BACKGROUND OF THE INVENTION

Field of the Invention

[0001] Embodiments of the present invention generally relate to a method and apparatus for measuring torque in a top drive system.

Description of the Related Art

[0002] A wellbore is formed to access hydrocarbon-bearing formations (e.g., crude oil and/or natural gas) or for geothermal power generation by the use of drilling. Drilling is accomplished by utilizing a drill bit that is mounted on the end of a drill string. To drill within the wellbore to a predetermined depth, the drill string is often rotated by a top drive on a surface rig. After drilling to a predetermined depth, the drill string and drill bit are removed and a section of casing is lowered into the wellbore. An annulus is thus formed between the string of casing and the formation. The casing string is hung from the wellhead. A cementing operation is then conducted in order to fill the annulus with cement. The casing string is cemented into the wellbore by circulating cement into the annulus defined between the outer wall of the casing and the borehole. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.

[0003] Top drives are equipped with a motor for rotating the drill string. The quill of the top drive is typically threaded for connection to an upper end of the drill pipe in order to transmit torque to the drill string. It is important to accurately measure the torque transmitted by the top drive to ensure proper engagement between the quill of the top drive and the drill string. Furthermore, the torque must be accurately measured to prevent overloading the drill string, drill head, and/or drill bit.

[0004] Therefore, there is a need for an apparatus and method for accurately measuring the torque provided by the top drive system. SUMMARY OF THE INVENTION

[0005] In one embodiment, a top drive system for use with a tool for handling tubulars on a drilling rig includes a motor unit; a coupling unit that transfers torque to the tool; a torque measurement device (TMD) coupled to at least one of the motor unit, the tool, or the coupling unit, wherein the TMD includes a sensing member coupled to an evaluation unit, wherein the sensing member is configured to measure a magnetostrictive effect and the evaluation unit is configured to calculate a magnitude of the torque reaction force based on the magnetostrictive effect.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

[0007] Figure 1 illustrates a motor unit of a top drive system, according to one embodiment of the present disclosure.

[0008] Figure 2A is a side-view of the motor unit coupled to a rail bracket.

[0009] Figure 2B is a top-view of the motor unit coupled to the rail bracket.

[0010] Figure 3A is an enlarged view of the motor unit having a torque measuring device according to one embodiment of the present disclosure in a first position.

[0011] Figure 3B is an enlarged view of the motor unit having the torque measuring device of Figure 3A in a second position.

[0012] Figure 4 is an enlarged view of the motor unit having a torque measuring device according to another embodiment of the present disclosure. [0013] Figure 5 is an enlarged view of the motor unit having a torque measuring device according to yet another embodiment of the present disclosure.

[0014] Figure 6 illustrates an alternative motor unit of a top drive system, according to one embodiment of the present disclosure.

[0015] Figure 7 is an enlarged view of the alternative motor unit having a torque measuring device according to another embodiment of the present disclosure.

[0016] Figure 8 is an enlarged view of the alternative motor unit having a torque measuring device according to yet another embodiment of the present disclosure.

[0017] Figure 9 is an enlarged view of the alternative motor unit having a torque measuring device according to yet another embodiment of the present disclosure.

[0018] Figure 10 illustrates a load transfer assembly of a tong assembly having a torque measuring device according to one embodiment of the present disclosure.

DETAILED DESCRIPTION

[0019] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0020] Figure 1 illustrates a motor unit 100 of a top drive system. An exemplary top drive system is disclosed in U.S. Patent Application Number 62/107,599, which is hereby fully incorporated by reference, in particular, paragraphs [0045]-[0058], [0063], [0086]-[0091 ], [0094]-[0096], and [0139]-[0142] and Figures 2A, 3, 4F-4K, 9A, and 9B.

[0021] The motor unit 100 is connected to a tool 102, as shown in Figures 1 -5. The tool 102 is configured for attachment to a casing, drilling, and/or cementing string. The motor unit 100 includes drive motors 104, a drive body 106, a swivel, a rail bracket 1 10 (Figures 2A and 2B), and motor gears 1 14 (Figure 2A).

[0022] In one embodiment, the motor unit 100 is attached to a coupling unit. The coupling unit transfers torque and load from the motor unit 100 to the tool 102. The coupling unit may include a drive gear 108 and a thread compensator 1 12. The drive gear 108 includes a bore therethrough and comprises an inner coupling mechanism that can connect one of several tools 102, such as a drilling tool exemplarily shown in Figure 1 . The compensator 1 12 is configured to remove strain on threads during make-up and break out of connections. The drive gear 108 is rotatable relative to the drive body 106. For example, an up-thrust bearing 1 16 and a down-thrust bearing 1 18 allow the drive gear 108 to rotate relative to the drive body 106. The drive motors 104 are operable to torsionally drive respective motor gears 1 14 via a shaft 1 15. The motor gears 1 14 are meshed with the drive gear 108 for torsional driving thereof.

