US20180252044A1

US20180252044A1 - Earth-boring tools including bearing element assemblies, and related methods

Info

Publication number: US20180252044A1
Application number: US15/972,537
Authority: US
Inventors: Brian E. Miller; Michael L. Doster; Kenneth R. Evans; Jason E. Hoines; Oliver Matthews; Chaitanya K. Vempati
Original assignee: Baker Hughes Inc
Current assignee: Baker Hughes Holdings LLC
Priority date: 2014-05-13
Filing date: 2018-05-07
Publication date: 2018-09-06
Also published as: US20150330153A1

Abstract

An earth-boring tool includes a body comprising a pocket in a leading end thereof for accepting at least a portion of a bearing element assembly. A bearing element assembly may be disposed within the pocket, and the bearing element assembly may include a retaining element at least partially disposed in a groove in a sidewall of the pocket and a bearing element. The bearing element may include a distal end having a bearing surface, a proximal end, and a side surface between the distal end and the proximal end, the side surface comprising a feature configured to abut the retaining element, wherein mechanical interference between the feature and the retaining element axially retains the bearing element within the pocket. Methods include disengaging a mechanical retention device retaining a bearing element within a pocket in a body of the earth-boring tool, and removing the bearing element from the pocket.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 14/276,587, filed May 13, 2014, pending. The subject matter of this application is related to the subject matter of U.S. patent application Ser. No. 15/155,470, filed May 16, 2016, pending, titled “Earth-Boring Tools Including Formation-Engaging Structures Having Retention Features and Related Methods,” which is a continuation of U.S. patent application Ser. No. 14/272,360, filed May 7, 2014, now U.S. Pat. No. 9,359,826, issued Jun. 7, 2016, titled “Formation-Engaging Structures Having Retention Features, Earth-Boring Tools Including Such Structures, and Related Methods,” to the subject matter of U.S. patent application Ser. No. 15/293,955, filed Oct. 14, 2016, pending, titled “Formation-Engaging Assemblies, Earth-Boring Tools Including Such Assemblies, and Associated Methods,” which is a continuation of U.S. patent application Ser. No. 14/272,369, filed May 7, 2014, now U.S. Pat. No. 9,476,257, issued Oct. 25, 2016, titled “Formation-Engaging Assemblies and Earth-Boring Tools Including Such Assemblies,” and to the subject matter of U.S. patent application Ser. No. 14/933,908, filed Nov. 5, 2015, pending, titled “Earth-Boring Tools Carrying Formation-Engaging Structures,” pending, the disclosure of each of which is hereby incorporated herein in its entirety by this reference.

TECHNICAL FIELD

Embodiments of the present disclosure relate to earth-boring tools including bearing element assemblies, and related methods.

BACKGROUND

Earth-boring tools are used to form boreholes (e.g., wellbores) in subterranean formations. Such earth-boring tools include, for example, drill bits, reamers, mills, etc. For example, a fixed-cutter earth-boring rotary drill bit (often referred to as a “drag” bit) generally includes a plurality of cutting elements secured to a face of a bit body of the drill bit. The cutters are fixed in place when used to cut formation materials. A conventional fixed-cutter earth-boring rotary drill bit includes a bit body having generally radially projecting and longitudinally extending blades. During drilling operations, the drill bit is positioned at the bottom of a well borehole and rotated.
A plurality of cutting elements is positioned on each of the blades. The cutting elements commonly comprise a “table” of superabrasive material, such as mutually bound particles of polycrystalline diamond, formed on a supporting substrate of a hard material, such as cemented tungsten carbide. Such cutting elements are often referred to as “polycrystalline diamond compact” (PDC) cutting elements or cutters. The plurality of PDC cutting elements may be fixed within cutting element pockets formed in rotationally leading surfaces of each of the blades. Conventionally, a bonding material, such as a braze alloy, may be used to secure the cutting elements to the bit body.
Some earth-boring tools may also include bearing elements that may limit the depth-of-cut (DOC) of the cutting elements, protect the cutting elements from excessive contact with the formation, enhance (e.g., improve) lateral stability of the tool, or perform other functions or combinations of functions. The bearing elements conventionally are located entirely rotationally behind associated leading cutting elements to limit DOC as the bearing elements contact and ride on an underlying earth formation, although bearing elements rotationally leading cutting elements are also known.

