CA2569451A1 - Rolling cone drill bit having cutter elements positioned in a plurality of differing radial positions - Google Patents

Rolling cone drill bit having cutter elements positioned in a plurality of differing radial positions Download PDF

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Publication number
CA2569451A1
CA2569451A1 CA002569451A CA2569451A CA2569451A1 CA 2569451 A1 CA2569451 A1 CA 2569451A1 CA 002569451 A CA002569451 A CA 002569451A CA 2569451 A CA2569451 A CA 2569451A CA 2569451 A1 CA2569451 A1 CA 2569451A1
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CA
Canada
Prior art keywords
cutter
array
cone
drill bit
cutting profile
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA002569451A
Other languages
French (fr)
Other versions
CA2569451C (en
Inventor
Amardeep Singh
Scott D. Mcdonough
Joshua Gatell
Mohammed Boudrare
Bryce A. Baker
Parveen K. Chandila
Brandon M. Moss
Allen D. White
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Smith International Inc
Original Assignee
Smith International Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Smith International Inc filed Critical Smith International Inc
Publication of CA2569451A1 publication Critical patent/CA2569451A1/en
Application granted granted Critical
Publication of CA2569451C publication Critical patent/CA2569451C/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/08Roller bits
    • E21B10/16Roller bits characterised by tooth form or arrangement

Abstract

A drill bit for drilling through earthen formations and forming a borehole. In an embodiment, the bit comprises a bit body having a bit axis. In addition, the bit comprises a plurality of cone cutters, each of the cone cutters being mounted on the bit body and adapted for rotation about a different cone axis. Further, at least one cone cutter on the bit comprises an array of cutter elements mounted in a band. Still further, the cutter elements in the array are mounted in a plurality of differing radial positions relative to the bit axis.

Claims (49)

1. A drill bit for drilling through earthen formations and forming a borehole, the bit comprising:

a bit body having a bit axis;

a plurality of cone cutters, each of the cone cutters being mounted on the bit body and adapted for rotation about a different cone axis;

wherein each cone cutter on the bit comprises a first array of cutter elements mounted in a first band and a second array of cutter elements mounted in a second band that is axially spaced apart from the first band relative to the cone axis;

wherein the cutter elements in each array are mounted in a plurality of differing radial positions relative to the bit axis.
2. The drill bit of claim 1 wherein each cone cutter further comprises a backface, a nose opposite the backface, a non-intermesh region adjacent to the backface, and an intermesh region between the non-intermesh region and the nose; and wherein at least one array is mounted within the intermesh region.
3. The drill bit of claim 1 wherein each cutter element within the first band and each cutter element in the second band is positioned in the cone to cut a bottom of the borehole.
4. The drill bit of claim 1 wherein at least one cone cutter includes a third array of cutter elements mounted in a third band axially spaced apart from the first band and the second band.
5. The drill bit of claim 1 wherein the cutter elements mounted on the plurality of cone cutters form a composite cutting profile when the plurality of cone cutters are rotated into a single plane, wherein each array at least partially overlaps with at least one other array on an adjacent cone in the composite cutting profile.
6. The drill bit of claim 5 wherein each cutter element has a base diameter and wherein each array overlaps with at least one other array on an adjacent cone by at least 10% of the base diameter of any cutter element within either of the overlapping arrays in composite rotated profile.
7. The drill bit of claim 5 wherein each cutter element has an extension height and wherein the composite cutting profile includes one or more cutting voids, wherein each cutting void has a height less than 75% of the extension height of any cutter element.
8. The drill bit of claim 7 wherein each cutting void is less than 50% of the extension height of any cutter element.
9. The drill bit of claim 1 wherein the cutter elements mounted on the plurality of cone cutters form a composite cutting profile when the plurality of cone cutters are rotated into a single plane, wherein the composite cutting profile includes an intermesh region, the intermesh region including one or more cutting voids less than 75% of an extension height of any cutter element.
10. The drill bit of claim 9 wherein each cutting void in the intermesh region is less than 50% of the extension height of any cutter element.
11. The drill bit of claim 1 wherein the cutter elements of each array form a cutting profile when rotated into a single plane, wherein each cutter element has a central axis, and wherein the cutting profile of each array includes at least two cutter elements having axes skewed relative to one another.
12. The drill bit of claim 1 wherein the cutter elements of each array form a cutting profile when rotated into a single plane, wherein each cutter element has a central axis, and wherein the axes of adjacent cutter elements in the cutting profile of each array are skewed relative to one another.
13. The drill bit of claim 1 wherein at least one cutter element in the first array differs from another cutter element in the first array by a characteristic selected from the group consisting of diameter, extension height, cutting surface shape, twist angle, and material composition.
14. The drill bit of claim 1 wherein each array comprises N cutter elements disposed in at least P differing radial positions, where P is at least three.
15. The drill bit of claim 14 wherein P is at least four.
16. The drill bit of claim 1 wherein at least one first array of cutter elements includes a first set of N1 cutter elements disposed in P1 differing radial positions and a second set of N2 cutter elements disposed in P2 radial positions relative to the bit axis;

