TUBULAR CONNECTION CONTROL USING DETECTABLE FEATURE

Abstract

A tubular string can include helical threads on respective tubulars, and a structural formation on at least one of the threads. The formation is configured to produce a change in torque as the threads are threaded together. A method of making up a threaded connection between tubulars can include producing a structural formation on at least one of threads of the respective tubulars, engaging the threads, and applying torque to the threaded connection, thereby causing the tubulars to shoulder up. The formation causes a change in the torque a predetermined number of turns prior to the shoulder up.

Description

BACKGROUND

This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an example described below, more particularly provides for use of detectable features on a tubular to control a connection between that tubular and another tubular.

When making up threaded connections between oilfield tubulars (such as, tubing, drill pipe, casing, liner, tubular well tools, etc.), it is beneficial to be able to make up each connection quickly, properly and safely. Making up connections quickly saves time and expense. Making up connections properly ensures high quality connections. Making up connections safely prevents damage or other harm to personnel and equipment.

It will, therefore, be readily appreciated that improvements are continually needed in the art of making up threaded connections in oilfield operations. Such improvements can be useful in a wide variety of different types of oilfield operations, such as, drilling, completions, stimulation, water or steam flooding, production, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative elevational view of an example of a well system and associated method which can embody principles of this disclosure.

FIGS. 2A & B are representative cross-sectional views of an example of a threaded connection being made up.

FIG. 3 is a representative graph of torque vs. turns for an example of the threaded connection make up process.

FIG. 4 is a representative graph of torque vs. turns for another example of the threaded connection make up process.

FIG. 5 is a representative graph of torque vs. turns for another example of the threaded connection make up process.

FIG. 6 is a representative partial cross-sectional view of an example of a structural formation on a thread of a tubular.

FIG. 7 is a representative side view of an example of a threaded connection with an external structural formation.

FIG. 8 is a representative graph of torque vs. turns for another example of the threaded connection make up process.

FIG. 9 is a representative graph of torque vs. turns for another example of the threaded connection make up process.

FIG. 10 is a representative partial cross-sectional view of another example of a structural formation on a thread of a tubular.

FIG. 11 is a representative side view of another example of a structural formation on a thread of a tubular.

FIG. 12 is a representative partial cross-sectional view of another example of a structural formation on a thread of a tubular.

FIG. 13 is a representative graph of torque vs. turns for another example of the threaded connection make up process.

FIG. 14 is a representative side view of another example of a threaded connection.

DETAILED DESCRIPTION

Representatively illustrated in FIG. 1 is a system 10 for use with a subterranean well, and an associated method, which can embody principles of this disclosure. However, it should be clearly understood that the system 10 and method are merely one example of an application of the principles of this disclosure in practice, and a wide variety of other examples are possible. Therefore, the scope of this disclosure is not limited at all to the details of the system 10 and method described herein and/or depicted in the drawings.

In the FIG. 1 system 10, a tubular string 12 is being installed into a wellbore (not shown) below a rig floor 14. The tubular string 12 may comprise any types of oilfield tubulars (such as, tubing, drill pipe, casing, liner, tubular well tools, etc.).

In this example, a tong assembly 16, including an upper rotary tong 18 and a lower backup tong 20, is used to make up a threaded connection 22 between an upper tubular 24 and a lower tubular 26. The rotary tong 18 grips, rotates and applies torque to the upper tubular 24, and the backup tong 20 grips the lower tubular 26 and reacts the torque applied by the rotary tong.

Note that it is not necessary for a tong assembly to be used to make up a threaded connection in keeping with the principles of this disclosure. Other types of equipment (such as, a top drive) may be used in other examples.

After the threaded connection 22 is properly made up, the tubular string 12 is lowered further into the wellbore, and then another tubular connection is made up. This process will be repeated many times.

It will be appreciated that, since the make up process is repeated many times, any saving of time in the process will be multiplied many times. It might be assumed that, in order to save time in the make up process, the rotational speed of the rotary tong 18 could simply be increased to thereby speed up the threading together of the tubulars 24, 26. However, the solution to the problem of saving time in the make up process is more complex than simply speeding up the process, at least in part because damage to the tong assembly 16 or the tubulars 24, 26, or safety risks to nearby personnel, could result from excessive speed or excessive torque due to the excessive speed.

