314  are started up to drive rollers  312 , the system pressure quickly jumps to an initial operating pressure P 1  and then gradually increases as the tubulars are threaded together. When the threaded intervals of the pin end and box approach a shouldering condition, the force required to continue the threading operation generally increases abruptly. As such, during this portion of the spin-in operation, system pressure also can be seen to increase abruptly, as shown in the region SP. When the tubulars shoulder up, the system pressure plateaus at a maximum pressure level Pmax. In cold weather operation of the same system, the system pressure will initially jump to a higher initial operating level P1cold, primarily due to increased viscosity in hydraulic system fluids and doping. However, the system pressure will gradually increase before undergoing an abrupt increase SPcold to eventually level off at maximum pressure when the tubulars being spun-in shoulder up. Maximum pressure during a cold operation may generally be substantially similar to the maximum pressure Pmax reached using that same system during warmer operating conditions. Cold weather operation may create a more linear increase over time from the initial operating pressure to a maximum pressure, wherein the pressure increase is less abrupt prior to shouldering up. 
     The maximum pressure Pmax of the tubular spinner hydraulic system can be determined such that an operator can establish a pressure threshold, Pthreshold, for the system. Pthreshold is substantially equal to Pmax. The operator can then actively or automatically control the system based on the pressure threshold established for the system. In particular, since the pressure threshold offers an indication of a shouldered up condition, an operator can monitor system pressure and use the established Pthreshold value to indicate a shouldered up condition. Pmax, and therefore the pressure threshold, may vary depending on the profile of the tubulars being handled, for example, thread type, tool joint design, etc. However, Pmax, and therefore Pthreshold, can be determined and recorded for a tubular spinner and for any of the various tubulars to be handled, such that during operation measured pressure can be compared against expected pressure conditions, such as the pressure threshold. In addition, since tubular strings often include many hundreds of similar connection types to be handled in direct succession, any established pressure conditions of interest can be used repeatedly and systems can be set up based thereon. 
     With reference to  FIG. 10 , in order to control operation of a tubular spinner, in one embodiment, a pressure transducer  519  or other component for measuring hydraulic system pressure, may be positioned in communication with the hydraulic drive system  520  for motors  314 , for example in or adjacent the pumping system  521 , and a control system  523  may be provided in monitoring communication C 1  with pressure transducer  519  and in control and monitoring communication C 2  with pumping system  521 . Pressure transducer  519  and control system  523  may be used to monitor operational hydraulic system pressure of the tubular spinner. In one embodiment, for example, control system has stored thereto a value for Pthreshold and the pressure transducer and control system monitor for Pthreshold in order to determine when shouldering up has been accomplished and, therefore, when the motors may be shut down. For example, in one embodiment, the control system may operate to shut the hydraulic system down when Pthreshold is reached, as sensed by pressure transducer  519 . Alternately, in another embodiment, the control system may activate or initiate other systems or steps when Pthreshold is sensed, as discussed below. 
     A control system that monitors the roller motor&#39;s hydraulic system pressure may be useful in systems to prevent roller slipping. For example, rollers can slip when the tubular that they are rotating shoulders up and can no longer be rotated. Thus, recalling that Pthreshold indicates that a tubular has shouldered up, it will be appreciated that shutting down the roller drive motors when Pthreshold is reached may prevent roller slipping. 
     However, additionally or alternately, further slip prevention options may be employed. For example, in one embodiment, hydraulic system pressure may be monitored to detect a slip condition occurring prior to shouldering up. If the rollers begin to slip on the tubular, the hydraulic system pressure for the spinner may cease to increase and may begin to fluctuate about a level lower than Pthreshold. If, for example with reference to  FIGS. 9 and 10 , the pressure sensed at pressure transducer  519 , as monitored by control system  523 , levels off at a pressure, shown by the line identified as SLIP, that is less than Pthreshold, the control system  523  may shut down the hydraulic system to thereby shut down motors  314 . Control system  523  may include or communicate with a timer  525  for timing the various system functions such as motor operation and/or for monitoring the duration of pressure plateaus. If desired, control system  523  may include a communication C 3  to an operator interface  529 . In a situation where slippage has been detected, as by detecting a plateaued pressure below Pthreshold substantially maintained for a selected period of time, control system  523  may shut down pumping system  521  to shut the motors down and/or may generate an error message at the operator interface to notify the operator that a slippage problem has occurred and/or that the tubular spinner has been shut down. 
