DOWNHOLE TOOL, METHOD AND ASSEMBLY

Abstract

A tool assembly (10) comprises a casing section (12), and a downhole tool (14) comprising a rotary drive (16) and a cutting member (18). In use, the tool assembly (10) is disposed in a well borehole (B) and the rotary drive (16) operated to drive rotation of the cutting member (18) to cut the borehole (B). The downhole tool (14) comprises a tubular housing (20) and a cartridge assembly (36), the cartridge assembly (36) disposed within the housing (20) of the downhole tool (14) and comprising the rotary drive (16) of the downhole tool (14). A clutch (78) is provided to enable free movement of the cutting member (18) during normal operation, engagement of the clutch (78) preventing rotation of the cutting member (18) and the housing (20).

Claims

1. A downhole tool comprising: a housing; and a cartridge assembly configured for location within the housing, the cartridge assembly comprising a rotary drive of the downhole tool.

2. The downhole tool of claim 1, wherein the cartridge assembly comprises a housing and a shaft, the housing of the cartridge assembly comprises a stator of the rotary drive and the shaft of the cartridge assembly comprises a rotor of the rotary drive.

3. The downhole tool of claim 1, wherein the rotary drive comprises a fluid driven rotary drive.

4. The downhole tool of claim 3, wherein the rotary drive comprises one of: a positive displacement motor; a turbine; an axial flow reaction turbine.

5. The downhole tool of claim 2, wherein the housing of the cartridge assembly is coupled to a housing of the downhole tool, the housing of the cartridge assembly secured to the housing of the downhole tool by at least one retainer, the retainer preventing axial and rotational movement of the housing of the cartridge assembly relative to the housing of the downhole tool.

6. The downhole tool of claim 1, wherein all or substantially all of the cartridge assembly is disposed within a drill through diameter of the downhole tool such that the cartridge assembly is removable in a drill through operation.

7. The downhole tool of claim 1, further comprising a cutting member configured for rotation relative to a housing of the downhole tool by the rotary drive of the cartridge assembly.

8. The downhole tool of claim 1, comprising a bearing.

9. The downhole tool of claim 8, wherein the bearing is fluid lubricated by fluid from the rotary drive.

10. The downhole tool of claim 9, wherein the bearing is disposed outside a drill through diameter of the downhole tool such that the bearing is retained in a drill through operation.

11. The downhole tool of claim 1, comprising a clutch.

12. The downhole tool of claim 11, wherein the clutch is a cone clutch.

13. A cartridge assembly for a downhole tool, the cartridge assembly comprising a rotary drive of the downhole tool.

14. A downhole tool assembly comprising: a tubular component; a downhole tool; and the cartridge assembly comprising a rotary drive of the downhole tool assembly.

15. A method of running a tubular string into a borehole, comprising: running a downhole tool into a borehole, the downhole tool comprising; a housing, and a cartridge assembly configured for location within the housing, the cartridge assembly comprising a rotary drive of the downhole tool, or the downhole tool comprising; a tubular component, a downhole tool, and a cartridge assembly, the cartridge assembly comprising at least one of, a housing and a shaft, the housing of the cartridge assembly comprising a stator of the rotary drive and the shaft of the cartridge assembly comprising a rotor of the rotary drive, the rotary drive comprising at least one of (i) a fluid driven rotary drive, and (ii) a positive displacement motor; and directing fluid through the rotary drive to operate the downhole tool.

16. A clutch for a downhole tool, the clutch comprising: a male cone provided on one of a rotor of a downhole tool and a stator of the downhole tool; a female cone provided on the other of the rotor of the downhole tool and the stator of the downhole tool and being operatively associated with the male cone, the male cone and the female cone configured to engage to rotationally fix the rotor of the downhole tool and the stator of the downhole tool, wherein at least one of the male cone and the female cone comprises at least one axial slot extending at least partially along the length of the male cone and/or the female cone.

17. A downhole tool comprising a clutch, the clutch comprising: a male cone provided on one of a rotor of a downhole tool and a stator of the downhole tool; a female cone provided on the other of the rotor of the downhole tool and the stator of the downhole tool and being operatively associated with the male cone, the male cone and the female cone configured to engage to rotationally fix the rotor of the downhole tool and the stator of the downhole tool, wherein at least one of the male cone and the female cone comprises at least one axial slot extending at least partially along the length of the male cone and/or the female cone.

