GENERATOR DRIVEN BY DRILL PIPE

Abstract

A rotating control device for sealing about a drill pipe can include a seal which can sealingly engage the drill pipe, and a generator which generates electricity in response to rotation of the drill pipe while the seal sealingly engages the drill pipe. A method of generating electricity from rotation of a drill pipe can include sealingly engaging the drill pipe with a seal of a rotating control device, and generating electricity in response to the rotation of the drill pipe. A system for generating electricity can include a rotating control device which seals about a drill pipe while the drill pipe rotates, the rotating control device comprising a seal and a generator which generates electricity in response to rotation of the drill pipe.

Description

TECHNICAL FIELD

This disclosure relates generally to equipment utilized and operations performed in conjunction with a well and, in one example described below, more particularly provides a way of generating electricity due to rotation of a drill pipe.

BACKGROUND

Rotation of a drill string is one way to drill a wellbore into the earth. In some situations, a rotating control device is used to seal off an annulus formed between the drill string and the wellbore at or near the earth's surface.

It will be appreciated that improvements are continually needed in the arts of drilling wellbores and supplying electrical power to components, such as, sensors, actuators, electronic devices, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative partially cross-sectional view of a well system and associated method which can embody principles of this disclosure.

FIG. 2 is an enlarged scale partially cross-sectional view of a rotating control device which can embody principles of this disclosure.

FIG. 3 is a cross-sectional view of the rotating control device, taken along line 3-3 of FIG. 2.

FIG. 4 is a schematic view of an electrical generation and utilization system which can embody the principles of this disclosure.

DETAILED DESCRIPTION

Representatively illustrated in FIG. 1 is a system 10 for use with a subterranean well, and an associated method, which system and method 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 example, a wellbore 12 is drilled by rotating a drill pipe 14, such as, by utilizing a drilling rig (not shown) at or near the earth's surface. The drill pipe 14 can be rotated by any means, e.g., a rotary table, a top drive, a positive displacement or turbine drilling motor, etc. Thus, it should be understood that the scope of this disclosure is not limited to any particular way of rotating the drill pipe 14.

The drill pipe 14 is part of an overall drill string 16, which can include a variety of different components. Preferably, a drill bit 18 is connected at a distal end of the drill string 16, so that the drill bit cuts into the earth when the drill string rotates and weight is applied to the drill bit.

An annulus 20 is formed radially between the drill string 16 and the wellbore 12. A drilling fluid 22 (commonly known as “mud,” although other fluids, such as brine water, may be used) is circulated downward through the drill string 16, exits the drill bit 18, and flows back to the surface via the annulus 20.

The drilling fluid 22 serves several purposes, including cooling and lubricating the drill bit 18, removing cuttings, maintaining a desired balance of pressures between the wellbore 12 and the surrounding earth, etc. In some situations (e.g., in managed pressure drilling or underbalanced drilling, or even in conventional overbalanced drilling), it may be desirable to seal off the annulus 20 at or near the earth's surface (for example, at a land or sea-based drilling rig, a subsea facility, a jack-up rig, etc.), so that communication between the annulus 20 and the earth's atmosphere or sea is prevented.

For this purpose, a rotating control device 24 can be used to seal about the drill string 16 during a drilling operation. In the example depicted in FIG. 1, the rotating control device 24 is connected to a blowout preventer stack 26 on a wellhead 28, but in other examples the rotating control device could be positioned in or on a riser string, in a subsea wellhead, in a wellbore, etc. The scope of this disclosure is not limited to any particular location of the rotating control device 24.

Referring additionally now to FIG. 2, an enlarged scale partially cross-sectional view of one example of the rotating control device 24 is representatively illustrated. In this view, it may be clearly seen that the rotating control device 24 includes two “passive” seals 30, 32 which seal against an exterior surface of the drill pipe 14 as the drill pipe rotates within an outer housing assembly 34 of the rotating control device. The FIG. 2 rotating control device 24 may be used with the system 10 and method of FIG. 1, or it may be used with other systems and methods.

In the FIG. 2 example, the outer housing assembly 34 is provided with a flange 36 at a lower end thereof for connection to the blowout preventer stack 26. However, in other examples, the outer housing assembly 34 could be provided with suitable connectors for installing the rotating control device 24 in or on a riser string, to a subsea wellhead, or at any other location.

As depicted in FIG. 2, the lower seal 30 is positioned in the outer housing assembly 34, whereas the upper seal 32 is positioned in an upper “pot” or enclosure 38. In other examples, either or both of the seals 30, 32 could be positioned inside or outside of the outer housing assembly 34, and other numbers of seals (including one) may be used. The scope of this disclosure is not limited to any particular number or positions of seals.

