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Multi-aggressiveness cuttting face on PDC cutters and method of drilling subterranean formations

Imported: 24 Feb '17 | Published: 06 Jan '04

Christopher C. Beuershausen

USPTO - Utility Patents

Abstract

Methods of drilling subterranean formations with rotary drag bits equipped with cutting elements including superabrasive, multi-aggressive cutting faces or profiles which are especially suitable for drilling formations of varying hardness and for directional drilling through formations of varying hardness are disclosed. Methods including providing and using rotary drill bits incorporating cutting elements having appropriately aggressive and appropriately positioned cutting surfaces so as to enable the cutting elements to engage the particular formation being drilled at an appropriate depth-of-cut at a given weight-on-bit to maximize rate of penetration without generating excessive, unwanted torque on bit are disclosed. The configuration, surface area, and effective backrake angle of each provided cutting surface, as well as individual cutter backrake angles, may be customized and varied to provide a cutting element having a cutting face aggressiveness profile that varies both longitudinally and radially along the cutting face of the cutting element.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 comprises a graphical representation of ROP versus WOB characteristics of various rotary drill bits in drilling Mancos Shale at 2000 psi bottomhole pressure;

FIG. 2 comprises a graphical representation of TOB versus WOB characteristics of various rotary drill bits in drilling Mancos Shale at 2,000 psi bottomhole pressure;

FIG. 3A comprises a frontal view of a small chamfer PDC cutter usable with the present invention, and FIG. 3B comprises a side sectional view of the small chamfer PDC cutter of FIG. 3A, taken along section lines B—B;

FIG. 4 comprises a frontal view of a large chamfer PDC cutter usable with the present invention;

FIG. 5 comprises a side sectional view of a first internal configuration for the large chamfer PDC cutter of FIG. 4;

FIG. 6 comprises a side sectional view of a second internal configuration for the large chamfer PDC cutter of FIG. 4;

FIG. 7 comprises a side perspective view of a PDC-equipped rotary drag bit according to one embodiment of the present invention;

FIG. 8 comprises a face view of the bit of FIG. 7;

FIG. 9 comprises an enlarged, oblique face view of a single blade of the bit of FIG. 8, illustrating the varying cutter chamfer sizes and angles and cutter rake angles employed;

FIG. 10 comprises a quarter-sectional side schematic of a bit having a profile such as that of FIG. 7, with the cutter locations rotated to a single radius extending from the bit centerline to the gage to show the radial bit face locations of the various cutter chamfer sizes and angle and cutter backrake angles employed in the bit;

FIG. 11 comprises a side view of a PDC cutter as employed with one embodiment of the present invention, depicting the effects of chamfer backrake and cutter backrake;

FIG. 12 is a frontal perspective view of a superabrasive table shown in isolation comprising a first exemplary multi-aggressive cutting face particularly suitable for use in practicing the present invention;

FIG. 13 is a side view of a cutting element incorporating the superabrasive table shown in FIG. 12;

FIG. 14 is a side view of the cutting element shown in FIG. 13 as the multi-aggressive aggressive cutting face engages a relatively hard formation at a relatively small depth of cut (DOC) in accordance with the present invention;

FIG. 15 is a side view of the cutting element shown in FIGS. 13 and 14 as the multi-aggressive cutting face engages a relatively soft formation at a relatively large depth of cut (DOC) in accordance with the present invention;

FIG. 16 is a side view of a cutting element provided with an alternative multi-aggressive cutting face particularly suitable for use in practicing the present invention;

FIG. 17 is a side view of a cutting element embodying another alternative multi-aggressive cutting face particularly suitable for use in practicing the present invention; and

FIG. 18 is a view of an isolated portion of the face of a representative drag bit comprising, as a nonlimiting example, cutting elements installed on a blade thereof which respectively comprise cutting faces configured to have differing multi-aggressive profiles.

Claims

1. A method of drilling subterranean formations comprising:

2. The method of claim 1, wherein drilling the relatively soft formation and drilling the relatively hard formation comprise drilling the relatively soft formation and the relatively hard formation at a generally constant weight-on-bit.