BRIEF SUMMARY

In one aspect of the disclosure, an earth-boring tool includes a body with a pocket in a leading end thereof for accepting at least a portion of a bearing element assembly. A bearing element assembly is disposed within the pocket, and the bearing element assembly includes a retaining element at least partially disposed in a groove in a sidewall of the pocket and a bearing element. The bearing element includes a distal end having a bearing surface, a proximal end, and a side surface between the distal end and the proximal end. The side surface includes a feature configured to abut the retaining element, and mechanical interference between the feature and the retaining element axially retains the bearing element within the pocket.
In another aspect of the disclosure, an earth-boring tool includes a body with a threaded receptacle in a leading end thereof for accepting at least a portion of a bearing element assembly. A bearing element assembly is disposed within the threaded receptacle, and the bearing element assembly may include a holder with a receptacle at a distal end thereof for receiving a bearing element, a threaded outer surface at a proximal end thereof for engagement with the threaded receptacle in the body of the earth-boring tool, and at least one feature proximate the distal end of the holder configured to interface with a tool adapted to apply torque to the holder.
In yet another aspect of the disclosure, a method of replacing a bearing element of an earth-boring tool includes disengaging a mechanical retention device retaining a first bearing element within a pocket in a body of the earth-boring tool, removing the first bearing element from the pocket, placing a second bearing element in the pocket, wherein the second bearing element comprises at least one of a shape of a bearing surface and an exposure of a bearing surface different from the first bearing element, and engaging the mechanical retention device to retain the second bearing element within the pocket.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present invention, various features and advantages of disclosed embodiments may be more readily ascertained from the following description when read with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an earth-boring drill bit with bearing element assemblies of the disclosure;

FIG. 2 is a side cross-sectional view of a bearing element assembly of the disclosure;

FIG. 3 is a side cross-sectional view of another bearing element assembly of the disclosure;

FIG. 4 is a side cross-sectional view of another bearing element assembly of the disclosure;

FIG. 5 is a side cross-sectional view of a bearing element assembly and sleeve of the disclosure;

FIG. 6 is a side cross-sectional side of another bearing element assembly and sleeve of the disclosure;

FIG. 7 is a perspective view of another bearing element assembly of the disclosure disposed in a blade of an earth-boring tool;

FIG. 8 is a perspective view of another bearing element assembly of the disclosure;

FIG. 9 is a perspective view of another bearing element assembly of the disclosure; and

FIG. 10 is a perspective view of the bearing element assembly of FIG. 9 installed in an earth-boring drill bit.

