Patent Description:
In many stages of the drilling and completion of an oil and gas well, tubular members are coupled end-to-end to form what is known as a string. Typically, tubular members are made up in approximately <NUM>-<NUM> (<NUM>-<NUM> foot) segments known as pipe stands, and include threaded couplings at each end. Commonly known as box and pin connections for the female and male portions, respectively, the threaded connections serve to both form a fluid seal between the tubular segments and to resiliently couple the adjacent tubulars.

When making up a drill string, multiple rotations of one of the tubulars are required to fully engage the threads of the box with the threads of the pin. Tongs are used to deliver torque to a set of jaws that grip the tubulars being threaded together. A power tong is used to deliver torque and rotation to one of the tubulars while a backup tong maintains the other tubular rotationally stationary. During makeup of a threaded connection, the power tong moves towards the backup tong as the tubulars are threaded together. In order to account for the threading together of the tubular members, the power tong needs to move a fixed distance known as the makeup loss. The makeup loss is determined based on the characteristics of the tubulars members, such as pipe size and thread type.

If the distance between the backup tong and the power tong is not sufficient to account for the makeup loss, the backup tong and power tong will collide unless the makeup operation is stopped. Likewise, the makeup loss must be accounted for when the power tong moves away from the backup tong when breaking out a threaded connection. Typically, axial limits of the power tong actuator prevent further movement of the power tong away from the backup tong at an upper limit. If the distance between the backup tong and the upper limit is not sufficient to account for the makeup loss during break out, the power tong will cease movement away from the backup tong, resulting in damage to the threaded connection.

Therefore, there is a need for improved methods and apparatus for monitoring distance between tongs for making up and breaking out a connection.

<CIT> discloses an automated roughneck which includes a backup tong and a makeup tong. The makeup tong and backup tong may be selectively movable relative to one another. The makeup tong and backup tong may include spinner and gripper assemblies respectively adapted to make up and break out threaded connections.

<CIT> discloses a drill fluid collecting device, in which a space between a power tong and a backup tong is provided with collecting means, and in which, on their respective sides facing the space, the power tong and the backup tong are provided with a seal which is sealingly movable against a pipe located in the tongs and sealingly connected to its respective tong.

<CIT> discloses apparatus for use in subsurface drilling which permits coupling and uncoupling of drill string sections while continuously moving the drill string.

<CIT> discloses a floating type automatic sucker rod screwing on and off device.

The present disclosure generally relates to apparatus and methods for making up and breaking out threadedly connected tubular members, and more particularly to a system for monitoring distance between tongs for making up and breaking out a connection.

The method according to the invention is set out in independent claim <NUM> with optional embodiments as set out in the dependent claims.

In one embodiment, a method of connecting or disconnecting a first tubular to a second tubular includes engaging the first tubular with a power tong; engaging the second tubular with a backup tong; and rotating the first tubular relative to the second tubular. The method also includes, while rotating, measuring a distance between the power tong and the backup tong using a sensor, utilizing a controller to monitor the distance between the backup tong and the power tong and comparing the distance to a first threshold value which is a predetermined value; and stopping rotation of the first tubular when the distance equals to the first threshold value. The method also includes comparing the distance to a second threshold value, wherein the second threshold value is a remaining distance for connecting or disconnecting the first tubular and the second tubular; and restarting rotation of the first tubular relative to the second tubular if the distance is greater than or equal to the second threshold value.

The method may comprise moving the power tong axially relative to the backup tong while rotating the first tubular relative to the second tubular; and stopping axial movement of the power tong when the distance reaches the first threshold value.

According to one embodiment, a tong assembly includes a power tong, a backup tong, a sensor configured to measure a distance between the power tong and the backup tong, and a controller configured to compare the distance to a threshold value. The sensor is a cable actuated sensor attached at a first end to the power tong and at a second end to the backup tong.

In the following description, numerous specific details are set forth to provide a more thorough understanding of the present disclosure. However, it will be apparent to one of skill in the art that the present disclosure may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present disclosure.

