Earth-boring tools including cutting elements having different characteristics in different regions of the earth-boring tools

Abstract

Cutting elements generally having different characteristics may be deployed in different regions of earth-boring tools, including the cone region, the nose region, and the shoulder region. Examples of such characteristics include: total chamfer thickness, concavity angle, greatest concavity depth, greatest tip width, tip angle, brim width, brim inner angle, and plow angle. One or more of the foregoing characteristics may vary from cone region to nose region, from nose region to shoulder region, or from cone region, to nose region, and to shoulder region.

Description

[0001] EARTH-BORING TOOLS INCLUDING CUTTING ELEMENTS HAVING DIFFERENT CHARACTERISTICS IN DIFFERENT REGIONS OF THE EARTH-BORING TOOLS

[0002] PRIORITY CLAIM

[0003] This application claims the benefit of the filing date of United States Patent Application Serial No. 19 / 084,522, filed March 19, 2025, for 'EARTH-BORING TOOLS INCLUDING CUTTING ELEMENTS HAVING DIFFERENT CHARACTERISTICS IN DIFFERENT REGIONS OF THE EARTH-BORING TOOLS,’’ which is a continuation-in-part of United States Patent Application Serial No. 19 / 075,042, filed March 10, 2025, titled EARTH-BORING TOOLS INCLUDING CUTTING ELEMENTS HAVING DIFFERENT CHARACTERISTICS IN DIFFERENT REGIONS OF THE EARTH-BORING TOOLS, the disclosure of each of which is hereby incorporated herein in their entireties by reference.

[0004] FIELD

[0005] This disclosure relates generally to earth-boring tools. More specifically, disclosed examples relate to earth-boring tools which may mitigate torsional excitability of an earthboring assembly, increase stability while engaging in an earth-boring operation, and increase efficiency of an earth-boring operation.

[0006] BACKGROUND

[0007] Wellbores are formed in subterranean formations for various purposes including, for example, extraction of oil and gas from the subterranean formation and extraction of geothermal heat from the subterranean formation. Wellbores may be formed in a subterranean formation using a drill bit such as, for example, an earth-boring rotary drill bit. Different types of earth-boring rotary drill bits are known in the art including, for example, fixed-cutter bits (which are often referred to in the art as “drag” bits), rolling-cutter bits (which are often referred to in the art as “rock” bits), diamond-impregnated bits, and hybrid bits (which may include, for example, both fixed cutters and rolling cutters). The drill bit is rotated and advanced into the subterranean formation. As the drill bit rotates, the cutters or abrasive structures thereof cut, crush, shear, and / or abrade away the formation material to form the wellbore. A diameter of the wellbore drilled by the drill bit may be defined by the cutting structures disposed at the largest outer diameter of the drill bit.The drill bit is coupled, either directly or indirectly, to an end of what is referred to in the art as a “drill string ’ which comprises a series of elongated tubular segments connected end-to-end that extends into the wellbore from the surface of the formation. Often various tools and components, including the drill bit, may be coupled together at the distal end of the drill string at the bottom of the wellbore being drilled. This assembly of tools and components is referred to in the art as a “bottom-hole assembly” (BHA).

[0008] The drill bit may be rotated within the wellbore by rotating the drill string from the surface of the formation, or the drill bit may be rotated by coupling the drill bit to a downhole motor, which is also coupled to the drill string and disposed proximate the bottom of the wellbore. The downhole motor may comprise, for example, a hydraulic Moineau-type motor having a shaft, to which the drill bit is mounted, that may be caused to rotate by pumping fluid (e.g., drilling mud or fluid) from the surface of the formation down through the center of the drill string, through the hydraulic motor, out from nozzles in the drill bit, and back up to the surface of the formation through the annular space between the outer surface of the drill string and the exposed surface of the formation within the wellbore.

[0009] DISCLOSURE

[0010] In some examples, earth-boring tools may include a body and cutting elements affixed to the body. The cutting elements exhibit at least two characteristics selected from: for each of the cutting elements located within a cone region of the body, a total chamfer thickness is greater than or equal to about 0.02 inch (about 0.05 cm), for each of the cutting elements located within a nose region of the body, the total chamfer thickness is in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), and for each of the cutting elements located within a shoulder region of the body, the total chamfer thickness is less than or equal to about 0.012 inch (about 0.03 cm); for each of the cutting elements located within the cone region of the body, a concavity angle defined by a shortest angular distance between a surface of a concavity7, the surface of the concavity located radially between a periphery of the concavity and a geometric center of a cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element is less than or equal to about -10°, for each of the cutting elements located within the nose region of the body, the concavity angle is in a range extending from about -10° to about 10°, and for each of the cutting elements located within the shoulder region of the body, the concavity angle is greater than or equal to about 10°; foreach of the cutting elements located within the cone region of the body, a greatest concavity depth is less than or equal to about 0 inch, for each of the cutting elements located within the nose region of the body, the greatest concavity depth is in a range extending from about 0 inch to about 0.01 inch (0.03 cm), and for each of the cutting elements located within the shoulder region of the body, the greatest concavity' depth is greater than or equal to about 0.01 inch (0.03 cm); for each of the cutting elements located within the cone region of the body, a greatest tip width defined by an angular distance over which a cutting edge extends proximate to a rotationally leading portion of the cutting element is about equal to one half of a circumference of a cutting face, for each of the cutting elements located within the nose region of the body, the tip width is in a range extending from about 0.18 divided by two times the maximum radius of the cutting face to about equal to one half of the circumference of the cutting face, and for each of the cutting elements located within the shoulder region of the body, the tip width is less than or equal to about 0.18 divided by' two times the maximum radius of the cutting face; for each of the cutting elements located w ithin the cone region of the body, a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element is about 180°, for each of the cutting elements located within the nose region of the body, the tip angle is in a range extending from about 100° to about 180°, and for each of the cutting elements located within the shoulder region of the body, the tip angle is less than or equal to about 100°; for each of the cutting elements located within the cone region of the body, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is about equal to a radius of the cutting face, for each of the cutting elements located within the nose region of the body, the brim width is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face, and for each of the cutting elements located within the shoulder region of the body, the brim width is less than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters; for each of the cutting elements located within the cone region of the body, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face is about 0°, for each of the cutting elements located within the nose region of the body, the brim inner angle is in a range extending from about 0° to about 10°, and for each of the cutting elements located within the shoulder region of the body, the brim inner angle is greater than or equalto about 10°; and for each of the cutting elements located within the cone region of the body, a plow angle is less than or equal to about 0°, for each of the cutting elements located within the nose region of the body, the plow angle is in a range extending from about 0° to about 15°, and for each of the cutting elements located within the shoulder region of the body, the plow angle is greater than or equal to about 15°.

[0011] In other examples, earth-boring tools may include a body and cutting elements affixed to the body. For each of the cutting elements located within a cone region of the body, a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavity located radially betw een a periphery’ of the concavity and a geometric center of a cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element may be less than or equal to about -10°. A greatest tip width defined by an angular distance over which a cutting edge extends proximate to a rotationally leading portion of the cutting element may be about equal to one half of a circumference of a cutting face. A plow’ angle may be less than or equal to about 0°. For each of the cutting elements located within a nose region of the body, the concavity angle may be in a range extending from about -10° to about 10°. The greatest tip width may be in a range extending from about 0.18 divided by two times the maximum radius of the cutting face to about equal to one half of the circumference of the cutting face. The plow angle may be in a range extending from about 0° to about 15°. For each of the cutting elements located within a shoulder region of the body, the concavity angle may be greater than or equal to about 10°. The greatest tip width may be less than or equal to about 0.18 divided by two times the maximum radius of the cutting face. The plow’ angle may be greater than or equal to about 15°.

[0012] In other examples, earth-boring tools may include a body and cutting elements affixed to the body. For each of the cutting elements located within a cone region of the body, a total chamfer thickness may be greater than or equal to about 0.02 inch (about 0.05 cm), a cutting face may be planar or convex, the cutting face may be at least substantially circular in peripheral shape, and a plow angle may be less than or equal to about 0°. For each of the cutting elements located within a nose region of the body, the total chamfer thickness may be in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), the cutting face may be concave, having a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavity located radially between a periphery of the concavity and a geometric center of the cutting face, and a planeoriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element in a range extending from about -10° to about 10°, and a greatest concavity depth in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm), the cutting face may be tipped in shape, having a greatest tip width defined by an angular distance over which a cutting edge extends proximate to a rotationally leading portion of the cutting element in a range extending from about 0.18 divided by two times the maximum radius of the cutting face to about equal to one half of the circumference of the cutting face and a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element in a range extending from about 100° to about 180°, the cutting face may define a brim around a concavity of the cutting face, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face may be in a range extending from about 0° to about 10°, and the plow angle may be in a range extending from about 0° to about 15°. For each of the cutting elements located within a shoulder region of the body, the total chamfer thickness may be less than or equal to about 0.012 inch (about 0.03 cm), the cutting face may be concave, having a concavity angle greater than or equal to about 10° and a greatest concavity depth greater than or equal to about 0.01 inch (about 0.03 cm), the cutting face may be tipped in shape, having a greatest tip width less than or equal to about 0.18 divided by two times the maximum radius of the cutting face and a tip angle less than or equal to about 100°, the cutting face may define a brim around a concavity of the cutting face, the brim width being greater than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters, the brim inner angle being greater than or equal to about 10°, and the plow angle may be greater than or equal to about 15°.