DETAILED DESCRIPTION

The illustrations presented herein are not actual views of any particular material, bearing element assembly, or earth-boring tool, but are merely idealized representations employed to describe embodiments of the present disclosure. Additionally, elements common between figures may retain the same numerical designation.
As used herein, the term “bearing element” means an element configured to be mounted on a body of an earth-boring tool, such as a drill bit, and to rub against a formation as the body of the earth-boring tool is rotated within a wellbore. Bearing elements include, for example, what are referred to in the art as depth-of-cut (DOC) control elements. Bearing elements do not include conventional PDC cutting elements configured to cut formation material by a shearing mechanism.
FIG. 1 is a perspective view of an embodiment of an earth-boring tool 100 of the present disclosure. The earth-boring tool 100 of FIG. 1 is configured as an earth-boring rotary drill bit. The earth-boring tool 100, more specifically, comprises a drag bit having a plurality of cutting elements 102 affixed to a body 104 of the earth-boring tool 100. The earth-boring tool 100 also includes one or more bearing element assemblies 106 that are attached to the body 104. The present disclosure relates to embodiments of earth-boring tools including bearing element assemblies 106 that enable replacement of bearing elements without returning the bit to a manufacturing facility, (i.e., embodiments that enable replacement in the field of use), and without requiring a brazing process to mount the bearing element to the body 104 of the earth-boring tool 100. The bearing element assemblies 106 may include features that interact with features of the earth-boring tool 100 to facilitate retention of the bearing element assemblies 106 within the earth-boring tool 100 and removal of the bearing element assemblies 106 from the earth-boring tool 100, as discussed in further detail below.
The body 104 of the earth-boring tool 100 may be secured to a shank 108 having a threaded connection portion 110, which may conform to industry standards, such as those promulgated by the American Petroleum Institute (API), for attaching the earth-boring tool 100 to a drill string (not shown).
The body 104 may include internal fluid passageways that extend between fluid ports 112 at the face of the body 104 and a longitudinal bore that extends through the shank 108 and partially through the body 104. Nozzle inserts 114 may be secured within the fluid ports 112 of the internal fluid passageways. The body 104 may further include a plurality of blades 116 that are separated by fluid courses 118, which may be referred to in the art as “junk slots.” In some embodiments, the body 104 may include gage wear plugs 120, wear knots 122, or both.
Each bearing element assembly 106 may be positioned on a blade 116 to rotationally trail at least one cutting element 102, as shown in FIG. 1. In some embodiments, the bearing element assemblies 106 may be positioned to rotationally follow cutting elements 102 on the same blade 116 at the same radius from the center of the earth-boring tool 100, or may be disposed at positions intermediate at least two cutting elements 102 along a radial axis. The bearing element assemblies 106 may be formed partially or fully of a wear-resistant material, such as cemented tungsten carbide, or distal ends thereof may comprise a wear-resistant material, such as cemented tungsten carbide or a superabrasive material such as polycrystalline diamond or cubic boron nitride. The wear-resistant material may comprise a coating or particles of the wear-resistant material over an entirety of the distal end, or inserts of the wear-resistant material embedded in a surface of the distal end.
Bearing element assemblies like the bearing element assemblies 106 may serve to limit the depth-of-cut (DOC) of the cutting elements 102. Drilling characteristics of a particular bit, such as DOC, may depend on exposure of bearing surfaces of the bearing element assemblies 106. Thus, bearing element assemblies having different exposures may impart different drilling characteristics to a particular bit design. Conventionally, bearing elements similar to bearing element assemblies 106 may be brazed into pockets in the earth-boring tool 100. Replacement of brazed bearing elements typically requires the earth-boring tool 100 to be returned to a manufacturing facility where the bit body may undergo heat cycles during a brazing process. Embodiments of the present disclosure relate to earth-boring tools and bearing element assemblies that enable replacement of the bearing element assemblies in the field of use.
Referring now to FIG. 2, a bearing element assembly 200 is shown disposed within a pocket 202 of a blade 204 of an earth-boring tool 100 (FIG. 1). The bearing element assembly 200 may include a bearing element 201 and a retaining element 216. The bearing element 201 may include a distal end 206 with a bearing surface 208. The bearing surface 208 may have a convex shape, such as a shape generally defined by a portion of a sphere. In some embodiments, the bearing surface 208 may be substantially hemispherical, substantially conical, or chisel-shaped. A bearing element assembly such as bearing element assembly 200 may be referred to in the art as an “ovoid.” In some embodiments, the bearing surface 208 may comprise an asymmetrical shape.
The bearing element 201 may comprise a proximal end 210 and a side surface 212 between the distal end 206 and the proximal end 210. The side surface 212 may also be characterized as a sidewall. In the embodiment shown in FIG. 2, the side surface 212 may comprise a circular transverse cross-sectional shape, imparting to the side surface 212 a substantially cylindrical shape. In other embodiments, the transverse cross-sectional shape may include, without limitation, other shapes such as ellipses, polygons, and shapes including both arcuate and rectilinear portions.
The pocket 202 may have a transverse cross-sectional shape generally similar to the transverse cross-sectional shape of the side surface 212 of the bearing element assembly 200. In some embodiments, the side surface 212 may be sized such that the bearing element 201 fits within the pocket 202 with an interference fit. In other embodiments, the side surface 212 and the pocket 202 may be sized such that a clearance exists between the side surface 212 of the bearing element 201 and a sidewall 203 of the pocket 202. Such a clearance may be provided intentionally to ease insertion and removal of the bearing element assembly 200, or the clearance may be the result of inaccuracy inherent in the manufacturing process.