An exemplary sensor system <NUM> is illustrated in <FIG>. In the illustrated embodiment, one or more sensors <NUM> are located on equipment <NUM> (e.g., a tong assembly, power tong, and/or backup tong) on a rig. Exemplary sensors <NUM> include cable-actuated sensors, optical imaging devices, optical devices such as laser measurement devices, ultrasonic sensors, etc. The sensors <NUM> may be configured to measure and/or monitor a distance between the power tong and the backup tong. The sensors <NUM> are positioned to be able to detect measurements <NUM> about a target <NUM> on equipment <NUM>. A local controller <NUM> is also located on the equipment <NUM>. The local controller <NUM> is functionally connected to the sensor <NUM>. In some embodiments, the local controller <NUM> is able to send commands <NUM> to the sensor <NUM>, and the sensor <NUM> is able to receive commands. In some embodiments, the local controller is able to receive information <NUM> from the sensor <NUM>, and the sensor <NUM> is able to send information <NUM>. For example, the information <NUM> may be a signal in response to detection of the target <NUM> by the sensor <NUM>. As another example, the information <NUM> may be an optical image, resulting from image processing or object detection, the measured and/or monitored distance between the power tong and the backup tong, etc. In some embodiments, the local controller <NUM> is able to store, analyze, and/or retransmit the information <NUM> received from the sensor <NUM>.

In some embodiments, the local controller <NUM> is able to send data <NUM> to a remote controller <NUM>, and remote controller <NUM> is able to receive data <NUM>. For example, the local controller is able to retransmit the information <NUM> as data <NUM>. In some embodiments, the local controller <NUM> analyzes and/or processes the information <NUM>, and the local controller <NUM> sends the results as data <NUM>. The data <NUM> may be for example, the measured and/or monitored distance between the backup tong and the power tong. The remote controller <NUM> may be remote from the equipment <NUM>. For example, the remote controller <NUM> is located in a control room of the rig, or the remote controller is at a location that is remote from the rig. The remote controller <NUM> may receive data <NUM> from the local controller <NUM> and/or other inputs (e.g., operator input, input from other systems on the rig, etc.). The remote controller <NUM> may analyze and/or process the data <NUM> and/or other inputs. The remote controller <NUM> may be able to send control commands <NUM> to local controller <NUM>, and local controller <NUM> may be able to receive commands <NUM>. Data, inputs, commands, and/or signals may be sent between local controller <NUM> and remote controller <NUM> over a variety of communication channels, including, for example, wires, fiber optics, hydraulic lines, pneumatic lines, and/or wirelessly, including electromagnetic or acoustic signaling.

In some embodiments, local controller <NUM> is functionally connected with other sensors <NUM> on equipment <NUM>. The other sensors <NUM> are differentiated from the sensors <NUM>. In some embodiments, the other sensors <NUM> acquire measurements about the operation of the equipment <NUM>. For example, the other sensors <NUM> may include torque sensors, pressure sensors, etc. In some embodiments, the other sensors <NUM> acquire measurements about one or more auxiliary sites <NUM> on the equipment <NUM>. In some embodiments, the local controller <NUM> is able to send commands <NUM> to the other sensors <NUM>, and the other sensors <NUM> are able to receive commands <NUM>. In some embodiments, the local controller <NUM> is able to receive information <NUM> from the other sensors <NUM>, and the other sensors <NUM> are able to send information <NUM>. In some embodiments, the local controller <NUM> is able to store, analyze, and/or retransmit the information <NUM> received from the other sensors <NUM>. For example, the local controller analyzes information <NUM> from sensors <NUM> in combination with information <NUM> from the other sensors <NUM>.

In some embodiments, local controller <NUM> is functionally connected with actuators <NUM> on equipment <NUM>. For example, in some embodiments, the local controller <NUM> is able to send commands <NUM> (e.g., control signals) to the actuators <NUM>, and the actuators <NUM> may be able to receive commands <NUM>. The commands <NUM> may be based on, or in response to, the information <NUM>, information <NUM>, and/or analysis of information <NUM>/<NUM>. In some embodiments, the commands <NUM> instruct the actuators <NUM> to cause action <NUM> (e.g., stopping rotation of the power tong and/or backup tong, stopping longitudinal movement of the power tong) at the equipment <NUM>.

