Hybrid drill bits having increased drilling efficiency

Patent metadata

Field	Value
Publication number	US-10190366-B2
Application number	US-201615137294-A
Country	US
Kind code	B2
Filing date	Apr 25, 2016
Priority date	Nov 15, 2011
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

An earth-boring drill bit is described, the bit having a bit body having a central longitudinal axis that defines an axial center of the bit body and configured at its upper extent for connection into a drill string; at least one primary fixed blade extending downwardly from the bit body and inwardly toward, but not proximate to, the central axis of the drill bit; at least one secondary fixed blade extending radially outward from proximate the central axis of the drill bit; a plurality of fixed cutting elements secured to the primary and secondary fixed blades; at least one bit leg secured to the bit body; and a rolling cutter mounted for rotation on the bit leg; wherein the fixed cutting elements on at least one fixed blade extend from a center of the bit outward toward a gage region of the bit but do not include a gage cutting region, and wherein at least one roller-cone cutter portion extends from substantially the drill bit's gage region inwardly toward the center of the bit, an apex of the roller-cone cutter being proximate to the terminal end of the at least one secondary fixed blade, but does not extend to the center of the bit.

First claim

What is claimed is:

1. An earth-boring drill bit comprising:
a bit body configured at its upper extent for connection to a drill string, the bit body having a central axis and a bit face comprising a cone region, a nose region, a shoulder region, and a radially outermost gage region;
at least one primary fixed blade extending downward from the bit body in the axial direction, the at least one primary fixed blade having a leading edge and a trailing edge and extending radially along the bit face;
a plurality of fixed-blade cutting elements arranged on the leading edge of the at least one primary fixed blade;
at least one secondary fixed blade extending downward from the bit body in the axial direction and having a leading edge and a trailing edge, the at least one secondary fixed blade extending radially outward along the bit face from proximate the bit axis through the cone region in substantial radial alignment with the at least one primary fixed blade; and
at least one rolling cutter mounted for rotation between the at least one primary fixed blade and the at least one secondary fixed blade.

2. A method of drilling a wellbore in a subterranean formation, the method comprising:
drilling a wellbore into a subterranean formation using the earth-boring drill bit of claim 1 .

3. The drill bit of claim 1 , wherein the at least one primary fixed blade extends from the shoulder region to the gage region, the secondary fixed blade extends from the central axis through the cone region, and the axis of the at least one rolling cutter is radially aligned with the primary fixed-blade and the secondary fixed-blade.

4. The drill bit of claim 3 , further comprising a bearing shaft within the at least one rolling cutter, the bearing shaft extending from the primary fixed blade through the at least one rolling cutter, wherein the bearing shaft extends through a top face of the at least one rolling cutter.

5. The drill bit of claim 4 , further comprising the bearing shaft extending into the at least one secondary fixed blade.

6. The drill bit of claim 4 , wherein the bearing shaft does not extend into the at least one secondary fixed blade.

7. The drill bit of claim 1 , wherein the at least one primary fixed blade extends through the gage region, the at least one secondary fixed blade extends through the nose region, and wherein the axis of the at least one rolling cutter is radially aligned with the at least one primary fixed blade and the at least one secondary fixed-blade.

8. The drill bit of claim 7 , further comprising a bearing shaft within the at least one rolling cutter, the bearing shaft extending from the at least one primary fixed blade through the at least one rolling cutter, wherein the bearing shaft extends through a top face of the at least one rolling cutter.

9. The drill bit of claim 8 , further comprising the bearing shaft extending into the at least one secondary fixed blade.

10. The drill bit of claim 8 , wherein the bearing shaft does not extend into the at least one secondary fixed blade.

11. The drill bit of claim 3 , wherein the axis of rotation of the at least one rolling cutter is advanced from the central axis of the drill bit so the at least one rolling cutter tracks in an outwardly offset direction from the drill bit during drilling.

12. The drill bit of claim 3 , wherein the axis of rotation of the at least one rolling cutter is retarded from the central axis of the drill bit so the at least one rolling cutter tracks in an inwardly offset direction from the drill bit during drilling.

13. A drill bit for earthen formations, comprising:
a bit body configured at its upper extent for connection to a drill string, the bit body having a central axis and a bit face including a cone region, a nose region, a shoulder region, and a radially outermost gage region;
at least one primary fixed-blade cutter extending downward from the bit body in the axial direction, the at least one primary fixed-blade cutter having a leading edge and a trailing edge and extending radially along the bit face from the shoulder region to the gage region;
a plurality of fixed-blade cutting elements arranged on the leading edge of the at least one primary fixed-blade cutter;
at least one secondary fixed-blade cutter extending downward from the bit body in the axial direction and having a leading edge and a trailing edge, the at least one secondary fixed-blade cutter extending radially outward along the bit face from proximate the bit axis through the cone region;
at least one rolling cutter mounted on a bit leg for rotation on the bit body and in substantial radial alignment with the at least one secondary fixed-blade cutter; and
at least one rolling cutter mounted on a bit leg for rotation on the bit body and not in substantial radial alignment with any of the at least one primary fixed-blade cutter and the at least one secondary fixed-blade cutter.

14. The drill bit of claim 13 , further comprising a bearing shaft within the at least one rolling cutter, the bearing shaft extending from the bit leg through the at least one rolling cutter, wherein the bearing shaft extends through a top face of the at least one rolling cutter.

15. The drill bit of claim 14 , wherein at least one end of the bearing shaft is affixed to the bit body.

16. The drill bit of claim 14 , wherein at least one end of the bearing shaft is affixed to the bit leg.

17. The drill bit of claim 14 , wherein a distal end of the bearing shaft extends through the at least one rolling cutter and is removably secured, and a proximal end of the bearing shaft is removably secured to the bit leg.

18. The drill bit of claim 13 , wherein the axis of rotation of the at least one rolling cutter is advanced from the central axis of the drill bit so the at least one rolling cutter tracks in an inwardly offset direction from the drill bit during operation.

19. The drill bit of claim 13 , wherein the axis of rotation of the at least one rolling cutter is retarded from the central axis of the drill bit so the at least one rolling cutter tracks in an outwardly offset direction from the drill bit during operation.

20. A method of drilling a wellbore in a subterranean formation, the method comprising:
drilling a wellbore into a subterranean formation using the drill bit of claim 13 .

Assignees

• Baker Hughes Inc

Inventors

• Zahradnik Anton F
• Buske Robert J
• Pessier Rudolf C
• Nguyen Don Q
• Cepeda Karlos
• Damschen Michael S
• Rothe Mitchell A
• Howard Johnathan
• Prevost Gregory C
• Vempati Chaitanya K
• Bradford John F

Classifications

• E21B10/14 Primary

  combined with non-rolling cutters other than of leading-portion type · CPC title

• E21B10/55

  with preformed cutting elements · CPC title

• E21B10/22

  characterised by bearing, lubrication or sealing details · CPC title

• E21B10/16

  characterised by tooth form or arrangement · CPC title

• E21B10/52

  with chisel- or button-type inserts · CPC title