The sidewall 203 of the pocket 202 may include a groove 214 in a plane generally normal to a central axis A_cof the pocket 202. The groove 214 may be substantially annular. A retaining element 216 may be at least partially disposed within the groove 214. The retaining element 216 may also be characterized as a mechanical retention device. As a non-limiting example, the retaining element 216 may have a substantially circular transverse cross-sectional shape (i.e., in the cross-section of FIG. 2) and partially surround a portion of the periphery of the side surface 212. In other words, the retaining element 216 may be substantially annularly shaped, but may include a gap to allow circumferential expansion and contraction of the retaining element 216. The retaining element 216 may have any suitable transverse cross-sectional shape, such as arcuate shapes, linear shapes, and combinations thereof. The retaining element 216 may comprise a resilient material, such as a steel alloy.
The side surface 212 of the bearing element 201 may include a feature against which a portion of the retaining element 216 may abut to retain the bearing element 201 within the pocket 202. For example, a portion of the retaining element 216 may extend from the groove 214 and into a recess 218 in the side surface 212 of the bearing element 201. Mechanical interference between the retaining element 216, a surface of the blade 204 within the groove 214, and a portion 220 of the side surface 212 of the bearing element 201 within the recess 218 may retain the bearing element 201 within the pocket 202.
One or more removal access holes may extend through an exterior surface of the blade 204 and intersect at least a portion of the pocket 202. For example, one or more channels 222 may be disposed in the sidewall 203 of the pocket 202. For example, the one or more channels 222 may extend into a surface of the blade 204 in a direction substantially parallel to the central axis A_cof the pocket 202, and may intersect the pocket 202 adjacent a portion of the side surface 212 of the bearing element assembly 200. The one or more channels 222 may be configured to accept a removal tool used to facilitate removal of the bearing element assembly 200 from the pocket 202 of the blade 204, as will be described in greater detail below. The one or more channels 222 may be spaced equidistantly about a circumference of the pocket 202. For example, in the embodiment of FIG. 2, two channels 222 may be spaced one hundred eighty degrees (180°) apart.
The side surface 212 of the bearing element 201 may include a notch 224 positioned adjacent the one or more channels 222. As a non-limiting example, the notch 224 may have an annular shape, i.e., the notch 224 may extend around a circumference of the side surface 212 of the bearing element 201.
To remove the bearing element 201 from the pocket 202 of the blade 204, an operator may insert a tool (e.g., a prying tool, such as a pry bar or flat-bladed screwdriver, or a pulling tool, such as a multi jawed puller) into the one or more channels 222, such that a portion of the tool rests within the notch 224 in the side surface 212. Using the tool, the operator may apply a force F generally parallel to the central axis A_cof the pocket 202, e.g., by prying or pulling against the bearing element 201 within the notch 224. Under the applied force F, a portion of the side surface 212 within the recess 218 may bear against the retaining element 216 and urge the retaining element 216 to expand circumferentially into the groove 214. The retaining element 216 may move free of the recess 218 to enable removal of the bearing element 201 from the pocket 202. The retaining element 216 may be left within the groove 214, or may be circumferentially compressed and removed from the groove 214 and the pocket 202. A replacement retaining element may be inserted into the pocket 202 and into the groove 214.
A replacement bearing element may be inserted into the pocket 202 by the operator. As shown in FIG. 2, the bearing element 201 may include a chamfered edge 226 in the side surface 212 adjacent the proximal end 210. As the bearing element 201 is inserted into the pocket 202, the chamfered edge 226 may cause the retaining element 216 to expand circumferentially into the groove 214 and slide along the side surface 212. When the bearing element 201 is fully inserted into the pocket 202, the retaining element 216 may circumferentially contract such that a portion of the retaining element 216 is disposed within the recess 218, as described above.
When necessary, the operator may replace the bearing element 201 with another bearing element having different characteristics, e.g., a different exposure or shape of the bearing surface 208, to impart to the earth-boring tool 100 (FIG. 1) different drilling characteristics.
Referring now to FIG. 3, an embodiment of a bearing element assembly 300 is shown. The bearing element assembly 300 may include a bearing element 301 and a retaining element 324. The bearing element assembly 300 may be disposed in a pocket 302 of a blade 304 of an earth-boring tool (e.g., earth-boring tool 100 shown in FIG. 1). The bearing element 301 may include a distal end 306 with a bearing surface 308. The bearing surface 308 may include any of the materials, shapes, and characteristics discussed above. The bearing element 301 may include a proximal end 310 and a side surface 314 between the distal end 306 and the proximal end 310.
A feature such as a flange 316 may extend from the side surface 314. As a non-limiting example, the flange 316 may be substantially annular. The pocket 302 may be shaped to receive the flange 316. For example, the pocket 302 may include a first portion 318 having a first diameter D₁, the first portion 318 extending a first depth Dp₁into the blade 304 along a central axis A_cof the pocket 302. The pocket 302 may have a second portion 320 having a second diameter D₂, the second portion 320 extending a second depth Dp₂into the blade 304 along the central axis A_c. The first diameter D₁may be greater than the second diameter D₂, and the first depth Dp₁may be less than the second depth Dp₂. The first diameter D₁may be substantially the same as a diameter of the flange 316, and the flange 316 may be substantially received within the first portion 318 of the pocket 302.
The first portion 318 of the pocket 302 may include a groove 322 in a sidewall thereof. A retaining element 324 may be disposed at least partially within the groove 322. In this embodiment, the groove 322 is substantially annular in shape. The retaining element 324 may abut a portion of the flange 316 to retain the bearing element 301 within the pocket 302. As a non-limiting example, the retaining element 324 may be a spiral snap ring. In other embodiments, the retaining element may be an internal split snap ring (which may be referred to in the art as a “circlip”).