3. A method of drilling subterranean formations comprising:

4. The method of claim 3, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face of the at least one cutting element with a third, radially innermost cutting surface oriented approximately perpendicular to the longitudinal axis of the at least one cutting element.

5. The method of claim 3, wherein drilling the relatively soft formation and drilling the relatively hard formation comprise drilling the relatively soft formation and the relatively hard formation at a generally constant weight-on-bit.

6. A method of drilling subterranean formations comprising:

7. The method of claim 6, wherein providing the rotary drill bit including a plurality of circumferentially spaced, longitudinally extending blade structures comprises providing a plurality of circumferentially spaced, longitudinally extending blade structures having a plurality of the at least one cutting elements oriented at preselected cutting element backrake angles.

8. The method of claim 6, wherein drilling the relatively soft formation and drilling the relatively hard formation comprise drilling the relatively soft formation and the relatively hard formation at a generally constant weight-on-bit.

9. A method of drilling subterranean formations comprising:

10. The method of claim 9, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with a first cutting surface having a width within a range of approximately 0.025 of an inch to approximately 0.075 of an inch and comprises providing a second cutting surface having a width within a range of approximately 0.025 of an inch to approximately 0.075 of an inch.

11. A method of drilling subterranean formations comprising:

12. The method of claim 11, wherein providing a third cutting surface comprises providing a third cutting surface having a diameter within a range of approximately 0.1 of an inch to approximately 0.5 of an inch.

13. The method of claim 12, wherein drilling the relatively soft formation and drilling the relatively hard formation comprise drilling the relatively soft formation and the relatively hard formation at a generally constant weight-on-bit.

14. The method of claim 11, wherein drilling the relatively soft formation and drilling the relatively hard formation comprise drilling the relatively soft formation and the relatively hard formation at a generally constant weight-on-bit.

15. The method of claim 11, Wherein drilling the relatively hard formation, the relatively soft formation, and the relatively very soft formation comprises drilling at a respectively selected weight-on-bit which maximizes a rate-of-penetration and which generates a torque-on-bit which is below a selected threshold.

16. A method of drilling subterranean formations of varying hardness with a rotary drill bit including a plurality of cutting elements having a multi-aggressive cutting profile and disposed at preselected cutting element backrake angles thereon comprising:

17. The method of claim 16, wherein at least one of the drilling a relatively hard formation and the drilling a relatively less hard formation comprises directional control of the drilling.

18. A method of drilling subterranean formations of varying hardness with a rotary drill bit including a plurality of cutting elements having a multi-aggressive cutting profile and disposed at preselected cutting element backrake angles thereon comprising:

19. The method of claim 18, wherein providing the rotary drill bit with the plurality of circumferentially spaced, longitudinally extending blade structures carrying at least one superabrasive cutting element having the generally more aggressive multi-aggressive cutting profile as compared to the multi-aggressive cutting profile of the at least one other cutting element carried on the same blade structure comprises providing a rotary drill with a plurality of circumferentially spaced, longitudinally extending blade structures carrying in a first region of each blade structure a plurality of cutting elements having a generally more aggressive multi-aggressive cutting profile as compared to a multi-aggressive cutting profile of a plurality of cutting elements carried in a second region of each blade structure.

20. The method of claim 18, wherein at least one of the drilling a relatively hard formation and the drilling a relatively less hard formation comprises directional control of the drilling.

21. A method of drilling subterranean formations comprising:

22. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element comprises providing the superabrasive, multi-aggressive cutting face with an additional, circumferentially extending chamfered surface positioned radially and axially intermediate the first cutting surface and a sidewall surface of the superabrasive, multi-aggressive cutting face.

23. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face of the at least one cutting element with a radially innermost cutting surface.

24. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face of the at least one cutting element with a radially innermost cutting surface oriented approximately perpendicular to the longitudinal axis of the at least one cutting element.

25. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing a rotary drill bit including a plurality of circumferentially spaced, longitudinally extending blade structures with at least one of the plurality of blade structures carrying the at least one cutting element.