[0023] The rail bracket 1 10 includes upper bridges 122a and 122b, lower bridges 124a and 124b, and a trolley 120 configured to counteract torque applied to the tool 102. The drive body 106 is coupled to the rail bracket 1 10, as shown in Figures 2A and 2B. In one embodiment, an upper end of the drive body 106 is fastened to the trolley 120 via the upper bridges 122a and 122b. The trolley 120 and the upper bridges 122a,b thereby torsionally restrain the upper end of the drive body 106 while allowing vertical movement of the motor unit 100. In one embodiment, a lower end of the drive body 106 is also coupled to the rail bracket 1 10, such as by fastening the drive body 106 to the trolley 120 via the lower bridges 124a and 124b. The trolley 120 and the lower bridges 124a,b thereby torsionally restrain the lower end of the drive body 106 while allowing vertical movement of the motor unit 100. The trolley 120 is movable vertically along a rail to raise and lower the casing, drilling, and/or cementing strings attached to the tool 102.

[0024] Referring again to Figure 1 , the tool 102 may include a head 102h, a neck 102n, a lifting shoulder 102s, and a torso 102r. In one embodiment, the compensator 1 12 includes a lock ring 1 13 having retractable lock pins, which when extended, are configured to engage respective slots formed in the head 102h of the tool 102, thereby connecting the lock ring 1 13 to the tool 102 and allowing a lift up via the compensator 1 12. Alternatively, a rotating latch ring may connect the lock ring 1 13 to the tool 102. The tool 102 is further secured relative to the drive body 106 by engagement with a bayonet profile 108b and a locking profile 108k on the drive gear 108 with respective profiles on the tool 102. As a result, the tool 102 is longitudinally and torsionally connected to the drive gear 108, thereby forming a top drive.

[0025] The motor unit 100 includes at least one torque measurement device for measuring a torque exerted on the motor unit 100. The torque measurement device may be disposed at any appropriate location on the motor unit 100 to increase accuracy and response time and decrease the influence of a weight load on the tool 102.

[0026] In one embodiment, the motor unit 100 includes a torque measurement device (TMD) 200 on the rail bracket 1 10, as shown in Figures 2A and 2B. For example, a respective TMD 200 is disposed on at least one of the bridges 122a,b and 124a, b. In one embodiment, two TMDs 200 are used on lower respective bridges 124a,b. In another embodiment, four TMDs 200 are disposed on respective upper and lower bridges 122a,b and 124a,b. In this embodiment, the TMDs are mounted on the upper and lower bridges to enhance measurement accuracy and compensation. Each TMD 200 may be disposed on an outer-facing surface (as shown in Figures 2A and 2B) or an inner-facing surface of each respective bridge. The TMD 200 includes any appropriate sensor for measuring torque. For example, the TMD 200 includes sensing members, such as any appropriate load cell for measuring strain and compression. The load cells may be appropriately positioned on the bridges 122a,b and 124a,b to measure the torque exerted on the motor unit 100. The TMD 200 may be connected to an evaluation unit, such as a processor, for interpreting torque measurements. For example, when torque is exerted on the motor unit 100, the torque changes an electrical resistance of the load cells in proportion to the torque. The change in electrical resistance of the load cell is transmitted to the evaluation unit, where the change is calibrated to correspond to a torque exerted on the tool 102. The upper and lower bridges 122a, b and 124a, b may tilt due to vertical or horizontal movement of the motor unit 100 relative to the bracket 1 10. The tilting of the bridges 122a,b and 124a,b changes the electrical resistance of the load cells in proportion to a tilting angle of the bridges 122a,b and 124a,b causing an incorrect torque measurement by the evaluation unit. The tilting angle of the bridges 122a,b, and 124a,b may be measured relative to the motor unit 100 and/or the bracket 1 10. The measured tilting angle and change in electrical resistance of the load cell is transmitted to the evaluation unit, where the change in electrical resistance and measured tilting angle are calibrated to correspond to a torque exerted on the tool 102. Alternatively, load measuring bolts may be used to connect the bridges 122a, b and 124a, b to the bracket 1 10 and motor unit 100. The load measuring bolts may measure the load exerted on the bridges 122a,b, and 124a,b due to vertical or horizontal movement of the motor unit 100 relative to the bracket 1 10. The measured load is transmitted to the evaluation unit with the change in electrical resistance of the load cell, where the change in electrical resistance and measured load are calibrated to correspond to a torque exerted on the tool 102.

[0027] Figures 3A and 3B show an enlarged view of the motor unit 100 having a torque measurement device (TMD) 300, according to another embodiment of the disclosure. As shown in Figure 3A, the TMD 300 is disposed on the drive gear 108. The TMD 300 includes an evaluation unit 302, such as a processor, connected to a sensing member 304 via cable 306. Alternatively, the evaluation unit 302 may communicate with the sensing member 304 wirelessly. The TMD 300 may also include a positioning device 308 having a positioning shaft 314 (Figure 3B) configured to move the sensing member 304 between a retracted position and an extended position. For example, the sensing member 304 is in the retracted position during the installation of the tool 102. After connecting the tool 102 to the motor unit 100, the positioning shaft 314 moves the sensing member 304 towards the extended position. The TMD 300 includes any appropriate sensing member 304 for high precision, contactless torque measurements. For example, the sensing member 304 is configured to measure a magnetostrictive effect on the tool 102.