Referring additionally now to FIGS. 2A & B, cross-sectional views of an example of a threaded connection 44 are representatively illustrated. The threaded connection 44 may be used for the threaded connection 22 in the system 10 of FIG. 1, or other types of threaded connections may be used with the system 10.

In FIG. 2A, an external tapered thread 40 on a lower end of the upper tubular 24 is engaged with an internal tapered thread 42 in an upper end of the lower tubular 26, thereby forming the threaded connection 44. However, it should be clearly understood that the scope of this disclosure is not limited to any particular type of threaded connection formed between any particular type of threads on any particular types of threaded components.

In the FIG. 2A example, a lower seal end 46 of the upper tubular 24 is making contact with an internal seal surface 48 in the lower tubular 26. At this point, a minimal seal may be formed between the seal end 46 and the seal surface 48, but the threaded connection 44 is not fully made up.

As depicted in FIG. 2B, further torque and rotation have been applied to the upper tubular 24, so that the upper tubular has advanced further into the lower tubular 26. As a result, the seal end 46 has deformed (the seal surface 48 may also be deformed somewhat), and an inclined shoulder 50 formed in the lower end of the upper tubular 20 abuts an inclined shoulder 52 formed in the upper end of the lower tubular 26. The deformation of the seal end 46 forms a pressure-tight seal with the seal surface 48.

At this point, the threaded connection 44 is shouldered-up, or at its shoulder point. The specification for the threaded connection 44 may require that further torque be applied to the connection, and/or that a certain number of additional turns of the upper tubular 20 be accomplished after the shoulder point, in order for the threaded connection 44 to be acceptable for use in the well.

Referring additionally now to FIG. 3, an example graph 54 of torque versus turns for an example threaded connection is representatively illustrated. For convenience of description, the graph 54 is made up of substantially linear segments 54a-c, with each of the segments having a different slope. An actual graph of torque versus turns for an actual threaded connection will typically not include segments with such linearity.

The graph 54 is described below as it may represent the make up of the FIGS. 2A & B threaded connection 44. However, the scope of this disclosure is not limited to any particular representation of the threaded connection 44 example of FIGS. 2A & B, or to any particular torque versus turns graph shape.

The segment 54a represents an initial threading of the upper tubular 24 into the lower tubular 26. Note that the applied torque gradually increases as the number of turns increases, but a slope of the segment 54a is relatively small.

Eventually, the seal end 46 of the upper tubular 24 contacts the seal surface 48 in the lower tubular 26. This seal contact point is represented in the graph 54 at point 56.

As mentioned above, further rotation of the upper tubular 24 after the seal end 46 contacts the seal surface 48 results in deformation of the seal end. Thus, due to this deformation of the seal end 46, the torque required to produce additional turns of the upper tubular 24 increases. Note the increased slope of the segment 54b (as compared to the slope of the segment 54a) after the seal contact point 56.

The further rotation of the upper tubular 24 after the seal contact point 56 eventually results in full contact between the shoulders 50, 52 of the upper tubular and the lower tubular 26. This shoulder point is represented in the graph 54 at point 58.

Still further rotation of the upper tubular 24 after the shoulder point 58 will be substantially resisted by the abutting contact between the shoulders 50, 52. Note the greatly increased slope of the segment 54c (as compared to the slopes of the segments 54a,b).

Eventually, the specification for the threaded connection 44 will be achieved at a point 60. For example, a certain minimum, optimal or range of torque will have been applied to the threaded connection 44, and/or a certain number of turns of the upper tubular 24 after the shoulder point 58 will have been achieved. At this point 60, the applied torque can be released (not shown in the graph 54).

If the speed of the upper tubular 24 rotation is increased in the make up process, there is an increased probability that the optimal torque will be exceeded (for example, note the relatively steep slope of the segment 54c). Such excessive torque could result in damage to the tong assembly 16 or the tubulars 24, 26 in the system 10, or safety risks to nearby personnel.

