MX2015001107A

MX2015001107A - Rotating control device having seal responsive to outer diameter changes.

Info

Publication number: MX2015001107A
Application number: MX2015001107A
Authority: MX
Inventors: Mohamed A Ahmed
Original assignee: Halliburton Energy Services Inc
Priority date: 2012-09-12
Filing date: 2012-09-12
Publication date: 2015-06-05
Also published as: AU2012389806B2; CA2884701A1; RU2015107981A; BR112015005487A2; EP2872732A4; AU2012389806A1; EP2872732A1; WO2014042631A1; US20140339772A1

Abstract

A rotating control device for sealing about a drill string having a change in outer diameter can include a seal which rotates with the drill string, the seal including at least two chambers connected by a passage, and a fluid which flows between the chambers via the passage in response to displacement of the outer diameter change through the seal. A method of sealing can include forming at least two chambers in a resilient material of a seal, displacing the outer diameter change into the seal, thereby transferring fluid from a first chamber to a second chamber, and displacing the outer diameter change out of the seal, thereby transferring the fluid from the first chamber to the second chamber. One of the chambers can increase in volume while the other of the chambers decreases in volume.

Description

ROTATING CONTROL DEVICE THAT HAS A SEAL THAT RESPONDES TO EXTERNAL DIAMETER CHANGES Field of the Invention This description relates in general to the equipment used and the operations performed in conjunction with an underground well and, in an example described below, more particularly provides a rotary control device with a seal that responds to changes in the external diameter of a string. of drilling.

Background of the Invention Rotary control devices generally include one or more seals to seal the drill pipe while the drill pipe rotates therein. These seals can be damaged by repeated displacement of the drill pipe connections (for example, collars or tool joints) or other changes in the external diameter through the seals. One reason is that the seals deform to allow the diameter of the drill pipe to deform to pass through them.

The seals are already compressed against the drill pipe (in order to seal them), so that the additional compression of the seals when the diameter changes, the passage through them puts additional stress on the seals. In addition, the drill pipe connections Ref.253684 they are typically not perfectly smooth, so that the seals can also be scraped, cut, subjected to abrasion, etc., when the connections pass through the seals already under tension.

Therefore, it will be appreciated that improvements are constantly needed in the rotating control devices and the seals in these.

Brief Description of the Figures Figure 1 is a cross-sectionally representative view of a well drilling system and the associated method that can embody the principles of this disclosure.

Figure 2 is a partially cross-sectional view, on an enlarged, representative scale, of a rotary control device that can be used in the system and method of Figure 1, and which can embody the principles of this description.

Figure 3 is an enlarged, representative, enlarged cross-sectional view of a seal that can be used in the rotating control device of Figure 2, and which can embody the principles of this disclosure.

Figure 4 is a cross sectional view, representative of the seal, with a change in external diameter of a drill string that is inserted into the seal.

Figure 5 is a cross-sectional view, representative of the seal, with the change in external diameter that is displaced in the seal.

Figure 6 is a cross-sectional view, representative of the seal, with the change in external diameter that is displaced away from the seal.

Detailed description of the invention Representatively illustrated in Figure 1 is a system 10 for use with an underground well, and an associated method, which system and method may embody the principles of this disclosure. However, it should be clearly understood that the system 10 and the method are merely an example of an application of the principles of this description in practice, and a wide variety of other examples are possible. Therefore, the scope of this description is not entirely limited to the details of the system 10 and the method described herein and / or described in the figures.

In the example of Figure 1, a borehole 12 is drilled by the rotation of a drill pipe 14, such as, by the use of a drilling rig (not shown) at or near the surface of the earth. The drill pipe 14 can be rotated by any means, for example, a rotary table, an upper impeller, a positive displacement or turbine drilling motor, etc. In this way, it should be understood that the scope of this description is not limited to some particular form of rotation of the drill pipe 14.

The drill pipe 14 is part of a general drill string 16, which may 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 ground when the drill string rotates and weight is applied to the drill bit.

A ring 20 is formed radially between the drill string 16 and the borehole 12. A drilling fluid 22 (commonly known as "mud", although other fluids, such as brine water) may be used is circulated downwardly through the drill string 16, it exits through the drill bit 18, and flows back to the surface via the ring 20.