[0013] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0014] While this disclosure concludes with claims particularly pointing out and distinctly claiming specific examples, various features and advantages of examples within the scope of this disclosure may be more readily ascertained from the following description when read in conjunction with the accompanying drawings. In the drawings:FIG. 1 is a schematic diagram of a drilling system;

[0015] FIG. 2 is a perspective view of an earth-boring tool usable with the drilling system of FIG. 1;

[0016] FIG. 3 is a cross-sectional side view of a portion of the earth-boring tool of FIG. 2; FIG. 4 is a partially cut-away perspective view of a cutting element usable with the earth-boring tool of FIG. 2;

[0017] FIG. 5A is a simplified cross-sectional view of the cutting element of FIG. 4 engaging an underlying earth formation;

[0018] FIG. 5B is a perspective side view of another example of a cutting element;

[0019] FIG. 5C is a plan view from above another example of a cutting element;

[0020] FIG. 6 is a simplified cross-sectional side view of another example of a cutting element usable with the earth-boring tool of FIG. 2;

[0021] FIG. 7 is a front surface view of another example of a cutting element usable with the earth-boring tool of FIG. 2;

[0022] FIG. 8 is a perspective side view of another example of a cutting element usable with the earth-boring tool of FIG. 2;

[0023] FIG. 9 is a leading end, face view of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool;

[0024] FIG. 10 is a leading end, face view of another example of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool;

[0025] FIG. 11 is a leading end, face view of another example of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool;

[0026] FIG. 12 is a leading end, face view of another example of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool;

[0027] FIG. 13 is a leading end, face view of another example of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool;

[0028] FIG. 14 is a leading end, face view of another example of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool; and

[0029] FIG. 15 is a leading end. face view of another example of an earth-boring tool accompanied by views of cutting elements affixed to the earth-boring tool.MODE(S) FOR CARRYING OUT THE INVENTION

[0030] The illustrations presented in this disclosure are not meant to be actual views of any particular drill string, earth-boring tool, or component thereof, but are merely idealized representations employed to describe illustrative examples. Thus, the drawings are not necessarily to scale.

[0031] Disclosed examples relate generally to earth-boring tools which may mitigate torsional excitability of an earth-boring assembly, increase stability while engaging in an earth-boring operation, and increase efficiency of an earth-boring operation. More specifically, disclosed are examples of earth-boring tools including cutting elements having different characteristics located in different regions of the earth-boring tools, which differences in characteristics may improve stability during an earth-boring operation.

[0032] Generally speaking, earth-boring tools may rotate about an axis while performing an earth-boring operation. As a result, cutting elements deployed close to the axis will exhibit a lower velocity than the velocity of cutting elements deployed far from the axis. Because velocity significantly affects cutting dynamics, some attempts have been made to deploy cutting elements having different properties at different distances from the axis. Some approaches for doing so known to the inventors have used efficiency, often as measured by mechanical specific energy (i.e., the amount of energy input required per unit of volume of subterranean material removed), as the standard by which performance may be measured.

[0033] Such an approach toward evaluating performance may place an undue focus on energy input at the expense of other factors that may impact the overall efficiency of an earthboring operation. For example, the foregoing approach toward design of an earth-boring tool may produce an earth-boring tool whose design is susceptible to greater impact forces and abrasive wear, which may reduce the useful life of the earth-boring tool. As another example, the foregoing approach toward design of an earth-boring tool may produce an earth-boring tool whose design is susceptible to greater instability, including torsional instability. Exhibiting instability may cause an earth-boring tool to wander away from a planned trajectory, and may further induce unintended vibrations, rotations, oscillations, and other undesirable dynamic behaviors that may damage or hasten wear of the earth-boring tool or other components of the drill string.

[0034] In accordance with this disclosure, cutting elements having different characteristics may be deployed in different regions of a body of an earth-boring tool. For example, the characteristics of cutting elements within the cone region at and immediately surroundingthe axis of rotation may differ from those of cutting elements within the nose region adjacent to and radially outward from the cone region, both of which may differ from those of cutting elements within the shoulder region adjacent to and radially outward from the cone region. In some examples, the characteristics of the cutting elements within a given region may be at least substantially the same as one another. In other examples, the characteristics of the cutting elements within a region may vary, as well as varying across regions. For example, the cutting elements may generally exhibit a gradient in characteristics as distance from the axis of rotation increases.

[0035] One characteristic that may be varied may be the presence and thickness of a chamfer at the transition between a side surface of the cutting element and a rotationally leading surface of the cutting element, such as the cutting face. For example, a total chamfer thickness for each of the cutting elements located within a cone region of the body may be greater than or equal to about 0.02 inch (about 0.05 cm). For each of the cutting elements located within a nose region of the body, the total chamfer thickness may be in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm). For each of the cuting elements located within a shoulder region of the body, the total chamfer thickness may be less than or equal to about 0.012 inch (about 0.03 cm).

[0036] Another characteristic that may be varied may be a concavity angle of a concavity of the cuting face. In some examples, all or a portion of the cutting face may be convex (e.g.. have a negative concavity), may be at least substantially flat (e.g., no concavity), or may be concave (e.g., may have a positive concavity). A concavity angle may be defined by a shortest angular distance between a surface of a concavity’, the surface of the concavity located radially betw een a periphery of the concavity’ and a geometric center of a cuting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of the relevant cuting element. For each of the cuting elements located within the cone region of the body, the concavity angle may be less than or equal to about -10° (e.g., the cuting elements may be domed or pointed or at least substantially flat). For each of the cutting elements located within the nose region of the body, the concavity angle is in a range extending from about -10° to about 10° (e.g.. the surface may be convex, at least substantially flat, or concave). For each of the cuting elements located within the shoulder region of the body, the concavity angle may be greater than or equal to about 10° (e.g., the surface may be concave).Another characteristic that may be varied may be a concavity depth of a concavity' of the cutting face. For each of the cutting elements located within the cone region of the body, a greatest concavity depth may be less than or equal to about 0 inch (e.g., the cutting face or a portion thereof may be convex or at least substantially flat). For each of the cutting elements located within the nose region of the body, the greatest concavity' depth may be in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm) (e.g., the cutting face or a portion thereof may be at least substantially flat or concave). For each of the cutting elements located within the shoulder region of the body, the greatest concavity depth may be greater than or equal to about 0.01 inch (about 0.03 cm) (e.g., the cutting face may be concave or include a concavity' in a portion thereof).

[0037] Another characteristic that may be varied may be a greatest tip width of each cutting element. The greatest tip width may be defined by a distance around a circumference of a cutting face over which a cutting edge extends proximate to a rotationally leading portion of the cutting element. For each of the cutting elements located within the cone region of the body, the greatest tip width may be about equal to one half of a circumference of a cutting face. For each of the cutting elements located within the nose region of the body, the tip width may be in a range extending from about 0.18 divided by two times the maximum radius of the cutting face to about equal to one half of the circumference of the cutting face. For each of the cutting elements located within the shoulder region of the body, the tip width may be less than or equal to about 0.18 divided by two times the maximum radius of the cutting face (e.g., in a range extending from about 0.001 divided by two times the maximum radius of the cutting face inch to about 0.18 divided by two times the maximum radius of the cutting face).

[0038] Another characteristic that may be varied may be a tip angle of each cutting element. The tip angle may be defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element. For each of the cutting elements located within the cone region of the body, the tip angle may be about 180°. For each of the cutting elements located within the nose region of the body, the tip angle may be in a range extending from about 100° to about 180°. For each of the cutting elements located within the shoulder region of the body, the tip angle may be less than or equal to about 100°.

[0039] Another characteristic that may be varied may be the presence or absence and width of a brim between a periphery’ of the cutting face and a concavity of the cutting face. Foreach of the cutting elements located within the cone region of the body, the brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face may be about equal to a radius of the cutting face (e.g., there may be no brim). For each of the cutting elements located within the nose region of the body, the brim width may be in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face. For each of the cutting elements located within the shoulder region of the body, the brim width may be less than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters.

[0040] Another characteristic that may be varied may be the inner angle formed by a brim. For each of the cutting elements located within the cone region of the body, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining a concavity of the cutting face may be about 0° (e.g., there may be no brim). For each of the cutting elements located within the nose region of the body, the brim inner angle may be in a range extending from about 0° to about 10°. For each of the cutting elements located within the shoulder region of the body, the brim inner angle may be greater than or equal to about 10°.

[0041] Another characteristic that may be varied may be a plow angle of the cutting element. For each of the cutting elements located within the cone region of the body, the plow angle may be less than or equal to about 0°. For each of the cutting elements located within the nose region of the body, the plow angle may be in a range extending from about 0° to about 15°. For each of the cutting elements located within the shoulder region of the body, the plow angle may be greater than or equal to about 15°.

[0042] In some examples, the foregoing characteristics may be consistently varied across the regions of a body of a given earth-boring tool. For example, one characteristic may be selected and consistently varied across the regions of the body of an earth-boring tool. As another example, groupings of the characteristics, such as two, three, most, or all of the characteristics, may be selected and consistently varied across the regions of the body of the earth-boring tool. In other examples, the characteristics may be employed as selection criteria for cutting elements. Thus, cutting elements in the cone region may meet one or more of the criteria, those in the nose region may meet one or more of the criteria, and those in the shoulder region may meet one or more of the criteria. The criteria met in the various regions may be the same as, overlapping with, or different from one another.Earth-boring tools in accordance with this disclosure may improve efficiency of earth-boring operations performed with such earth-boring tools. For example, such earthboring tools may experience less impact damage and abrasive wear, resulting in fewer trips out of and back into a borehole to repair and / or replace the earth-boring tool. Such earthboring tools may spend less time boring away from a target trajectory, requiring less redirection and re-boring. When evaluated wholistically, including these factors and not just mechanical specific energy, such earth-boring tools may exhibit improved efficiency when compared to other designs for earth-boring tools known to the inventors.

[0043] As used in this disclosure, the term “earth-boring tool” means and includes any t pe of tool having cutting elements secured to the tool used for material removal during the creation or enlargement of a wellbore in a subterranean formation. For example, earth-boring tools include fixed-cutter bits, rolling cone bits, percussion bits, core bits, eccentric bits, bicenter bits, mills, drag bits, hybrid bits, reamers, and other drilling bits and tools known in the art.

[0044] As used in this disclosure, the terms “polycrystalline table” and “polycrystalline material” mean and include any structure or material comprising grains (e.g., crystals) of a material (e.g., a superabrasive material) that are bonded directly together by inter-granular bonds. The crystal structures of the individual grains of the material may be randomly oriented in space within the poly crystalline table. For example, polyciystalline tables include poly crystalline diamond compacts (PDCs) characterized by diamond grains that are directly bonded to one another to form a matrix of diamond material with interstitial spaces among the diamond grains.

[0045] As used herein, the term “inter-granular bond” and “interbonded” mean and include any direct atomic bond (e.g., covalent, metallic, etc.) between atoms in adjacent grains of superabrasive material.

[0046] As used herein, the term “superhard” means and includes any material having a Knoop hardness value of about 3,000 Kgf / mm2(29,420 MPa) or more. Superhard materials include, for example, diamond and cubic boron nitride. Superhard materials may also be characterized as “superabrasive” materials.

