METHOD AND APPARATUS TO THWART BIT BALLING OF DRILL BITS

Abstract

Disclosed herein is a drill bit. The drill bit includes, a body of the drill bit having at least two blades defining a junk slot therebetween, at least one cutter positioned on at least one of the at least two blades, and at least one diverter positioned downstream of the at least one cutter defined by a direction of travel of the cuttings, the at least one diverter configured to divert cuttings to travel along a trajectory more parallel to a profile of the junk slot.

Description

BACKGROUND

Typical drill bits for drilling wellbores into earth formations include a plurality of blades defining junk slots therebetween for routing and subsequent removal of cuttings cut by cutters attached to the blades. When the junk slots become clogged and no longer effectively evacuate cuttings freely, a condition known as bit balling may occur which results in a reduction in the rate of penetration of the drilling operation. Methods and apparatuses that thwart bit balling of drill bits would be well received in the industry.

BRIEF DESCRIPTION

Disclosed herein is a drill bit. The drill bit includes, a body of the drill bit having at least two blades defining a junk slot therebetween, at least one cutter positioned on at least one of the at least two blades, and at least one diverter positioned downstream of the at least one cutter defined by a direction of travel of the cuttings, the at least one diverter configured to divert cuttings to travel along a trajectory more parallel to a profile of the junk slot.

Further disclosed herein is a method of routing cuttings through a junk slot of a drill bit while drilling. The method includes, positioning at least one diverter downstream of at least one cutter and upstream of a junk slot, and altering a direction of travel of cuttings cut by the at least one cutter to increase an angle of incidence with a profile of the junk slot.

Further disclosed herein is a drill bit cuttings diverter. The diverter includes, a surface positioned substantially between at least one cutter and a junk slot profile of a drill bit, the surface is configured to increase an angle of incidence between a trajectory of the cuttings and the junk slot profile.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 depicts a partial cross-sectional view of a drill bit disclosed herein;

FIG. 2 depicts a partial perspective view of the drill bit of FIG. 1; and

FIG. 3 depicts a partial cross-sectional view of an alternate drill bit disclosed herein.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIGS. 1 and 2, an embodiment of a partial view of a bit balling resistant drill bit disclosed herein is illustrated generally at 10. The drill bit 10 includes, a body 12 having a plurality of blades 14 (one of which is shown), a plurality of cutters 18, a junk slot 22, and three cuttings diverters 26. Without the cuttings diverters 26, cuttings cut by the cutters 18 tend to travel in a direction normal to a surface the formation 30 being cut. For example, cuttings cut by the cutter 18A tend to travel in a direction along arrow 34. The cuttings continue substantially along this trajectory until they impact a junk slot profile 38, typically at a very shallow angle of incidence 42. Consequently, the cuttings need to significantly change direction to travel along arrow 46, for example, to be evacuated through the junk slot 22 or clogging of the junk slot 22 may occur resulting in what is commonly known as bit balling. Consequently, the arrow 46 trajectory is substantially directed radially outwardly.

The cuttings diverters 26 disclosed herein are positioned downstream from the cutters 18, as defined by the flow of cuttings cut by the cutters 18. The cuttings diverters 26 are oriented in such a way as to present a surface 50 that is configured to be contacted by the moving cuttings. Cuttings that contact the cuttings diverters 26 will change direction to a direction, for example, along arrow 54, which significantly increases the angle of incidence 42 with the junk slot profile 38. This redirection may be enough to keep the cuttings from impacting the junk slot profile 38 completely. Regardless of whether the cuttings impact the junk slot profile 38, the cuttings diverters 26, in directing the cuttings to a path more parallel to the junk slot profile 38, encourage the cuttings, and other material positioned within the junk slot 22, to keep moving through the junk slot 22, thereby decreasing the likelihood of balling within that junk slot.

In this embodiment, the surface 50 of the cuttings diverters 26 is curved, although non-curved surfaces can also be used. The curvature is such that an amount of redirection of cuttings contacting the surface 50 increases the further the cuttings move along the surface 50. This varying of angle of the curved surface 50 allows the cuttings to contact the surface 50 at a shallow angle 56 that is less likely to abrade the surface 50 than configurations having greater angles 56.

The cuttings diverters 26 in this embodiment are attached to a wall 58 of the blade 14. Attachment of the cuttings diverters 26 to the wall 58 can be through one of a variety of mechanisms including, welding, brazing, fastening, adhesively bonding, and integrally forming therewith, for example. And the diverters 26 can be made of a variety of materials including metal, ceramic and polymer, for example, and fabricated by known processes such as machining and molding. The shapes of each of the cuttings diverters 26 can be different from one another. Additionally, the cuttings diverters 26 can have features designed to interact with one or more of the other cuttings diverters 26. For example, the cuttings diverter 26B has a ramped face 62 that blends with the wall 58 at a first end 66 and protrudes a distance from the wall 58 at a second end 70 by perhaps ⅛ to ½ of an inch. The ramped face 62 forces cuttings exiting the cuttings diverter 26A away from the wall 58, thereby decreasing friction between cuttings and the wall 58 that could otherwise contribute to bit balling.