The drilling fluid 22 serves various purposes, including cooling and lubricating the drill bit 18, removing the cuttings, maintaining a desired balance of pressures between the borehole 12 and the surrounding land, etc. In some situations (for example, in drilled pressure drilling or under-balanced drilling, or even in conventional over-balanced drilling), it may be desirable to seal the ring 20 at or near the surface of the earth (e.g. on a land-based or sea-based drilling rig, an installation submarine, a self-elevating platform, etc.), so that the communication between the ring 20 and the terrestrial atmosphere or the sea is prevented.

For this purpose, a rotating control device 24 can be used to seal around the drill string 16 during a drilling operation. In the example described in Figure 1, the rotary control device 24 is connected to an explosion prevention stack 26 on a wellhead 28, but in other examples the rotary control device could be placed on or on a rising string , in an underwater wellhead, in a borehole, etc. The scope of this description is not limited to any particular placement of the rotating control device 24.

Referring now further to Figure 2, a cross-sectional view, on an enlarged scale, of an example of the rotary control device 24 is representatively illustrated. In this view, it can be clearly seen that the rotary control device 24 includes two ring seals 30, 32 which seal against an outer surface of the drill pipe 14 as the drill pipe rotates within an external housing assembly 34 of the rotary control device. In Figure 2, the rotary control device 24 can be used with the system 10 and the method of Figure 1, or it can be used with other systems and methods.

In the example of Figure 2, the outer housing assembly 34 is provided with a flange 36 at a lower end thereof for connection to the explosion prevention stack 26. However, in other examples, the outer housing assembly 34 could be provided with suitable connectors for the installation of the rotary control device 24 in or on a rising string, towards an underwater wellhead, or at any other site.

As described in Figure 2, the lower seal 30 is placed in the outer housing assembly 34, while the upper seal 32 is placed in a "container" or upper housing 38. In other examples, one or both of the stamps 30, 32 could be placed inside or outside of the external housing assembly 34, and other stamp numbers (including one) can be used. The scope of this description is not limited to any particular number or stamp positions.

The seals 30, 32 are in a "passive" direction, since they sealingly engage the drill pipe 14, while the drill pipe is placed in the rotary control device 24, without any need to actuate the seals to effect such stamping. However, seals 30, 32 can also be considered "active" seals, so they respond to change their sealing characteristics when activated by a stimulus, as described further completely later.

In the example of Figure 2, the seals 30, 32 are mounted to a bearing assembly 40, which is secured to the outer housing assembly 34 by a bracket 42. The bearing assembly 40 includes the bearings 44, which allow that a generally tubular internal mandrel 46 rotates relative to the external housing assembly 34.

In other examples, a detent mechanism or other device could be used in place of the clamp 42. The bearing assembly 40 and both seals 30, 32 could be placed completely inside the outer housing assembly 34. Thus, the reach of this description is not limited to any particular arrangement or particular configuration of the various components of the rotary control device 24.

Note that, as described in Figure 2, the seals 30, 32 rotate with the housing 38 and the mandrel 46 relative to the outer housing assembly 34, when the piercing tube 14 rotates in the rotary control device 24. Preferably , the drill pipe 14 is sealed and fully coupled by the seals 30, 32.

With further reference to Figure 3, the seal 30 is representatively illustrated apart from the rest of the rotary control device 24. The seal 30 may be used in the rotary control device 24 of the Figure 2, or it can be used in other types of rotary control devices, maintaining the principles of this description.

In the example of Figure 3, the drill string 16 includes an external diameter change 48. The external diameter change 48 may be in the form of a tool joint, a collar, another type of drill pipe connection, a drilling tool, etc. Any type of external diameter change can be included in the drill string 16, within the scope of this description.

In this example, the external diameter change 48 comprises an increased outer diameter of the drill pipe 14. It is desired that the seal 30 continue to seal against the change in outer diameter 48 and the adjacent drill pipe 14 as the change in external diameter passes. through the seal, without incurring any damage to the seal, shortening its useful life, etc.

For this purpose, the seal 30 includes chambers 50, 52 filled with fluid in an elastic material 54 of the seal. The material 54 may comprise, for example, an elastomer (such as, a nitrile, fluoro-elastomer, EPDM, etc.).