wherein the P1 differing radial positions each differ from the P2 differing radial positions.
17. The drill bit of claim 1 wherein each cutter element in each array is disposed in a different radial position.
18. A drill bit for drilling through earthen formations and forming a borehole, the bit comprising:

a bit body having a bit axis;

a rolling cone cutter mounted on the bit body and adapted for rotation about a cone axis;

an array of cutter elements mounted in a plurality of differing radial positions within a band on the cone cutter, wherein each cutter element of the array has a diameter, a central axis, and a crest;

wherein the cutter elements of the array form a cutting profile when rotated into a single plane, wherein the cutting profile of the array includes at least two cutter elements spaced apart by a distance measured between the axes of the two cutter elements at crest of the two cutter elements that is at least 50% of the diameter of any cutter element within the array.
19. The drill bit of claim 18 comprising at least two rolling cone cutters mounted on the bit body and adapted for rotation about a cone axis, wherein each cone cutter includes a plurality of cutter elements, a backface, a nose opposite the backface, a non-intermesh region adjacent the backface, an intermesh region between the non-intermesh region and the nose, wherein the array of cutter elements is positioned within the intermesh region.
20. The drill bit of claim 18 wherein the distance is at least 60% of the diameter of any cutter element within the array.
21. The drill bit of claim 18 wherein the distance is at least 75% of the diameter of any cutter element within the array.
22. The drill bit of claim 18 wherein the distance is at least equal to the diameter of any cutter element within the array.
23. The drill bit of claim 20 comprising at least two rolling cone cutters mounted on the bit body and adapted for rotation about a cone axis, wherein each cone cutter includes a plurality of cutter elements, a backface, a nose opposite the backface, a non-intermesh region adjacent the backface, an intermesh region between the non-intermesh region and the nose, wherein the array of cutter elements is positioned within the non-intermesh region..[TF5]
24. The drill bit of claim 19 wherein the array comprise N cutter elements disposed in at least P differing radial positions, where P is at least three.
25. The drill bit of claim 24 where P is at least four.
26. The drill bit of claim 18 wherein the cutting profile of the array includes at least two cutter elements whose axes are skewed relative to one another.
27. The drill bit of claim 18 wherein a first cutter element in the array differs from a second cutter element in the array by a characteristic selected from the group consisting of diameter, extension height, cutting surface shape, twist angle, and material composition.
28. A drill bit for creating a borehole in earthen formations, comprising:
a bit body having a bit axis;

a plurality of cone cutters, wherein each of the cone cutters is mounted on the bit body and adapted for rotation about a different cone axis and includes an intermesh region;

wherein each cone cutter includes at least one array of cutter elements mounted in a plurality of differing radial positions within a band in the intermesh region, wherein each cutter element has an extension height;

wherein the cutter elements of each array form a cutting profile when rotated into a single plane;

wherein the cutter elements mounted on the plurality of cones form a composite cutting profile when the plurality of cones are rotated into a single plane, the composite cutting profile including an intermesh region;

wherein the cutting profile of each array in the composite cutting profile at least partially overlaps with the cutting profile of another array on an adjacent cone;

wherein the composite cutting profile includes a plurality of cutting voids;
and wherein each cutting void within the intermesh region of the composite cutting profile has a depth less than 75% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
29. The drill bit of claim 28 wherein the cutter elements in each array are mounted in at least three differing radial positions.
30. The drill bit of claim 29 wherein the cutter elements in each array are mounted in at least four differing radial positions.
31. The drill bit of claim 28 wherein each cutting void within the intermesh region of the composite cutting profile has a depth less than 50% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
32. The drill bit of claim 31 wherein each cutting void within the intermesh region of the composite cutting profile has a depth less than 33% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
33. The drill bit of claim 28 wherein each cutting void within the intermesh region of the composite cutting profile has a depth less than 20% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
34. The drill bit of claim 28 wherein each cone cutter includes a first array of cutter elements mounted within a first band and a second array of cutter elements mounted within a second band spaced axially apart from the first band, wherein the cutter elements in each array are mounted in a plurality of differing radial positions relative to the bit axis, and wherein the first array and second array of one cone cutter are mounted within the intermesh region of each cone.
35. The drill bit of claim 28 wherein each cutter element has a central axis and wherein the cutting profile of at least two cutter elements in one of said arrays includes at least two cutter elements having skewed axes relative to each other.
36. The drill bit of claim 35 wherein the cutting profile of each array includes at least two cutter elements having skewed axes relative to each other.
37. A drill bit for drilling through earthen formations and forming a borehole, the bit comprising:

a bit body having a bit axis;

at least two rolling cone cutters mounted on the bit body and adapted for rotation about a different cone axis, wherein each cone cutter includes an intermesh region;

an array of cutter elements mounted in a plurality of differing radial positions within a band disposed in the intermesh region of one rolling cone cutter, wherein each cutter element within the array has a central axis; and wherein the cutter elements of the array form a cutting profile when rotated into a single plane that includes at least two cutter elements having skewed axes relative to one another.
38. The drill bit of claim 37 wherein each cone cutter comprises an array of cutter elements mounted in a plurality of differing radial positions within a band disposed in the intermesh region, wherein each cutter element has a central axis; and wherein the cutter elements of each array form a cutting profile when rotated into a single plane that includes at least two cutter elements having skewed axes relative to one another.
39. The drill bit of claim 38 wherein the cutter elements mounted to each cone cutter form a composite cutting profile when the at least two cones are rotated into a single plane, and wherein the cutting profile of each array at least partially overlaps with the cutting profile of another array on an adjacent cone in the composite cutting profile.
40. The drill bit of claim 39 wherein each cutter element of each array has an extension height; and wherein the composite cutting comprises an intermesh region including a plurality of cutting voids, wherein each cutting void within the intermesh region of the composite cutting profile has a depth less than 75% of the extension height of any cutter element within the intermesh region of the composite cutting profile.
41. The drill bit of claim 40 wherein each cutting void within the intermesh region of the composite cutting profile has a depth less than 50% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
42. The drill bit of claim 37 comprising N cutter elements in each array disposed in at least P differing radial positions, where P is at least three.
43. The drill bit of claim 42 wherein P is at least four.
44. A drill bit for creating a borehole in earthen formations, comprising:
a bit body having a bit axis;

a plurality of rolling cone cutters mounted on the bit body and adapted for rotation about a different cone axis, wherein each cone cutter includes an intermesh region;

a first array of cutter elements mounted in a plurality of differing radial positions within a band disposed in the intermesh region of a first cone cutter, wherein the cutter elements of the first array for a cutting profile when rotated into a single plane;

a plurality of cutter elements mounted in the intermesh region of a second cone cutter that form a cutting profile when rotated into a single plane;

wherein each cutter element has an extension height;

wherein the cutter elements mounted on the plurality of cone cutters form a composite cutting profile when the plurality of cone cutters are rotated into a single plane that includes an intermesh region;

wherein the cutting profile of the first array of cutter elements at least partially overlaps with the cutting profile of at least one cutter element of the second cone cutter in the composite cutting profile;

wherein the composite cutting profile includes a cutting void between the cutting profile of the first array of cutter elements and the cutting profile of the at least one cutter element of the second cone that at least partially overlaps with the cutting profile of the first array of cutter elements;

wherein the cutting void has a depth of less than 75% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
45. The drill bit of claim 44 wherein the cutting void has a depth of less than 33% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
46. The drill bit of claim 44 further comprising an second array of cutter elements mounted in a plurality of differing radial positions within a band disposed in the intermesh region of the second cone cutter;

wherein the cutter elements of the second array form a cutting profile when rotated into a single plane;

wherein the cutting profile of the first array of the first cone cutter at least partially overlaps with the cutting profile of the second array of the second cone cutter in the composite cutting profile;

wherein the composite cutting profile includes a cutting void between the cutting profile of the first array and the cutting profile of the second array;

wherein the cutting void has a depth of less than 75% of the extension height of any cutter element in the intermesh region of the composite cutting profile.
47. A drill bit for drilling through earthen formations and forming a borehole, the bit comprising:

a bit body having a bit axis;

a plurality of rolling cone cutters mounted on the bit body and adapted for rotation about a cone axis;