[0028] In one embodiment, the sensing member 304 includes at least one inverse magnetostrictive sensor. At least a portion of the tool 102 includes ferromagnetic material. For example, the tool includes magnetized areas 310a and 310b. As shown, the magnetized areas 310a,b are disposed on the neck 102n of the tool 102. The magnetized areas 310a,b are axially aligned with a corresponding number of sensors in the sensing member 304, such as inverse magnetostrictive sensors 312a and 312b. As shown, the magnetized areas 310a,b and the sensors 312a,b are laterally spaced apart. When the tool 102 is subject to torque, a strain on an outer surface of the tool 102 changes the dimensions of the magnetized areas 310a,b, thereby changing a magnetic field between the magnetized areas 310a,b and the sensors 312a,b. The inverse magnetostrictive sensors 312a,b are configured to measure the magnetic field changes in real time. Thereafter, the sensing member 304 transmits the magnetic field measurements to the evaluation unit 302 via the cable 306. The evaluation unit 302 calculates the magnitude of torque exerted on the magnetized areas 310a,b of the tool 102 based on the change in the magnetic field measured by the sensors 312a,b.

[0029] In another embodiment, the sensing member 304 includes an anisotropic magnetostrictive sensor. In this embodiment, the sensing member 304 is axially aligned with a magnetized area, such as area 310a or 310b. In operation, torque exerted on the tool 102 may cause a compressive stress and/or tensile stress on the magnetized area. The permeability for magnetization in a direction of compressive stress is different in comparison to magnetization in a direction of tensile stress. The anisotropic magnetostrictive sensor in the sensing member 304 is configured to measure the difference in permeability and transmit the measurements to the evaluation unit 302 via the cable 306. Thereafter, the evaluation unit 302 calculates the magnitude of torque exerted on the magnetized area of the tool 102 based on the difference in permeability.

[0030] As shown in Figure 3B, the TMD 300 may be disposed on the drive body 106. For example, the TMD 300 is attached to a lower end of the drive body 106. As shown, the magnetized areas 310a,b are disposed on the torso 102r of the tool 102. In one embodiment, the sensing member 304 having the inverse magnetostrictive sensors 312a,b is axially aligned with corresponding magnetized areas 310a,b for measuring the change in magnetic field therebetween. In another embodiment, the sensing member 304 having the anisotropic magnetostrictive sensor is axially aligned with a corresponding magnetized area 310a or 310b for measuring permeability in compression and tension.

[0031] Figure 4 shows an enlarged view of the motor unit 100 having a torque measurement device (TMD) 400, according to another embodiment of the disclosure. As shown, the TMD 400 is disposed on the neck 102n of the tool 102. The TMD 400 may also, or alternatively, be disposed on the torso 102r of the tool 102. The TMD 400 includes any appropriate sensor for high precision, contactless torque measurements, such as an optical sensor. The TMD 400 includes an evaluation unit 402, such as a processor, connected to a coupling member 408 via a cable 409. Alternatively, the evaluation unit 402 may communicate with the coupling member 408 wirelessly. The drive gear 108 includes a device 410 for transmitting energy and data with the coupling member 408. The coupling member 408 is configured to wirelessly and continuously transfer measurements processed by the evaluation unit 402 to the device 410. Power transmission from the device 410 to the coupling member 408 is performed by using induction. Alternatively, power and data transmission between the device 410 and the coupling member 408 is performed via cables through the swivel. Alternatively, power may be generated directly at the tool 102 or stored for use in a battery or an electrical accumulator.

[0032] The evaluation unit 402 is also coupled to an optical transmitter/receiver 404 via a cable 406. Alternatively, the evaluation unit 402 may communicate with the optical transmitter/receiver 404 wirelessly. Alternatively, a separate optical transmitter and receiver are provided. The optical transmitter/receiver 404 is coupled to an upper grid plate 412 via a first optical fiber cable 414 and a lower grid plate 416 via a second optical fiber cable 418. The upper and lower grid plates 412, 416 may be disposed on the neck 102 and/or the torso 102r of the tool 102. The optical transmitter/receiver 404 is configured to transmit light onto each of the upper and lower grid plates 412, 416 via respective first and second optical fiber cables 414, 418. The light is transmitted back to the optical transmitter/receiver 404 via the same or additional respective fiber cables 412, 416. Under zero torque conditions, the light transmissions from the upper and lower grid plates 412, 416 are in phase with each other. When torque is applied to the tool 102, the reflected light from the upper and lower grid plates 412, 416 is modulated. Phase change measurements are received by the optical transmitter/receiver 404 and transmitted to the evaluation unit 402, where the magnitude of torque exerted on the tool 102 is calculated based on the phase difference.

