ROTATING CONTROL DEVICE ASSEMBLY FOR USE WITH A SUBTERRANEAN WELL

Abstract

A rotating control device can include an inner mandrel rotatably mounted in a bearing housing, and a pump rotor that rotates with the inner mandrel. A method can include installing a rotating control device including a pump rotor that rotates with an inner mandrel relative to a bearing housing. A system for use with a subterranean well can include a rotating control device assembly with an outer housing connected in a riser string, and a rotating control device including an inner mandrel rotatably mounted by a bearing assembly, the bearing assembly including thrust bearings on respective opposite sides of a radially enlarged bearing support formed on the inner mandrel, and biasing devices biasing the respective thrust bearings toward the bearing support.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S. provisional application no. 63/758,873, filed on 14 Feb. 2025. The entire disclosure of the prior application is incorporated herein by this reference for all purposes.

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 a rotating control device assembly and associated methods.

A rotating control device is used with well operations to seal about a tubular string deployed in a well. For example, in well drilling operations a rotating control device can seal about drill pipe extending through the rotating control device, in order to isolate the well from the atmosphere at the surface.

It will, therefore, be readily appreciated that improvements are continually needed in the art of designing, constructing and utilizing rotating control devices. Such improvements can be used with rotating control devices in a variety of different well operations and configurations.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 2 is a representative partially cross-sectional view of an example of a rotating control device assembly that may be used in the FIG. 1 system and method.

FIG. 3 is a representative cross-sectional view of an example of a rotating control device.

FIG. 4 is a representative cross-sectional view of a bearing assembly of the rotating control device.

FIG. 5 is a representative cross-sectional view of a portion of the bearing assembly.

FIG. 6 is a representative cross-sectional view of the bearing assembly being filled with lubricant.

FIG. 7 is a representative cross-sectional view of an upper rotary seal portion of the bearing assembly.

FIG. 8 is a representative cross-sectional view of a debris exclusion arrangement of the bearing assembly.

FIG. 9 is a representative partially cross-sectional view of a rotor of the debris exclusion arrangement.

FIG. 10 is a representative cross-sectional view of a lower rotary seal portion of the bearing assembly.

FIG. 11 is a representative cross-sectional view of a seal vent arrangement for the upper rotary seal.

FIG. 12 is a representative cross-sectional view of a seal vent arrangement for the lower rotary seal.

FIG. 13 is another representative cross-sectional view of the seal vent arrangement for the lower rotary seal, FIG. 13 being rotationally offset from FIG. 12.

DETAILED DESCRIPTION

Representatively illustrated in FIG. 1 is a system 10 and 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 example, a rotating control device (RCD) assembly 14 includes a rotating control device 12, an outer housing 16 and a latch 18. The outer housing 16 includes upper and lower flanges 20, 22 for connection of the RCD assembly 14 as part of a riser string 24.

The RCD assembly 14 may be connected in the riser string 24 above or below a tension ring of an offshore or other water-based rig. However, the scope of this disclosure is not limited to the use of an RCD on or with a water-based or other particular type of rig. For example, the FIG. 1 RCD assembly 14 could be used with a land-based rig, with appropriate modifications.

The RCD 12 is used to seal off an annulus 26 surrounding a tubular string 28 positioned in the riser string 24. For this purpose, the RCD 12 includes one or more annular seals 30 that sealingly engage an outer surface of a tubular 32 received in the RCD. Another annular seal 34 seals radially between a bearing assembly 36 of the RCD 12 and the latch 18 in the outer housing 16.

The latch 18 is used to releasably secure the RCD 12 in the outer housing 16. In this example, the latch 18 includes latch members 38 that are displaced radially into or out of engagement with a profile 40 formed on the bearing assembly 36. Any type of actuator (such as, including pistons, wedges, motors, etc.) may be used to displace the latch members 38. The scope of this disclosure is not limited to use of any particular type or configuration of a latch used to releasably secure an RCD in an outer housing.

The bearing assembly 36 is used to provide for rotation of the annular seal 30 with the tubular string 28. As described more fully below, the bearing assembly 36 includes bearings that rotatably support an inner mandrel 42 to which the annular seal 30 is attached.

In the FIG. 1 example, an installation and retrieval tool 44 is connected at an upper end of the RCD 12. The tool 44 includes J-shaped profiles 46 at an upper end thereof for engagement with a mating tool conveyed with the tubular string 28 for installation of the RCD 12 into the outer housing 16, and for retrieval of the RCD from the outer housing.

