Rotary cutting tool

Patent metadata

Field	Value
Publication number	US-10781640-B2
Application number	US-201615579221-A
Country	US
Kind code	B2
Filing date	Jun 2, 2016
Priority date	Jun 3, 2015
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

A downhole cutting tool which may be a reamer or a mill has a rotary tool body with at least one block which carries hard-faced cutters and projects or is extensible from the tool body. A radially outward facing part of the cutter block defines a channel for fluid flow which extends generally axially along the cutter block. The channel is configured such that at least the rotationally trailing edge of the channel extends along the block in one or more directions which are inclined relative to the tool axis. This reduces or avoids the amount of channel edge parallel to the tool axis and thereby mitigates whirling and/or or vibration.

First claim

The invention claimed is:

1. A downhole cutting tool for enlarging a diameter of a borehole, the tool comprising:
a rotary tool body with at least one support member carrying cutters and extensible from the tool body, the rotary tool body and the at least one support member being rotatable about a tool axis of the rotary tool body,
wherein the at least one support member has rotationally leading and trailing side faces and at least one outward facing surface between the side faces,
wherein the at least one outward facing surface of the support member defines a channel for fluid flow, the channel having rotationally leading and trailing edges extending axially along the support member between opposing upper and lower axial ends of the support member, and
wherein at least the rotationally trailing edge of the channel extends along the support member in one or more directions which are inclined relative to the tool axis and the leading side face, with the channel remaining within a width of the support member along a full length of the channel.

2. The tool according to claim 1 wherein at least 75% of a length of the trailing edge of the channel is inclined at an angle in a range from about 10° to 45° relative to the tool axis.

3. The tool according to claim 1 wherein at least 75% of a length of the trailing edge of the channel is inclined at an angle in a range from about 15° to 45° relative to the tool axis, such that a distance varies between the trailing edge of the channel and a leading edge of the at least one support member, the leading edge of the support member being at an interface between the leading side face and the at least one outward facing surface.

4. The tool according to claim 1 wherein at least 75% of the lengths of the leading and trailing edges of the channel are inclined at an angle in a range from about 15° to 45° relative to the tool axis.

5. The tool according to claim 1 wherein the channel is of approximately constant width along at least 75% of a length of the channel.

6. The tool according to claim 1 wherein the at least one support member is a block to which hard faced cutters are attached.

7. The tool according to claim 1 wherein the at least one support member comprises a cutting region with cutters at progressively increasing radial distance from the tool axis and a stabilising pad positioned to contact the borehole at the diameter to which the cutters enlarge the borehole and wherein the channel extends over the cutting region and the stabilising pad.

8. The tool according to claim 1 wherein the tool comprises at least three support members distributed azimuthally around the tool body, each support member is a block with a plurality of hard faced cutters attached to the block, and a radially outward facing part of each block comprises the channel.

9. The tool according to claim 8 wherein the channels on the support members differ from each other in their shape or in their positions on the support members.

10. The tool according to claim 1 wherein the tool comprises a plurality of support members distributed azimuthally around the tool body and the tool body comprises a mechanism for extending the support members outwardly from the tool body.

11. A method of enlarging a borehole, the method comprising:
inserting a tool in accordance with claim 1 into the borehole, and
rotating the tool to enlarge the diameter of the borehole while flowing fluid from at or near a surface of the Earth to the tool and returning fluid from the tool to the surface while at least part of the fluid flow-travels along the channel of the at least one support member.

12. The downhole cutting tool of claim 1 , the channel extending a full length of the support member.

13. The downhole cutting tool of claim 1 , wherein at least the rotationally trailing edge of the channel extends along the support member in a path that includes portions that are angled at an angle of 15° to 45° relative to the tool axis.

14. The downhole cutting tool of claim 1 , the channel having an outlet at each of the opposing axial ends of the support member.

15. The downhole cutting tool of claim 1 , the rotationally leading edge of the channel extending along the support member in one or more directions which are inclined relative to the tool axis and the leading and trailing side faces and at a different angle than the at least one rotationally trailing edge.

16. A downhole cutting tool for enlarging a diameter of a borehole, the tool comprising:
a rotary tool body with at least one support member carrying cutters and extensible from the tool body, the rotary tool body and the at least one support member being rotatable about a tool axis of the rotary tool body,
wherein the at least one support member has rotationally leading and trailing side faces and at least one outward facing surface between the side faces,
wherein the at least one outward facing surface of the support member defines a channel for fluid flow, the channel having rotationally leading and trailing edges extending axially along the support member between opposing upper and lower axial ends of the support member, and
wherein at least the rotationally trailing edge of the channel extends along the support member in one or more directions which are inclined relative to the tool axis, with the channel remaining within a width of the support member along a full length of the channel, the rotationally trailing edge of the channel including a first portion extending in a first direction inclined toward the rotationally leading side face and a second portion extending in a second direction inclined toward the rotationally trailing side face.

17. The downhole cutting tool of claim 16 , the rotationally trailing edge of the channel including a connecting portion between the first and second portions, where the connecting portion is rotationally offset from the rotationally leading and trailing side faces.

18. The downhole cutting tool of claim 17 , the connecting portion extending parallel to the tool axis.

19. The downhole cutting tool of claim 16 , the rotationally trailing edge of the channel including a third portion extending in a third direction inclined toward the rotationally leading side face.

20. The downhole cutting tool of claim 19 , the rotationally trailing edge of the channel including one or more connecting portions, the one or more connecting portions connecting at least one of the first portion to the second portion or connecting the second portion to the third portion, each of the one or more connecting portions being rotationally offset from the rotationally leading and trailing side faces.

Assignees

• Schlumberger Technology Corp

Inventors

• Johnson Ashley Bernard
• Hird Jonathan Robert

Classifications

• E21B10/325

  the cutter being shifted by a spring mechanism · CPC title

• E21B10/322 Primary

  cutter shifted by fluid pressure (E21B10/345 takes precedence) · CPC title

• E21B7/28

  Enlarging drilled holes, e.g. by counterboring · CPC title

• E21B29/005

  with a radially-expansible cutter rotating inside the pipe, e.g. for cutting an annular window · CPC title

• E21B10/26

  Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers (percussion drill bits with leading portion E21B10/40) · CPC title