Another exemplary sensor system <NUM> is illustrated in <FIG>. The sensor system <NUM> may assist during operation of a tong assembly to makeup a tubular connection.

The sensor system <NUM> may be mounted on a tong assembly. In one embodiment, the tong assembly may be coupled to and moved by a positioning system, such as a power arm. The tong assembly includes a power tong <NUM> and a backup tong <NUM>. The power tong <NUM> is configured to receive a pin end of a tubular joint and to engage and grip the pin end of the tubular joint. The backup tong <NUM> is configured to receive a box end of a tubular string and to engage and grip the box end of the tubular string. The power tong <NUM> and the backup tong <NUM> may be used to makeup or breakout a connection between the tubular joint and the tubular string.

The sensor system <NUM> may detect a distance between the power tong <NUM> and the backup tong <NUM>. In <FIG>, the backup tong <NUM> is shown in a neutral position. During operation of the tong assembly, the relative position between the power tong <NUM> and the backup tong <NUM> may be in a continuous range <NUM> between the upper limit <NUM> and the lower limit <NUM>. For example, as the tubular joint is lowered during makeup, the power tong <NUM> will move lower and closer to the backup tong <NUM>. The sensor system <NUM> may monitor the distance between the power tong <NUM> and the backup tong <NUM>. If the backup tong <NUM> reaches the upper limit <NUM>, damage may result to the power tong <NUM>, backup tong <NUM>, or other components of the tong assembly. In some instances, damage to the tubular connection could also occur. Similarly, during breakout, the power tong <NUM> will move higher and away from the backup tong <NUM>. As a result, the backup tong <NUM> will move closer to the lower limit <NUM>, which be determined by monitoring the distance between the power tong <NUM> and the backup tong <NUM>. The sensor system <NUM> may be configured to stop the operation of the tong assembly if the backup tong <NUM> approaches either of the upper limit <NUM> or lower limit <NUM>.

In one embodiment, the sensor system <NUM> includes a sensor <NUM>. The sensor <NUM> may be a cable actuated sensor. The cable actuated sensor may span the distance between the power tong <NUM> and the backup tong <NUM>. In some embodiments, a reel of the cable actuated sensor is mounted to an underside of the power tong <NUM>. An end opposite the reel is mounted to the top of the backup tong <NUM>. In some embodiments, the reel is mounted to the top of the backup tong <NUM> and the end opposite the reel is mounted to the underside of the power tong <NUM>. The cable actuated sensor may have a length slightly greater than the upper and lower limits of movement of the tong assembly. For example, the cable actuated sensor may have a length of cable five to ten percent greater than, or three to twenty percent greater than, the upper and lower limits of movement of the tong assembly. The cable actuated sensor may be configured to feed out or retract a length of cable in response to relative movement between the power tong <NUM> and the backup tong <NUM>. For example, as the power tong <NUM> moves away from the backup tong <NUM> while breaking out a tubular connection, the reel of the cable actuated sensor may feed out a corresponding length of cable equal to the distance moved by the power tong <NUM>.

The sensor <NUM> may be functionally connected to local controller <NUM>. Local controller <NUM> may be able to send data to and/or receive commands from a remote controller. The location of sensor <NUM> on the tong assembly may be changed according to operational and/or manufacturing specifications.

During operation, the sensor <NUM> may monitor and/or measure a distance between the backup tong <NUM> and the power tong <NUM>. The local controller <NUM> may be able to receive information from the sensor <NUM>. The information may include the monitored and/or measured distance between the backup tong <NUM> and the power tong <NUM>. The information may be analyzed to determine further information. In some embodiments, the local controller <NUM> transmits the information to a remote controller. The remote controller may be able to receive information from the local controller <NUM>. In some embodiments, the local controller <NUM> may calculate the distance between the backup tong <NUM> and the power tong <NUM>. For example, the sensor <NUM> may transmit information regarding the speed of emitted sound waves and the time it takes for sound waves to return. Based on the information, the local controller <NUM> may calculate the measured and/or monitored distance between the backup tong <NUM> and the power tong <NUM>. In some embodiments, the remote controller may calculate the measured and/or monitored distance between the backup tong <NUM> and the power tong <NUM> based on the information.