26. The method of claim 25, wherein providing the rotary drill bit including the plurality of circumferentially spaced, longitudinally extending blade structures comprises providing a rotary drill bit comprising a plurality of cutting elements on each of the plurality of blade structures.

27. The method of claim 26, wherein providing the rotary drill bit including a plurality of circumferentially spaced, longitudinally extending blade structures comprises providing a plurality of circumferentially spaced, longitudinally extending blade structures having a plurality of the at least one cutting element at a preselected cutting element backrake angle.

28. The method of claim 26, wherein drilling the relatively hard formation and the relatively soft formation comprises drilling the relatively hard formation and the relatively soft formation at a respectively selected weight-on-bit which maximizes the rate-of-penetration through each formation and which generates a respective torque-on-bit which is below a selected threshold.

29. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the second cutting surface oriented at the second angle with respect to the reference line parallel to the longitudinal axis of the at least one cutting element and orienting the second cutting surface at a second angle ranging between approximately 30° and approximately 60°.

30. The method of claim 29, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the fourth cutting surface oriented at the fourth angle with respect to the reference line parallel of the longitudinal axis of the at least one cutting element and orienting the fourth cutting surface at a fourth angle approximately equal to the second angle.

31. The method of claim 30, wherein providing the superabrasive, multi-aggressive cutting face with the second cutting surface oriented at the second angle and the fourth cutting surface oriented at the fourth angle approximately equal to the second angle comprises orienting the second and fourth cutting surfaces at an angle of approximately 45°.

32. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the first cutting surface oriented at the first angle with respect to the reference line extending parallel to the longitudinal axis of the at least one cutting element not exceeding approximately 30°.

33. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the third cutting surface oriented at the third angle with respect to the reference line extending parallel to the longitudinal axis of the at least one cutting element approximately equal to the first angle.

34. The method of claim 33, wherein providing the superabrasive, multi-aggressive cutting face with the first cutting surface oriented at the first angle and the third cutting surface oriented at the third angle approximately equal to the first angle comprises orienting the first and third cutting surfaces at an angle ranging between approximately 60° and approximately 70°.

35. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the first cutting surface oriented at the first angle with respect to the reference line parallel to the longitudinal axis of the at least one cutting element and orienting the first cutting surface at the first angle ranging between approximately 30° and approximately 60°.

36. The method of claim 35, wherein providing the rotary drill bit including at least one cutting element thereon comprises orienting the fourth cutting surface at the fourth angle approximately equal to the second angle.

37. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon further comprises providing a fifth cutting surface positioned radially inward of the fourth cutting surface, the fifth cutting surface being oriented at a fifth angle with respect to the reference line extending parallel to the longitudinal axis.

38. The method of claim 37, wherein providing the fifth cutting surface positioned radially inward of the fourth cutting surface comprises orienting the fifth cutting surface at the fifth angle approximately equal to the first angle.

39. The method of claim 38, wherein orienting the fifth cutting surface at the fifth angle approximately equal to the first angle comprises orienting the third cutting surface at the third angle approximately equal to the first and fifth angles.

40. The method of claim 39, wherein orienting the fifth cutting surface at the fifth angle approximately equal to the first angle and orienting the third cutting surface at the third angle approximately equal to the first and fifth angles comprises the first, third, and fifth cutting surfaces being angled within a range of approximately 30° to approximately 60°.

41. The method of claim 40, wherein providing the superabrasive, multi-aggressive cutting face with the first cutting surface, the third cutting surface, and the fifth cutting surface being angled within a range of approximately 30° to approximately 60° comprises orienting the first, third, and fifth cutting surfaces at an angle of approximately 45°.

42. The method of claim 38, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the fourth cutting surface oriented at the fourth angle with respect to the reference line extending parallel to the longitudinal axis of the at least one cutting element approximately equal to the second angle.

43. The method of claim 21, wherein providing the rotary drill bit including at least one cutting element thereon comprises providing the superabrasive, multi-aggressive cutting face with the second cutting surface oriented at the second angle with respect to the reference line extending parallel to the longitudinal axis of the at least one cutting element of approximately 90°so as to orient the second cutting surface generally perpendicular to the longitudinal axis.