One or more removal access holes may extend through an exterior surface of the blade 304 and intersect the pocket 302 adjacent a portion of the bearing element 301. For example, the one or more removal access holes may be defined by one or more channels 326 disposed in a sidewall 303 of the pocket 302. The one or more channels 326 may extend from an exterior surface of the blade 304 into the blade 304 in a direction generally parallel to the central axis A_cof the pocket 302. The one or more channels 326 may intersect the first portion 318 of the pocket 302 adjacent a portion of the flange 316. The one or more channels 326 may be equidistantly spaced around a circumference of the pocket 302. For example, three channels 326 may be spaced about one hundred twenty degrees (120°) apart.
To remove the bearing element 301, an operator may remove the retaining element 324 by, e.g., prying an end of the retaining element 324 out of the groove 322 and gradually prying the retaining element 324 from the groove 322 around a circumference thereof in the case of a spiral snap ring. As another example, the operator may use snap ring pliers or a similar tool to circumferentially contract a split ring and remove it from the groove 322. A removal tool such as a prying or pulling tool as described above may be inserted into the one or more channels 326, such that a portion of the removal tool contacts a proximal surface 328 of the flange 316. Using the tool, the operator may apply a force F generally along the central axis A_c, e.g., by prying or pulling, to release the bearing element 301 from the pocket 302.
Referring now to FIG. 4, a bearing element assembly 400 may be disposed within a pocket 402 of a blade 404. The bearing element assembly 400 may include a bearing element 401 and a retaining element 416. A removal access hole may be defined by a bore 406 that extends through an exterior surface of the blade 404 and intersects a floor 408 of the pocket 402 adjacent a proximal surface 410 of the bearing element 401. The pocket 402 may include a groove 414 in a sidewall thereof, and a retaining element 416 at least partially disposed within the groove 414 and contacting a recess 418 in a side surface 412 of the bearing element 401.
To remove the bearing element 401 from the pocket 402, an operator may insert a portion of a tool 420 into the bore 406. For example, the tool 420 may be a tool with an elongated shank at a working end, such as a pin punch. The operator may drive the tool 420 into the bore 406 until the tool abuts the proximal surface 410 of the bearing element 401. Driving the tool 420 further into the bore 406 may cause the tool 420 to bear against the proximal surface 410 of the bearing element 401 and force the bearing element 401 from the pocket 402.
In some embodiments of the present disclosure, bearing element assemblies may include a bearing element disposed within a receptacle of a holder. The holder may include a mechanical retention device (e.g., a threaded outer surface configured to interface with a threaded receptacle in a blade of an earth-boring tool 100 (FIG. 1)) to enable retention and replacement of the bearing element assemblies.
For example, referring now to FIG. 5, a bearing element assembly 500 may include a bearing element 502 and a holder 504. The bearing element 502 may have a bearing surface 503 including any of the shapes and materials discussed above in connection with bearing surface 208 (FIG. 2). The holder 504 may include a distal end 506 with a receptacle 508 in which the bearing element 502 is disposed. The bearing element 502 may be affixed within the receptacle 508 by brazing, an interference fit, adhesives, or other methods. The holder 506 may include a proximal end 510 with a threaded outer surface 512, which may also be characterized as a threaded shank. In other embodiments, the bearing element assembly 500 may be a unitary structure, i.e., the bearing element 502 and the holder 504 may be formed as a single component.
In FIG. 5, the threaded outer surface 512 is shown threaded into a sleeve 514 with a threaded inside diameter 516 and a substantially smooth outside diameter 518. The sleeve 514 may be received (e.g., affixed) within a pocket of a blade of an earth-boring tool to form a threaded receptacle, as described below in connection with FIG. 7.
A mechanical locking device 520 may be disposed between a distal surface 522 of the sleeve 514 and a proximal surface 524 of the holder 504. The mechanical locking device 522 may include, as non-limiting examples, a locking washer such as a split washer or star washer, a Belleville (i.e., conical) washer, or other locking washers.
Referring now to FIG. 6, a bearing element assembly 600 may include a bearing element 602 and a holder 604. The holder 604 may include a distal end 606 with a receptacle 608 in which the bearing element 602 may be disposed. The holder 604 may include a proximal end 610 with a threaded outer surface 612. The threaded outer surface 612 may be threaded into a sleeve 614 with a threaded inside diameter 616 and a substantially smooth outside diameter 618.
The holder 604 may include a conical portion 620 between the distal end 606 and the proximal end 610. The sleeve 614 may include a corresponding conical surface 622 on an inner diameter at a location distal to the threaded inside diameter 616. Contact between the conical portion 620 of the holder 604 and the conical surface 622 of the sleeve 614 may enhance (e.g., increase) a frictional force between the holder 604 and the sleeve 614, preventing the holder 604 from rotating relative to the sleeve 614 and consequently loosening from the sleeve 614.
Referring now to FIG. 7, a bearing element assembly 700 similar to bearing element assemblies 500 and 600 (FIGS. 5 and 6) is shown disposed within a threaded receptacle 702 of a blade 704. The bearing element assembly 700 may include features configured to interface with a tool adapted to apply torque to the bearing element assembly 700. As a non-limiting example, the bearing element assembly 700 may include surfaces arranged in a hexagonal pattern (e.g., wrench flats 706) for interfacing with a tool such as a socket wrench. It should be understood that any known feature, shape, surface, or configuration thereof that enables the bearing element assembly 700 to interface with a tool adapted to apply torque to the bearing element assembly 700 is within the scope of the present disclosure.