In some embodiments, the local controller <NUM> may stop operation of the tong assembly if the backup tong <NUM> approaches either the upper limit <NUM> or the lower limit <NUM>. For example, the local controller <NUM> can analyze the information from the sensor <NUM>, and the local controller <NUM> can calculate and compare the measured and/or monitored distance to a first threshold value. The first threshold value may correspond to the upper limit <NUM> of movement or the lower limit <NUM> of movement. In some embodiments, the first threshold value may be within a predetermined range, such as within <NUM> (an inch), or within a range of <NUM> to <NUM> (<NUM> inches to two inches), of the upper limit <NUM> or the lower limit <NUM>. In some embodiments, if the local controller <NUM> determines the measured and/or monitored distance is equal or greater than the first threshold value, then the local controller <NUM> can instruct the tong assembly to stop operation, thereby stopping rotation of the first threaded tubular relative to the second threaded tubular.

In some embodiments, the first threshold value corresponds to a manufacturer's specification. The manufacturer's specification may be based on the tubular specification, tong assembly specification, or a combination thereof. In some embodiments, the local controller <NUM> calculates and compares the measured and/or monitored distance to the first threshold value. In some embodiments, if the local controller <NUM> determines the measured and/or monitored distance is equal or greater than the first threshold value, then the local controller <NUM> can determine the tubular connection is close to makeup or breakout based on the tubular specification, tong assembly specification, or a combination thereof. In some embodiments, the local controller <NUM> determines the remaining distance required for makeup or breakout based on the tubular specification, tong assembly specification, or a combination thereof. The local controller <NUM> can compare the determined remaining distance required with the measured and/or monitored distance between the backup tong <NUM> and the power tong <NUM>. If the determined remaining distance is less than the distance between the tongs <NUM>, <NUM>, then the local controller <NUM> may instruct the tong assembly to continue operation. If the determined remaining distance is greater than the distance between the tongs <NUM>, <NUM>, then the local controller <NUM> may instruct the tong assembly to stop operation.

In some embodiments, the sensor system <NUM> measures the distance between the backup tong <NUM> and the power tong <NUM> before beginning rotation of the tubulars. The sensor <NUM> may transmit information to the local controller <NUM> to calculate the distance between the backup tong <NUM> and the power tong <NUM>. The local controller <NUM> may compare the measured distance to a first threshold value. The first threshold value may correspond to a manufacturer's specification, such as the distance required to makeup or breakout a connection between a first tubular and a second tubular. In some embodiments, if the local controller <NUM> determines the measured distance is equal to or greater than the first threshold value, then the local controller <NUM> can instruct the tong assembly to begin operation by rotating the first threaded tubular relative to the second threaded tubular. In some embodiments, if the local controller <NUM> determines the measured distance is less than the first threshold value, then the backup tong <NUM> is repositioned to increase the distance between the power tong <NUM> and the backup tong <NUM>. In some embodiments, the sensor system can measure the distance between the new position of the backup tong <NUM> and the power tong <NUM>. If the local controller <NUM> determines the new distance is greater than or equal to the first threshold value, then the local controller <NUM> can instruct the tong assembly to begin operation.

In some embodiments, slippage between the power tong <NUM> and/or backup tong <NUM> and the tubulars may occur. As a result, the initial comparison and determination based on the first threshold value made by the local controller <NUM> may now be incorrect. In some embodiments, the sensor system <NUM> measures and/or monitors the distance between the backup tong <NUM> and the power tong <NUM> and compares the measured and/or monitored distance to a second threshold value. The second threshold value may correspond to the upper limit <NUM> of movement or lower limit <NUM> of movement. The second threshold value may be within <NUM> (an inch), or within a range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), of the upper limit <NUM> or lower limit <NUM>. In some embodiments, the second threshold value is equal to the upper limit <NUM> or lower limit <NUM>. In some embodiments, the local controller <NUM> receives information from the sensor <NUM>, and the local controller <NUM> determines the measured and/or monitored distance between the backup tong <NUM> and the power tong <NUM>. The local controller <NUM> can compare the measured and/or monitored distance to the second threshold value. The local controller <NUM> may instruct the tong assembly to stop operation if the distance between the tongs is equal to or greater than the second threshold value, thereby stopping rotation of the tubulars. If the distance between the tongs is less than the second threshold value, then the local controller <NUM> may instruct the tong assembly to continue operation.