As mentioned above, the seals 30, 32 are passive, in that they sealingly engage the drill pipe 14 whenever the drill pipe is positioned in the rotating control device 24, without any need of actuating the seals to effect such sealing. In other examples, the seals 30, 32 (or either of them) could be “active” seals, so that they sealingly engage the drill pipe 14 in response to an applied stimulus.

For example, one or both of the seals 30, 32 could be inflated by introducing pressure into the seals, an actuator could be used to displace the seals inward into contact with the drill pipe, etc. The scope of this disclosure is not limited to any particular manner of causing the seals 30, 32 to sealingly engage the drill pipe 14.

In the FIG. 2 example, the seals 30, 32 are mounted to a bearing assembly 40, which is secured to the outer housing assembly 34 by a clamp 42. The bearing assembly 40 includes bearings 44, which permit an inner generally tubular mandrel 46 to rotate relative to the outer housing assembly 34.

In other examples, a latch mechanism or other device could be used in place of the clamp 42. The bearing assembly 40 and both seals 30, 32 could be positioned entirely within the outer housing assembly 34. Thus, the scope of this disclosure is not limited to any particular arrangement or configuration of the various components of the rotating control device 24.

Note that, as depicted in FIG. 2, the seals 30, 32 rotate with the enclosure 38 and mandrel 46 relative to the outer housing assembly 34 when the drill pipe 14 rotates in the rotating control device 24. Preferably, the drill pipe 14 is grippingly engaged by the seals 30, 32, so that the seals transfer torque from the drill pipe to the mandrel 46.

Rotation of the mandrel 46 by the drill pipe 14 (via the seals 30, 32) operates an electrical generator 48, so that electricity is generated in response to the drill pipe rotation. This can be very beneficial in circumstances where electrical power may not otherwise be available at or near the rotating control device 24, there is a desire to reduce or eliminate the use of power cables extending to the area about the rotating control device, etc.

In this example, the generator 48 is located in the bearing assembly 40, which is desirably sealed off from well fluids and the atmosphere, and is provided with a lubricant. However, in other examples, the generator 48 could be otherwise located, the generator could be exposed to well fluids or the atmosphere, etc. The scope of this disclosure is not limited to any particular placement, configuration or environment of the generator 48.

Referring additionally now to FIG. 3, a cross-sectional view of the rotating control device 24 is representatively illustrated. In this example, the generator 48 includes multiple permanent magnets 50 affixed to, and circumferentially distributed on, the mandrel 46.

As the mandrel 46 rotates, the magnets 50 displace by a coil 52. As will be appreciated by those skilled in the art, a changing magnetic field about the coil 52 (due to the displacement of the magnets 50 by the coil) will cause electrical current to flow in the coil. The mandrel 46 and magnets 50, thus, comprise a rotor 66 of the generator 48, and the coil 52 and outer bearing assembly 40 comprise a stator 68 of the generator 48.

The electrical current generated by the generator 48 can be used to supply electrical power to any of a variety of different types of electrical devices. For example, electrical power could be supplied from the generator 48 to electronic circuitry, sensors, actuators, latching devices, interlocks, etc. The electrical power can be stored in one or more batteries for use, for example, when the drill pipe 14 is not rotating in the rotating control device 24.

Although the generator 48 is depicted in FIG. 3 as including the magnets 50 and coil 52, in other examples, other means of producing electrical power could be used. For example, magneto- or electro-strictive devices could be used to produce electricity in response to rotation of the drill pipe 14. The scope of this disclosure is not limited to any particular way of producing electricity from rotation of the drill pipe 14.

In the FIG. 3 example, the single coil 52 remains stationary while the magnets 50 secured to the mandrel 46 displace by the coil. However, in other examples, multiple coils 52 could be used, and/or the coil(s) could be secured to the mandrel 46 or otherwise made to displace by one or more of the magnets 50.

It may be desired to have the coil 52 displace, for example, if a component supplied with electrical power by the generator 48 also displaces. Thus, it should be understood that the scope of this disclosure is not limited to any particular location, arrangement or configuration of the elements of the generator 48.

Referring additionally now to FIG. 4, a system 54 for generating and utilizing electrical power is representatively illustrated. The system 54 may be used with the rotating control device 24 described above, or it may be used with other rotating control devices, or with other types of well tools.