     In another embodiment, a shoulder-up time limit can be established for any particular type of tubular connection to be handled by a tubular spinner. The time required to spin-in and shoulder up a tubular connection will be affected by the number of threads, flow rate of the hydraulic system, etc. and can be determined by testing. If the rollers begin to slip, the threading in operation may be delayed or never be completed such that the connection does not shoulder in the expected connection time. In such an embodiment, a timer, such as timer  525  can be used to monitor the length of time from system start, when the motors begin to drive rollers  312  to spin the tubular, until a shoulder up condition is detected, for example, when Pthreshold is reached. If through timer  525  and pressure sensing, as by use of transducer  519 , it is determined that Pthreshold has not been reached in an expected time frame, the system may determine that a problem has occurred and shut down the motors. Again, an error message may be sent to an operator interface  529 . 
     In accordance with an implementation of the invention, the pressure sensing and control systems may employ high-speed sense and communication electronics to effectively monitor and analyze the system pressure during operation. 
     As noted above, after a shouldering-up, the motors may be shut down. However, in accordance with another embodiment of the invention, after shouldering-up, the tubular spinner may be permitted to operate for an additional period to apply additional torque to the connection being made up. This additional time may be termed a “grunt” time, as shown in  FIG. 9 . For example, a “grunt” timer may be employed to run the spinner motors  314  for a controlled period of time at high torque, to squeeze out the pipe dope. Thus, when Pthreshold is detected, indicating shouldering up, the hydraulic pressure can be maintained to drive the driven rollers  312  for a selected additional period, at the expiration of which the spin-in operation is shut down. A control system and a timer, such as, for example, control system  523  and timer  525 , may be employed to control the grunt time. The time period to which the timer may be set initially is dependent on environmental conditions and varies with doping viscosity, but may be selected readily by observation of the tubular spinner operation. 
     The spin-out operation is started subsequent to the loosening of a connection between tubulars  30  and  31 . The spin rollers  312  may be used to unthread enough of the tubular threads to allow disengagement of the tubulars  30  and  31 . However, as soon as the pin and box threads disengage, the last thread of the upper tubular  30  drops down on the first thread of the lower tubular  31 , called jumping. If the upper tubular  30  continues to be rotated after it is disengaged from the lower tubular  31  the last thread will repeatedly ride up the first thread of the lower tubular and drop down. During jumping, the threads may be damaged to a lesser or greater extent by the impact therebetween. Thus, it may be useful to know when tubular  30  has been spun-out and the threads have disengaged, to allow removal of the upper tubular  30  before it ever or repeatedly drops down on the tubular below it. On the other hand, attempting to remove tubular  30  prior to thread disengagement may result in the tubulars  30  and  31  snagging and may possibly cause thread damage. 
     In accordance with another embodiment of the invention, the tubular spinner may include a spin-out detection system to identify when a pair of tubulars has been fully or nearly spun-out so that the motors driving the rollers of the tubular spinner can be shut down. In one embodiment, for example, a system may be employed to monitor the number of tubular revolutions (angular displacement) that the tubular undergoes during a spin-out operation and this can be compared against a known number of tubular revolutions required to disengage the threads of the tubulars being handled. For many oilfield tubulars, it may take between 2 to 21 turns of one tubular relative to the other to disengage the threads. Depending on the tubular type being employed it may only require 3 to 4 turns to disengage the threads, but in some situations it may take between 10 to 20 turns to disengage the threads. The number of turns required to disengage a pair of tubulars, is readily determinable and may already be publicly known for some tubular types. In such a system, an encoder may be employed to count the number of tubular revolutions being driven by the tubular spinner. 