In another embodiment, the sensor <NUM> is an ultrasonic sensor. In some embodiments, the ultrasonic sensor is mounted to the underside of the power tong <NUM>. In some embodiments, the ultrasonic sensor is oriented towards a top of the backup tong <NUM>. The ultrasonic sensor may be configured to emit and receive sound waves. For example, the ultrasonic sensor emits sound waves from a position on the underside of the power tong <NUM> towards a top of the backup tong <NUM>. The sound waves reflect off the surface of the backup tong <NUM> and back towards the ultrasonic sensor. A receiver of the ultrasonic sensor may receive the returning sound waves. In some embodiments, the ultrasonic sensor determines a distance between the backup tong <NUM> and the power tong <NUM>. For example, the ultrasonic sensor emits sound waves and measures the time in which it takes reflected sound waves to return. The sensor <NUM> or local controller <NUM> may analyze the information and calculate a distance between the backup tong <NUM> and the power tong <NUM> based on the speed of the emitted sound waves and the time it takes for the reflected sound waves to return.

In another embodiment, the sensor system <NUM> includes an optical imaging device. Exemplary optical imaging devices include cameras, 3D cameras, high speed cameras, time lapse cameras, infrared cameras, light detector, charged-coupled device, wide-angled lens camera, high resolution camera, time-of-flight camera, stop motion camera, motion picture camera, etc. The optical imaging device may be positioned to be able to capture an optical image of a focus area. For example, if the optical imaging device utilizes visible light to capture an optical image, then the optical imaging device is positioned to have a clear line of sight to the focus area. In some embodiments, as part of capturing the optical image, the optical imaging device may emit energy (e.g., focusing light) towards the focus area. In some embodiments, the optical imaging device may have a light source (e.g., flasher) to emit the energy. A light source on the optical imaging device may improve the reliability to properly identify targets regardless of the presence of additional or different lights in the rig environment. The optical imaging device may then capture an optical image, either responsive to the emission of energy, or of the focus area in a native state (without prompting from the optical imaging device). In some embodiments, the optical image may be a series of images captured over time (e.g., as with a motion picture camera). In some embodiments, the optical imaging device may be capable of performing image processing and/or object detection.

<FIG> illustrates exemplary operations <NUM> that may be performed, for example, by a control device, such as local controller <NUM>, to control the tong assembly at a work location, in accordance with embodiments of the present disclosure. Operations <NUM> begin at <NUM>, where the control device transmits a first signal representative of a menu of options to a remote interface, such as remote controller <NUM>. The menu of options may, for example, represent operation commands for the tong assembly. At <NUM>, the control device receives from the remote interface a second signal representative of a first operation command. At <NUM>, the control device transmits a third signal representative of the first operation command to the tong assembly, which may cause the sensor system to activate. At <NUM>, the sensor system measures a distance between the backup tong <NUM> and the power tong <NUM>. At <NUM>, the control device receives a fourth signal from the sensor system representative of the measured distance. At <NUM>, the control device compares the measured distance to a first threshold value. At <NUM>, the control device transmits a fifth signal to the tong assembly based on the comparison. If the measured distance is less than the threshold value, then the control device causes the tong assembly to operate and rotate the tubulars to make or break a connection. If the measured distance is equal to or greater than the threshold value, then the control device causes the tong assembly to stop operation. The fifth signal may be representative of a second operation command.

<FIG> illustrates operations <NUM> that may be performed, for example, by a control device, such as local controller <NUM>, to control the tong assembly at a work location, in accordance with embodiments of the present disclosure. Operations <NUM> may begin at <NUM>, where the control device transmits a first signal representative of a menu of options to a remote interface, such as remote controller <NUM>. The menu of options may, for example, represent operation commands for the tong assembly. At <NUM>, the control device receives from the remote interface a second signal representative of a first operation command. At <NUM>, the control device transmits a third signal representative of the first operation command to the tong assembly, which may cause the tong assembly to operate and rotate the tubulars to make or break a connection. At <NUM>, the sensor system monitors a distance between the backup tong <NUM> and the power tong <NUM>. At <NUM>, the control device receives a fourth signal from the sensor system representative of the monitored distance. At <NUM>, the control device compares the monitored distance to a first threshold value. At <NUM>, the control device transmits a fifth signal representative of a second operation command, which may cause the tong assembly to stop operation and rotation of the tubulars to make or break a connection.