In operation, the annulus 26 is in fluid communication with a wellbore of the well. Fluid 48 can flow between the annulus 26 and a rig choke manifold and rig fluid conditioning equipment (such as, including a shaker, a fluid-gas separator, mud tanks, etc.) via a port 50 formed through a sidewall of the outer housing 16.

Referring additionally now to FIG. 2, a representative partially cross-sectional view of an example of the rotating control device assembly 14 is depicted. For convenience, the FIG. 2 RCD assembly 14 is described below as it may be used with the FIG. 1 system 10 and method, but the RCD assembly may be used with other systems and methods in other examples.

As depicted in FIG. 2, the bearing assembly 36 includes thrust bearings 52 and radial bearings 54 that support the inner mandrel 42 for rotation relative to a bearing housing 56. A pressurized lubricant 58 is supplied to the bearings 52, 54 via various passages formed in the bearing assembly 36.

Pairs of dynamic rotary seals 60, 62 seal radially between the bearing assembly 36 and sleeves 64, 66 carried on the inner mandrel 42. The sleeves 64, 66 rotate with the inner mandrel 42 relative to the rotary seals 60, 62. The rotary seals 60, 62 seal above and below the bearings 52, 54, thereby isolating the interior of the bearing assembly 36 from the well fluid 48.

Referring additionally now to FIG. 3, a representative cross-sectional view of an example of the rotating control device 12 is representatively illustrated. For convenience, the RCD 12 is described below as it may be used with the FIG. 2 RCD assembly 14, but the FIG. 3 RCD 12 may be used with other RCD assemblies in other examples.

In the FIG. 3 example, two annular seals 30 are secured at respective opposite ends of the inner mandrel 42. At an upper end of the inner mandrel 42, a seal housing 68 supports a seal carrier 70. The upper annular seal 30 is attached to the seal carrier 70, which is connected to the inner mandrel 42 via the seal housing 68.

At a lower end of the inner mandrel 42, a seal carrier 72 is threaded onto the inner mandrel. The seal carrier 72 supports the annular seal 30 below the lower end of the inner mandrel 42.

Note that the seal housing 68 and the seal carrier 72 are threaded onto the opposite ends of the inner mandrel 42. As described more fully below, the RCD 12 includes features which enable effective and reliable threaded connection of the seal housing 68 and seal carrier 72 to the inner mandrel 42.

Referring additionally now to FIG. 4, a representative cross-sectional view of the bearing assembly 36 is depicted. In this view, internal components of the bearing assembly 36 can be more clearly seen.

In the FIG. 4 example, the thrust bearings 52 are positioned on opposing sides of a radially enlarged annular bearing support 74 formed on the inner mandrel 42. The thrust bearings 52 are biased toward the bearing support 74 by biasing devices 76 (such as, Belleville springs, wave springs, an elastomer, etc.). Additional biasing devices 78 bias the radial bearings 54 in opposite axial directions.

As depicted in FIG. 4, a torque lock 80 in the form of a threaded screw or bolt is threaded through the bearing housing 56. The torque lock 80 is received in a recess 82 formed on the mandrel 42 bearing support 74. In this manner, during assembly of the RCD 12 the inner mandrel 42 can be prevented from rotating relative to the bearing assembly 36 when the seal housing 68 (see FIG. 3) and seal carrier 72 are threaded and tightened onto the inner mandrel.

Referring additionally now to FIG. 5, a representative cross-sectional view of a portion of the bearing assembly 36 is depicted. In this view it may be seen that the torque lock 80 (see FIG. 4) has been removed from the bearing assembly 36. A plug 84 is installed in the bearing housing 56 in place of the torque lock 80. The inner mandrel 42 is now permitted to rotate relative to the bearing assembly 36.

A vacuum may be applied to the interior of the bearing assembly 36 prior to dispensing the lubricant 58 into the bearing assembly. As depicted in FIG. 5, a vacuum pulling tool 86 is connected to the bearing assembly 36. The tool 86 opens a valve 88 to permit flow from the interior of the bearing assembly 36 to the tool 86 and connected vacuum equipment.

Referring additionally now to FIG. 6, a representative cross-sectional view of the bearing assembly 36 being filled with lubricant 58 is depicted. In the FIG. 6 example, a lubricant filling tool 90 is connected to the bearing assembly 36 in order to dispense lubricant 58 into the bearing assembly. When connected, the tool 90 is used to flow the lubricant 58 from the tool, through the valve 88 and into the bearing assembly 36 to lubricate the bearings 52, 54 and rotary seals 60, 62.

After the lubricant 58 has filled the interior of the bearing assembly 36 (including a reservoir 92 pressurized by a spring 94 biased piston 96), a plug can be installed in place of the tool 90. The valve 88 will prevent inadvertent escape of the (now pressurized) lubricant 58 from the interior of the bearing assembly 36.