18. A downhole tool assembly comprising: a tubular component; a downhole tool; and a clutch comprising a male cone provided on one of a rotor of a downhole tool and a stator of the downhole tool and a female cone provided on the other of the rotor of the downhole tool and the stator of the downhole tool and being operatively associated with the male cone, the male cone and the female cone configured to engage to rotationally fix the rotor of the downhole tool and the stator of the downhole tool, wherein at least one of the male cone and the female cone comprises at least one axial slot extending at least partially along the length of the male cone and/or the female cone.

19. The downhole tool of assembly of claim 18, wherein the clutch comprises a male cone and a female cone, wherein at least one of the male cone and the female cone comprises at least one axial slot extending at least partially along the length of the male cone and/or the female cone.

20. A method of running a tubular string into a borehole, the method comprising: running a downhole tool into a borehole, the downhole tool comprising; a tubular component, a downhole tool, and a male cone provided on one of a rotor of a downhole tool and a stator of the downhole tool and a female cone provided on the other of the rotor of the downhole tool and the stator of the downhole tool and being operatively associated with the male cone, the male cone and the female cone configured to engage to rotationally fix the rotor of the downhole tool and the stator of the downhole tool, wherein at least one of the male cone and the female cone comprises at least one axial slot extending at least partially along the length of the male cone and/or the female cone; and directing fluid, such as drill fluid, through the rotary drive to operate the downhole tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0135] These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0136] FIG. 1 shows a diagrammatic view of a downhole tool assembly according to an embodiment of the present invention;

[0137] FIG. 2 shows a longitudinal half section view of an upper portion of a downhole tool and cartridge assembly according to an embodiment of the present invention;

[0138] FIG. 3 shows a longitudinal half section view of a mid-section of the downhole tool and cartridge assembly;

[0139] FIG. 4 shows an enlarged cross-sectional view of the rotary drive shown in FIGS. 2 and 3; and

[0140] FIGS. 5 and 6 show longitudinal half section views of a lower portion of the downhole tool and cartridge assembly, showing the bearings.

[0141] FIG. 7 shows a clutch as shown in FIG. 5;

[0142] FIG. 8 shows an alternative clutch for use in embodiments of the invention; and

[0143] FIG. 9 shows the axial slot shown in FIG. 8.

DETAILED DESCRIPTION

[0144] Referring first to FIG. 1, there is shown a diagrammatic view of a downhole tool assembly 10 according to an embodiment of the present invention. As shown in FIG. 1, the assembly 10 comprises a bore-lining tubular in the form of a casing section or casing string 12, and a downhole tool 14 comprising a rotary drive 16 and a cutting member 18. In use, the assembly 10 is disposed in a well borehole (shown schematically as B) and the rotary drive 16 operated to drive rotation of the cutting member 18 to cut the borehole B.

[0145] Beneficially, the provision of a downhole rotary drive 16 facilitates cutting, such as reaming or drilling, of the borehole B without the requirement to rotate the casing or casing string 12.

[0146] In some embodiments, the cutting member 18 comprises a drill bit, the tool assembly 10 being utilised to perform a drilling with casing operation in the borehole B. In other embodiments, the cutting member 18 comprises a reaming bit, the tool assembly 10 being utilised to perform a reaming with casing operation in the borehole B.

[0147] Referring now to FIGS. 2 to 7 of the accompanying drawings, there is shown an exemplary downhole tool 14 according to an embodiment of the present invention. As shown in FIG. 2, the downhole tool 14 comprises a tubular housing 20. An upper end portion 22 of the housing 20 is coupled to a lower end portion 24 of a tubular connector sub 26 via a threaded connection 28, the upper end portion 22 of the housing 20 defining a recess 30 for receiving the lower end portion 24 of the connector sub 26. An upper end portion 32 of the connector sub 26 defines a threaded box connector 34 for coupling the connector sub 26 to the lower end of a casing section, such as casing string 12 shown in FIG. 1. While in the illustrated embodiment, the downhole tool 14 is indirectly coupled to the casing section/casing string 12 it will be recognised that the housing 20 of the downhole tool 14 may alternatively be directly coupled to the casing section/casing string 12.

[0148] A cartridge assembly 36 is disposed within the housing 20 of the downhole tool 14, an upper part of which is shown in FIG. 2. The cartridge assembly 36 comprises a tubular housing 38 (referred to below as the cartridge assembly housing 38) which is disposed within, and which is coupled to, the housing 20 of the downhole tool 14. In use, the cartridge assembly housing 38 defines a stator of the rotary drive 16.