The chambers 50, 52 are preferably formed by molding them within the seal 30 when the seal is manufactured. However, the scope of this description is not limited to any particular method of training the cameras 50, 52 The annular passage 56 connects the chambers 50, 52. The passage 56 can also be formed of elastic material 54, or it can be formed of a rigid material or other non-elastic material, if desired.

It will be appreciated that the fluid 58 can flow between the chambers 50, 52 via the passage 56. Thus, if one of the chambers 50, 52 is compressed or reduced in volume, the fluid 58 can flow into the other chamber via the passageway. , which enlarges a volume of the other camera.

The fluid 58 is preferably a compressible fluid (for example, a liquid or a gas, such as silicone fluid, nitrogen gas, etc.). In this way, the compression of the fluid 58 will function to elastically bias the seal 30 into sealing contact with the drill pipe 14 and any change in external diameter 48.

With further reference to Figure 4, the seal 30 is representatively illustrated after the change in diameter 48 has entered an upper portion of the seal. The increased outer diameter of the drill pipe 14 has caused a volume of the upper chamber 50 to decrease, whereby some or all of the fluid 58 in the chamber 50 is forced to flow via the passage 56 towards the other chamber 52.

The increased volume of fluid 58 in lower chamber 52 is beneficial, since it causes the lower portion of the seal 30 is increasingly biased into sealing contact with the drill pipe 14 below the diameter change 48. This is due in part to the volume of the lower chamber 52 which increases as a result of the additional fluid 58 in it.

Referring now further to Figure 5, the seal 30 is representatively illustrated after the change in diameter 48 has been further displaced downward in the seal 30. The change in diameter 48 in this view is now positioned opposite the lower chamber 52 The lower chamber 52 is radially compressed by the presence of the diameter change 48 in the seal 30, whereby the fluid 58 is forced from the lower chamber towards the upper chamber 50 via the passage 56. In this way, the volume of the lower chamber 52 decreases, while the volume of upper chamber 50 increases.

The increased volume of the fluid 58 in the upper chamber 50 is beneficial, since it causes the upper portion of the seal 30 to be deviated more and more into sealing contact with the drill pipe 14 above the diameter change 48. This is because in part to the volume of the upper chamber 50 which increases as a result of the additional fluid 58 in it.

With reference now further to Figure 6, the seal 30 is representatively illustrated after the change in diameter 48 has been displaced in a downward direction. of the seal. The upper and lower chambers 50, 52 have now returned to their respective volumes of Figure 3, with some of the fluid 58 that has flowed from the upper chamber 50 back into the lower chamber 52.

The transfer of the fluid 58 between the chambers 50, 52 during the passage of the diameter change 48 through the seal 30, allows the seal to be enlarged as necessary, and where necessary, to prevent over-tension of the seal, thus such as abrasions and cuts, due to the change in diameter. However, instead of decreasing the seal capacity of the seal 30, the transfer of the fluid 58 to a particular chamber 50 or 52 allows a respective portion of the seal to be deviated more and more into sealing contact with the perforation tube 14, which increases the sealing capacity of the seal.

Note that these benefits can be obtained, even without the application of any external pressure to the cameras 50, 52. In this way, it is preferably not necessary to connect any external source of pressure (for example, a pump, compressed gas bottles, etc.). .) to seal 30. This simplifies the construction and operation of the rotary control device 24, thereby reducing manufacturing, operation and maintenance costs, while increasing the reliability and sealing capacity of the rotary control device . However, in some examples, an external source of pressure could be connected to seal 30.

Although the diameter change 48 is described in Figures 3-6 moving down through the seal 30, similar benefits are obtained when the change in diameter is shifted upwardly through the seal. In this case, the fluid 58 could travel in opposite directions, and the chambers 50, 52 could expand and contract, in the reverse order to that described above for Figures 3-6.

Although the diameter change 48 is described in Figures 3-6 comprising an increase in diameter, similar benefits can be obtained when the change in diameter comprises a decrease in diameter. In this case, the fluid 58 could travel in opposite directions, and the chambers 50, 52 could expand and contract, in the reverse order to that described above for Figures 3-6.