Referring additionally now to FIG. 7, a representative cross-sectional view of an upper rotary seal portion of the bearing assembly 36 is depicted. In this view it may be seen that the rotary seals 60 dynamically seal against an outer cylindrical seal surface 64a of the sleeve 64.

In this example, the rotary seals 60 are of the type known to those skilled in the art as “controlled leak” seals that tend to permit a small amount of leakage past the seals in use. This ensures that the interface between the seals 60 and the seal surface 64a is continuously lubricated in use and thereby helps to prevent damage or wear to the seal surface 64a and seals 60.

As depicted in FIG. 7, an annulus 98 is formed axially between the seals 60. The annulus 98 provides an area for accumulation of lubricant 58 that has leaked past the lower rotary seal 60. As described more fully below, a check valve 100 can be used to permit escape of the lubricant 58 from the annulus 98 to an exterior of the bearing assembly 36, but prevent any fluid 48 or debris from entering the annulus 98 via the check valve.

Referring additionally now to FIG. 8, a representative cross-sectional view of a debris exclusion arrangement of the bearing assembly 36 is depicted. In this view it may be seen that a pump rotor 102 is positioned on the inner mandrel 42 above the upper rotary seals 60. The pump rotor 102 is secured to the inner mandrel 42, so that it rotates with the inner mandrel relative to the bearing assembly 36.

The pump rotor 102 is constructed in a manner that induces flow of fluid 104 away from the rotary seals 60 when the pump rotor is rotated. The fluid 104 flows from the pump rotor 102 downwardly through a frustoconical annular channel 106 to a debris discharge port 108 formed through a sidewall of the installation and retrieval tool 44.

Any debris 110 descending through an annulus 112 formed radially between the tool 44 and the seal housing 68 will be flushed by the fluid 104 out of the port 108 to an annular chamber 136 (see FIG. 2) on the exterior of the bearing assembly 36. In addition, due to a downward inclination of the annular channel 106 in a radially outward direction, the debris 110 will be influenced by gravity to not displace toward the rotary seals 60. In this manner, the debris 110 is prevented from displacing to the rotary seals 60.

Referring additionally now to FIG. 9, a representative partially cross-sectional view of the pump rotor 102 is depicted. In this view it may be seen that the pump rotor 102 is in the form of a sleeve 114 with a helical profile 116 formed on an outer surface thereof.

Rotation of the helical profile 116 displaces the fluid 104 between the inner mandrel 42 and the bearing assembly 36. In the FIG. 9 example, the profile 116 is right-handed, so that upward flow of the fluid 104 is induced in response to right-hand or clockwise rotation of the inner mandrel 42, as viewed from above.

Referring additionally now to FIG. 10, a representative cross-sectional view of a lower rotary seal portion of the bearing assembly 36 is depicted. In this view it may be seen that the lower rotary seals 62 are configured in a manner similar to the upper rotary seals 60.

The lower rotary seals 62 dynamically seal against an outer cylindrical seal surface 66a of the sleeve 66. The rotary seals 62 are of the “controlled leak” type. This ensures that the interface between the seals 62 and the seal surface 66a is continuously lubricated in use and thereby helps to prevent damage or wear to the seal surface 66a and seals 62.

As depicted in FIG. 10, an annulus 118 is formed axially between the seals 62. The annulus 118 provides an area for accumulation of lubricant 58 that has leaked past the upper rotary seal 62. As described more fully below, a check valve 120 can be used to permit escape of the lubricant 58 from the annulus 118 to an exterior of the bearing assembly 36, but prevent any fluid 48 or debris from entering the annulus 118 via the check valve.

Referring additionally now to FIG. 11, a representative cross-sectional view of a seal vent arrangement for the upper rotary seals 60 is depicted. In this view a manner in which the annulus 98 can be vented to the exterior of the bearing assembly 36 can be seen. Note that the FIG. 11 view is rotationally offset somewhat relative to the FIG. 8 view.

In the FIG. 11 example, a flow passage 122 provides fluid communication between the annulus 98 and the check valve 100. The check valve 100 includes an elastomeric closure 124 in the form of an annular seal (such as, an o-ring) sealingly received in an annular recess 126. The check valve 100 permits flow of lubricant 58 or other fluid from the annulus 98 via the flow passage 122 to the exterior of the bearing assembly 36, but prevents flow of fluid, debris, etc., from the exterior of the bearing assembly into the annulus 98.