[0149] An upper end portion 40 of the cartridge assembly housing 38 comprises a recess or groove 42 for receiving a seal element 44. In the illustrated embodiment, the seal element 44 comprises an o-ring and in use prevents fluid leakage between the cartridge assembly housing 38 and the housing 20 of the downhole tool 14.

[0150] The cartridge assembly 36 is secured to the housing 20 by one or moreand in the illustrated embodiment a plurality of circumferentially arrangedretainers 46 disposed between the cartridge assembly housing 38 and the housing 20. In the illustrated embodiment, the retainer 46 prevents axial and rotational movement of the cartridge assembly 36 relative to the housing 20.

[0151] The cartridge assembly 36 further comprises a shaft 48, the shaft 48 in use defining a rotor of the rotary drive 16. As shown in the illustrated embodiment, the shaft 48 is hollow, the shaft 48 comprising a throughbore 50 (see FIG. 4).

[0152] Referring now also to FIGS. 3 and 4 of the accompanying drawings, which shows a mid-section of the downhole tool 14 and cartridge assembly 36 shown in FIG. 2, the rotary drive 16 formed by the cartridge assembly housing 38 and the shaft 48 comprises a positive displacement motor with a fluid passage 52 defined between the outside of the shaft 48 and the inside of the cartridge assembly housing 38. In use, passage of fluid, such as drill fluid, mud or the like, through the fluid passage 52 drives rotation of the shaft 48 at high speed relative to the cartridge assembly housing 38and thus relative to the casing section/casing string 12.

[0153] As shown in FIG. 3, a u-joint 54 is disposed between the lower end of the rotary drive 16 and the upper end of the cutting member 18, an upper end portion 56 of the u-joint coupled to a lower end portion 58 of the cartridge assembly housing 38 and a lower end portion 60 of the u-joint 54 coupled to an upper end portion 62 of the cutting member 18.

[0154] Referring now in particular to FIG. 3 and also to FIGS. 5 and 6 of the accompanying drawings, fluid exiting the rotary drive 16 passes into a fluid flow annulus 64 before passing into cutting member 18 via port 66 (see FIGS. 5 and 6). Although not specifically shown in the drawings, the cutting member 18 may be provided with jetting nozzles or outlet ports for directing the fluid into an annulus between the downhole tool 12 and the borehole B for return to surface.

[0155] As shown in FIGS. 5 and 6, the cutting member 18which in the illustrated embodiment takes the form of a reaming membercomprises a generally tubular body 68 coupled to the u-joint 54 and a nose 70.

[0156] A sub 72 comprising a ball bearing package 74 is coupled to the housing 20 as shown in FIG. 5. As shown in FIG. 5, the ball bearing package 74 is disposed outside a drill through diameter D, such that drilling through can be achieved without the requirement to remove the ball bearing package 74.

[0157] A thrust bearing package 76 is disposed around the outside of the cutting member upper portion 62.

[0158] A clutch in the form of a cone clutch 78 is disposed between the outside of the cutting member 18 and the housing 20. Beneficially, the cone clutch 78 facilitates mill out or drill through operations to be carried out.

[0159] An exemplary arrangement for the clutch 78 is shown in FIG. 7 of the accompanying drawings.

[0160] In use, the clutch 78 is designed to enable free rotation of the cutting member 18 during normal operation and may be engaged or activated on demand by any suitable method. Beneficially, the clutch 78 prevents or at least mitigates unwanted rotation of the cutting member 18 upon drilling thereof, which may otherwise hinder rotation of the cutting member 18.

[0161] In the illustrated embodiment, the clutch 78 takes the form of a cone clutch having a female cone 80 and a male cone 82. In this embodiment, the male cone 82 is integral with output shaft 84 of the rotary drive 16 and the female cone 80 is integral with housing 20. However, it will be recognised that the male cone 82 and/or the female cone 80 may alternatively comprise a separate component and may be coupled to the output shaft 84 and housing 20, respectively. As shown in FIG. 7, the rotary drive 16 is coupled to the output shaft 84 by a thread connection 86.

[0162] As described above, the housing 20 is coupled to a tubular connector sub 26, the connector sub 26 in turn being couplable to a tubular component, which in the illustrated embodiment comprises a casing string 12 (shown diagrammatically in FIG. 7). Lock-up of the output shaft 84 to the housing 20 permits rotation of the cutting member 18 directly by rotation of the casing string 12.

[0163] When the clutch 78 is engaged, the male cone 82 is locked into the female cone 80. As shown in FIG. 7, taper angle 1 of the female cone 80 and taper angle 2 of the male cone 82 match and in the illustrated embodiment, the taper angles 1, 2 self-lock.