The threaded receptacle 702 of the blade 704 may include a pocket 708 and a sleeve 710 disposed in the pocket 708. The sleeve 710 may be similar to sleeves 514 and 614 described above with reference to FIGS. 5 and 6, respectively. In some embodiments, the sleeve 710 may be brazed within the pocket 708.
The pocket 708 may include a slot 712 adjacent an outside diameter 718 of the sleeve 710. The slot 712 may extend through the blade 704 to expose a portion of the outside diameter 718 of the sleeve 710, as shown in FIG. 7. The slot 712 may provide an access location for brazing the sleeve into the pocket 708. For example, heat and braze material may be applied to the outside diameter 718 of the sleeve 710 through the slot 712 as the sleeve 710 is rotated to ensure the braze material is distributed around substantially the entire outside diameter 718 of the sleeve 710.
To remove the bearing element assembly 700 from the blade 704, an operator may place a tool, e.g., a socket wrench, over the wrench flats 706 and apply a rotational force with the tool to the bearing element assembly 700. The operator may remove the bearing element assembly 700 from the sleeve 710 and pocket 708. The operator may place a replacement bearing element assembly 700 within the pocket 708 and use the tool to tighten threads (e.g., threaded shank 512, 612 of holders 504, 604 shown in FIGS. 5 and 6, respectively) of the bearing element assembly 700 into a threaded inside diameter (e.g., 516, 616 of FIGS. 5 and 6) of the sleeve 710. As described above, the bearing element assembly 700 may be replaced when necessitated by damage, or when changed drilling conditions require different bit characteristics that can be obtained by replacing the bearing element assembly 700 with a bearing element assembly having a different exposure of a bearing surface (e.g., bearing surface 503 (FIG. 5)).
FIG. 8 shows another embodiment of a bearing element assembly 800 according to the disclosure. The bearing element assembly 800 includes a bearing element 802 and a holder 804. The bearing element 802 may exhibit an exposure above the holder 804 that may be chosen based on the desired bit depth-of-cut characteristics, as described above. The holder 804 may comprise one or more notches 806 configured to interface with a tool adapted to apply torque to the holder 804. For example, the one or more notches 806 may be arranged around a periphery of the holder 804 and may be configured to receive protrusions of a tool (e.g., protrusions on a wrench or a socket wrench specially configured to interface with the notches 806). The holder 804 may include a threaded outer surface 808 configured to interface with threads of a threaded receptacle in an earth-boring tool 100 (FIG. 1). The threaded receptacle may include a pocket and a threaded sleeve, e.g., pocket 708 and threaded sleeve 710 (FIG. 7), or the threaded receptacle may include threads formed directly in the body of the earth-boring tool 100. Such threads may be machined in a bit body comprising a metal alloy, e.g., a steel-bodied bit, or may be cast in a bit body comprising a particle-matrix composite material.
The threaded outer surface 808 may be configured substantially identically to an outer surface of a nozzle insert 114 (FIG. 1) also mounted on the earth-boring tool 100. In other words, the lateral exterior side surfaces of the holder 804 may have a configuration (size, shape, and dimensions) substantially similar, or even identical to the exterior side surfaces of at least one nozzle insert 114 also mounted to the earth-boring tool 100. For example, parameters such as a diameter and thread shape of the threaded outer surface may be substantially identical to the diameter and thread shape of the outer surface of the nozzle insert 114. Accordingly, a drill bit manufacturer may use methods and tooling associated with the production of nozzle inserts 114 and threaded interiors of fluid ports 112 (FIG. 1) to produce bearing element holders, e.g., bearing element holders 804, and threaded receptacles in bit bodies as described above. Thus, such bearing element holders and threaded receptacles in bit bodies may be produced economically, as the drill bit manufacturer may not have to make a significant investment in new or additional tooling.
Referring now to FIG. 9, a bearing element assembly 900 includes a bearing element 902 disposed in a holder 904, the bearing element 902 having an elongated side surface 910 and one or more fluid outlets 912 in communication with an internal fluid passageway 914 (indicated with broken lines). The internal fluid passageway 914 may extend through a proximal end 916 of the bearing element assembly 900. The bearing element assembly 900 may include a threaded outer surface 908 configured substantially identically to an outer surface of a nozzle insert, e.g., nozzle insert 114 (FIG. 1). In other words, the bearing element assembly 900 may be configured to be threaded into fluid ports 112 (FIG. 1) in place of nozzle inserts 114. Fluid flow from the fluid ports 112 may flow into the internal fluid passageway 914 and exit the one or more fluid outlets 912. A height H of the elongated side surface 906 may be chosen so that the bearing element 902 extends from the fluid port 112 a sufficient distance to limit the DOC of cutting elements 102 (FIG. 1) a desired amount. As a non-limiting example, the holder 904 may include notches 906 configured to interface with a tool adapted to apply torque to the holder 904, as described in FIG. 8 in connection with notches 806.
Referring now to FIG. 10, a bearing element assembly 1000 similar to the bearing element assembly 900 described in connection with FIG. 9 is shown installed in an earth-boring tool 1002. The bearing element assembly 1000 may be installed in a fluid port 1004 disposed in the bottom surface within a fluid course 1006 between blades 1008 of the earth-boring tool 1002. The bearing element assembly 1000 may extend from the fluid port 1004 toward leading ends 1010 of the blades 1008 a distance sufficient to limit a DOC of cutting elements 1012 disposed in the leading ends 1010 of the blades 1008. During use, a flow of drilling fluid exiting the fluid port 1004 may flow into an internal fluid passageway (not shown) in the bearing element assembly 1000 similar to internal fluid passageway 910 described above in connection with FIG. 9. The fluid may flow from outlet ports 1014 and into the fluid course 1006 to flush formation cuttings and drilling debris away from the blades 1008 and cutting elements 1012.
Additional non-limiting example embodiments of the disclosure are set forth below.