Therefore, it will be appreciated that it would be desirable to decrease the speed of rotation prior to the segment 54c (such as, prior to the shoulder point 58), so that the optimal torque (or number of turns after a desired minimum torque) can be applied with a suitably controllable rotational speed. Accordingly, it would be desirable to provide an indication of the impending shoulder point 58 prior to the shoulder point occurring.

This indication could be observed by an operator, so that the operator could manually decrease the rotational speed of the upper tubular 24. Alternatively, and more practically, a control system for the tong assembly 16 could be designed to automatically decrease the rotational speed of the upper tubular 24 when the indication is provided. Technology such as artificial intelligence could be trained to recognize when the indication is provided, and then control the rotational speed of the upper tubular 24, so that the optimal torque is applied to the threaded connection 44 (or a desired number of turns is applied after a desired minimum torque is applied).

Referring additionally now to FIG. 4, another example of the torque versus turns graph 54 is representatively illustrated. In this example, a number of variations or changes in torque are indicated, prior to the shoulder point 58. Specifically, there are three sets 62a-c of momentary torque increases prior to the shoulder point 58.

In this example, a number of the torque increases in each set 62a-c varies. That is, the first set 62a includes three torque increases, the second set 62b includes two torque increases, and the third set 62c includes one torque increase.

It will be appreciated that the decreasing number of torque increases in the sets 62a-c as the shoulder point 58 approaches represents a “countdown” that provides an indication of the approaching shoulder point, so that an operator or control system will be advised of when the shoulder point will occur. For example, the last set 62c could be provided a known, predetermined number of turns prior to the shoulder point 58.

In other examples, the numbers of torque changes in the sets 62a-c may not decrease with increasing turns (for example, the numbers of torque changes could be the same, or could increase as the shoulder point 58 is approached), or may not represent a “countdown.” In addition, spacings t1, t2 between the sets 62a-c of torque changes may be substantially the same, or the spacings may vary.

Referring additionally to FIG. 5, another example of the torque versus turns graph 54 is representatively illustrated. In this example, a change in torque 62 is provided a predetermined number of turns prior to the shoulder point 58. The change in torque is not momentary (as in the FIG. 4 example), but is instead a sustained step increase in the applied torque.

Referring additionally now to FIG. 6, an example of a thread 64 having structural formations 66 thereon is representatively illustrated. The thread 64 may be used for either or both of the threads 40, 42 described above on the respective tubular 24, 26 in the FIG. 1 system 10 and method, or it may be used in other systems and methods.

The multiple formations 66 depicted in FIG. 6 may be used to produce multiple torque changes in a threaded connection make up (e.g., the sets 62a-c of torque changes in the FIG. 4 graph 54). Alternatively, a single formation 66 could be used to produce a sustained torque change in a threaded connection make up (e.g., the sustained torque increase 62 in the FIG. 5 graph 54). The scope of this disclosure is not limited to use of any particular number or arrangement of the formation(s) 66.

As depicted in FIG. 6, the thread 64 is an internal thread (such as, in the lower tubular 26), but in other examples the formations 66 may be produced on an external thread (such as, on the upper tubular 24). The formations 66 are depicted as protrusions formed on the thread 64 by deformations of the thread. In other examples, the formations 66 could be produced by welding, laser deposition, 3D printing, or any other suitable method. The formations 66 could be formed by removing material from the thread 64, instead of by adding material to the thread.

The formations 66 are preferably located on the thread 64 a predetermined number of turns away from a shoulder (not shown), so that corresponding torque changes will be produced the predetermined number of turns prior to shouldering up in a threaded connection make up process. Any number, arrangement or configuration of the formations 66 may be used in keeping with the scope of this disclosure.

Referring additionally now to FIG. 7, another example of the threaded connection 44 is representatively illustrated. In this example, sets 68a-c of structural formations 66 are provided on a helical path 70 on an exterior surface of the upper tubular 24 a predetermined number of turns before shoulder up. In other examples, the sets 68a of formations 66 could be provided on an internal surface and/or on another component (such as, the lower tubular 26 in the FIG. 1 system 10).

In the FIG. 7 example, the presence of each of the formations 66 is detected by a sensor 72 (such as, a proximity, Hall effect, optical or contact sensor). The sensor 72 could be connected to the tong assembly 16 control system described above.