[0164] Axial restraints in the form of shear pins 88 (two of which are shown in FIG. 7) are operatively associated with the clutch 78. In use, the shear pins 88 are configured to permit the clutch 78 to be engaged when a selected minimum axial force is applied, that is where the axial force reaches or exceeds a predetermined force threshold.

[0165] In some embodiments, the clutch 78 is engaged by applying axial force onto the output shaft 84 or via axial movement of components of the rotary drive 16. Reaching or exceeding a selected force threshold causes the shear pins 88 to shear and allow the female cone 80 and the male cone 82 of the clutch 78 to engage.

[0166] However, in the illustrated embodiment, the clutch 78 is engaged by increasing the fluid flow rate through the rotary drive 16. Increasing the fluid flow rate through the rotary drive 16 increases the pressure drop of the rotary drive 16 until a predetermined pressure dropcorresponding to an axial force sufficient to shear the shear pins 88is reached.

[0167] Referring now to FIGS. 8 and 9 of the accompanying drawings, there is shown an alternative clutch 178 according to another embodiment of the present invention.

[0168] The clutch 178 is similar to the clutch 78 described above and like numerals are represented by like reference signs incremented by 100.

[0169] As in the clutch 78, the clutch 178 takes the form of a cone clutch having a female cone 180 and a male cone 182. In this embodiment, the male cone 182 is integral with output shaft 184 of the rotary drive 116 and the female cone 180 is integral with housing 120. However, as in the clutch 78 it will be recognised that the male cone 182 and/or the female cone 180 of the clutch 178 may alternatively comprise a separate component and may be coupled to the output shaft 184 and housing 120, respectively. The rotary drive 116 is coupled to the output shaft 184 by a thread connection 186.

[0170] The housing 120 is coupled to a tubular connector sub 126, the connector sub 126 in turn being couplable to a tubular component, which in the illustrated embodiment comprises a casing string 112 (shown diagrammatically in FIG. 8). Lock-up of the output shaft 184 to the housing 120 permits rotation of the cutting member 118 directly by rotation of the casing string 112.

[0171] When the clutch 178 is engaged, the male cone 182 is locked into the female cone 180. As shown in FIG. 8, taper angle 3 of the female cone 180 and taper angle 4 of the male cone 182 match and in the illustrated embodiment, the taper angles 3, 4 self-lock.

[0172] Axial restraints in the form of shear pins 188 (two of which are shown in FIG. 8) are operatively associated with the clutch 178. In use, the shear pins 188 are configured to permit the clutch 178 to be engaged when a selected minimum axial force is applied, that is where the axial force reaches or exceeds a predetermined force threshold.

[0173] As shown in FIG. 9, in this second embodiment the clutch 178 comprises an axial slot 90 configured to trap between the female cone 180 and the male cone 182 any debris carried along with drilling fluid. A single slot 90 is shown in FIG. 9. However, more than one slot 90 may be provided. The axial slot 90 is configured to receive debris and retain it away from the female and male cones 180, 182 of the clutch 178. The axial slot 90 is dimensioned to receive an expected amount of debris. For example, the slot 90 is configured to drive debris away from the clutch 178. Beneficially, the axial slot 90 may thus allow the clutch 178 to operate as designed, unaffected by the presence of any debris that may have been driven into the downhole tool during its operation.

[0174] As shown in FIG. 8, the clutch 178 also has axial clearance gap 92. In use, the clearance gap 92 may provide axial allowance to engage the clutch 178. The axial clearance gap 92 may be any suitable distance, but in the illustrated embodiment is 15 mm.

[0175] In use, the clutch 178 is designed to enable free rotation of the cutting member 118 during normal operation and may be engaged or activated on demand by any suitable method. Beneficially, the clutch 178 prevents or at least mitigates unwanted rotation of the cutting member 118 upon drilling thereof, which may otherwise hinder rotation of the cutting member 118.

[0176] It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the invention.

[0177] For example, it will be recognised that the clutches 78, 178 are not limited in use to the downhole tool and assemblies described above and may be used in a variety of downhole tools, such as for example the tools shown and described in European Patent 1989390, in European Patent 2334890 or the completion system shown and described in International Patent Publication WO 2011/048368, the contents of which are incorporated by reference.

[0178] It should be understood that the embodiments described herein are merely examples and that various modifications may be made thereto without departing from the scope of the invention. The scope of the invention shall be limited only by the claims appended hereto.