[0033] Figure 5 shows an enlarged view of the motor unit 100 having a torque measurement device (TMD) 500, according to another embodiment of the disclosure. As shown, the TMD 500 is disposed on the neck 102n of the tool 102. The TMD 500 may also, or alternatively, be disposed on the torso 102r of the tool 102. The TMD 500 includes any appropriate sensor for high precision, contactless torque measurements. The TMD 500 includes an evaluation unit 502, such as a processor, connected to a coupling member 508 via cable 509. Alternatively, the evaluation unit 502 may communicate with the coupling member 508 wirelessly. The drive gear 108 includes a device 510 for transmitting energy and data with the coupling member 508. For example, the coupling member 508 is configured to wirelessly and continuously transfer measurements processed by the evaluation unit 502 to the device 510. Power transmission from the device 510 to the coupling member 508 is performed by using induction. Alternatively, power and data transmission between the device 510 and the coupling member 508 is performed via cables through the swivel. Alternatively, power may be generated directly at the tool 102 or stored for use in a battery or electrical accumulator.

[0034] The evaluation unit 502 is also coupled to a sensing member 504 via cable 506. Alternatively, the evaluation unit 502 may communicate with the sensing member 504 wirelessly. In one embodiment, the sensing member 504 includes a surface acoustic wave (SAW) sensor. In one embodiment, the SAW sensor includes a piezoelectric substrate having an input transducer separated by a distance from an output transducer. A surface wave propagates between the input and output transducers on the piezoelectric substrate. Under zero torque conditions, the surface wave has a phase associated with a zero torque applied to the tool 102. When torque is applied to the tool 102, the distance between the input and output transducers changes and the surface wave exhibits a phase different from the zero torque phase. The phase measurements are transmitted from the sensing member 504 to the evaluation unit 502, where the magnitude of the torque exerted on the tool 102 is calculated based on the phase difference. In another embodiment, the SAW sensor is used as a resonant element. For example, the SAW sensor includes the piezoelectric substrate having spaced apart interdigital electrodes. When zero torque is applied to the tool 102, a surface wave with a baseline resonant frequency propagates on the substrate between the electrodes. When torque is applied to the tool 102, the spacing between the electrodes changes, thereby changing the resonant frequency of the surface wave between the electrodes. If used as an amplifier feedback, the resonant frequency and the distance between the electrodes can be measured and evaluated.

[0035] In another embodiment, the sensing member 504 includes strain/compression load cells as described herein. The load cells may be appropriately positioned on the neck 102n and/or the torso 102r in order to accurately measure the torque and/or load exerted on the tool 102. The load cells may be connected to the evaluation unit 502 for interpreting gathered measurements. For example, when torque and/or load is exerted on the tool 102, the strain changes an electrical resistance of the load cells in proportion to the torque and/or load. The change in electrical resistance of the load cell is transmitted to the evaluation unit 502, where the torque and/or load exerted on the tool 102 is calculated based on the change in electrical resistance.

[0036] Figure 6 illustrates a motor unit 600 of a top drive system. The motor unit 600 is connected to a tool 602, as shown in Figures 6-9. The tool 602 is configured for attachment to a casing, drilling, and/or cementing string. The motor unit 600 includes drive motors 604, a drive body 606, and a drive gear 608. The drive body 606 may include a lower tubular portion with a bore therethrough and openings at respective longitudinal ends thereof. The drive gear 608 may be disposed in an inner cavity of the drive body 606.

[0037] In one embodiment, the motor unit 600 is attached to a coupling unit. The coupling unit transfers torque and load from the motor unit 600 to the tool 602. The coupling unit may be at least partially disposed in the lower tubular portion of the drive body 606. The coupling unit may include a shaft 609, a housing 61 1 , and a thread compensator 612. The shaft 609 may include a neck 609n. The shaft 609 may have couplings, such as threaded couplings, formed at a lower longitudinal end thereof on an outer surface of the shaft 609 that can connect to the housing 61 1 and on an inner surface of the shaft 609 that can connect one of several tools 602, such as a drilling tool exemplarily shown in Figure 6. The housing 61 1 may be tubular and have a longitudinal bore therethrough. The housing 61 1 may have a coupling, such as a threaded coupling, formed at a longitudinal end thereof for connection to the corresponding coupling of the shaft 609. The housing 61 1 may have a shoulder 61 1 s located at a lower longitudinal end thereof. The compensator 612 is configured to remove strain on threads during make-up and break out of connections. The drive gear 608 may be coupled to and disposed on an outside of the shaft 609. The drive gear 608 may be integrally connected to the shaft 609. The drive gear 608 and shaft 609 are rotatable relative to the drive body 606. For example, thrust bearings 616, 617, 618 allow the drive gear 608 and shaft 609 to rotate relative to the drive body 606. The drive motors 604 are operable to torsionally drive respective motor gears (not shown) via a shaft (not shown). The motor gears are meshed with the drive gear 608 for torsional driving thereof.