Embodiment 1

An earth-boring tool, comprising: a body comprising a pocket in a leading end thereof for accepting at least a portion of a bearing element assembly; and a bearing element assembly disposed within the pocket, the bearing element assembly comprising: a retaining element at least partially disposed in a groove in a sidewall of the pocket; and a bearing element comprising: a distal end having a bearing surface; a proximal end; and a side surface between the distal end and the proximal end, the side surface comprising a feature configured to abut the retaining element, wherein mechanical interference between the feature and the retaining element axially retains the bearing element within the pocket.

Embodiment 2

The earth-boring tool of Embodiment 1, further comprising at least one removal access hole extending through an exterior surface of the body and intersecting the pocket, wherein the at least one removal access hole is configured to receive a removal tool.

Embodiment 3

The earth-boring tool of Embodiment 2, wherein the at least one removal access hole is defined by a channel in the sidewall of the pocket and extending in a direction substantially parallel to a central axis of the pocket.

Embodiment 4

The earth-boring tool of Embodiment 3, wherein the at least one removal access hole comprises a plurality of channels spaced equidistantly around the sidewall of the pocket.

Embodiment 5

The earth-boring tool of Embodiment 3 or Embodiment 4, wherein the side surface of the bearing element comprises a notch adjacent the channel.

Embodiment 6

The earth-boring tool of any one of Embodiments 2 through 5, wherein the at least one removal access hole comprises a bore extending through an exterior surface of the body and intersecting the pocket.

Embodiment 7

The earth-boring tool of Embodiment 6, wherein the bore intersects the pocket adjacent a proximal surface of the bearing element.

Embodiment 8

The earth-boring tool of any one of Embodiments 1 through 7, wherein the protrusion comprises a substantially annular flange extending laterally from the side surface of the bearing element.

Embodiment 9

The earth-boring tool of Embodiment 8, wherein the sidewall of the pocket comprises a first portion having a first diameter extending into the body a first depth along a central axis of the pocket and a second portion having a second diameter extending into the body a second depth along the central axis of the pocket, wherein the first diameter is greater than the second diameter and the second depth is greater than the first depth.

Embodiment 10

The earth-boring tool of any one of Embodiments 1 through 7, wherein the feature comprises a portion of the side surface of the bearing element within a substantially annular recess.

Embodiment 11

The earth-boring tool of any one of Embodiments 1 through 10, wherein the earth-boring tool is a fixed-cutter rotary drill bit.

Embodiment 12

An earth-boring tool, comprising: a body comprising a threaded receptacle in a leading end thereof for accepting at least a portion of a bearing element assembly; and a bearing element assembly disposed within the threaded receptacle, the bearing element assembly comprising: a holder with a receptacle at a distal end thereof for receiving a bearing element and a threaded outer surface at a proximal end thereof for engagement with the threaded receptacle in the body of the earth-boring tool; and at least one feature proximate the distal end of the holder configured to interface with a tool adapted to apply torque to the holder.

Embodiment 13

The earth-boring tool of Embodiment 12, wherein the threaded receptacle comprises a sleeve with an at least partially threaded inner diameter and a generally smooth outer diameter, and the sleeve is disposed within a pocket of the body.

Embodiment 14

The earth-boring tool of Embodiment 12 or Embodiment 13, further comprising a slot extending from an exterior surface of the body to a portion of an outer surface of the sleeve.

Embodiment 15

The earth-boring tool of any one of Embodiments 12 through 14, wherein the threaded outer surface of the holder is configured substantially identically to an outer surface of a nozzle insert for insertion in a fluid outlet port in the body of the earth-boring tool.

Embodiment 16

The earth-boring tool of Embodiment 15, wherein the bearing element assembly comprises an internal fluid passageway in communication with a fluid port in the body of the earth-boring tool and in communication with one or more fluid outlets in a side surface of the bearing element.

Embodiment 17

A method of replacing a bearing element of an earth-boring tool, comprising: disengaging a mechanical retention device retaining a first bearing element within a pocket in a body of the earth-boring tool; removing the first bearing element from the pocket; placing a second bearing element in the pocket, wherein the second bearing element comprises at least one of a shape of a bearing surface and an exposure of a bearing surface different from the first bearing element; and engaging the mechanical retention device to retain the second bearing element within the pocket.

Embodiment 18

The method of Embodiment 17, wherein disengaging the mechanical retention device comprises rotating the bearing element relative to the pocket to disengage threads on an outer surface of the bearing element from threads in a sidewall of the pocket.

Embodiment 19

The method of Embodiment 17, wherein disengaging the mechanical retention device comprises removing a retaining element from a groove in a sidewall of the pocket.