wherein at least one cone cutter on the bit comprises a first array of bottom hole cutter elements mounted in a first band and a second array of bottom hole cutter elements mounted in a second band that is axially spaced apart from the first band relative to the cone axis of the at least one cone cutter;

wherein the at least one cone cutter comprises a total number X of bottom hole cutter elements positioned in Y different radial positions, where the ratio of Y to X is at least 0.20.
48. The drill bit of claim 47 wherein the ratio of Y to X is at least 0.30.
49. The drill bit of claim 48 wherein the ratio of Y to X is at ]east 0.40.
CA2569451A 2006-09-28 2006-11-30 Rolling cone drill bit having cutter elements positioned in a plurality of differing radial positions Active CA2569451C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/536,299 US7686104B2 (en) 2005-08-15 2006-09-28 Rolling cone drill bit having cutter elements positioned in a plurality of differing radial positions
US11/536,299 2006-09-28

Publications (2)

Publication Number Publication Date
CA2569451A1 true CA2569451A1 (en) 2008-03-28
CA2569451C CA2569451C (en) 2010-08-17

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CA2569451A Active CA2569451C (en) 2006-09-28 2006-11-30 Rolling cone drill bit having cutter elements positioned in a plurality of differing radial positions

Country Status (4)

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US (1) US7686104B2 (en)
CA (1) CA2569451C (en)
GB (2) GB2442232B (en)
SG (3) SG151248A1 (en)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8678111B2 (en) 2007-11-16 2014-03-25 Baker Hughes Incorporated Hybrid drill bit and design method
US9074431B2 (en) * 2008-01-11 2015-07-07 Smith International, Inc. Rolling cone drill bit having high density cutting elements
US20100025114A1 (en) * 2008-01-22 2010-02-04 Brady William J PCD Percussion Drill Bit
US20090260890A1 (en) * 2008-04-21 2009-10-22 Baker Hughes Incorporated Anti-tracking feature for rock bits
CA2773897A1 (en) 2009-09-16 2011-03-24 Baker Hughes Incorporated External, divorced pdc bearing assemblies for hybrid drill bits
SA111320565B1 (en) 2010-06-29 2014-09-10 Baker Hughes Inc Hybrid Drill Bit With Anti-Tracking Feature
CN101886522B (en) * 2010-07-16 2012-07-25 西南石油大学 Wheel-type drill for breaking rock in cutting mode
CN101892810B (en) * 2010-07-16 2012-07-25 西南石油大学 Combined drill breaking rocks by cutting method
US9782857B2 (en) 2011-02-11 2017-10-10 Baker Hughes Incorporated Hybrid drill bit having increased service life
MX337212B (en) 2011-02-11 2016-02-17 Baker Hughes Inc System and method for leg retention on hybrid bits.
US9353575B2 (en) 2011-11-15 2016-05-31 Baker Hughes Incorporated Hybrid drill bits having increased drilling efficiency
US9464490B2 (en) 2012-05-03 2016-10-11 Smith International, Inc. Gage cutter protection for drilling bits
BR112016027337A8 (en) 2014-05-23 2021-05-04 Baker Hughes Inc hybrid drill with mechanically fixed cutter assembly
US11428050B2 (en) 2014-10-20 2022-08-30 Baker Hughes Holdings Llc Reverse circulation hybrid bit
WO2017003709A1 (en) * 2015-07-02 2017-01-05 Smith International, Inc. Roller cone drill bit with evenly loaded cutting elements
US10767420B2 (en) 2015-07-02 2020-09-08 Smith International, Inc. Roller cone drill bit with evenly loaded cutting elements
US11136830B2 (en) 2018-02-09 2021-10-05 Schlumberger Technology Corporation Downhole tools with variable cutting element arrays
AU2019279892A1 (en) 2018-05-29 2020-12-17 Quanta Associates, L.P. Horizontal directional reaming