The change in diameter 48 could comprise a combination of increases and decreases in diameter. Thus, the scope of this description is not limited to any of the specific details of the diameter change 48, the seal 30 (or any other elements of the rotating control device 24) or the method described above and / or detailed in the figures It can now be fully appreciated that a rotary control device 24 is provided to the technician by the above description. In a previously described example, the rotary control device 24 seals around of a drill string 16 having a change in outer diameter 48. The rotary control device 24 may comprise a seal 30 rotating with the drill string 16. The seal 30 may include at least first and second chambers 50, 52 connected by at least one passage 56, and a fluid 58 flowing between the first and second chambers 50, 52 via the passage 56 in response to the displacement of the external diameter change 48 through the seal 30.

One of the first and second chambers 50, 52 may decrease in volume in response to an increase in the volume of the other of the first and second chambers 50, 52. Each of the first and second chambers 50, 52 may be increased in volume and decreasing in volume in response to displacement of diameter change 48 through seal 30 in any direction.

The first and second chambers 50, 52 are preferably free of any connection to an external pressure source. The fluid 58 may comprise a compressible fluid.

Each of the first and second chambers 50, 52 may be formed of an elastic material 54 of the seal 30, although non-elastic materials may be used, if desired. The passage 56 may comprise an annular space formed of an elastic material 54 of the seal 30. The passage 56 in other examples could be formed of a rigid material or other material not elastic, and is not necessarily annular (for example, holes could be used in various ways).

A sealing method around a drill string 16 having an external diameter change 48 is also described above. In one example, the method comprises: forming at least first and second chambers 50, 52 of an elastic material 54 of a seal 30; the displacement of the external diameter change 48 within the seal 30, whereby the fluid 58 is transferred from the first chamber 50 to the second chamber 52; and the displacement of the outer diameter change 48 outside the seal 30, whereby the fluid 58 is transferred from the first chamber 50 to the second chamber 52.

The displacement of the external diameter change 48 within the seal 30 can include the flow of the fluid 58 through at least one passage 56 connecting the first and second chambers 50, 52, and / or increasing a volume of the second chamber 52. The displacement of the external diameter change 48 within the seal 30 can be accomplished without any of the first and second chambers 50, 52 being connected to an external pressure source.

The method may include forming the passage 56 in the elastic material 54.

The displacement of the external diameter change 48 outside the seal 30 may include the flow of the fluid 58 from the second chamber 52 to the first chamber 50 via the passage 56, and / or the increase of a volume of the first chamber 50.

The passage 56 may comprise an annular space.

The method may include the displacement of the external diameter change 48 within the seal 30, thereby moving the fluid 58 from the second chamber 52 to the first chamber 50.

Also described above is a seal 30 for sealing around a drill string 16 in a rotary control device 24, the drill string 16 has an external diameter change 48. In one example, the seal 30 may include at least the first and second chambers 50, 52. One of the first and second chambers 50, 52 increases in volume, while the other of the first and second chambers 50, 52 decreases in volume.

The first of the first and second chambers 50, 52 decreases in volume in response to an increase in the volume of the other of the first and second chambers 50, 52.

Each of the first and second chambers 50, 52 increases in volume and decreases in volume in response to the displacement of the external diameter change 48 through the seal 30. This displacement can be in any direction. The diameter change 48 can be an increase and / or decrease in diameter.

The first and second chambers 50, 52 may be free of any connection to an external pressure source. Each ima of the first and second chambers 50, 52 can be formed of an elastic material 54 of the seal 30.

The first and second chambers 50, 52 are preferably connected by at least one passage 56. The passage 56 may comprise an annular space formed of an elastic material 54 of the seal 30.

The seal 30 may include a fluid 58 which flows between the first and second chambers 50, 52 via the passage 56 in response to the displacement of the diameter change 48 through the seal 30. The fluid 58 may comprise a compressible fluid, although it or compressible fluids can be used in addition to, or instead of, compressible fluid.

Although several examples have been described above, with each example having certain characteristics, it should be understood that it is not necessary that a particular characteristic of an example be used exclusively with that example. Rather, any of the features described above and / or detailed in the figures may be combined with any of the examples, in addition to or in substitution by any of the other features of those examples. The characteristics of an example are not mutually exclusive of the characteristics of another example. Rather, the scope of this description encompasses any combination of any of the features.