[0038] The tool 602 may include a head 602h and a torso 602r. In one embodiment, the compensator 612 includes a lock ring 613 having retractable lock pins, which when extended, are configured to engage respective slots formed in the head 602h of the tool 602, thereby connecting the lock ring 613 to the tool 602 and allowing a lift up via the compensator 612. Alternatively, a rotating latch ring may connect the lock ring 613 to the tool 602. The head 602h rests on the shoulder 61 1 s of the housing, transferring the load of the tool 602 to the drive gear 608 through the shaft 609 via the compensator 612 and housing 61 1 . The housing 61 1 may include a locking profile on an inner surface thereof for engagement with a respective profile on the tool head 602h. As a result, torque may be transferred from the drive gear 608 to the tool 602 via the couplings between the shaft 609 and the housing 61 1 and via the profiles in the housing 61 1 and the head 602h. As a result, the tool 602 is longitudinally and torsionally connected to the drive gear 608, thereby forming a top drive.

[0039] The motor unit 600 includes at least one torque measurement device for measuring a torque exerted on the motor unit 600. The torque measurement device may be disposed at any appropriate location on the motor unit 600 to increase accuracy and response time and decrease the influence of a weight load on the tool 602.

[0040] In one embodiment, the motor unit 600 includes the torque measurement device (TMD) 200, as shown in Fig. 2A and 2B. Motor unit 600 may replace the motor unit 100. Motor unit 600 may include the rail bracket 1 10 and bridges 122a,b, 124a,b, as shown in Figures 2A and 2B. For example, a respective TMD 200 is disposed on at least one of the bridges 122a, b and 124a, b. In one embodiment, two TMDs 200 are used on lower respective bridges 124a, b. In another embodiment, four TMDs 200 are disposed on respective upper and lower bridges 122a,b and 124a,b. In this embodiment, the TMDs are mounted on the upper and lower bridges to enhance measurement accuracy and compensation. Each TMD 200 may be disposed on an outer-facing surface (as shown in Figures 2A and 2B) or an inner-facing surface of each respective bridge. The TMD 200 includes any appropriate sensor for measuring torque. For example, the TMD 200 includes sensing members, such as any appropriate load cell for measuring strain and compression. The load cells may be appropriately positioned on the bridges 122a,b and 124a,b to measure the torque exerted on the motor unit 600. The TMD 200 may be connected to an evaluation unit, such as a processor, for interpreting torque measurements. For example, when torque is exerted on the motor unit 600, the torque changes an electrical resistance of the load cells in proportion to the torque. The change in electrical resistance of the load cell is transmitted to the evaluation unit, where the change is calibrated to correspond to a torque exerted on the tool 602. The upper and lower bridges 122a,b and 124a,b may tilt due to vertical or horizontal movement of the motor unit 600 relative to the bracket 1 10. The tilting of the bridges 122a, b and 124a, b causes additional loading of the bridges that increase the measured tensional strain and therefore changes the electrical resistance of the load cells in proportion to a tilting angle of the bridges 122a,b and 124a,b causing an incorrect torque measurement by the evaluation unit. The tilting angle of the bridges 122a,b, and 124a,b may be measured relative to the motor unit 600 and/or the bracket 1 10. The measured tilting angle and change in electrical resistance of the load cell is transmitted to the evaluation unit, where the change in electrical resistance and measured tilting angle are calibrated to correspond to a torque exerted on the tool 602. Alternatively, load measuring bolts may be used to connect the bridges 122a, b and 124a, b to the bracket 1 10 and/or motor unit 600. The load measuring bolts may measure the load exerted on the bridges 122a,b, and 124a,b due to vertical or horizontal movement of the motor unit 600 relative to the bracket 1 10. The measured load is transmitted to the evaluation unit with the change in electrical resistance of the load cell, where the change in electrical resistance and measured load are calibrated to correspond to a torque exerted on the tool 602.

[0041] In one embodiment, the motor unit 600 includes a torque measurement device (TMD) 700, as shown in Figure 7. Figure 7 shows an enlarged view of the motor unit 600. The TMD 700 is disposed on the lower tubular portion of the drive body 606. The TMD 700 may be similar to the TMD 300. The TMD 700 includes an evaluation unit 702, such as a processor, connected to a sensing member 704 via cable 706. Alternatively, the evaluation unit 702 may communicate with the sensing member 704 wirelessly. The TMD 700 may also include a positioning device 708 having a positioning shaft configured to move the sensing member 704 between a retracted position and an extended position. For example, the sensing member 704 is in the extended position during the operation of the motor unit 600 and/or the tool 602. The positioning shaft moves the sensing member 704 towards the retracted position during non-operational times of the motor unit 600 and/or the tool 602. The TMD 700 includes any appropriate sensing member 704 for high precision, contactless torque measurements. For example, the sensing member 704 is configured to measure a magnetostrictive effect on the shaft 609.