[0047] As used herein, the term “circumference,” as applied to a cutting edge around a cutting face of a cutting element, means and includes a distance around a perimeter of such cutting edge and cutting face. Though some cutting faces may be circular in shape, the term“circumference” is not used in a restrictive sense to limit cutting faces to circular shapes. Cutting faces may be ovoid, obround, tombstone, or may have other shapes.

[0048] As used herein, the term “diameter,” as applied to a cutting face of a cutting element, means and includes a distance between at least substantially equidistant points on a perimeter of the cutting face. Though some cutting faces may be circular in shape, the term “diameter” is not used in a restrictive sense to limit cutting faces to circular shapes. Cutting faces may be ovoid, obround. tombstone, or may have other shapes.

[0049] As used herein, the terms “storage device” and “memory” shall be interpreted to exclude transitory signals.

[0050] As used herein, the terms “substantially” and “about” in reference to a given parameter, property, or condition means and includes to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially or about a specified value may be at least about 90% the specified value, at least about 95% the specified value, at least about 99% the specified value, or even at least about 99.9% the specified value.

[0051] FIG. 1 through FIG. 5 depict example systems and apparatuses with which earthboring tools and their components in accordance with this disclosure may be utilized. Thus, FIG. 1 through FIG. 3 and portions of FIG. 4 and FIG. 5 are intended to provide context and enabling information to ensure that those of ordinary skill in the art have familiarity with the hardware that may be improved in accordance with this disclosure. Additional detail regarding hardware in accordance with this disclosure itself is provided in connection with FIG. 4 through FIG. 15.

[0052] FIG. 1 is a schematic diagram of an illustrative earth-boring system 100 that may utilize earth-boring tools 200 made according to the disclosure herein. FIG. 1 shows a wellbore 102 having an upper section 104 with a casing 106 installed therein and a lower section 108 being drilled with a drill string 110. The drill string 110 is shown to include a tubular member 112 with a bottom-hole-assembly 114 (BHA) attached at its leading end. The tubular member 112 may be made up by joining drill pipe sections or it may be a coiled tubing. An earth-boring tool 200 (e g., a drill bit) is shown attached to the bottom end of the BHA 114 for disintegrating the rock formation 116 to drill the wellbore 102 to a selected diameter.Drill string 110 is shown conveyed into the wellbore 102 from a rig 118 at the surface 120. The illustrative rig 118 shown is a land rig for ease of explanation. The apparatus and methods disclosed herein may also be utilized with an offshore rig used for drilling wellbores under water. A rotary table 122 or a top drive (not shown) coupled to the drill string 110 may be utilized to rotate the drill string 110 to rotate the BHA 114 and thus the earth-boring tool 200 to drill the wellbore 102. A drilling motor 124 (also referred to as the '“mud motor’7) may be provided in the BHA 114 to rotate the earth-boring tool 200. The drilling motor 124 may be used alone to rotate the earth-boring tool 200 or to superimpose the rotation of the drill bit by the drill string 110. A control unit (or controller) 126, which may be a computer-based unit, may be placed at the surface 120 to receive and process data transmitted by the sensors in the earth-boring tool 200 and the sensors in the BHA 114, and to control selected operations of the various devices and sensors in the BHA 114. The surface controller 126, in one embodiment, may include a processor 128, a data storage device (or a computer-readable medium) 130 for storing data, algorithms, and computer programs 132. The data storage device 130 may be any suitable device including, but not limited to, a readonly memory (ROM), a random-access memory (RAM), a flash memory, a magnetic tape, a hard disk, and an optical disk. During drilling, a drilling fluid 134 from a source thereof is pumped under pressure into the tubular member 112. The drilling fluid discharges at the leading end of the earth-boring tool 200 and returns to the surface via the annular space (also referred to as the “annulus”) between the drill string 110 and the inside wall 136 of the wellbore 102.

[0053] Still referring to FIG. 1, the earth-boring tool 200 includes a face section (or bottom section) 138. The face section 138, or a portion thereof, faces the formation in front of the drill bit or the wellbore bottom during drilling. The BHA 114 may further include one or more downhole sensors (collectively designated by numeral 140). The sensors 140 may include any number and type of sensors including, but not limited to, sensors generally known as the measurement-while-drilling (“MWD”) sensors or the logging-while-drilling (“LWD”) sensors, and sensors that provide information relating to the behavior of the BHA 114, such as drill bit rotation (revolutions per minute or “RPM”), tool face, pressure, vibration, whirl, bending, and stick-slip.

[0054] The BHA 114 may further include a control unit (or controller) 142 configured to control the operation of components of the BHA 114 and for at least partially processing data received from the sensors 140. The controller 142 may include, among other things, circuitsto process the sensor 140 signals (e.g., amplify and digitize the signals), a processor 144 (such as a microprocessor) to process the digitized signals, a data storage device 146 (such as a solid-state-memory), and a computer program 148. The processor 144 may process the digitized signals, control the operation of the components of the BHA 114, process data from other sensors downhole, control other downhole devices and sensors, and communicate data information with the controller 126 at the surface 120 via a two-way telemetry unit 150.

[0055] Referring to FIG. 2. a perspective view of an earth-boring tool 200 is shown. The particular earth-boring tool 200 shown may be characterized as, for example, a fixed-cutter drill bit (e.g., a drag bit). The earth-boring tool 200 may include a body 202 having a leading end 204 and a trailing end 206. At the trailing end 206, the body 202 may include a connection member 208 (e.g., an American Petroleum Institute (API) threaded connection) configured to connect the earth-boring tool 200 to a drill string. At the leading end 204, the body 202 may include blades 210 extending axially outwardly from a remainder of the body 202 and radially outw ardly from a rotational axis 212, which may also be a central axis, of the body 202 across the leading end 204. A crown 214 of the body 202 of the earth-boring tool 200 may comprise an outer surface defined by the blades 210 and the remainder of the body 202 at the leading end 204 of the body 202. Cutting elements 216 may be affixed to the body 202. For example, the cutting elements 216 may be partially located in pockets 218 formed in rotationally leading surfaces of the blades 210 and brazed to the surfaces of the blades 210 defining the pockets 218 to secure the cutting elements 216 to the body 202. The cutting elements 216 may be distributed over the crown 214 to form a cutting structure configured to engage with and remove an underlying earth formation as the earth-boring tool 200 is rotated during use. Gage pads 220 may be located at a periphery7222 of the body 202 and may define a radially outermost portion of the earth-boring tool 200 in some embodiments. In other embodiments, additional cutting elements 216 may be secured to the body' 202 at the periphery' 222 to define the radially outermost portion of the earth-boring tool 200.

[0056] Given the manner in which cutting elements 216 are affixed to the body 202, the cutting elements 216 may be replaceable. For example, a braze material affixing a given cutting element 216 to the body 202 at least partially within the pocket 218 may be reflowed responsive to the application of heat (e.g., using a torch), and the cutting element 216 may be removed from the pocket 218. The same cutting element 216, repaired or in the same state, or a different cutting element may later be affixed to the body 202 at least partiallywithin that pocket 218. This ability may enable repair and replacement of cutting elements 216 and earth-boring tools 200. Cutting elements 216 engage with and remove an underlying earth formation, which may cause the cutting elements 216 to have a substantial impact on the dynamic response of the earth-boring tool 200 during an earth-boring operation. Thus, changing cutting elements 216 may represent a less burdensome way of affecting the dynamic response of an earth-boring tool 200, as compared to a complete redesign, including the anticipated behavior of a newly designed and manufactured earthboring tool 200, as well as that of a repaired and / or retrofitted earth-boring tool 200, where one or more of the cutting elements 216 are being replaced.

[0057] Referring to FIG. 3, a cross-sectional side view of a portion of the earth-boring tool 200 of FIG. 2 is shown. The crown 214 may be defined by a series of regions extending radially outwardly from the rotational axis 212 of the body 202 to the periphery 222. For example, the crown 214 may be defined by a first cone region 302 located at and immediately surrounding the rotational axis 212. The cone region 302 may be characterized by a sloping surface extending downwardly (when the rotational axis 212 is oriented vertically with the leading end 204 facing down) and located at and immediately surrounding the rotational axis 212, which may generally resemble an inverted cone shape. A second shoulder region 304 may be located radially outward from the cone region 302 adjacent the periphery 222 of the body 202. The shoulder region 304 may be characterized by a rounded, upwardly curving surface transitioning to the periphery 222 of the body 202. A third nose region 306 may be interposed between and adjacent to both the cone region 302 and the shoulder region 304. The nose region 306 may be characterized by a transition from the sloping surface of the cone region 302 curving toward horizontal and beginning to curve upwardly into the shoulder region 304. A fourth gage region 308 may be located radially outward from and adjacent to the shoulder region 304 and may define the periphery 222 of the body 202.

[0058] In some examples, the cone region 302 may extend from about the axis 212 of rotation of the body 202 to about one-third of a maximum radius 310 of the body 202, as measured from the axis 212 of rotation to the periphery 222 in a direction at least substantially perpendicular to the axis 212 of rotation. The nose region 306 may extend, for example, from about one-third of the maximum radius 310 of the body 202 to about two-thirds of the maximum radius of the body 202. As a continued example, the shoulderregion 304 may extend from about two-thirds of the maximum radius 310 of the body 202 to about the maximum radius of the body 202.

[0059] Cutting elements 216 may be distributed radially across at least a portion of the crown 214 at the leading end 204 of the body 202. In some examples, the cutting elements 216 may be limited to cutting elements located at the rotationally leading face of a blade 210, as shown in FIG. 2. In other examples, the cutting elements 216 may include backup cutting elements rotationally trailing leading cutting elements secured to the same blade 210.

[0060] Drilling conditions in the different regions 302, 304, 306, and 308 may significantly differ from one another. For example, cutting elements 216 in the cone region 302 may be subjected to high axial forces (i.e.. forces acting in a direction parallel to the rotational axis 212 of the earth-boring tool 200) resulting from the weight forcing the earth-boring tool 200 toward the underlying earth formation (e.g., weight-on-bit (W.O.B.)) or a combination of high axial forces and high tangential forces (i.e., forces acting in a direction perpendicular to the rotational axis 212 of the earth-boring tool 200) resulting from engagement of the cutting elements 216 with the underlying earth formation, may traverse relatively short helical cutting paths with each rotation of the earth-boring tool 200, and may have a high depth of cut. Cutting elements 21 in the shoulder region 304, by contrast, may be subjected to low axial forces, and high tangential forces may traverse relatively long helical cutting paths with each rotation of the earth-boring tool 200, and may have a low depth of cut. Cutting elements 216 in the nose region 306 may experience use conditions intermediate to those present in the cone region 302 and shoulder region 304. Cutting elements in the gage region 308 may not be subjected to significant axial forces, may traverse relatively long helical paths with each rotation of the earth-boring tool 200, and may have a low depth of cut. Such differences in drilling conditions may produce stresses at different levels and oriented in different directions and operational temperatures at different intensities in the cutting elements 216 in different regions 302, 304, 306, and 308 of the crown 214 of the earth-boring tool 200.