An angle or pitch of the helical path 70 in this example is the same as a pitch of the thread 40, so that the sensor 72 can conveniently detect the formations 66 as the upper tubular 24 is threaded into the lower tubular 26. The formations 66 may be in the form of protrusions or recesses, or any other suitable shape, and may be formed using any suitable process.

There may be any number of sets 68a-c of the formations 66. The number of formations 66 in each set 68a-c may be the same or the numbers may be different. The numbers of formations in the sets 68a-c detected by the sensor 72 may increase, decrease or remain the same as the upper tubular 24 is rotated. A spacing between the sets 68a-c of formations 66 may increase, decrease or remain the same along the helical path 70.

The spacing and/or quantity of the formations 66 in each of the sets 68a-c may be used to encode or modulate data (such as, thread type, tubular size, turns to shoulder up, or optimal torque). Such sets 68a-c of formations 66 may be used with any of the threaded connection 44 and thread 40, 42, 64 examples described herein.

Referring additionally now to FIG. 8, another example of the torque versus turns graph 54 is representatively illustrated. In this example, a spacing between adjacent pairs of the formations 66 (corresponding to torque changes in the graph 54) decreases as the shoulder point 58 is approached, so that the rotational speed can be appropriately decreased prior to the shoulder point. Any of the threaded connection 44 examples and formation 66 examples described herein may be used with the FIG. 8 graph 54.

In one example, a rotational speed of the upper tubular 24 corresponds to a frequency of the torque changes (momentary torque increases in the FIG. 8 example). It may be desirable to configure the tong assembly 16 control system, so that the frequency of the torque changes remains substantially constant. In this manner, the rotational speed will be decreased as the spacing between the formations 66 decreases, prior to the shoulder point 58. The control system could vary the rotational speed as needed to maintain a substantially constant frequency of the torque changes.

Referring additionally now to FIG. 9, another example of the torque versus turns graph 54 is representatively illustrated. In this example, data 74 is encoded or modulated on the torque variations. The modulated data 74 can be demodulated using conventional signal processing techniques in real time while the threaded connection 44 is being made up, and the demodulated data may be used by the control system to control operation of the tong assembly 16. The data modulations are preferably provided a predetermined number of turns prior to the shoulder point 58.

The data 74 may comprise thread type, tubular size, turns to shoulder up, optimal torque, or any other data or combinations of data that might be useful for controlling make up of a threaded connection.

Referring additionally now to FIG. 10, another example of a structural formation 66 on a thread 64 of a tubular (such as the tubular 26) is representatively illustrated. In this example, the formation 66 is configured so that the data 74 (see FIG. 9) is encoded or modulated on the torque used to make up the threaded connection 44.

As depicted in FIG. 10, the formation 66 comprises fluctuations or undulations formed on the thread 64 in a manner that modulates the data 74. Any suitable method may be used to form the formation 66 on the thread 64. Preferably, the formation 66 is formed on the thread 64 a predetermined number of turns prior to shoulder up.

Referring additionally now to FIG. 11, another example of the structural formation 66 on a thread 64 of the tubular 24 is representatively illustrated. The FIG. 11 formation 66 is similar to the formation 66 of the FIG. 9 example, in that the formation is configured to modulate the data 74 on the torque used to make up the threaded connection 44. However, in the FIG. 11 example the thread 64 on which the formation 66 is formed is an external thread.

Referring additionally now to FIG. 12, another example of the thread 64 having formations 66 thereon is representatively illustrated. In the FIG. 12 example, the formations 66 comprise deformable structures secured to the thread 64 by any suitable method (such as, welding, bonding, brazing, soldering, etc.).

In the FIG. 12 example, the formations 66 may be secured to any surface, side or flank of the thread 64. The formations 66 may be secured to internal or external threads.

When a formation 66 is deformed (e.g., by a mating thread), a sustained increase in torque may be produced (for example, as depicted in FIG. 5). Preferably, the formation 66 is positioned a predetermined number of turns prior to shoulder up of the threaded connection 44.