[0042] In one embodiment, the sensing member 704 includes at least one inverse magnetostrictive sensor. At least a portion of the tool 602 includes ferromagnetic material. For example, the tool includes magnetized areas 710a and 710b. As shown, the magnetized areas 710a,b are disposed on the neck 609n of the shaft 609. The magnetized areas 710a,b are axially aligned with a corresponding number of sensors in the sensing member 704, such as inverse magnetostrictive sensors 712a and 712b. As shown, the magnetized areas 710a, b and the sensors 712a,b are laterally spaced apart. When the shaft 609 is subject to torque, a strain on an outer surface of the shaft 609 changes the dimensions of the magnetized areas 710a,b thereby changing a magnetic field between the magnetized areas 710a,b and the sensors 712a,b. The inverse magnetostrictive sensors 712a,b are configured to measure the magnetic field changes in real time. Thereafter, the sensing member 704 transmits the magnetic field measurements to the evaluation unit 702 via the cable 706. The evaluation unit 702 calculates the magnitude of the torque exerted on the magnetized areas 710a,b of the shaft 609 based on the change in the magnetic field measured by the sensors 712a,b.

[0043] In another embodiment, the sensing member 704 includes an anisotropic magnetostrictive sensor. In this embodiment, the sensing member 704 is axially aligned with a magnetized area, such as area 710a or 710b. In operation, torque exerted on the shaft 609 may cause a compressive stress and/or tensile stress on the magnetized area. The permeability for magnetization in a direction of compressive stress is different in comparison to magnetization in a direction of tensile stress. The anisotropic magnetostrictive sensor in the sensing member 704 is configured to measure the difference in permeability and transmit the measurements to the evaluation unit 702 via the cable 706. Thereafter, the evaluation unit 702 calculates the magnitude of torque exerted on the magnetized area of the shaft 609 based on the difference in permeability.

[0044] Figure 8 shows an enlarged view of the motor unit 600 having a torque measurement device (TMD) 800, according to another embodiment of the disclosure. The TMD 800 may be similar to the TMD 400. As shown, the TMD 800 is disposed on the neck 609n of the shaft 609. The TMD 800 may also, or alternatively, be disposed on the torso 602r of the tool 602. The TMD 800 includes any appropriate sensor for high precision, contactless torque measurements, such as an optical sensor. The TMD 800 includes an evaluation unit 802, such as a processor, connected to a coupling member 808 via a cable 809. Alternatively, the evaluation unit 802 may communicate with the coupling member 808 wirelessly. The drive body 606 includes a device 810 for transmitting energy and data with the coupling member 808. The coupling member 808 is configured to wirelessly and continuously transfer measurements processed by the evaluation unit 802 to the device 810. Power transmission from the device 810 to the coupling member 808 is performed by using induction. Alternatively, power and data transmission between the device 810 and the coupling member 808 is performed via cables through a swivel of the motor unit 600. Alternatively, power may be generated directly at the tool 602 or stored for use in a battery or electrical accumulator.

[0045] The evaluation unit 802 is also coupled to an optical transmitter/receiver 804 via a cable 806. Alternatively, the evaluation unit 802 may communicate with the optical transmitter/receiver 804 wirelessly. Alternatively, a separate optical transmitter and receiver are provided. The optical transmitter/receiver 804 is coupled to an upper grid plate 812 via a first optical fiber cable 814 and a lower grid plate 816 via a second optical fiber cable 818. The upper and lower grid plates 812, 816 may be disposed on the neck 609n of the shaft 609 and/or the torso 602r of the tool 602. The optical transmitter/receiver 804 is configured to transmit light onto each of the upper and lower grid plates 812, 816 via respective first and second optical fiber cables 814, 818. The light is transmitted back to the optical transmitter/receiver 804 via the same or additional respective fiber cables 812, 816. Under zero torque conditions, the light transmissions from the upper and lower grid plates 812, 816 are in phase with each other. When torque is applied to the shaft 609 and tool 602, the reflected light from the upper and lower grid plates 812, 816 is modulated. Phase change measurements are received by the optical transmitter/receiver 804 and transmitted to the evaluation unit 802, where the magnitude of torque exerted on the shaft 609 and/or tool 602 is calculated based on the phase difference.

[0046] Figure 9 shows an enlarged view of the motor unit 600 having a torque measurement device (TMD) 900, according to another embodiment of the disclosure. The TMD 900 may be similar to the TMD 500. As shown, the TMD 900 is disposed on the neck 609n of the shaft 609. The TMD 900 may also, or alternatively, be disposed on the torso 602r of the tool 602. The TMD 900 includes any appropriate sensor for high precision, contactless torque measurements. The TMD 900 includes an evaluation unit 902, such as a processor, connected to a coupling member 908 via cable 909. Alternatively, the evaluation unit 902 may communicate with the coupling member 908 wirelessly. The drive body 606 includes a device 910 for transmitting energy and data with the coupling member 908. For example, the coupling member 908 is configured to wirelessly and continuously transfer measurements processed by the evaluation unit 902 to the device 910. Power transmission from the device 910 to the coupling member 908 is performed by using induction. Alternatively, power and data transmission between the device 910 and the coupling member 908 is performed via cables through the swivel. Alternatively, power may be generated directly at the tool 602 or stored for use in a battery or electrical accumulator.