In the system 54, the generator 48 generates electrical power in response to rotation of the drill pipe 14. This electrical power is supplied to a battery 56, sensors 58, electronic circuitry 60, an actuator 62, and an alerting or indicating device 64. However, note that these components of the system 54 are merely examples of a wide variety of different types of devices which can be supplied with electrical power, and thus, the scope of this disclosure is not limited to use of the electrical power by any particular device(s).

In the FIG. 4 example, the sensors 58 could include any type of sensors, such as pressure, temperature, proximity, etc., sensors. For example, the sensors 58 could measure pressure and/or temperature of lubricant in the bearing assembly 40, pressure and/or temperature of a coolant, pressure and/or temperature of well fluid in the annulus 20 below the seal 30, whether or not the clamp 42 is completely opened or closed, etc. The scope of this disclosure is not limited to use of any particular type of sensor.

The electronic circuitry 60 could include at least one processor and other electronic components for monitoring outputs of the sensors 58, controlling operation of the actuator 62, activating the device 64, communicating with external control systems, etc. The scope of this disclosure is not limited to any particular use of the electronic circuitry 60.

The actuator 62 may be used to operate the clamp 42 (or a latching or interlock mechanism), to actuate “active” seals, etc. The scope of this disclosure is not limited to any particular manner of operating the actuator 62.

The device 64 may be used to indicate whether the clamp 42 is open or closed, whether temperature in the bearing assembly 40 is excessive, whether the seal 30 is leaking, etc. The scope of this disclosure is not limited to any particular use of the device 64.

The battery 56 can be used to store electrical power generated by the generator 48, to condition such power, etc. In this manner, the electrical power can be available to the sensors 58, circuitry 60, actuator 62 and device 64 whether or not the drill pipe 14 is rotating at a particular moment.

However, the scope of this disclosure is not limited to use of the battery 56 for storing electrical power generated by the generator 48. Other electrical storage devices could include relatively large capacity capacitors (e.g., “super capacitors,” etc.).

It may now be fully appreciated that the disclosure above provides significant advancements to the art. In an example described above, electrical power is generated in response to rotation of the drill pipe 14. Torque is transferred from the drill pipe 14 to the electrical generator 48 via the seals 30, 32, which both seal against and grippingly engage the drill pipe.

The above disclosure provides to the art a rotating control device 24 for sealing about a drill pipe 14. In one example, the rotating control device 24 can include at least one seal 30, 32 which can sealingly engage the drill pipe 14, and a generator 48 which generates electricity in response to rotation of the drill pipe 14 while the seal 30, 32 sealingly engages the drill pipe 14.

The seal 30, 32 may rotate with the drill pipe 14. In other examples, the seal 30, 32 may not rotate with the drill pipe 14.

The generator 48 can be mechanically coupled to the drill pipe 14 via the seal 30, 32. In other examples, there may be no mechanical coupling between the drill pipe 14 and the seal 30, 32

The seal 30, 32 may grippingly engage the drill pipe 14 and thereby transfer torque to the generator 48. In other examples, torque could be transferred directly from the drill pipe 14 to the generator 48, or via the mandrel 46, etc.

The seal 30 may be contained in an outer housing assembly 34, and the seal 30 may rotate relative to the outer housing assembly 34 in response to rotation of the drill pipe 14. In other examples, the seal 30 may not be contained in the outer housing assembly, and/or may not rotate relative to the outer housing assembly 34.

The generator 48 may be contained in a bearing assembly 40. In other examples, the generator 48 is not necessarily in a bearing assembly.

The generator 48 can comprise a rotor 66 which rotates relative to a stator 68 of the generator 48 in response to rotation of the seal 30, 32. In other examples, electricity could be generated by other means, such as, electro- or magneto-strictive devices, etc.

The rotating control device 24 may include an actuator 62, and the generator 48 may supply electrical power to the actuator 62. In other examples, an actuator may not be supplied with electrical power by the generator 48.

The rotating control device 24 may include a sensor 58, and the generator 48 may supply electrical power to the sensor 58. In other examples, a sensor may not be supplied with electrical power by the generator 48.

The rotating control device 24 may include a battery 56, and the generator 48 may charge the battery 56. In other examples, the generator 48 may not charge a battery.

The rotating control device 24 may include electronic circuitry 60, and the generator 48 may supply electrical power to the electronic circuitry. In other examples, the generator 48 may not supply electrical power to electronic circuitry.

A method of generating electricity from rotation of a drill pipe 14 is also described above. In one example, the method can comprise: sealingly engaging the drill pipe 14 with a seal 30, 32 of a rotating control device 24; and generating electricity in response to the rotation of the drill pipe 14.