Referring additionally now to FIG. 12, a representative cross-sectional view of a seal vent arrangement for the lower rotary seals 62 is depicted. In this view it may be seen that the lower rotary seal vent arrangement is similar to the upper rotary seal arrangement of FIG. 11. Note that the FIG. 12 view is rotationally offset somewhat relative to the FIG. 10 view.

In the FIG. 12 example, a flow passage 128 provides fluid communication between the annulus 118 and the check valve 120. The check valve 120 includes an elastomeric closure 130 in the form of an annular seal (such as, an o-ring) sealingly received in an annular recess 132. The check valve 120 permits flow of lubricant 58 or other fluid from the annulus 118 via the flow passage 128 to the exterior of the bearing assembly 36, but prevents flow of fluid, debris, etc., from the exterior of the bearing assembly into the annulus 118.

Referring additionally now to FIG. 13, another representative cross-sectional view of the seal vent arrangement for the lower rotary seals 62 is depicted. Note that the FIG. 13 view is rotationally offset from the FIG. 12 view. In FIG. 13 it may be seen that a flow passage 134 provides fluid communication between the check valve 120 and the exterior of the bearing assembly 36.

It may now be fully appreciated that the above disclosure provides significant benefits to the art of designing, constructing and utilizing rotating control devices. In an example described above and depicted in the drawings, the RCD assembly 14 includes beneficial features that enhance the effectiveness and long term reliability of the RCD assembly.

In one aspect, a rotating control device 12 for use with a subterranean well is described above. In one example, the rotating control device 12 can comprise: a bearing housing 56, an inner mandrel 42 rotatably mounted in the bearing housing 56, and a pump rotor 102 configured to rotate with the inner mandrel 42.

The rotor 102 may be configured to pump fluid 104 away from a rotary seal 60. The rotary seal 60 may seal against a seal surface 64a positioned radially between the bearing housing 56 and the inner mandrel 42.

The rotor 102 may be configured to pump fluid 104 through a downwardly inclined annular channel 106 toward a chamber 136 external to the bearing housing 56. A debris discharge port 108 may be positioned between the rotor 102 and the chamber 136. The debris discharge port 108 may be in fluid communication with an annulus 112 surrounding a seal housing 68.

The rotor 102 may comprise a sleeve 114, and a helical profile 116 formed on the sleeve. The inner mandrel 42 may be received in the rotor sleeve 114.

Also provided to the art by the above disclosure is a method for use with a subterranean well. In one example, the method can comprise: installing a rotating control device 12 in an outer housing 16, the rotating control device 12 including an inner mandrel 42, a bearing housing 56, and a pump rotor 102 that rotates with the inner mandrel 42 relative to the bearing housing 56; securing the rotating control device 12 in the outer housing 16; and sealing about a tubular 32 in the rotating control device 12.

The method may include installing a torque lock 80 through the bearing housing 56 and into a recess 82 formed on the inner mandrel 42, and then tightening a seal carrier 72 and a seal housing 68 onto respective opposite ends of the inner mandrel 42.

The method may include positioning first and second thrust bearings 52 on respective opposite sides of a radially enlarged bearing support 74 formed on the inner mandrel 42, and first and second biasing devices 76 biasing the respective first and second thrust bearings 52 toward the bearing support 74.

The method may include positioning first and second radial bearings 54 radially between the inner mandrel 42 and the bearing housing 56, and first and second biasing devices 78 applying axial biasing forces to the respective first and second radial bearings 54.

The rotating control device 12 may include first and second rotary seals 60 that seal radially between the inner mandrel 42 and the bearing housing 56, a flow passage 122 extending between an annulus 98 formed axially between the first and second rotary seals 60 and a chamber 136 external to the rotating control device 12, and a check valve 100 that permits flow from the flow passage 122 to the chamber 136 but prevents flow from the chamber 136 to the flow passage 122.

The method may include rotating the inner mandrel 42, thereby pumping a fluid 104 away from a rotary seal 60. The pumping step may include pumping the fluid 104 through a downwardly inclined channel 106 to a debris discharge port 108.

A system 10 for use with a subterranean well is also provided to the art by the above disclosure. In one example, the system 10 can comprise: a rotating control device assembly 14 comprising an outer housing 16 configured for connection in a riser string 24, and a rotating control device 12 releasably secured in the outer housing 16. The rotating control device 12 can comprise at least one annular seal 30 configured to seal about a tubular 32 received in the rotating control device 12, and an inner mandrel 42 rotatably mounted by a bearing assembly 36. The bearing assembly 36 can comprise first and second thrust bearings 52 on respective opposite sides of a radially enlarged bearing support 74 formed on the inner mandrel 42, and first and second biasing devices 76 biasing the respective first and second thrust bearings 52 toward the bearing support 74.