[0047] The evaluation unit 902 is also coupled to a sensing member 904 via cable 906. Alternatively, the evaluation unit 902 may communicate with the sensing member 904 wirelessly. In one embodiment, the sensing member 904 includes a surface acoustic wave (SAW) sensor. In one embodiment, the SAW sensor includes a piezoelectric substrate having an input transducer separated by a distance from an output transducer. A surface wave propagates between the input and output transducers on the piezoelectric substrate. Under zero torque conditions, the surface wave has a phase associated with a zero torque applied to the shaft 609 and tool 602. When torque is applied to the shaft 609 and tool 602, the distance between the input and output transducers changes and the surface wave exhibits a phase different from the zero torque phase. The phase measurements are transmitted from the sensing member 904 to the evaluation unit 902, where the magnitude of the torque exerted on the shaft 609 and/or the tool 602 is calculated based on the phase difference. In another embodiment, the SAW sensor is used as a resonant element. For example, the SAW sensor includes the piezoelectric substrate having spaced apart interdigital electrodes. When zero torque is applied to the shaft 609 and the tool 602, a surface wave with a baseline resonant frequency propagates on the substrate between the electrodes. When torque is applied to the shaft 609 and the tool 602, the spacing between the electrodes changes, thereby changing the resonant frequency of the surface wave between the electrodes. If used as an amplifier feedback, the resonant frequency and the distance between the electrodes can be measured and evaluated.

[0048] In another embodiment, the sensing member 904 includes strain/compression load cells as described herein. The load cells may be appropriately positioned on the shaft 609 and/or the torso 602r in order to accurately measure the torque exerted on the shaft 609 and/or the tool 602. The load cells may be connected to the evaluation unit 902 for interpreting gathered measurements. For example, when torque is exerted on the shaft 609 and the tool 602, the strain changes an electrical resistance of the load cells in proportion to the torque. The change in electrical resistance of the load cell is transmitted to the evaluation unit 902, where the torque exerted on the shaft 609 and/or the tool 602 is calculated based on the change in electrical resistance.

[0049] Figure 10 illustrates a load transfer assembly 1000 of a tong assembly. An exemplary tong assembly is disclosed in P.C.T. Patent Application Number US2016/030992, which is hereby fully incorporated by reference, in particular, paragraphs [0027]-[0036] and Figures 1 D and 1 E.

[0050] The load transfer assembly 1000 may include two links 1030, two bell cranks 1032, and a torque bar 1034. The links 1030a,b are coupled between the support legs 1024 and the bell cranks 1032. Each link 1030a,b is coupled to the corresponding support leg 1024 by a pivot connection 1038. The two bell cranks 1032 are joined together through the torque bar 1034. In one embodiment, the bell cranks 1032 may be fixedly coupled to the torque bar 1034 at opposite ends of the torque bar 1034. The bell cranks 1032 are further coupled to the frame 1008 of the power tong 1002 by pivot connections 1040.

[0051] In one embodiment, the tong assembly includes a torque measurement device (TMD) 1 100 on the load transfer assembly 1000. For example, a respective TMD 1 100 is disposed on at least one of the links 1030a,b. In one embodiment, at least one TMD 1 100 is disposed on each link 1030a, b. In this embodiment, the TMDs are mounted on the links 1030a,b to enhance measurement accuracy and compensation. Each TMD 1 100 may be disposed on an outer-facing surface or an inner-facing surface of each respective link 1030a,b. The TMD 1 100 includes any appropriate sensor for measuring torque. For example, the TMD 1 100 includes sensing members, such as any appropriate load cell for measuring strain and compression. The load cells may be appropriately positioned on the links 1030a,b to measure the torque exerted on the tong assembly. The TMD 1 100 may be connected to an evaluation unit, such as a processor, for interpreting torque measurements. For example, when torque is exerted on the tong assembly, the torque changes an electrical resistance of the load cells in proportion to the torque. The change in electrical resistance of the load cell is transmitted to the evaluation unit, where the change is calibrated to correspond to a torque exerted on the tubular.

[0052] Each of the evaluation units described herein may be linked to a data network, monitoring, or control system for receiving the processed torque magnitude. The embodiments described herein may be included in the motor units 100, 600 in any combination to provide multiple torque measurements. For example, the TMD may be appropriately disposed on the drive body 106, 606, drive gear 108, 608, and/or the tool 102, 602 to measure the torque exerted on the tool 102, 602. Furthermore, multiple embodiments of the TMD may be combined to provide multiple measurements of torque for increased accuracy.

[0053] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0054] In one embodiment, a top drive system for use with a tool for handling tubulars on a drilling rig includes a motor unit; a coupling unit that transfers torque to the tool; a torque measurement device (TMD) coupled to at least one of the motor unit, the tool, or the coupling unit, wherein the TMD includes a sensing member coupled to an evaluation unit, wherein the sensing member is configured to measure a magnetostrictive effect and the evaluation unit is configured to calculate a magnitude of the torque reaction force based on the magnetostrictive effect.

