Downhole cutting tool

Patent metadata

Field	Value
Publication number	US-9410379-B2
Application number	US-201213728435-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Dec 27, 2011
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A tool for reaming a borehole includes a tubular body having a central axis, an uphole reamer section mounted to the body, and a downhole reamer section mounted to the body. Each reamer section includes a first blade extending radially from the body. Each blade has an uphole end, a downhole end opposite the uphole end, and a formation-facing surface. The formation facing surface of the first blade of the uphole reamer section is disposed at a radius R 1 that increases moving from the uphole end to the downhole end. The formation facing surface of the first blade of the downhole reamer section is disposed at a radius R 1 ′ that decreases moving from the uphole end to the downhole end. The tool also includes a cutter element mounted to the formation facing surface of the first blade of each reamer section.

First claim

What is claimed is:

1. A tool for reaming a borehole, the tool comprising:
a tubular body having a central axis, a first end, and a second end opposite the first end;
an uphole eccentric reamer section mounted to the tubular body, wherein the uphole eccentric reamer section is eccentric about the central axis of the tubular body;
a downhole eccentric reamer section mounted to the tubular body and axially positioned below the uphole eccentric reamer section, wherein the downhole eccentric reamer section is eccentric about the central axis of the tubular body;
wherein each eccentric reamer section includes a first blade extending radially from the tubular body, wherein the first blade of each eccentric reamer section has an uphole end and a downhole end axially positioned below of the uphole end, wherein the first blade of the uphole eccentric reamer section circumferentially overlaps with the first blade of the downhole eccentric reamer section;
wherein the first blade of the uphole eccentric reamer section extends helically about the tubular body in a first helical direction moving from the uphole end of the first blade of the uphole eccentric reamer section to the downhole end of the first blade of the uphole eccentric reamer section:
wherein the first blade of the downhole eccentric reamer section extends helically about the tubular body in a second helical direction moving from the uphole end of the first blade of the downhole eccentric reamer section to the downhole end of the first blade of the downhole eccentric reamer section;
wherein the second helical direction is opposite the first helical direction; and
a cutter element mounted to the first blade of each eccentric reamer section;
wherein the cutter element mounted to the first blade of the uphole reamer section and the cutter element mounted to the first blade of the downhole reamer section are each configured to engage and ream the borehole.

2. The tool of claim 1 , wherein the uphole eccentric reamer section includes a pass through diameter and is configured to ream a borehole to a diameter larger than the pass through diameter of the uphole eccentric reamer section when the tubular body is rotated about the central axis in a cutting direction;
wherein the downhole eccentric reamer section includes a pass through diameter and is configured to ream a borehole to a diameter that is larger than the pass through diameter of the downhole eccentric reamer section when the tubular body is rotated about the central axis in the cutting direction;
wherein each first blade has a formation-facing surface extending from the uphole end to the downhole end, and a forward-facing surface extending radially from the tubular body to the formation-facing surface;
wherein the formation facing surface of the first blade of the uphole eccentric reamer section is disposed at a radius R 1 measured perpendicularly from the central axis, wherein the radius R 1 increases moving from the uphole end to the downhole end of the first blade of the uphole eccentric reamer section;
wherein the formation facing surface of the first blade of the downhole eccentric reamer section is disposed at a radius R 1 ′ measured perpendicularly from the central axis, wherein the radius R 1 ′ decreases moving from the uphole end to the downhole end of the downhole eccentric reamer section; and
wherein the cutter element of each first blade is mounted to the formation facing surface of the first blade of each eccentric reamer section, wherein the cutter element mounted to the first blade of the uphole eccentric reamer section extends to a radius relative to the central axis that is less than or equal to the radius R 1 at the downhole end of the first blade of the uphole eccentric reamer section, and the cutter element mounted to the first blade of the downhole eccentric reamer section extends to a radius relative to the central axis that is less than or equal to the radius R 1 ′ at the uphole end of the first blade of the downhole eccentric reamer section.

3. The tool of claim 2 , further comprising a plurality of cutter elements mounted to the formation facing surface of the first blade of each eccentric reamer section;
wherein the plurality of cutter elements mounted to the formation facing surface of the first blade of each eccentric reamer section includes the cutter element mounted to the formation facing surface of the first blade of the corresponding eccentric reamer section;
wherein the plurality of cutter elements mounted to the first blade of the uphole eccentric reamer section are arranged in a row proximal the uphole end of the first blade of the uphole eccentric reamer section;
wherein the plurality of cutter elements mounted to the first blade of the downhole eccentric reamer section are arranged in a row proximal the downhole end of the first blade of the downhole eccentric reamer section;
wherein each cutter element mounted to the first blade of the uphole eccentric reamer section extends to a radius relative to the central axis that is less than or equal to the radius R 1 at the downhole end of the first blade of the uphole eccentric reamer section, and each cutter element mounted to the first blade of the downhole eccentric reamer section extends to a radius relative to the central axis that is less than or equal to the radius R 1 ′ at the uphole end of the first blade of the downhole eccentric reamer section.

4. The tool of claim 3 , wherein the uphole eccentric reamer section includes a second blade circumferentially spaced from the first blade of the uphole eccentric reamer section;
wherein the downhole eccentric reamer section includes a second blade circumferentially spaced from the first blade of the downhole eccentric reamer section;
wherein the second blade of the uphole eccentric reamer section extends radially to a maximum radius R 2 measured perpendicularly from a reamer axis that is parallel to and radially offset from the central axis, wherein the maximum radius R 2 is less than the radius R 1 at the downhole end of the first blade of the uphole eccentric reamer section; and
wherein the second blade of the downhole eccentric reamer section extends radially to a maximum radius R 2 ′ measured perpendicularly from the reamer axis, wherein the maximum radius R 2 ′ is less than the radius R 1 ′ at the uphole end of the first blade of the downhole eccentric reamer section.

5. The tool of claim 4 , wherein the first blade and the second blade of the uphole eccentric reamer section are uniformly circumferentially spaced about the central axis;
wherein the first blade and the second blade of the downhole eccentric reamer section are uniformly circumferentially spaced about the central axis;
wherein the first blade and the second blade of the uphole eccentric reamer section are oriented parallel to each other; and
wherein the first blade and the second blade of the downhole eccentric reamer section are oriented parallel to each other.

6. The tool of claim 5 , wherein each second blade includes an uphole end and a downhole end opposite the uphole end;
wherein the downhole end of each blade of the uphole eccentric reamer section leads the uphole end of the corresponding blade of the uphole eccentric reamer section relative to a cutting direction;
wherein the uphole end of the each blade of the downhole eccentric reamer section leads the downhole end of the corresponding blade of the downhole eccentric reamer section relative to the cutting direction.

7. The tool of claim 4 , wherein the uphole eccentric reamer section includes another first blade that is circumferentially adjacent to the first blade of the uphole reamer section, such that the uphole reamer section includes a pair circumferentially adjacent first bla

Assignees

• Nat Oilwell Dht Lp

Inventors

• Silva Roger H

Classifications

• E21B17/1078

  Stabilisers or centralisers for casing, tubing or drill pipes (E21B17/1007 - E21B17/1064 take precedence) · CPC title

• E21B7/00

  Special methods or apparatus for drilling · CPC title

• E21B10/32

  with expansible cutting tools · CPC title

• E21B10/30

  Longitudinal axis roller reamers, e.g. reamer stabilisers · CPC title

• E21B10/26 Primary

  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