Embodiments may include any number of cuttings diverters 26, with the actual number, size and shape of the cuttings diverters 26 being selected in accordance with the needs of particular applications. These needs being influenced by such things as, downhole conditions, formation structure and drill bit design, for example. As such, some drill bits may have a separate cuttings diverter in operable communication with each cutter, while other drill bits may have cuttings diverters that are in operable communication with more than one cutter.

Referring to FIG. 3, an alternate embodiment of a drill bit 110 disclosed herein is illustrated. The drill bit 110 includes, a blade 114, with cutters 118 attached thereto, a junk slot 122 and cuttings diverters 126. A primary difference between the drill bit 10 and the drill bit 110 is the positioning of the cuttings diverters 126. The cuttings diverters 126 are positioned further from the cutters 118, and are attached to a body 128 of the drill bit 110 at an intersection of a wall 158 of the blade 14 and a junk slot profile 138. Such a positioning of the cuttings diverters 126 can make them easier to form as an integral part of the body 128. Additionally, the cuttings diverters 126 have non-curved surfaces 130 with angles that vary according to the cutter 118 that each cuttings diverter 126 is in operable communication with.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Claims

1. A drill bit, comprising:

a body of the drill bit having at least two blades defining a junk slot therebetween;

at least one cutter positioned on at least one of the at least two blades; and

at least one diverter positioned downstream of the at least one cutter defined by a direction of travel of the cuttings, the at least one diverter configured to divert cuttings to travel along a trajectory more parallel to a profile of the junk slot.

2. The drill bit of claim 1, wherein the at least one diverter is attached to one of the at least two blades.

3. The drill bit of claim 1, wherein the at least one diverter is attached the profile of the junk slot.

4. The drill bit of claim 1, wherein the at least one diverter is attached to the body by one selected from the group consisting of welding, brazing, fastening, adhesively bonding and integrally forming with the body.

5. The drill bit of claim 1, wherein the at least one diverter is configured to divert cuttings radially outwardly of a rotational axis of the drill bit.

6. The drill bit of claim 1, wherein the at least one diverter is configured to divert cuttings away from a wall of the at least two blades.

7. The drill bit of claim 1, wherein the at least one diverter extends from a surface of one of the at least two blades by ⅛ to ½ inch.

8. The drill bit of claim 1, wherein the at least one diverter is configured to divert cuttings to travel in a direction more parallel to the profile of the junk slot.

9. The drill bit of claim 1, wherein a surface of the diverter is curved.

10. The drill bit of claim 9, wherein curvature of the surface increases a redirection of cuttings contacting therewith as the cuttings move along the surface.

11. The drill bit of claim 1, wherein a surface of the diverter is non-curved and angled in relation to the cutter.

12. The drill bit of claim 1, wherein each of the at least one diverter is in operable communication with the at least one cutter.

13. The drill bit of claim 1, wherein the at least one diverter is selected from the group consisting of metal, ceramic and polymer.

14. The drill bit of claim 1, wherein the at least one diverter is a polymer fabricated by molding.

15. The drill bit of claim 1, wherein the trajectory is radially outwardly.

16. A method of routing cuttings through a junk slot of a drill bit while drilling, comprising:

positioning at least one diverter downstream of at least one cutter and upstream of a junk slot; and

altering a direction of travel of cuttings cut by the at least one cutter to increase an angle of incidence with a profile of the junk slot.

17. The method of routing cuttings through a junk slot of a drill bit while drilling of claim 16, wherein the altering a direction of travel of cuttings includes contacting the at least one diverter with the cuttings.

18. The method of routing cuttings through a junk slot of a drill bit while drilling of claim 16, wherein the altering a direction of travel of cuttings includes aligning a trajectory of the cuttings with a desired flow path through the junk slot.

19. A drill bit cuttings diverter, comprising a surface positioned substantially between at least one cutter and a junk slot profile of a drill bit, the surface being configured to increase an angle of incidence between a trajectory of the cuttings and the junk slot profile.

20. The drill bit cuttings diverter of claim 19, wherein the surface is curved.

21. The drill bit cuttings diverter of claim 19, wherein the surface is attached to a body of the drill bit.

22. The drill bit cuttings diverter of claim 19, wherein the surface is integral with a body of the drill bit.