[0061] Referring to FIG. 4, a partially cut-away perspective view of a cutting element 216 is shown. Cutting element 21 includes a substrate 402 having a table 404 of superabrasive material, such as a polycrystalline superhard material (e.g., polycrystalline diamond material), thereon. The table 404 may be formed on the substrate 402, or the table 404 and the substrate 402 may be separately formed and subsequently attached together. In someexamples, the table 404 may have a chamfer 406. The chamfer 406 of the cutting element 216 in FIG. 4 is depicted as a single chamfer surface 408, although the chamfer 406 also may have additional chamfer surfaces, and such chamfer surfaces may be oriented at chamfer angles that differ from the chamfer angle of the chamfer surface 408 shown in FIG. 4. The table 404 also has a side surface 410 extending from the chamfer surface 408 to the interface between the table 404 and the substrate 402.

[0062] The substrate 402 may have a generally cylindrical shape. A face 412 of the cutting element defined by the table 404 and located at a rotationally leading end of the cutting element 216 may be at least substantially planer in some examples. In lieu of the chamfer 406. or in addition to the chamfer 406, the face may be have a non-planar shape (e.g.. rounded, domed, chisel-shaped) in other examples.

[0063] In some examples, the inclusion or omission of the chamfer 406, as well as its total chamfer thickness 414, may be one of the characteristics of the cutting element 216 that may be varied. The total chamfer 406 thickness may be measured from a cutting edge 418 located at a periphery of the face 412 at a location where the cutting element 216 first engages an earth formation to the side surface 410 of the table 404 in a direction at least substantially parallel to a geometrically central axis 416 of the cutting element 216. In examples where the chamfer 406 of the cutting element 216 includes multiple chamfer surfaces, the total chamfer thickness 414 may include the thicknesses of each such chamfer surface, from the rotationally leading cutting edge 418 to the most rotationally trailing portion of the most rotationally trailing chamfer surface.

[0064] Cutting elements 216 located within a cone region of a body of an earth-boring tool may include a chamfer 406, and the total chamfer thickness 414 of the chamfer 406 may be, for example, greater than or equal to about 0.02 inch (about 0.05 cm) (e.g., in a range extending from about 0.02 inch to about 0.25 inch (about 0.05 cm to about 0.64 cm)). For each of the cutting elements 216 located within a nose region of the body, the total chamfer thickness 414 may be, for example, in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm). For each of the cutting elements 216 located within a shoulder region of the body, the total chamfer thickness 414 may be less than or equal to about 0.012 inch (about 0.03 cm) (e.g., in a range extending from about 0 inch to about 0.012 inch (about 0.03 cm)). In some examples, the cutting elements 216 may lack a chamfer 406, particularly those located within the shoulder region.The substrate 402 may be formed from a material that is relatively hard and resistant to wear. For example, the substrate 402 may be formed from and include a ceramic-metal composite material (which is often referred to as “cermet” material). More specifically, the substrate 402 may include a cemented carbide material, such as a cemented tungsten carbide material, in which tungsten carbide particles are cemented together in a metallic binder material. The metallic binder material may include, for example, cobalt, nickel, iron, or alloys and mixtures thereof. Alternatively, other substrate materials may be used.

[0065] Referring to FIG. 5, a simplified cross-sectional view of a cutting element 216 engaging an underlying earth formation 502 is shown. Cutting elements 216 attached to blades 210 of earth-boring tools 200 may be oriented at rake angles 504 with respect to such earth formations 502. The rake angle 504 may be a smallest angle at which the cuting element 216 engages the earth formation 502 relative to a vertical line at the point of engagement. When the cuting elements 216 are oriented such that the rake angle 504 trails the vertical line at the point of engagement, the rake angle 504 may be said to be negative. When the cuting elements 216 are oriented such that the rake angle 504 leads to the vertical line at the point of engagement, the rake angle 504 may be said to be positive.

[0066] As the earth-boring tool 200 rotates within the borehole, at least some of the cuting elements 216 may engage the underlying earth formation 502 to facilitate its removal. Cuting actions by the cuting elements 216 may involve gouging, crushing, and / or shearing away the earth formation 502, depending on the shape, plow angle 506, depth of cut, and other characteristics affecting the performance of the cuting elements 216.

[0067] In some examples, the rake angle 504 may be a characteristic or one of the characteristics of the cuting elements 216 that may vary from region to region of the body of an earth-boring tool. For each of the cuting elements 600 located within the cone region of the body, for example, a rake angle 504 may be less than or equal to about 0° (e.g., in a range extending from about -60° to about 0°). More specifically, the rake angle 504 of the cutting elements 600 in the cone region may be, for example, neutral or negative. For each of the cutting elements 600 located within the nose region of the body, for example, the rake angle 504 may be in a range extending from about 0° to about 15°. More specifically, the rake angle 504 of the cuting elements 600 in the nose region may be, for example, neutral or positive. For each of the cuting elements 600 located within the shoulder region of the body, for example, the rake angle 504 may be greater than or equal to about 15° (e.g., in a range extending from about 15° to about 60°). More specifically, the rake angle 504 of thecuting elements 600 in the shoulder region may be, for example, at least as positive as, or more positive than, that of the cuting elements 600 in the nose region.

[0068] FIG. 5B is a perspective side view of another example of a cutting element 510. The cuting element 510 may have a geometrically central axis 514 extending longitudinally at least substantially along a geometrical center of the cuting element 510 in approximately a direction tangent to a direction of rotation of the cutting element 510 when engaging an underlying earth formation. The axis 514 may be intersected by a line 516 extending at least substantially perpendicular to the axis 514, located longitudinally along the axis 514 in a position at least substantially the same as a cuting tip 518 of the cuting element 510, and oriented such that portions of the line 516 located proximate to a periphery of the cuting element 510 may be at least substantially equidistant from the cuting tip 518.

[0069] A plow angle 506 may be defined as the shortest angle, as measured from the line 516 toward a rotationally trailing portion of the cuting element 510, between the line 516 and a plow face 508 of the cuting element 510 located at a rotationally leading end of the cutting element 510 and radially inward from any chamfer of the cuting element 510. In examples where the cuting element 510 lacks chamfers, the plow face 508 may extend radially to a periphery of the cuting element 510. In some examples, the plow face 508 may extend longitudinally beyond the table 522 having polyciystalline. superhard material and onto the substrate 520, such as, for example, when the plow angle is large (e.g., greater than about 15°). In examples where the plow face 508 is curved, the plow angle 506 may be measured from the line 516 angularly to a plane tangent to the plow face 508 at a rotationally leading portion of the plow face 508.

[0070] FIG. 5C is a plan view from above another example of a cuting element 512. The view of FIG. 5C may be taken in a plane at least substantially tangent to a cuting trajectory of the cuting element 512, which may approximately be described as a spiral trajectory, and looking downward on the cuting element 512 and toward where an underlying earth formation would be located when the cuting element 512 is in use. When viewed in this orientation, the plow angle may be measured from the line 516 to the plow face 508 at a rotationally leading portion of the plow face 508.

[0071] In some examples, the plow angle 506 may be a characteristic or one of the characteristics of the cuting elements 216 that may vary from region to region of the body of an earth-boring tool. For each of the cuting elements 600 located within the cone region of the body, for example, a plow angle 506 may be less than or equal to about 0° (e.g., in arange extending from about -60° to about 0°). More specifically, the plow angle 506 of the cutting elements 600 in the cone region may be, for example, neutral or negative. For each of the cutting elements 600 located within the nose region of the body, for example, the plow angle 506 may be in a range extending from about 0° to about 15°. More specifically, the plow angle 506 of the cutting elements 600 in the nose region may be, for example, neutral or positive. For each of the cutting elements 600 located within the shoulder region of the body, for example, the plow angle 506 may be greater than or equal to about 15° (e.g., in a range extending from about 15° to about 60°). More specifically, the plow angle 506 of the cutting elements 600 in the shoulder region may be, for example, at least as positive as, or more positive than, that of the cutting elements 600 in the nose region.

[0072] FIG. 6 is a simplified cross-sectional side view of another example of a cutting element 600 usable with the earth-boring tool 200 of FIG. 2. In some examples, the cutting element 600 may include a concavity 602 proximate to the rotationally leading end 604 of the cutting element 600. The concavity 602 may be located in, and defined by, a table 606 of superhard material, which may in turn be affixed to a substrate 608. The concavity 602 may be defined by a portion of a cutting face 61 , which may be recessed, extending in a rotationally trailing direction back tow ard the substrate 402, when compared to a rotationally most leading portion of the cutting face 610.

[0073] The concavity 602, when present, may form a concavity angle 612, which may be defined by a surface 614 of the concavity 602 located radially between a periphery of the concavity 602 and a geometric center 616 of a cutting face 610 of the cutting element 600. In particular, the concavity' angle 612 may be defined by a shortest angular distance betw een the surface 614 of the concavity' 602 and a plane 620 oriented at least substantially perpendicular to a geometrically central axis 618 of the corresponding cutting element 216. For each of the cutting elements 600 located within the cone region of the body, the concavity angle 612 may be, for example, less than or equal to about -10° (e.g., in a range extending from about -60° to about -10°). More specifically, the cutting elements 600 located within the cone region may, for example, be convex or include a negative concavity in a portion of the cutting face 610. For each of the cutting elements 600 located within the nose region of the body, the concavity angle 612 may be in a range extending from about - 10° to about 10°. More specifically, the cutting face 610 of the cutting elements 600 located within the nose region may, for example, be concave, flat, or convex or may include a concavity' in a portion thereof, lack a concavity, or include a negative concavity in a portion thereof. For each ofthe cuting elements 600 located within the shoulder region of the body, the concavity angle 612 may be, for example, greater than or equal to about 10° (e.g.. in a range extending from about 10° to about 90°). More specifically, the cutting face 610 of the cuting elements 600 located within the shoulder region may, for example, be concave or include a concavity 602 in a portion thereof.