Embodiment 20

The method of Embodiment 17, wherein disengaging the mechanical retention device comprises applying a force to a surface of the bearing element with a tool inserted in a removal access hole extending through an exterior surface of the body and intersecting the pocket.
Although the foregoing description contains many specifics, these are not to be construed as limiting the scope of the present invention, but merely as providing certain exemplary embodiments. Similarly, other embodiments of the invention may be devised, which do not depart from the spirit or scope of the present disclosure. For example, features described herein with reference to one embodiment also may be provided in others of the embodiments described herein. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the disclosed embodiments, which fall within the meaning and scope of the claims, are encompassed by the present disclosure.

Claims

1. An earth-boring tool, comprising:

a body comprising a threaded receptacle in a leading end thereof for accepting at least a portion of a bearing element assembly; and

a bearing element assembly located within the threaded receptacle, the bearing element assembly comprising:

a holder with a receptacle at a distal end thereof for receiving a bearing element and a threaded outer surface at a proximal end thereof for engagement with the threaded receptacle in the body of the earth-boring tool; and

at least one feature proximate the distal end of the holder configured to interface with a tool configured to apply torque to the holder.

2. The earth-boring tool of claim 1, wherein the threaded receptacle comprises a sleeve with an at least partially threaded inner diameter and a generally smooth outer diameter, and the sleeve is affixed within a pocket of the body.

3. The earth-boring tool of claim 2, further comprising a slot extending from an exterior surface of the body to a portion of an outer surface of the sleeve.

4. The earth-boring tool of claim 1, wherein the threaded outer surface of the holder is configured substantially identically to an outer surface of a nozzle insert for insertion in a fluid outlet port in the body of the earth-boring tool.

5. The earth-boring tool of claim 4, wherein the bearing element assembly comprises an internal fluid passageway in communication with a fluid port in the body of the earth-boring tool and in communication with one or more fluid outlets in a side surface of the bearing element.

6. The earth-boring tool of claim 2, wherein the holder comprises a conical portion, and the sleeve comprises a corresponding conical surface on an inner surface thereof.

7. The earth-boring tool of claim 1, wherein the body of the earth-boring tool comprises:

a plurality of generally radially projecting and longitudinally extending blades rotationally separated by fluid courses; and

at least one cutting element attached to one of the plurality of blades.

8. The earth-boring tool of claim 7, wherein the bearing element is a non-cutting bearing element positioned and oriented on the body as a rubbing surface configured to rub against a formation as the body of the earth-boring tool is rotated within a wellbore, the bearing element assembly located rotationally behind the at least one cutting element on the one of the plurality of blades.

9. The earth-boring tool of claim 7, wherein the bearing element assembly is located within one of the fluid courses between adjacent blades of the plurality of blades.

10. The earth-boring tool of claim 1, wherein the threaded receptacle in the leading end of the body comprises a removal access hole configured to receive the tool.

11. The earth-boring tool of claim 1, wherein the body of the earth-boring tool comprises a metal alloy, and the threaded receptacle comprises threads machined directly into an inner surface of a cavity of the body.

12. The earth-boring tool of claim 1, wherein the bearing element and the holder comprise an integral unitary body.

13. The earth-boring tool of claim 1, wherein the at least one feature comprises surfaces of the bearing element assembly arranged in a hexagonal pattern and configured to interface with a socket wrench.

14. The earth-boring tool of claim 1, wherein the at least one feature comprises at least one notch arranged around a periphery of the holder, the at least one notch configured to receive protrusions of the tool.

15. A method of replacing a bearing element of an earth-boring tool, comprising:

disengaging a mechanical retention device retaining a first bearing element within a pocket in a body of the earth-boring tool by rotating the bearing element relative to the pocket to disengage threads on an outer surface of the bearing element from threads in a sidewall of the pocket;

removing the first bearing element from the pocket;

placing a second bearing element in the pocket, wherein the second bearing element comprises at least one of a shape of a bearing surface and an exposure of a bearing surface different from the first bearing element; and

engaging the mechanical retention device to retain the second bearing element within the pocket.

16. The method of claim 15, wherein disengaging the mechanical retention device comprises applying a force to a surface of the bearing element with a tool inserted in a removal access hole extending through an exterior surface of the body and intersecting the pocket.

17. The method of claim 16, wherein applying the force to the surface of the bearing element with the tool inserted in the removal access hole comprises inserting the tool into the removal access hole extending through a leading end of the body.

18. The method of claim 15, wherein disengaging the mechanical retention device comprises rotating the bearing element relative to a sleeve within the pocket in the body of the earth-boring tool to disengage the threads on the outer surface of the bearing element from threads in an inner sidewall of the sleeve.

19. The method of claim 15, wherein:

removing the first bearing element comprises removing a first non-cutting bearing element; and

placing the second bearing element comprises placing a second non-cutting bearing element, each of the first non-cutting bearing element and the second non-cutting bearing element being positioned and oriented on the body as a rubbing surface configured to rub against a formation as the body of the earth-boring tool is rotated within a wellbore.

20. The method of claim 15, wherein engaging the mechanical retention device comprises securing the second bearing element with a mechanical locking device.