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

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

In the above description in the representative examples, the directional terms (such as "above", "below", "superior", "inferior", etc.) are used for convenience with reference to the appended figures. However, it should be clearly understood that the scope of this disclosure is not limited to any of the particular addresses 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, device, device, etc., is described as "that includes "a certain characteristic or element, the system, the method, the apparatus, the device, etc., may include that characteristic or element, and may also include other characteristics or elements." Similarly, the term "comprises" is considered which means "understands, but is not limited to".

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

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A rotating control device for sealing around a drill string having a change in external diameter, characterized in that it comprises: a seal rotating with the drill string, the seal includes at least first and second chambers connected by at least one passage, and a fluid flowing between the first and second chambers via the passage in response to the displacement of the external diameter change to through the seal.

2. The rotating control device according to claim 1, characterized in that one of the first and second chambers decreases in volume in response to an increase in the volume of the other of the first and second chambers.

3. The rotary control device according to claim 1, characterized in that each of the first and second chambers increases in volume and decreases in volume in response to displacement of the diameter change through the seal.

4. The rotating control device according to claim 1, characterized in that the first and second chambers are free of any connection to an external pressure source.

5. The rotary control device according to claim 1, characterized in that the fluid comprises a compressible fluid.

6. The rotary control device according to claim 1, characterized in that each of the first and second chambers is formed of an elastic seal material.

7. The rotary control device according to claim 1, characterized in that the passage comprises an annular space formed of an elastic seal material.

8. A method for sealing around a drill string having a change in external diameter, characterized in that it comprises: forming at least first and second chambers of an elastic material of a seal; displacing the external diameter change of the seal, thereby transferring the fluid from the first chamber to the second chamber; Y move the outside diameter change out of the seal, thereby transferring the fluid from the first camera towards the second camera.

9. The method in accordance with the claim 8, characterized in that the displacement of the external diameter change within the seal further comprises the flow of the fluid through the at least one passage connecting the first and second chambers.

10. The method in accordance with the claim 9, characterized in that it also comprises the formation of the passage in the elastic material.

11. The method according to claim 9, characterized in that the displacement of the external diameter change outside the seal further comprises the flow of the fluid from the second chamber to the first chamber via the passage.

12. The method according to claim 9, characterized in that the passage comprises an annular space.

13. The method according to claim 8, characterized in that the displacement of the external diameter change within the seal further comprises the increase of a volume of the second chamber.

14. The method according to claim 13, characterized in that the displacement of the external diameter change outside the seal further comprises the increase of a volume of the first chamber.

15. The method according to claim 8, characterized in that the displacement of the external diameter change within the seal is performed without the first and second chambers being connected to an external pressure source.

16. The method according to claim 8, characterized in that it further comprises the displacement of the external diameter change within the seal, whereby the fluid is moved from the second chamber to the first chamber.

17. A seal for sealing around a drill string in a rotating control device, the drill string having an external diameter change, characterized in that it comprises: at least first and second cameras, and wherein one of the first and second chambers increases in volume while the other of the first and second chambers decreases in volume.

18. The seal according to claim 17, characterized in that one of the first and second chambers decreases in volume in response to an increase in the volume of the other of the first and second chambers.

19. The seal according to claim 17, characterized in that each of the first and second chambers increases the volume and decreases the volume in response to the displacement of the external diameter change through the seal.

20. The seal according to claim 17, characterized in that the first and second chambers are free of any connection to an external pressure source.

21. The stamp in accordance with the claim 17, characterized in that each of the first and second chambers is formed of an elastic seal material.

22. The seal according to claim 17, characterized in that the first and second chambers are connected by at least one passage.

23. The seal according to claim 22, characterized in that the passage comprises an annular space formed of an elastic seal material.

24. The stamp in accordance with the claim 22, characterized in that it further comprises a fluid flowing between the first and second chambers via the passage, in response to the displacement of the diameter change through the seal.

25. The stamp in accordance with the claim 24, characterized in that the fluid comprises a compressible fluid.