[0074] In some examples, a greatest concavity depth 622 of the concavity 602 may be another characteristic of the cuting element 600 which may be varied from region to region of the body of an earth-boring tool. The greatest concavity depth 622 may be measured from a rotationally leading portion of the concavity 602, which may be coincident with the cuting face 610, to a most rotationally trailing portion of the concavity' 602, as measured in the direction at least substantially parallel to the geometrically central axis 618 of the cuting element 600. For each of the cuting elements 600 located within the cone region of the body, the greatest concavity depth 622 may be, for example, less than or equal to about 0 inch (e.g., in a range extending from about -0.25 inch (about -0.64 cm) to about 0 inch). More specifically, the cutting face 610 may be, for example, flat, lacking a concavity, or may be, for example, convex or include a negative concavity. For each of the cuting elements 600 located within the nose region of the body, the greatest concavity’ depth 622 may be in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm). More specifically, the cutting face 610 may be, for example, flat, lacking a concavity, or may be, for example, concave or include a concavity 602 in a portion thereof. For each of the cutting elements 600 located within the shoulder region of the body, the greatest concavity depth 622 may be, for example, greater than or equal to about 0.01 inch (about 0.03 cm) (e.g., in a range extending from about 0.01 inch to about 0.25 inch (about 0.03 cm to about 0.64 cm)). More specifically, the cuting face 610 may be, for example, concave or include a concavity 602 in a portion thereof.

[0075] FIG. 7 is a front surface view of another example of a cuting element 700 usable with the earth-boring tool of FIG. 2. In some examples, one or more characteristics of a cutting tip 702 of the cutting element 700 may be varied from region to region. The cutting tip 702 may be positioned, and the cuting element 700 may be oriented, such that the cuting tip 702 may be the first portion of the cuting element 700 to engage an underlying earth formation when conducting an earth-boring operation.

[0076] One example of such a characteristic of the cuting tip 702 may be a greatest tip width 704. The greatest tip width 704 may be defined by an angular distance over which acuting edge 706 extends proximate to a rotationally leading portion of the cuting element. For each of the cuting elements 700 located within the cone region of the body, the greatest tip width 704 may be, for example, about equal to one half of a circumference of a cuting face 710. More specifically, the cuting edge 706 may be, for example, contiguous and uninterrupted, lacking intersections with other edges and lacking points, extending around a formation-facing portion of an at least substantially circular cutting edge 706. For each of the cuting elements 700 located within the nose region of the body, the greatest tip width 704 may be, for example, in a range extending from about 0.18 divided by 16 multiplied by the maximum diameter of the cuting face in millimeters to about equal to one half of the circumference of the cuting face 710. More specifically, the cuting edge 706 may be, for example, contiguous and uninterrupted, lacking intersections with other edges and lacking points, extending around a formation-facing portion of an at least substantially circular cutting edge 706. Alternatively, the cuting edge 706 may be, for example, discontinuous and interrupted, including intersections with other edges 708 at a periphery7of the cuting face 710 and including points, such that the cuting edge 706 extends only partially around the periphery of the cuting edge 706 and the cutting face 710 defines a non-circular peripheral shape. For each of the cuting elements 700 located within the shoulder region of the body, the greatest tip width 704 may be, for example, less than or equal to about 0.18 divided by 16 multiplied by the maximum diameter of the cuting face 710 in millimeters (e.g.. in a range extending from about 0.001 divided by two times the maximum radius of the cuting face 710 to about 0.18 divided by 16 multiplied by the maximum diameter of the cutting face 710 in millimeters). More specifically, the cutting edge 706 may be, for example, discontinuous and interrupted, including intersections with other edges 708 at a periphery7of the cuting face 710 and including points, such that the cuting edge 706 extends only partially around the periphery of the cuting edge 706 and the cuting face 710 defines a noncircular peripheral shape.

[0077] Another example of a characteristic of the cuting elements 700 that may be varied from region to region of an earth-boring tool is a tip angle 712 of the cutting tip 702 of the cutting element 700. The tip angle 712 may be defined as an included angle between opposing edges, such as the other edges 708, of the cuting face 710 proximate to the rotationally leading portion of the cutting element. For each of the cuting elements 700 located within the cone region of the body, the tip angle 712 may be, for example, about 180°. For each of the cuting elements 700 located within the nose region of the body, the tipangle 712 may be, for example, in a range extending from about 100° to about 180°. For each of the cutting elements 700 located within the shoulder region of the body, the tip angle 712 may be, for example, less than or equal to about 100° (e.g., in a range extending from about 30° to about 100°).

[0078] FIG. 8 is a perspective side view of another example of a cutting element 800 usable with the earth-boring tool 200 of FIG. 2. In some examples, one or more cutting elements 800 may include a brim 802. For example, the cutting element 800 may have a concavity 804, which concavity 804 may not extend radially to the periphery of the cutting face 806. The brim 802 may be defined by the portion of the cutting face 806 located betw een the cutting edge 808 at the periphery of the cutting face 806 and the concavity 804.

[0079] Another example of a characteristic of the cutting elements 800 that may be varied from region to region of an earth-boring tool is a brim width 810 defined by a greatest distance between a cutting edge 808 of the cutting face 806 and a concavity 804 of the cutting face 806. For each of the cutting elements 800 located within the cone region of the body, the brim width 810 may be, for example, about equal to a radius of the cutting face 806 (e.g., the cutting element 800 may lack a concavity 804 and may lack a brim 802). For each of the cutting elements 800 located within the nose region of the body, the brim width 810 may be, for example, in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face 806. For each of the cutting elements 800 located within the shoulder region of the body, the brim width 810 may be, for example, less than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters (e.g., in a range extending from about 0.001 inch to about 0.03 inch (about 0.003 cm to about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters).

[0080] Still another example of a characteristic of the cutting elements 800 that may be varied from region to region of an earth-boring tool is a brim inner angle 812 of the brim 802 of the cutting elements 800. The brim inner angle 812 may be defined by a shortest angular distance between a rotationally leading portion of the cutting face 806 and a sidewall 814 defining the concavity 804 of the cutting face 806. For each of the cutting elements 800 located within the cone region of the body, the brim inner angle 812 may be, for example, about 0° (e.g., there may be no concavity 804). For each of the cutting elements 800 located within the nose region of the body, the brim inner angle 812 may be, for example, in a rangeextending from about 0° to about 10°. For each of the cutting elements 800 located within the shoulder region of the body, the brim inner angle 812 may be, for example, greater than or equal to about 10° (e.g., in a range extending from about 10° to about 180°).

[0081] FIG. 9 is a leading end, face view of an earth-boring tool 900 accompanied by a view of cutting elements 902, 904, and 906 affixed to the earth-boring tool 900. Cutting elements of a set of first cutting elements 902 may generally have, for example, a flat or convex cutting face, a chamfer, and a continuous, at least substantially circular cutting edge, which cutting edge may lack points and intersections with other edges. More specifically, the first cutting elements 902 may have, for example, a total chamfer thickness greater than or equal to about 0.02 inch (about 0.05 cm), a concavity angle less than or equal to about -10°, a greatest concavity depth less than or equal to about 0 inch, a greatest tip width about equal to one half of a circumference of the cutting face, a tip angle of about 180°, a brim width about equal to a radius of the cutting face, a brim inner angle of about 0°, and, as deployed on the earth-boring tool 900, a plow angle less than or equal to about 0°. In brief, some of the cutting elements affixed to the earth-boring tool 900, such as, for example, the first cutting elements 902, may meet all criteria for deployment within a given region of the earth-boring tool 900, such as, for example, the cone region 908, and may be deployed in that region. The first cutting elements 902 are identified in FIG. 9 with a prominent “S” marking.

[0082] Cutting elements of a set of second cutting elements 904 may generally have, for example, a convex, flat, or concave cutting face (as shown in FIG. 9, the second cutting elements 904 may have a triangular concavity with rounded comers surrounded by a brim), a chamfer smaller than the chamfer of the first cutting elements 902, and a discontinuous cutting edge, including intersections with other edges so as to define a cutting tip (as shown in FIG. 9, the second cutting elements 904 may have a triangular cutting face with rounded comers). More specifically the second cutting elements 904 may have, for example, a total chamfer thickness in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), a concavity' angle in a range extending from about -10° to about 10°, a greatest concavity depth in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm), a brim width in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by' a maximum radius of the cutting face in millimeters to about the radius of the cutting face, and a plow angle is in a range extending from about 0° to about 15°. In brief, some of the cutting elements affixed to the earth-boring tool 900, such as, for example, the second cutting elements 904, may meet some criteria for deployment within agiven region of the earth-boring tool 900, such as, for example, the nose region 910, and may be deployed in that region. The second cutting elements 904 are identified in FIG. 9 with a prominent "P” marking.

[0083] Cutting elements of a set of third cutting elements 906 may generally have, for example, a flat or concave cutting face (as shown in FIG. 9, the third cutting elements 906 may have an at least substantially flat cutting face), a chamfer at least substantially equal to or smaller than the chamfer of the second cutting elements 904, and a discontinuous cutting edge, including intersections with other edges so as to define a cutting tip (as shown in FIG. 9, the third cutting elements 906 may have a partially circular cutting face interrupted by two intersecting lines). More specifically, the third cutting elements 906 may have, for example, a total chamfer thickness less than or equal to about 0.012 inch (about 0.03 cm), a greatest tip width greater than or equal to about 0.18 divided by 16 multiplied by the maximum diameter of the cutting face in millimeters, a tip angle less than or equal to about 100°, and a plow' angle greater than or equal to about 15°. In brief, some of the cutting elements affixed to the earth-boring tool 900, such as, for example, the third cutting elements 906, may meet some criteria for deployment within a given region of the earthboring tool 900, such as, for example, the shoulder region 912, and may be deployed in that region. The third cutting elements 906 are identified in FIG. 9 with a prominent “A” marking.

[0084] When a given cutting element's location on the earth-boring tool 900 is intersected by a boundary between regions, the cutting element positioned in that location may have the characteristics for inclusion in either of the adjacent regions, or may have some characteristics for inclusion in one region and other characteristics for inclusion in the other region. As shown in FIG. 9, those cutting elements intersected by the boundary between the cone region 908 and the nose region 910 may be the first cutting elements 902, and those cutting elements intersected by the boundary between the nose region 910 and the shoulder region 912 may7be the second cutting elements 904. In other examples, those cutting elements intersected by the boundary7betw een the cone region 908 and the nose region 910 may be the second cutting elements 904, and those cutting elements intersected by the boundary between the nose region 910 and the shoulder region 912 may be the third cutting elements 906.