<FIG> illustrates operations <NUM> that may be performed, for example, by a control device, such as local controller <NUM>, to control the tong assembly at a work location, in accordance with embodiments of the present disclosure. Operations <NUM> may begin at <NUM>, where the control device transmits a first signal representative of a menu of options to a remote interface, such as remote controller <NUM>. The menu of options may, for example, represent operation commands for the tong assembly. At <NUM>, the control device receives from the remote interface a second signal representative of a first operation command. At <NUM>, the control device transmits a third signal representative of the first operation command to the tong assembly, which may cause the tong assembly to operate and rotate the tubulars to make or break a connection. At <NUM>, the power tong may engage a first tubular. At <NUM>, the backup tong may engage a second tubular. At <NUM>, the tong assembly may rotate the first tubular relative to the second tubular. At <NUM>, while rotating, the sensor system monitors a distance between the backup tong and the power tong. At <NUM>, while rotating, the control device compares the monitored distance to a first threshold value. At <NUM>, the control device transmits a fifth signal to the tong assembly based on the comparison, which may cause the tong assembly to operate and rotate the tubulars to make or break a connection. The fifth signal may be representative of a second operation command.

<FIG> illustrates exemplary operations <NUM> that may be performed, for example, by a control device, such as local controller <NUM>, to control the tong assembly at a work location, in accordance with embodiments of the present disclosure. Operations <NUM> begin at <NUM>, where the control device transmits a first signal representative of a menu of options to a remote interface, such as remote controller <NUM>. The menu of options may, for example, represent operation commands for the tong assembly. At <NUM>, the control device receives from the remote interface a second signal representative of a first operation command. At <NUM>, the control device transmits a third signal representative of the first operation command to the tong assembly, which causes the tong assembly to operate and rotate the tubulars to make or break a connection. At <NUM>, the power tong engages a first tubular. At <NUM>, the backup tong engages a second tubular. At <NUM>, the sensor system measures a distance between the backup tong and the power tong. At <NUM>, the control device compares the measured distance to a first threshold value. At <NUM>, the control device transmits a fifth signal to the tong assembly based on the comparison. If the measured distance is less than the first threshold value, then the tong assembly continues to operate and rotate the tubulars to make or break a connection. If the measured distance is equal to or greater than the first threshold value, then the fifth signal will cause the tong assembly stop operation. The fifth signal may be representative of a second operation command.

Operations <NUM>, <NUM>, <NUM>, and/or <NUM> may further include one or more of the following steps: comparing the measured and/or monitored distance to a second threshold value; based on the second comparison, stopping rotation of the first threaded tubular relative to the second threaded tubular; disengaging the first threaded tubular from the power tong; disengaging the second threaded tubular from the backup tong; moving the power tong relative to the backup tong; re-engaging the first threaded tubular with the power tong; re-engaging the second threaded tubular with the backup tong; and further rotating the first threaded tubular relative to the second threaded tubular.

Operations <NUM>, <NUM>, <NUM>, and/or <NUM> may further include one or more of the following steps: while further rotating the first threaded tubular relative to the second threaded tubular, measuring the distance between the backup tong and the power tong; after stopping rotation, comparing the distance to a second threshold value; based on the second comparison, restarting rotation of the first tubular relative to the second tubular; wherein comparing the distance to a first threshold value further comprises determining whether the distance is within one inch of the first threshold value; and wherein moving the power tong relative to the backup tong further comprises biasing the backup tong towards a neutral position.