[0055] In one or more of the embodiments described herein, the motor unit includes a drive body, a drive motor, and a drive ring torsionally connected to a rotor of the drive motor and the motor unit selectively connects to the tool via at least one of a latch profile, a load shoulder, a threaded connection, and friction.

[0056] In one or more of the embodiments described herein, the coupling unit is configured to support a tubular and the tool is configured to generate the torque reaction force when the tubular is rotated.

[0057] In one or more of the embodiments described herein, the sensing member includes an anisotropic magnetostrictive sensor.

[0058] In one or more of the embodiments described herein, the sensing member includes an inverse magnetostrictive sensor.

[0059] In one or more of the embodiments described herein, the sensing member is axially aligned with a magnetized area on the tool. [0060] In one or more of the embodiments described herein, the TMD is coupled to a drive gear in the motor unit.

[0061] In one or more of the embodiments described herein, the TMD is coupled to a drive body in the motor unit.

[0062] In one or more of the embodiments described herein, the TMD is coupled to the motor unit.

[0063] In one or more of the embodiments described herein, the TMD is coupled to the coupling unit.

[0064] In another embodiment, a top drive system for use with a tool for handling tubulars on a drilling rig includes a motor unit; a coupling unit that transfers torque to the tool and a torque measurement device (TMD) coupled to at least one of the motor unit or the tool, wherein the TMD includes: : an optical transmitter, an optical receiver configured to receive an optical signal from the transmitter, an evaluation unit coupled to the receiver, wherein the evaluation unit is configured to calculate a magnitude of the torque reaction force based on the optical signal.

[0065] In one or more of the embodiments described herein, the motor unit includes a drive body, a drive motor, and a drive ring torsionally connected to a rotor of the drive motor and the motor unit selectively connects to the tool via at least one of a latch profile, a load shoulder, a threaded connection, and friction.

[0066] In one or more of the embodiments described herein, the coupling unit is configured to support a tubular and the tool is configured to generate the torque reaction force when the tubular is rotated.

[0067] In one or more of the embodiments described herein, the tool includes a grid plate configured to reflect the optical signal from the transmitter.

[0068] In one or more of the embodiments described herein, wherein the tool includes the TMD. [0069] In another embodiment, a top drive system for use with a tool for handling tubulars on a drilling rig includes a motor unit; a coupling unit that transfers torque to the tool and a torque measurement device (TMD) coupled to at least one of the motor unit or the tool, wherein the TMD includes: a sensing member coupled to an evaluation unit, wherein the sensing member is configured to measure a phasing of an RF signal and the evaluation unit is configured to calculate a magnitude of the torque reaction force based on the shift of the phasing of the RF signal.

[0070] In one or more of the embodiments described herein, the motor unit includes a drive body, a drive motor, and a drive ring torsionally connected to a rotor of the drive motor and the motor unit selectively connects to the tool via at least one of a latch profile, a load shoulder, a threaded connection, and friction.

[0071] In one or more of the embodiments described herein, the motor unit includes a device configured to provide power to the evaluation unit by induction.

[0072] In one or more of the embodiments described herein, power and data transmission between a device configured to provide power to the evaluation unit is performed via cables through a swivel.

[0073] In one or more of the embodiments described herein, power and data transmission between a device configured to provide power to the evaluation unit is generated at the tool or stored for use in a battery or an electrical accumulator.

[0074] In one or more of the embodiments described herein, wherein the tool includes the TMD.

[0075] In another embodiment, a method of calculating torque for a top drive system includes applying a torque to a tool using a coupling unit, measuring a magnetostrictive effect using a sensing member, transmitting the measured magnetostrictive effect to an evaluation unit, and calculating the torque based on the measured magnetostrictive effect.

[0076] In another embodiment, a method of calculating torque for a top drive system includes applying a torque to a tool using a coupling unit, measuring an optical signal using a sensing member, transmitting the measured optical signal to an evaluation unit, and calculating the torque based on the measured optical signal.

[0077] In another embodiment, a method of calculating torque for a top drive system includes, applying a torque to a tool using a coupling unit, measuring a phasing of an RF signal using a sensing member, transmitting the measured phasing of the RF signal to an evaluation unit, and calculating the torque based on the measured phasing of the RF signal.

[0078] In another embodiment, a method of calculating torque for a top drive system including applying a torque to a tool using a coupling unit, measuring a change in electrical resistance using a sensing member, transmitting the measured change in electrical resistance to an evaluation unit, and calculating the torque based on the measured change in electrical resistance.

[0079] In another embodiment, a top drive system for use with a tool for handling tubulars on a drilling rig includes a motor unit, wherein the motor unit includes a drive body, a drive motor, and a drive ring torsionally connected to a rotor of the drive motor and the motor unit selectively connects to the tool via at least one of a latch profile, a load shoulder, a threaded connection, and friction, wherein the tool is configured to generate a torque reaction force; and a bracket coupled to the motor unit, wherein the bracket includes at least one sensing member configured to measure a change in electrical resistance and the evaluation unit is configured to calculate a magnitude of the torque reaction force based on the change in electrical resistance.