[0085] In some examples, the cutting elements affixed to the earth-boring tool 900, including the first cutting elements 902, second cutting elements 904, and third cutting elements 906, may exhibit, for example, at least three of the characteristics disclosed herein for evaluating,selecting, and deploying cutting elements located within the regions of the earth-boring tool 900, including the cone region 908, the nose region 910, and the shoulder region 912. More specifically, the cutting elements affixed to the earth-boring tool 900 may exhibit, for example, a majority of the characteristics disclosed herein for evaluating, selecting, and deploying cutting elements located within the regions of the earth-boring tool 900. As a specific, nonlimiting example, the cutting elements affixed to the earth-boring tool 900 may exhibit, for example, each of the characteristics disclosed herein for evaluating, selecting, and deploying cutting elements located within the regions of the earth-boring tool 900.

[0086] In some examples, the characteristics of each of the cutting elements in the cone region 908, such as the first cutting elements 902, may be at least substantially the same. More specifically, each of the first cutting elements 902 in the cone region 908 may have, for example, at least substantially the same design and may additionally have at least substantially the same deployed orientation with respect to an underlying earth formation. The characteristics of each of the cutting elements in the nose region 910, such as the second cutting elements 904, may be, for example, at least substantially the same. More specifically, each of the second cutting elements 904 in the nose region 910 may have, for example, at least substantially the same design and may additionally have at least substantially the same deployed orientation with respect to an underlying earth formation. The characteristics of each of the cutting elements in the shoulder region 912, such as the third cutting elements 906, may be. for example, at least substantially the same. More specifically, each of the third cutting elements 906 in the shoulder region 912 may have, for example, at least substantially the same design and may additionally have at least substantially the same deployed orientation with respect to an underlying earth formation.

[0087] FIG. 10 is a leading end. face view of another example of an earth-boring tool 1000 accompanied by views of cutting elements 902, 906, 1002 affixed to the earth-boring tool 1000. Some of those cutting elements may be the first cutting elements 902 labeled with the letter “S” and the third cutting elements 906 labeled with the letter “A” described previously in connection with FIG. 9. The third cutting elements 906 affixed to the earthboring tool 1000 of FIG. 10 may be located within the nose region 1006, rather than the shoulder region 1008. As it relates to characteristics suited for deployment in the nose region 1006, and potential minor modifications relative to the versions of the third cutting elements 906 utilized on the earth-boring tool 900 of FIG. 9, the third cutting elements 906 affixed to the earth-boring tool 1000 in the nose region 1006 may have, for example, a totalchamfer thickness less than or equal to about 0.012 inch (about 0.03 cm), a concavity angle greater than or equal to about 10°, a greatest concavity depth greater than or equal to about 0.01 inch (about 0.03 cm), a greatest tip width greater than or equal to about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters, a brim inner angle greater than or equal to about 10°, and plow angle greater than or equal to about 15°.

[0088] Cutting elements of a set of fourth cutting elements 1002 may generally have, for example, a concave cutting face, a chamfer smaller than the chamfer of the second cutting elements 904, or no chamfer, and a discontinuous cutting edge, including intersections with other edges so as to define a cutting tip (as show n in FIG. 10, the fourth cutting elements 1002 may have a pointed cutting tip). More specifically, the fourth cutting elements 1002 may have, for example, atotal chamfer thickness less than or equal to about 0.012 inch (0.03 cm), a concavity angle greater than or equal to about 10°, a greatest concavity depth greater than or equal to about 0.01 inch (about 0.03 cm), a greatest tip width greater than or equal to about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters, a tip angle less than or equal to about 100°. and a plow angle greater than or equal to about 15°. In brief, some of the cutting elements affixed to the earth-boring tool 1000, such as, for example, the fourth cutting elements 1002, may meet some criteria for deployment within a given region of the earth-boring tool 1000 such as, for example, the shoulder region 1008, and may be deployed in that region. The fourth cutting elements 1002 are identified in FIG. 10 with a prominent “F” marking.

[0089] FIG. 11 is a leading end, face view of another example of an earth-boring tool 1100 accompanied by views of cutting elements 902, 906, 1002, and 1102 affixed to the earthboring tool 1100. Some of those cutting elements may be the first cutting elements 902 labeled with the letterC'S,” the third cutting elements 906 labeled with the letter “A,” and the fourth cutting elements 1002 labeled with the letter “F,” described previously in connection with FIG. 9 and FIG. 10.

[0090] Cutting elements of a set of fifth cutting elements 1102 may generally have, for example, an at least substantially flat or concave cutting face (in FIG. 11, the fifth cutting elements 1 102 are depicted as having an at least substantially flat cutting face), a chamfer smaller than the chamfer of the first cutting elements 902 or no chamfer, and an at least substantially continuous cutting edge, lacking intersections with other edges or points. More specifically, the fourth cuting elements 1002 may have, for example, a total chamferthickness in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), a concavity angle in a range extending from about -10° to about 10°, a greatest concavity depth in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm), a greatest tip width in a range extending from about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters to about equal to one half of the circumference of the cutting face, a tip angle in a range extending from about 100° to about 180°. a brim width in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face, a brim inner angle in a range extending from about 0° to about 10°, and a plow angle in a range extending from about 0° to about 15°. In brief, some of the cutting elements affixed to the earth-boring tool 1000. such as, for example, the third cutting elements 906 and the fifth cutting elements 1102, may meet some criteria for deployment within a given region of the earth-boring tool 1000 such as, for example, the nose region 1106, and may be deployed in that region. The fifth cutting elements 1102 are identified in FIG. 11 with a prominent C marking.

[0091] In some examples, such as that shown in FIG. 11, at least one characteristic of at least one of the cutting elements in one or more of the regions of the earth-boring tool 1100 may differ from a corresponding characteristic of at least another of the cutting elements in the same region as those one or more cutting elements. For example, at least one characteristic of at least one of the cutting elements 906 or 1102 in the nose region 1106 may differ from a corresponding characteristic of at least another of the cutting elements 906 or 1102 in the nose region 1106. More specifically, the nose region 1106 may have cutting elements having two or more different designs, such as, for example, the group of third cutting elements 906 and the group of fifth cutting elements 1102, affixed to the earth-boring tool 1100 within the nose region 1106. As a specific, nonlimiting example, each blade 1110 of the earth-boring tool 1100 save one (which has only one fifth cutting element 1102 located within the nose region 1106) may have one of the third cutting elements 906 and one of the fifth cutting elements 1102 affixed thereto within the nose region 1106, and which cutting element 906 or 1102 is located radially closer to an axis of rotation of the earth-boring tool 1100 may alternate from blade 1110 to blade 1110.

[0092] FIG. 12 is a leading end, face view of another example of an earth-boring tool 1200 accompanied by views of cutting elements 902, 906, 1102, and 1102 affixed to the earthboring tool 1200. In many respects, the earth-boring tool 1200 of FIG. 12 may be at leastsubstantially similar to that of FIG. 11. As one modification, each blade 1208 of the earthboring tool 1200 may have one or more of the third cutting elements 906 or of the fifth cutting elements 1102 affixed thereto within the nose region 1106, and which cutting element 906 or 1102 is located on a given blade 1208 may alternate from blade 1208 to blade 1208.

[0093] FIG. 13 is a leading end, face view of another example of an earth-boring tool 1300 accompanied by views of cutting elements 902, 906, 1002, 1102 affixed to the earth-boring tool 1300. In many respects, the earth-boring tool 1300 of FIG. 13 may be at least substantially similar to those of FIG. 11 and FIG. 12. As one modification, each blade 1308 of the earth-boring tool 1300 save one (which has only one third cutting element 906 located within the nose region 1304) may have one of the third cutting elements 906 and one of the fifth cutting elements 1102 affixed thereto within the nose region 1304. and which cutting element 906 or 1102 is located radially closer to an axis of rotation of the earth-boring tool 1300 may consistently be a third cutting element 906 or a fifth cutting element 1102 (in FIG. 13, the fifth cutting elements 1102 are consistently closer to the axis of rotation of the earth-boring tool 1300).

[0094] FIG. 14 is a leading end, face view of another example of an earth-boring tool 1400 accompanied by views of cutting elements 902, 906, 1002, and 1102 affixed to the earthboring tool 1400. In many respects, the earth-boring tool 1400 of FIG. 14 may be at least substantially similar to those of FIG. 11, FIG. 12, and FIG. 13. As modifications, the earthboring tool 1400 may have fifth cutting elements 1102, as well as first cutting elements 902, affixed thereto in the cone region 1402, only fifth cutting elements 1102 affixed thereto in the nose region 1404, and third cutting elements 906, as well as fourth cutting elements 1002, affixed thereto in the shoulder region 1406.

[0095] When a given cutting element's location on the earth-boring tool 1400 is intersected by a boundary between regions, the cutting element positioned in that location may have the characteristics for inclusion in either of the adjacent regions, or may have some characteristics for inclusion in one region and other characteristics for inclusion in the other region. As shown in FIG. 14, those cutting elements intersected by the boundary between the cone region 1402 and the nose region 1404 may be the first fifth cutting elements 1102 and those cutting elements intersected by the boundary between the nose region 1404 and the shoulder region 1406 may likewise be the fifth cutting elements 1102, which fifth cutting elements 1102 may otherwise generally be concentrated within the nose region 1404. In other examples, those cutting elements intersected by the boundary between the cone region 1402and the nose region 1404 may be those more generally concentrated within the cone region 1402, and those cuting elements intersected by the boundary between the nose region 910 and the shoulder region 912 may be those more generally concentrated within the shoulder region 1406.