     In accordance with an implementation of this embodiment of the invention, an encoder may be employed to sense number of turns of a component of the tubular spinner, such as the motor  314 , or rollers  310 ,  312 , for example rotations of the motor shaft, motor gears, roller shaft, etc. This count can be used to determine the number of times the tubular  30  is rotated about its axis. As will be appreciated, such a correlation may be made based on the diameter of the roller and the diameter of the pipe being rotated. During operation, an operator may input a pipe diameter being handled to a control system such that the tubular spinner may be automatically controlled to stop after the selected number of tubular rotations for that pipe diameter. If desired, a detector may be employed on the tubular spinner, for example, to detect the space between the rollers to automatically determine the pipe diameter of the pipe being handled and therefore, the ratio of a roller rotation to a pipe rotation. 
     It is to be noted, however, that in practice the spin-out operation may start with the driven rollers  312  skipping over the surface of the tubular being handled which does not preserve the ratio of motor  314  revolutions to tubular  30  revolutions thus introducing errors in the counting of the turns; the discrepancy being non-determinable. Also, if the tubular  30  being unthreaded is not clean, this may also introduce problems in sensing/measuring tubular rotation. These possible errors must be considered in the use of a tubular rotation count to detect a spun-out condition. 
     In accordance with another implementation of the embodiment of the invention, an accelerometer may be employed to detect acceleration or jerk (changes in acceleration) during thread jumps. An accelerometer may be employed with high-speed feedback electronics to monitor the accelerometer output. The accelerometer may be installed adjacent the tubular being handled, such as a portion of the spinner frame for example on arm  300  or extensions  304  to monitor vertical tubular accelerations and, in particular, the G forces generated by the tubular. The accelerometer may generate a signal for handling by a control system, for example to alert an operator or for processing for automated operation. In the high vibration environment of well bore drilling; the accelerometer may be affected by false triggering. Also, at least one thread jump must be incurred for the accelerometer to trigger and a thread jump occurs in such a short period that normal electronic monitoring rates sometimes can miss one or more thread jump events. 
     In accordance with a further implementation of the embodiment of the invention, a linear transducer may be employed to detect linear separation between the upper and lower tubulars  30  and  31 , reverse linear displacement in the separation indicating thread jump. The linear transducer may be installed on a stationary structure, such as a portion of the spinner or torque wrench frame, adjacent the tubular being handled. The linear transducer may be installed between a stationary point and the tubular or the rollers, which tend to move vertically with the tubular, to monitor vertical displacements of the tubular vs. time. Again, with the thread jump being very sudden and occurring during a short duration of time, a highly sensitive linear transducer and high-speed feedback electronics may be employed to read the linear transducer output and feed that to a control system. In the high vibration environment of well bore drilling; the linear transducer may be affected by false triggering. Also, at least one thread jump must be incurred for the linear transducer to trigger. 
     In accordance with yet another implementation of the embodiment of the invention, a spin-out timer may be employed based on spinner motor  314  operations to spin-out the tubular  30  before reassessing tubular disengagement. The spin-out timer, which may for example be a timer component  525  of a control system  523 , is started as the spin-out operation is started (i.e. when the motors start rotating) and given tubular parameters such as, but not limited to: the thread taper, thread pitch and spin-out speed, may typically be set at 3 to 5 sec roughly corresponding to 3 to 4 revolutions of the tubular  30 . After the allocated spin-out time elapses, as monitored by the timer, the motors are shut down to stop the spin-out process. If the tubulars  30  and  31  have not disengaged within the period allowed by the timer, tubular  30  may be spun again for another, possibly shorter, period of time. An established time for disconnection for any particular tubular connection type in any particular tubular spinner may be stored to control system and the breaking out process can be controlled by the control system employing its timer component. 
     In the above it is understood that employing various of these systems, may require a comparator for comparing measured values to the established values of interest. It is further understood that employing a values of interest may require the storage of the values, possibly in memory storage. This is true for example in some systems employing pressure thresholds, system pressures, operational times, etc. 
     It is understood that the various aspects of the invention and that various elements of the implementation described may be employed alone, severally and in various combinations to improve spin-in and spin-out detection in making-up and breaking-out tubular strings, without limiting the invention. 
     The previous description of the disclosed embodiments is provided to enable any person of ordinary skill in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”.