Referring additionally now to FIG. 13, another example of the torque versus turns graph 54 is representatively illustrated. In this example, the segment 54a of the graph 54 includes a single momentary increase in torque 76. This increase in torque 76 is preferably produced a predetermined number of turns prior to the shoulder point 58, so that an operator or control system for the tong assembly 16 can appropriately react to decrease the rotational speed of the rotary tong 18 prior to shoulder up of the threaded connection 44.

Referring additionally now to FIG. 14, another example of the threaded connection 44 is representatively illustrated. In this example, a deformable or frangible ring 78 is positioned between external shoulders 46, 48 of the respective upper and lower tubulars 24, 26.

As the threaded connection 44 is being made up, the ring 78 will eventually become compressed between the external shoulders 46, 48. This will produce a torque increase (such as, the torque increase 76 depicted in FIG. 13).

In the FIG. 14 example, the ring 78 is provided with a weak point 80. The weak point 80 ensures that the ring 78 will break reliably and fall away, prior to the shoulders 46, 48 making contact with each other.

The ring 78 may be made of a deformable plastic material, a frangible material or another suitable material that will not interfere with the make up of the threaded connection 44. A thickness or width of the ring 78 may be selected, so that the torque increase 76 is produced a desired number of turns prior to shoulder up of the threaded connection 44.

In any of the examples of the thread 64 described above, the thread 64 may be internal or external, and the thread 64 may be used for either or both of the threads 40, 42 on the respective tubular 24, 26 in the threaded connection 44.

It may now be fully appreciated that the above disclosure provides significant benefits to the art of making up threaded connections. In examples described above changes in torque are produced a known number of turns prior to shoulder up of the threaded connection, so that a rotational speed can be appropriately decreased to avoid damage to threads or other equipment, and to enhance personnel safety.

The above disclosure provides to the art a tubular string 12 for use with a subterranean well. In one example, the tubular string 12 can include first and second helical threads 40, 42 on respective first and second tubulars 24, 26; and a structural formation 66 on at least one of the first and second threads 40, 42. The formation 66 is configured to produce a change in torque as the first and second threads 40, 42 are threaded together.

The formation 66 may be further configured so that the change in torque is produced a predetermined number of turns from a shoulder up of the first and second tubulars 24, 26.

The formation 66 may be further configured so that the change in torque comprises a sustained increase in torque.

The formation 66 may be further configured so that the change in torque comprises a fluctuation in torque.

The formation 66 may be further configured so that the change in torque comprises modulated data 74. The data 74 may be selected from the group consisting of thread type, tubular size, turns to shoulder up, and optimal torque.

The formation 66 may comprise a deformation of the at least one of the first and second threads 40, 42.

The formation 66 may comprise a deformable structure secured to the at least one of the first and second threads 40, 42.

The formation 66 may comprise a series of protuberances on the at least one of the first and second threads 40, 42, with a predetermined spacing t1, t2, t3 between each adjacent pair of the protuberances. The spacings t1, t2, t3 may be consistent between all adjacent pairs of the protuberances. The spacings t1, t2, t3 may vary between the adjacent pairs of the protuberances. The spacings t1, t2, t3 may comprise modulated data 74.

The formation 66 may comprise a series of sets 68a-c of protuberances on the at least one of the first and second threads 40, 42. Numbers of the protuberances in the sets 68a-c may vary.

The above disclosure also provides to the art a method of making up a threaded connection 44 between first and second tubulars 24, 26. In one example, the method can comprise: producing a structural formation 66 on at least one of first and second threads 40, 42 of the respective first and second tubulars 24, 26; engaging the first and second threads 40, 42; and applying torque to the threaded connection 44, thereby causing the first and second tubulars 24, 26 to shoulder up. The formation 66 causes a change in the torque a predetermined number of turns prior to the shoulder up.

In the applying step, the formation 66 may cause a sustained increase in the torque.

In the applying step, the formation 66 may cause a fluctuation in torque.

In the applying step, the change in the torque may comprise modulated data 74.

In the producing step, the formation 66 may comprise a deformation of the at least one of first and second threads 40, 42.

In the producing step, the formation 66 may comprise a series of protuberances on the at least one of first and second threads 40, 42, with a predetermined spacing t1, t2, t3 between each adjacent pair of the protuberances.