Also described above is a system 54 for generating electricity. In one example, the system 54 can include a rotating control device 24 which seals about a drill pipe 14 while the drill pipe 14 rotates. The rotating control device 24 can include a seal 30, 32 and a generator 48 which generates electricity in response to rotation of the drill pipe 14.

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.

In the above description of the representative examples, directional terms (such as “above,” “below,” “upper,” “lower,” etc.) are used for convenience in referring to the accompanying drawings. However, it should be clearly understood that the scope of this disclosure is not limited to any particular directions described herein.

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 rotating control device for sealing about a drill pipe, comprising:

at least one seal which can sealingly engage the drill pipe; and

a generator which generates electricity in response to rotation of the drill pipe while the seal sealingly engages the drill pipe.

2. The rotating control device of claim 1, wherein the seal rotates with the drill pipe.

3. The rotating control device of claim 1, wherein the generator is mechanically coupled to the drill pipe via the seal.

4. The rotating control device of claim 1, wherein the seal grippingly engages the drill pipe and thereby transfers torque to the generator.

5. The rotating control device of claim 1, wherein the seal is contained in an outer housing assembly, and wherein the seal rotates relative to the outer housing assembly in response to rotation of the drill pipe.

6. The rotating control device of claim 1, wherein the generator is positioned in a bearing assembly.

7. The rotating control device of claim 1, wherein the generator comprises a rotor which rotates relative to a stator of the generator in response to rotation of the seal.

8. The rotating control device of claim 1, further comprising an actuator, and wherein the generator supplies electrical power to the actuator.

9. The rotating control device of claim 1, further comprising a sensor, and wherein the generator supplies electrical power to the sensor.

10. The rotating control device of claim 1, further comprising a battery, and wherein the generator charges the battery.

11. The rotating control device of claim 1, further comprising electronic circuitry, and wherein the generator supplies electrical power to the electronic circuitry.

12. A method of generating electricity from rotation of a drill pipe, the method comprising:

sealingly engaging the drill pipe with at least one seal of a rotating control device; and

generating electricity in response to the rotation of the drill pipe.

13. The method of claim 12, wherein the seal and generator are components of a rotating control device which seals about the drill pipe as the drill pipe rotates.

14. The method of claim 12, wherein the generating further comprises rotating the seal with the drill pipe.

15. The method of claim 12, further comprising mechanically coupling the generator to the drill pipe via the seal.

16. The method of claim 12, further comprising the seal grippingly engaging the drill pipe and thereby transferring torque to the generator.

17. The method of claim 12, wherein the seal is contained in an outer housing assembly, and wherein the seal rotates relative to the outer housing assembly in response to rotation of the drill pipe.

18. The method of claim 12, wherein the generator is positioned in a bearing assembly.

19. The method of claim 12, wherein the generator comprises a rotor which rotates relative to a stator of the generator in response to rotation of the seal.

20. The method of claim 12, wherein the generating further comprises the generator supplying electrical power to an actuator.

21. The method of claim 12, wherein the generating further comprises the generator supplying electrical power to a sensor.

22. The method of claim 12, wherein the generating further comprises the generator charging a battery.

23. The method of claim 12, wherein the generating further comprises the generator supplying electrical power to electronic circuitry.

24. A system for generating electricity, comprising:

a rotating control device which seals about a drill pipe while the drill pipe rotates, the rotating control device comprising at least one seal and a generator which generates electricity in response to rotation of the drill pipe.

25. The system of claim 24, wherein the seal rotates with the drill pipe.

26. The system of claim 24, wherein the generator is mechanically coupled to the drill pipe via the seal.

27. The system of claim 24, wherein the seal grippingly engages the drill pipe and thereby transfers torque to the generator.

28. The system of claim 24, wherein the seal is contained in an outer housing assembly, and wherein the seal rotates relative to the outer housing assembly in response to rotation of the drill pipe.

29. The system of claim 24, wherein the generator is positioned in a bearing assembly.

30. The system of claim 24, wherein the generator comprises a rotor which rotates relative to a stator of the generator in response to rotation of the seal.

31. The system of claim 24, further comprising an actuator, and wherein the generator supplies electrical power to the actuator.

32. The system of claim 24, further comprising a sensor, and wherein the generator supplies electrical power to the sensor.

33. The system of claim 24, further comprising a battery, and wherein the generator charges the battery.

34. The system of claim 24, further comprising electronic circuitry, and wherein the generator supplies electrical power to the electronic circuitry.