The rotating control device 12 may include a pump rotor 102 that rotates with the inner mandrel 42 relative to the bearing assembly 36. The pump rotor 102 may be configured to pump fluid 104 away from a rotary seal 60. The pump rotor 102 may be configured to pump fluid 104 toward a chamber 136 external to the bearing assembly 36.

The rotating control device 12 may include first and second rotary seals 60 that seal radially between the inner mandrel 42 and the bearing assembly 36, a flow passage 122 for providing fluid communication between an annulus 98 formed axially between the first and second rotary seals 60 and a chamber 136 external to the rotating control device 12, and a check valve 100 that permits flow from the flow passage 122 to the chamber 136 but prevents flow from the chamber 136 to the flow passage 122.

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,” “upward,” “downward,” 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 use with a subterranean well, the rotating control device comprising:

a bearing housing;

an inner mandrel rotatably mounted in the bearing housing; and

a pump rotor configured to rotate with the inner mandrel, in which the rotor comprises a sleeve with a helical profile formed on an outer diameter of the sleeve.

2. The rotating control device of claim 1, in which the rotor is configured to pump fluid away from a rotary seal.

3. The rotating control device of claim 2, in which the rotary seal seals against a seal surface positioned radially between the bearing housing and the inner mandrel.

4. The rotating control device of claim 1, in which the rotor is configured to pump fluid through a downwardly inclined annular channel toward a chamber external to the bearing housing.

5. The rotating control device of claim 4, in which a debris discharge port is positioned between the rotor and the chamber.

6. The rotating control device of claim 5, in which the debris discharge port is in fluid communication with an annulus surrounding a seal housing.

7. (canceled)

8. The rotating control device of claim 1, in which the inner mandrel is received in the rotor sleeve.

9. A method for use with a subterranean well, the method comprising:

installing a rotating control device in an outer housing, the rotating control device comprising an inner mandrel, a bearing housing, and a pump rotor that rotates with the inner mandrel relative to the bearing housing, in which the rotor comprises a sleeve with a helical profile formed on an outer diameter of the sleeve;

securing the rotating control device in the outer housing; and

sealing about a tubular in the rotating control device.

10. The method of claim 9, further comprising installing a torque lock through the bearing housing and into a recess formed on the inner mandrel, and then tightening a seal carrier and a seal housing onto respective opposite ends of the inner mandrel.

11. The method of claim 9, further comprising positioning first and second thrust bearings on respective opposite sides of a radially enlarged bearing support formed on the inner mandrel, and first and second biasing devices biasing the respective first and second thrust bearings toward the bearing support.

12. The method of claim 9, further comprising positioning first and second radial bearings radially between the inner mandrel and the bearing housing, and first and second biasing devices applying axial biasing forces to the respective first and second radial bearings.

13. The method of claim 9, in which the rotating control device further comprises first and second rotary seals that seal radially between the inner mandrel and the bearing housing, a flow passage extending between an annulus formed axially between the first and second rotary seals and a chamber external to the rotating control device, and a check valve that permits flow from the flow passage to the chamber but prevents flow from the chamber to the flow passage.

14. The method of claim 9, further comprising rotating the inner mandrel, thereby pumping a fluid away from a rotary seal.

15. The method of claim 14, in which the pumping comprises pumping the fluid through a downwardly inclined channel to a debris discharge port.

16. A system for use with a subterranean well, the system comprising:

a rotating control device assembly comprising an outer housing configured for connection in a riser string, and a rotating control device releasably secured in the outer housing,

the rotating control device comprising at least one annular seal configured to seal about a tubular received in the rotating control device, and an inner mandrel rotatably mounted by a bearing assembly, and

the bearing assembly comprising first and second thrust bearings on respective opposite sides of a radially enlarged bearing support formed on the inner mandrel, and first and second biasing devices biasing the respective first and second thrust bearings toward the bearing support, in which the rotating control device further comprises first and second rotary seals that seal radially between the inner mandrel and the bearing assembly, a flow passage configured to provide fluid communication between an annulus formed axially between the first and second rotary seals and a chamber external to the rotating control device, and a check valve that permits flow from the flow passage to the chamber but prevents flow from the chamber to the flow passage.

17. The system of claim 16, in which the rotating control device further comprises a pump rotor that rotates with the inner mandrel relative to the bearing assembly.

18. The system of claim 17, in which the pump rotor is configured to pump fluid away from a rotary seal.

19. The system of claim 17, in which the pump rotor is configured to pump fluid toward a chamber external to the bearing assembly.

20. (canceled)