In one or more of the embodiments described herein, a method of connecting or disconnecting a first tubular to a second tubular includes engaging the first tubular with a power tong; engaging the second tubular with a backup tong; and rotating the first tubular relative to the second tubular. The method also includes, while rotating, measuring a distance between the power tong and the backup tong using a sensor, utilizing a controller to monitor a distance between the backup tong and the power tong and comparing the distance to a first threshold value which is a predetermined value; and stopping rotation of the first tubular when the distance equals to the first threshold value.

In one or more of the embodiments described herein, the method further includes comparing the distance to a second threshold value.

In one or more of the embodiments described herein, the method further comprising based on the comparison, stopping rotation of the first threaded tubular relative to the second threaded tubular.

In one or more of the embodiments described herein, the method further including disengaging the first threaded tubular from the power tong; disengaging the second threaded tubular from the backup tong; and moving the power tong relative to the backup tong.

In one or more of the embodiments described herein, the method further including re-engaging the first threaded tubular with the power tong; re-engaging the second threaded tubular with the backup tong; and further rotating the first threaded tubular relative to the second threaded tubular.

In one or more of the embodiments described herein, the method further comprising while further rotating the first threaded tubular relative to the second threaded tubular, measuring the distance between the backup tong and the power tong.

In one or more of the embodiments described herein, a tong assembly, comprising: a power tong; a backup tong; a sensor configured to measure a distance between the power tong and the backup tong; and a controller configured to compare the distance to a threshold value.

In one or more of the embodiments described herein, wherein the sensor is an optical sensor.

In one or more of the embodiments described herein, wherein the sensor is a cable actuated sensor.

In one or more of the embodiments described herein, the method further comprises moving the power tong axially relative to the backup tong while rotating the first threaded tubular relative to the second threaded tubular;and stopping axial movement of the power tong when the distance reaches the first threshold value.

In one or more of the embodiments described herein, a method of connecting or disconnecting a first threaded tubular to a second threaded tubular includes engaging the first threaded tubular with a power tong, engaging the second threaded tubular with a backup tong, measuring a distance between the backup tong and the power tong, comparing the distance to a first threshold value, and based on the comparison, rotating the first threaded tubular relative to the second threaded tubular, thereby connecting or disconnecting the tubulars.

In one or more of the embodiments described herein, the method further includes, after stopping rotation, comparing the distance to a second threshold value.

In one or more of the embodiments described herein, the method further includes stopping axial movement of the power tong when the distance reaches the second threshold value.

In one or more of the embodiments described herein, wherein the first threshold value is within a predetermined range of an upper limit of movement of the backup tong relative to the power tong.

In one or more of the embodiments described herein, wherein the first threshold value is within a predetermined range of a lower limit of movement of the backup tong relative to the power tong.

In one or more of the embodiments described herein, wherein the second threshold value is a remaining distance for connecting or disconnecting the first tubular and the second tubular.

In one or more of the embodiments described herein, wherein comparing the distance to a first threshold value further comprises determining whether the distance is within one inch of the first threshold value.

In one or more of the embodiments described herein, a tong assembly includes a power tong, a backup tong, a sensor configured to measure a distance between the power tong and the backup tong, and a controller configured to compare the distance to a threshold value.

In one or more of the embodiments described herein, wherein moving the power tong relative to the backup tong further comprises biasing the backup tong towards a neutral position.

In one or more of the embodiments described herein, wherein the sensor is an ultrasonic sensor.

Claim 1:
A method of connecting or disconnecting first and second threaded tubulars, comprising:
engaging the first threaded tubular with a power tong (<NUM>);
engaging the second threaded tubular with a backup tong;
rotating the first threaded tubular relative to the second tubular;
while rotating:
measuring a distance between the power tong (<NUM>) and the backup tong (<NUM>) using a sensor (<NUM>);
utilizing a controller (<NUM>) to monitor the distance between the backup tong (<NUM>) and the power tong (<NUM>);
comparing the distance to a first threshold value;
stopping rotation of the first tubular when the distance is equal to or greater than the first threshold value;
comparing the distance to a second distance threshold value, wherein the second distance threshold value is a remaining distance for connecting or disconnecting the first threaded tubular and the second threaded tubular; and
restarting rotation of the first threaded tubular relative to the second tubular if the distance is greater than or equal to the second distance threshold value.