[0096] In some examples, such as that shown in FIG. 14, at least one characteristic of at least one of the cutting elements in one or more of the regions of the earth-boring tool 1400 may differ from a corresponding characteristic of at least another of the cuting elements in the same region as those one or more cuting elements. For example, at least one characteristic of at least one of the cuting elements 902 or 1102 in the cone region 1402 may differ from a corresponding characteristic of at least another of the cuting elements 902 or 1102 in the cone region 1402. More specifically, the cone region 1402 may have cuting elements having two or more different designs, such as, for example, the group of first cuting elements 902 and the group of fifth cuting elements 1102, affixed to the earth-boring tool 1100 within the cone region 1402. As a specific, nonlimiting example, each primary blade 1408 of the earthboring tool 1400 (i.e., those blades 1408 which extend into the cone region 1402) may have one of the first cuting elements 902 and one of the fifth cuting elements 1102 affixed thereto at least partially within the cone region 1402, and which cuting element 902 or 1102 is located radially closer to an axis of rotation of the earth-boring tool 1100 may be consistent from blade 1408 to blade 1408 (in FIG. 14, the first cuting elements 902 are shown as consistently being closer to the axis of rotation of the earth-boring tool 1400).

[0097] As another example, at least one characteristic of at least one of the cuting elements 906 or 1002 in the shoulder region 1406 may differ from a corresponding characteristic of at least another of the cuting elements 906 or 1002 in the shoulder region 1406. More specifically, the shoulder region 1406 may have cuting elements having two or more different designs, such as, for example, the group of third cuting elements 906 and the group of fourth cuting elements 1002, affixed to the earth -boring tool 1400 within the shoulder region 1406. As a specific, nonlimiting example, each blade 1408 of the earthboring tool 1400 may have the third cutting elements 906 or the fourth cuting elements 1002 affixed thereto within the shoulder region 1406, which cuting element 906 or 1002 is located on a given blade 1408 may generally alternate from blade 1408 to blade 1408 (in FIG. 14, there is one adjacent pair of blades 1408 both having the fourth cuting elements 1002 affixed thereto, as there is an odd number of blades 1408; in other examples with odd numbers ofblades 1408, there may be an adjacent pair both having third cutting elements 906 affixed thereto).

[0098] FIG. 15 is a leading end, face view of another example of an earth-boring tool 1500 accompanied by views of cutting elements 902, 904, 906, 1002, and 1102 affixed to the earth-boring tool 1500. In many respects, the earth-boring tool 1500 of FIG. 15 may be at least substantially similar to those of FIG. 11, FIG. 12. FIG. 13, and FIG. 14. As modifications, the earth-boring tool 1500 may have only first cutting elements 902 affixed thereto in the cone region 1502, a combination of second cutting elements 904, third cutting elements 906, and fifth cutting elements 1102 affixed thereto in the nose region 1504, and only fourth cutting elements 1002 affixed thereto in the shoulder region 1506.

[0099] Earth-boring tools and / or cutting elements configured, designed, manufactured, positioned, oriented, and deployed in accordance with this disclosure may improve operational performance when compared to other earth-boring tools and / or cutting elements known to the inventors, especially in terms of operational stability. Specifically, deploying cutting elements having characteristics as disclosed herein may enable increased stability , and particularly torsional stability. Such increases in stability may increase the useful life of the earth-boring tool and associated cutting elements, and improve ability to remain on a target trajectory. It is further expected that doing so may reduce unstable earth-boring behaviors, and particularly torsional instability (e.g., slip-stick vibrations), reduce impact damage and abrasive wear on the earth-boring tool and its components, reduce time spent outside of an intended trajectory, and reduce detours and re-boring when compared to other designs known to the inventors.

[0100] Additional, nonlimiting examples within the scope of this disclosure include:

[0101] Example 1: An earth-boring tool, comprising: a body; and cutting elements affixed to the body, wherein the cutting elements exhibit at least two characteristics selected from: for each of the cutting elements located within a cone region of the body, a total chamfer thickness is greater than or equal to about 0.02 inch (about 0.05 cm), for each of the cutting elements located within a nose region of the body, the total chamfer thickness is in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), and for each of the cutting elements located within a shoulder region of the body, the total chamfer thickness is less than or equal to about 0.012 inch (about 0.03 cm); for each of the cutting elements located within the cone region of the body, a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavitylocated radially between a periphery of the concavity and a geometric center of a cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element is less than or equal to about -10°, for each of the cutting elements located within the nose region of the body, the concavity angle is in a range extending from about -10° to about 10°, and for each of the cutting elements located within the shoulder region of the body, the concavity angle is greater than or equal to about 10°; for each of the cutting elements located within the cone region of the body, a greatest concavity depth is less than or equal to about 0 inch, for each of the cutting elements located within the nose region of the body, the greatest concavity depth is in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm), and for each of the cutting elements located within the shoulder region of the body, the greatest concavity depth is greater than or equal to about 0.01 inch (about 0.03 cm); for each of the cutting elements located within the cone region of the body, a greatest tip width defined by a distance around a circumference of a cutting face over which a cutting edge extends proximate to a rotationally leading portion of the cutting element is about equal to one half of a circumference of a cutting face, for each of the cutting elements located within the nose region of the body, the tip width is in a range extending from about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters to about equal to one half of the circumference of the cutting face, and for each of the cutting elements located within the shoulder region of the body, the tip width is less than or equal to about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters; for each of the cutting elements located within the cone region of the body, a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element is about 180°, for each of the cutting elements located within the nose region of the body, the tip angle is in a range extending from about 100° to about 180°, and for each of the cutting elements located within the shoulder region of the body, the tip angle is less than or equal to about 100°; for each of the cutting elements located within the cone region of the body, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is about equal to a radius of the cutting face, for each of the cutting elements located within the nose region of the body, the brim width is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face, and for each of the cutting elements located within the shoulder region of the body, the brim width is less than or equal to about 0.03 inch(about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters; for each of the cutting elements located within the cone region of the body, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face is about 0°, for each of the cutting elements located within the nose region of the body, the brim inner angle is in a range extending from about 0° to about 10°, and for each of the cutting elements located within the shoulder region of the body, the brim inner angle is greater than or equal to about 10°; and for each of the cutting elements located within the cone region of the body, a plow angle is less than or equal to about 0°, for each of the cutting elements located within the nose region of the body, the plow angle is in a range extending from about 0° to about 15°, and for each of the cutting elements located within the shoulder region of the body, the plow angle is greater than or equal to about 15°.

[0102] Example 2: The earth-boring tool of Example 1, wherein the cutting elements exhibit at least three of the characteristics.

[0103] Example 3: The earth-boring tool of Example 1, wherein the cutting elements exhibit a majority of the characteristics.

[0104] Example 4: The earth-boring tool of Example 1, wherein the cutting elements exhibit each of the characteristics.

[0105] Example 5 : The earth-boring tool of any one of Examples 1 through 4, wherein the cone region extends from about an axis of rotation of the body to about one-third of a maximum radius of the body.

[0106] Example 6: The earth-boring tool of any one of Examples 1 through 5, wherein the nose region extends from about one-third of the maximum radius of the body to about two-thirds of the maximum radius of the body.

[0107] Example 7 : The earth-boring tool of any one of Examples 1 through 6, wherein the shoulder region extends from about two-thirds of the maximum radius of the body to about the maximum radius of the body.

[0108] Example 8: The earth-boring tool of any one of Examples 1 through 7, wherein the characteristics of each of the cutting elements in the cone region are at least substantially the same.

[0109] Example 9: The earth-boring tool of any one of Examples 1 through 8, wherein the characteristics of each of the cutting elements in the nose region are at least substantially the same.Example 10: The earth-boring tool of any one of Examples 1 through 9, wherein the characteristics of each of the cutting elements in the shoulder region are at least substantially the same.

[0110] Example 11: The earth-boring tool of any one of Examples 1 through 7, 9, and 10, wherein at least one characteristic of at least one of the cutting elements in the cone region differs from a corresponding characteristic of at least another of the cutting elements in the cone region.

[0111] Example 12: The earth-boring tool of any one of Examples 1 through 8, 10, and 11, wherein at least one characteristic of at least one of the cutting elements in the nose region differs from a corresponding characteristic of at least another of the cutting elements in the nose region.

[0112] Example 13: The earth-boring tool of any one of Examples 1 through 9, 11, and 12, wherein at least one characteristic of at least one of the cutting elements in the shoulder region differs from a corresponding characteristic of at least another of the cutting elements in the shoulder region.

[0113] Example 14: An earth-boring tool, comprising: a body; and cutting elements affixed to the body, wherein: for each of the cutting elements located within a cone region of the body, a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavity located radially between a periphery of the concavity and a geometric center of a cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element is less than or equal to about -10°, a greatest tip width defined by a distance around a circumference of the cutting face over which a cutting edge extends proximate to a rotationally leading portion of the cutting element is about equal to one half of a circumference of a cutting face, and a plow angle is less than or equal to about 0°; for each of the cutting elements located within a nose region of the body, the concavity angle is in a range extending from about -10° to about 10°, the greatest tip width is in a range extending from about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters to about equal to one half of the circumference of the cutting face, and the plow angle is in a range extending from about 0° to about 15°; and for each of the cutting elements located within a shoulder region of the body, the concavity7angle is greater than or equal to about 10°, the greatest tip width is less than or equal to about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters, and the plow angle is greater than or equal to about 15°.Example 15: The earth-boring tool of Example 14, wherein: for each of the cutting elements located within the cone region of the body, a total chamfer thickness is greater than or equal to about 0.02 inch (about 0.05 cm); for each of the cutting elements located within the nose region of the body, the total chamfer thickness is in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm); and for each of the cutting elements located within the shoulder region of the body, the total chamfer thickness is less than or equal to about 0.012 inch (about 0.03 cm).

[0114] Example 16: The earth-boring tool of Example 14 or Example 15, wherein: for each of the cutting elements located within the cone region of the body, a greatest concavity depth is less than or equal to about 0 inch; for each of the cutting elements located within the nose region of the body, the greatest concavity depth is in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm); and for each of the cutting elements located within the shoulder region of the body, the greatest concavity depth is greater than or equal to about 0.01 inch (about 0.03 cm).

[0115] Example 17: The earth-boring tool of any one of Examples 14 through 16, wherein: for each of the cutting elements located within the cone region of the body, a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element is about 180°; for each of the cutting elements located within the nose region of the body, the tip angle is in a range extending from about 100° to about 180°; and for each of the cutting elements located within the shoulder region of the body, the tip angle is less than or equal to about 100°.

[0116] Example 18: The earth-boring tool of any one of Examples 14 through 17, wherein: for each of the cutting elements located within the cone region of the body, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is about equal to a radius of the cutting face; for each of the cutting elements located within the nose region of the body, the brim width is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face; and for each of the cutting elements located within the shoulder region of the body, the brim width is greater than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters.