In the producing step, the formation 66 may comprise a series of sets 68a-c of protuberances on the at least one of first and second threads 40, 42. Numbers of the protuberances in the sets 68a-c may vary.

Although various examples have been described above, with each example having certain features, it should be understood that it is not necessary for a particular feature of one example to be used exclusively with that example. Instead, any of the features described above and/or depicted in the drawings can be combined with any of the examples, in addition to or in substitution for any of the other features of those examples. One example's features are not mutually exclusive to another example's features. Instead, the scope of this disclosure encompasses any combination of any of the features.

Although each example described above includes a certain combination of features, it should be understood that it is not necessary for all features of an example to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used.

It should be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of this disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.

The terms “including,” “includes,” “comprising,” “comprises,” and similar terms are used in a non-limiting sense in this specification. For example, if a system, method, apparatus, device, etc., is described as “including” a certain feature or element, the system, method, apparatus, device, etc., can include that feature or element, and can also include other features or elements. Similarly, the term “comprises” is considered to mean “comprises, but is not limited to.”

Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of this disclosure. For example, structures disclosed as being separately formed can, in other examples, be integrally formed and vice versa. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the invention being limited solely by the appended claims and their equivalents.

Claims

1. A tubular string for use with a subterranean well, the tubular string comprising: first and second helical threads respectively formed on first and second tubular members; anda structural formation on at least one of the first and second threads, the formation configured to produce a change in torque as the first and second threads are threaded together, in which the first tubular member is configured to form a pressure-tight seal directly with the second tubular member when the first thread is fully engaged with the second thread.

2. The tubular string of claim 1, in which the formation is further configured so that the change in torque is produced a predetermined number of turns from a shoulder up of the first and second tubular members.

3. The tubular string of claim 1, in which the formation is further configured so that the change in torque comprises a sustained increase in torque.

4. The tubular string of claim 1, in which the formation is further configured so that the change in torque comprises a fluctuation in torque.

5. The tubular string of claim 1, in which the formation is further configured so that the change in torque comprises modulated data.

6. The tubular string of claim 5, in which the data is selected from the group consisting of thread type, tubular size, turns to shoulder up, and optimal torque.

7. The tubular string of claim 1, in which the formation comprises a deformation of the at least one of the first and second threads.

8. The tubular string of claim 1, in which the formation comprises a deformable structure secured to the at least one of the first and second threads.

9. The tubular string of claim 1, in which the formation comprises a series of protuberances on the at least one of the first and second threads, with a predetermined spacing between each adjacent pair of the protuberances.

10. The tubular string of claim 9, in which the spacings are consistent between all adjacent pairs of the protuberances.

11. The tubular string of claim 9, in which the spacings vary between the adjacent pairs of the protuberances.

12. The tubular string of claim 9, in which the spacings comprise modulated data.

13. The tubular string of claim 1, in which the formation comprises a series of sets of protuberances on the at least one of the first and second threads, and in which numbers of the protuberances in the sets vary.

14. A method of making up a threaded connection between first and second tubular members, the method comprising: producing a structural formation on at least one of first and second threads respectively formed on the first and second tubular members;engaging the first and second threads; andapplying torque to the threaded connection, thereby causing the first and second tubular members to shoulder up, in which the formation causes a change in the torque a predetermined number of turns prior to the shoulder up, and in which the first tubular member forms a pressure-tight seal directly with the second tubular member when the first thread is fully engaged with the second thread.

15. The method of claim 14, in which in the applying, the formation causes a sustained increase in the torque.

16. The method of claim 14, in which in the applying, the formation causes a fluctuation in torque.

17. The method of claim 14, in which in the applying, the change in the torque comprises modulated data.

18. The method of claim 14, in which in the producing, the formation comprises a deformation of the at least one of first and second threads.

19. The method of claim 14, in which in the producing, the formation comprises a series of protuberances on the at least one of first and second threads, with a predetermined spacing between each adjacent pair of the protuberances.

20. The method of claim 14, in which in the producing, the formation comprises a series of sets of protuberances on the at least one of first and second threads, and in which numbers of the protuberances in the sets vary.