Family Cites Families (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2147926A (en) * 1936-12-07 1939-02-21 Hughes Tool Co Four-cone bit
US2687575A (en) * 1951-02-23 1954-08-31 Anchor Hocking Glass Corp Indicating device
BE510209A (en) 1951-11-20
US3726350A (en) 1971-05-24 1973-04-10 Hughes Tool Co Anti-tracking earth boring drill
US4187922A (en) 1978-05-12 1980-02-12 Dresser Industries, Inc. Varied pitch rotary rock bit
US4304440A (en) 1979-01-05 1981-12-08 Posciri Charles L Roller cutter
US4420050A (en) 1979-07-30 1983-12-13 Reed Rock Bit Company Oil well drilling bit
US4408671A (en) 1980-04-24 1983-10-11 Munson Beauford E Roller cone drill bit
US4334586A (en) 1980-06-05 1982-06-15 Reed Rock Bit Company Inserts for drilling bits
US4393948A (en) 1981-04-01 1983-07-19 Boniard I. Brown Rock boring bit with novel teeth and geometry
US4427081A (en) 1982-01-19 1984-01-24 Dresser Industries, Inc. Rotary rock bit with independently true rolling cutters
SE459436B (en) 1985-10-11 1989-07-03 Sandvik Ab DRILL HEAD AND CUTTING ROLL INTENDED TO USE THIS
USRE34167E (en) 1985-10-11 1993-01-26 Santrade Limited Drill bit and roller cutter for said drill bit
US4815342A (en) 1987-12-15 1989-03-28 Amoco Corporation Method for modeling and building drill bits
US4940099A (en) 1989-04-05 1990-07-10 Reed Tool Company Cutting elements for roller cutter drill bits
US4936398A (en) 1989-07-07 1990-06-26 Cledisc International B.V. Rotary drilling device
US5224560A (en) 1990-10-30 1993-07-06 Modular Engineering Modular drill bit
US5429201A (en) 1994-01-07 1995-07-04 Dresser Industries, Inc. Drill bit with improved rolling cutter tooth pattern
US5456328A (en) 1994-01-07 1995-10-10 Dresser Industries, Inc. Drill bit with improved rolling cutter tooth pattern
US5547033A (en) * 1994-12-07 1996-08-20 Dresser Industries, Inc. Rotary cone drill bit and method for enhanced lifting of fluids and cuttings
US6390210B1 (en) 1996-04-10 2002-05-21 Smith International, Inc. Rolling cone bit with gage and off-gage cutter elements positioned to separate sidewall and bottom hole cutting duty
US5839526A (en) 1997-04-04 1998-11-24 Smith International, Inc. Rolling cone steel tooth bit with enhancements in cutter shape and placement
CA2244457C (en) 1997-08-05 2007-02-20 Smith International, Inc. Drill bit with ridge cutting cutter elements
CA2246466A1 (en) 1997-09-04 1999-03-04 Smith International, Inc. Cutter element with expanded crest geometry
AU1072999A (en) 1997-10-06 1999-04-27 Michael A. Anderson Small disc cutters, and drill bits, cutterheads, and tunnel boring machines emp loying such rolling disc cutters
US6206116B1 (en) 1998-07-13 2001-03-27 Dresser Industries, Inc. Rotary cone drill bit with machined cutting structure
FR2805845B1 (en) 2000-03-01 2002-06-07 Armines Ass Pour La Rech Et Le SELF-PENETRATING DRILLING PROCESS AND PUSH-GENERATING TOOL FOR IMPLEMENTING THE PROCESS
GB2399373B (en) 2000-05-18 2004-11-24 Smith International Earth-boring bit
DE60120294D1 (en) 2000-08-23 2006-07-20 Camco Int Uk Ltd Indicator for the failure of the bearing of a roller drill bit
US6834733B1 (en) 2002-09-04 2004-12-28 Varel International, Ltd. Spiral wave bladed drag bit
US6942045B2 (en) 2002-12-19 2005-09-13 Halliburton Energy Services, Inc. Drilling with mixed tooth types
US7195078B2 (en) 2004-07-07 2007-03-27 Smith International, Inc. Multiple inserts of different geometry in a single row of a bit
US7370711B2 (en) 2005-08-15 2008-05-13 Smith International, Inc. Rolling cone drill bit having non-circumferentially arranged cutter elements
US7549490B2 (en) 2005-11-23 2009-06-23 Smith International, Inc. Arrangement of roller cone inserts

Also Published As

Publication number Publication date
GB2442232B (en) 2009-10-21
GB2452861C (en) 2009-12-02
SG141292A1 (en) 2008-04-28
SG151247A1 (en) 2009-04-30
US7686104B2 (en) 2010-03-30
GB2452861A (en) 2009-03-18
GB0817707D0 (en) 2008-11-05
GB2452861B (en) 2009-10-21
GB2452861A8 (en) 2009-04-22
GB0623478D0 (en) 2007-01-03
GB2442232A (en) 2008-04-02
CA2569451C (en) 2010-08-17
US20070034414A1 (en) 2007-02-15
SG151248A1 (en) 2009-04-30

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