[0117] Example 19: The earth-boring tool of any one of Examples 14 through 18, wherein: for each of the cutting elements located within the cone region of the body, a brim innerangle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face is about 0°; for each of the cutting elements located within the nose region of the body, the brim inner angle is in a range extending from about 0° to about 10°; and for each of the cutting elements located within the shoulder region of the body, the brim inner angle is greater than or equal to about 10°.

[0118] Example 20: An earth-boring tool, comprising: a body; and cutting elements affixed to the body, wherein: for each of the cutting elements located within a cone region of the body, a total chamfer thickness is greater than or equal to about 0.02 inch (about 0.05 cm), a cutting face is planar or convex, the cutting face is at least substantially circular in peripheral shape, and a plow angle is less than or equal to about 0°; for each of the cutting elements located within a nose region of the body, the total chamfer thickness is in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), the cutting face is concave, having a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavity located radially between a periphery of the concavity and a geometric center of the cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element in a range extending from about -10° to about 10°, and a greatest concavity depth in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm), the cutting face is tipped in shape, having a greatest tip width defined by a distance around the cutting face over which a cutting edge extends proximate to a rotationally leading portion of the cutting element in a range extending from about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters to about equal to one half of the circumference of the cutting face and a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element in a range extending from about 100° to about 180°, the cutting face defines a brim around a concavity of the cutting face, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the radius of the cutting face, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face is in a range extending from about 0° to about 10°, and the plow angle is in a range extending from about 0° to about 15°; and for each of the cutting elements locatedwithin a shoulder region of the body, the total chamfer thickness is less than or equal to about 0.012 inch (about 0.03 cm), the cutting face is concave, having a concavity angle greater than or equal to about 10° and a greatest concavity depth greater than or equal to about 0.01 inch (about 0.03 cm), the cutting face is tipped in shape, having a greatest tip width less than or equal to about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters and a tip angle less than or equal to about 100°, the cutting face defines a brim around a concavitv of the cutting face, the brim width being greater than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters, the brim inner angle being greater than or equal to about 10°, and the plow angle is greater than or equal to about 15°.

[0119] While certain illustrative examples have been described in connection with the figures, those of ordinary skill in the art will recognize and appreciate that the scope of this disclosure is not limited to those examples explicitly shown and described in this disclosure. Rather, many additions, deletions, and modifications to the examples described in this disclosure may be made to produce additional examples within the scope of this disclosure, such as those specifically claimed, including legal equivalents. In addition, features from one disclosed example may be combined with features of another disclosed example while still being within the scope of this disclosure.

Claims

CLAIMSWhat is claimed is:

1. An earth-boring tool, comprising:a body; andcutting elements affixed to the body, wherein the cutting elements exhibit at least two characteristics selected from:for each of the cutting elements located within a cone region of the body, a total chamfer thickness is greater than or equal to about 0.02 inch (about 0.05 cm), for each of the cutting elements located within a nose region of the body, the total chamfer thickness is in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), and for each of the cutting elements located within a shoulder region of the body, the total chamfer thickness is less than or equal to about 0.012 inch (about 0.03 cm);for each of the cutting elements located within the cone region of the body, a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavity located radially between a periphery of the concavity and a geometric center of a cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element is less than or equal to about -10°. for each of the cutting elements located within the nose region of the body, the concavity angle is in a range extending from about -10° to about 10°, and for each of the cutting elements located within the shoulder region of the body, the concavity7angle is greater than or equal to about 10°;for each of the cutting elements located within the cone region of the body, a greatest concavity depth is less than or equal to about 0 inch, for each of the cutting elements located within the nose region of the body, the greatest concavity depth is in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm), and for each of the cutting elements located within the shoulder region of the body, the greatest concavity depth is greater than or equal to about 0.01 inch (about 0.03 cm);for each of the cutting elements located within the cone region of the body, a greatest tip width defined by a distance around a circumference of the cutting face over which a cutting edge extends proximate to a rotationally leading portion of the cutting element is about equal to one half of a circumference of the cutting face, for each of the cutting elements located within the nose region of the body, the tip width is in a range extending from about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters to about equal to one half of the circumference of the cutting face, and for each of the cutting elements located within the shoulder region of the body, the tip width is less than or equal to about 0.18 divided by 16 multiplied by the maximum diameter of the cutting face in millimeters;for each of the cutting elements located within the cone region of the body, a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element is about 180°, for each of the cutting elements located within the nose region of the body, the tip angle is in a range extending from about 100° to about 180°, and for each of the cutting elements located within the shoulder region of the body, the tip angle is less than or equal to about 100°;for each of the cutting elements located within the cone region of the body, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is about equal to a radius of the cutting face, for each of the cutting elements located within the nose region of the body, the brim width is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the maximum radius of the cutting face, and for each of the cutting elements located within the shoulder region of the body, the brim width is less than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by the maximum radius of the cutting face in millimeters; for each of the cutting elements located within the cone region of the body, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face is about 0°, for each of the cutting elements located within the nose region of the body, the brim inner angle is in a range extending from about 0° to about 10°, and for each of the cutting elements located within the shoulder region of the body, the brim inner angle is greater than or equal to about 10°; andfor each of the cutting elements located within the cone region of the body, a plow angle is less than or equal to about 0°, for each of the cutting elements located within the nose region of the body, the plow angle is in a range extending from about 0° to about 15°, and for each of the cutting elements located within the shoulder region of the body, the plow angle is greater than or equal to about 15°.

2. The earth-boring tool of claim 1. wherein the cutting elements exhibit at least three of the characteristics.

3. The earth-boring tool of claim 1, wherein the cutting elements exhibit a majority of the characteristics.

4. The earth-boring tool of claim 1, wherein the cutting elements exhibit each of the characteristics.

5. The earth-boring tool of claim 1, wherein the cone region extends from about an axis of rotation of the body to about one-third of a maximum radius of the body.

6. The earth-boring tool of claim 1, wherein the nose region extends from about one-third of the maximum radius of the body to about two-thirds of the maximum radius of the body.

7. The earth-boring tool of claim 1, wherein the shoulder region extends from about two-thirds of the maximum radius of the body to about the maximum radius of the body.

8. The earth-boring tool of claim 1, wherein the characteristics of each of the cutting elements in the cone region are at least substantially the same.

9. The earth-boring tool of claim 1, wherein the characteristics of each of the cutting elements in the nose region are at least substantially the same.

10. The earth-boring tool of claim 1 , wherein the characteristics of each of the cutting elements in the shoulder region are at least substantially the same.

11. The earth-boring tool of claim 1 , wherein at least one characteristic of at least one of the cutting elements in the cone region differs from a corresponding characteristic of at least another of the cutting elements in the cone region.

12. The earth-boring tool of claim 1 , wherein at least one characteristic of at least one of the cutting elements in the nose region differs from a corresponding characteristic of at least another of the cutting elements in the nose region.

13. The earth-boring tool of claim 1 , wherein at least one characteristic of at least one of the cutting elements in the shoulder region differs from a corresponding characteristic of at least another of the cutting elements in the shoulder region.

14. An earth-boring tool, comprising:a body; andcutting elements affixed to the body, wherein:for each of the cutting elements located within a cone region of the body, a concavity angle defined by a shortest angular distance between a surface of a concavity, the surface of the concavity located radially between a periphery of the concavity and a geometric center of a cutting face, and a plane oriented at least substantially perpendicular to a geometrically central axis of a corresponding cutting element is less than or equal to about -10°, a total chamfer thickness is greater than or equal to about 0.02 inch (about 0.05 cm), a greatest tip width defined by a distance around a circumference of the cutting face over which a cutting edge extends proximate to a rotationally leading portion of the cutting element is about equal to one half of a circumference of a cutting face, and a plow angle is less than or equal to about 0°;for each of the cutting elements located within a nose region of the body, the concavity angle is in a range extending from about -10° to about 10°, the total chamfer thickness is in a range extending from about 0.012 inch to about 0.02 inch (about 0.03 cm to about 0.05 cm), the greatest tip width is in a range extending from about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters to about equal to one half of the circumference of the cutting face, and the plow angle is in a range extending from about 0° to about 15°; andfor each of the cutting elements located within a shoulder region of the body, the concavity angle is greater than or equal to about 10°, the total chamfer thickness is less than or equal to about 0.012 inch (about 0.03 cm), the greatest tip width is less than or equal to about 0.18 divided by 16 multiplied by a maximum diameter of the cutting face in millimeters, and the plow angle is greater than or equal to about 15°.

15. The earth-boring tool of claim 14, wherein:for each of the cutting elements located within the cone region of the body, a greatest concavity depth is less than or equal to about 0 inch;for each of the cutting elements located within the nose region of the body, the greatest concavity depth is in a range extending from about 0 inch to about 0.01 inch (about 0.03 cm); andfor each of the cutting elements located within the shoulder region of the body, the greatest concavity’ depth is greater than or equal to about 0.01 inch (about 0.03 cm).

16. The earth-boring tool of claim 14, wherein:for each of the cutting elements located within the cone region of the body, a tip angle defined as an included angle between opposing edges of the cutting face proximate to the rotationally leading portion of the cutting element is about 180°;for each of the cutting elements located within the nose region of the body, the tip angle is in a range extending from about 100° to about 180°; andfor each of the cutting elements located within the shoulder region of the body, the tip angle is less than or equal to about 100°.

17. The earth-boring tool of claim 14, wherein:for each of the cutting elements located within the cone region of the body, a brim width defined by a greatest distance between an edge of the cutting face and a concavity of the cutting face is about equal to a radius of the cutting face;for each of the cutting elements located within the nose region of the body, the brim width is in a range extending from about 0.03 inch (about 0.08 cm) divided by 8 multiplied by a maximum radius of the cutting face in millimeters to about the maximum radius of the cutting face; andfor each of the cutting elements located within the shoulder region of the body, the brim width is greater than or equal to about 0.03 inch (about 0.08 cm) divided by 8 multiplied by the maximum radius of the cutting face in millimeters.

18. The earth-boring tool of claim 14, w herein:for each of the cutting elements located within the cone region of the body, a brim inner angle defined by a shortest angular distance between a rotationally leading portion of the cutting face and a sidewall defining the concavity of the cutting face is about 0°; for each of the cutting elements located within the nose region of the body, the brim inner angle is in a range extending from about 0° to about 10°; andfor each of the cutting elements located within the shoulder region of the body, the brim inner angle is greater than or equal to about 10°.

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