Patent Description:
During drilling of a wellbore, cutting tools such as drill bits and underreamers are used to remove material from the earth to extend or enlarge the wellbore. The cutting tools include cutting elements that may experience wear or damage during the cutting operations. Damaged or lost cutting elements can reduce the effectiveness of the cutting tool and slow or stop work on the wellbore. Additionally, the cutting elements of the cutting tool may reach the end of their operational lifetime before the body of the cutting tool itself.

<CIT> describes a drill bit including a bit body, a plurality of blades extending radially from the bit body, a plurality of cutter pockets disposed on the plurality of blades and at least one rolling cutter disposed in one of the cutter pockets. Each rolling cutter has a substrate, a cutting face, a cutting edge, and a side surface, and at least one blocker positioned adjacent to each of the at least one rolling cutters on a leading face of the blade. Each blocker has a retention end positioned adjacent to a portion of the cutting face of each rolling cutter to retain the rolling cutter in the cutter pocket and an attachment end attached to a portion of the blade.

The present invention resides in a downhole tool as defined in claim <NUM>. Preferred embodiments of the downhole tool are defined in claims <NUM> to <NUM>.

In another aspect, the present invention resides in a method of manufacturing a downhole tool as defined in claim <NUM>. Preferred embodiments of the method are defined in claims <NUM> to <NUM>.

In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. Except for drawings that are clearly schematic or exaggerated in nature, drawings should be considered to scale for some embodiments of the present disclosure, but not to scale for other embodiments. Understanding that the drawings depict some example embodiments, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:.

Embodiments of this disclosure generally relate to devices, systems, and methods for increasing operational lifetime and/or decreasing downtime in a cutting tool. More particularly, embodiments of the present disclosure relate to devices, systems, and methods for positioning a replaceable cutting element segment on a cutting tool, where the segment has a higher wear or erosion resistance than a body or blade material of the cutting tool.

In some embodiments, a cutting tool according to the present disclosure has one or more cutting elements to remove material in a downhole environment. During cutting operations, the area at or near the cutting element may experience high abrasion and/or erosion conditions. A cutting tool according to the present disclosure may include one or more segments of a high wear and erosion resistance material positioned adjacent to or fully or partially around the cutting element to increase the operational lifetime and reparability of the cutting tool.

<FIG> shows one example of a drilling system <NUM> for drilling an earth formation <NUM> to form a wellbore <NUM>. The drilling system <NUM> includes a drill rig <NUM> used to rotate a drilling tool assembly <NUM> that extends downward into the wellbore <NUM>. The drilling tool assembly <NUM> may include a drill string <NUM>, a bottomhole assembly ("BHA") <NUM>, and a bit <NUM>, attached to the downhole end of drill string <NUM>.

The drill string <NUM> may include several joints of drill pipe <NUM> a connected end-to-end through tool joints <NUM>. The drill string <NUM> transmits drilling fluid through a central bore and transmits rotational power from the drill rig <NUM> to the BHA <NUM>. In some embodiments, the drill string <NUM> further includes additional components such as subs, pup joints, etc. The drill pipe <NUM> provides a hydraulic passage through which drilling fluid is pumped from the surface. The drilling fluid discharges through nozzles, jets, or other orifices in the bit <NUM> and/or the BHA <NUM> for the purposes of cooling the bit <NUM> and cutting structures thereon, and for transporting cuttings out of the wellbore <NUM>.

The BHA <NUM> may include the bit <NUM> or other components. An example BHA <NUM> may include additional or other components (e.g., coupled between to the drill string <NUM> and the bit <NUM>). Examples of additional BHA components include drill collars, stabilizers, measurement-while-drilling ("MWD") tools, logging-while-drilling ("LWD") tools, downhole motors, underreamers, section mills, hydraulic disconnects, jars, vibration or dampening tools, other components, or combinations of the foregoing. The bit <NUM> may also include other cutting structures in addition to or other than a drill bit, such as milling or underreaming tools.

In general, the drilling system <NUM> may include other drilling components and accessories, such as make-up/break-out devices (e.g., iron roughnecks or power tongs), valves (e.g., kelly cocks, blowout preventers, and safety valves), other components, or combinations of the foregoing. Additional components included in the drilling system <NUM> may be considered a part of the drilling tool assembly <NUM>, the drill string <NUM>, or a part of the BHA <NUM> depending on their locations in the drilling system <NUM>.

The bit <NUM> in the BHA <NUM> may be any type of bit suitable for degrading formation or other downhole materials. For instance, the bit <NUM> may be a drill bit suitable for drilling the earth formation <NUM>. Example types of drill bits used for drilling earth formations are fixed-cutter or drag bits, roller cone bits, and percussion hammer bits. In some embodiments, the bit <NUM> is an expandable underreamer used to expand a wellbore diameter. In other embodiments, the bit <NUM> is a mill used for removing metal, composite, elastomer, other downhole materials, or combinations thereof. For instance, the bit <NUM> may be used with a whipstock to mill into a casing <NUM> lining the wellbore <NUM>. The bit <NUM> may also be used to mill away tools, plugs, cement, other materials within the wellbore <NUM>, or combinations thereof. Swarf or other cuttings formed by use of a mill may be lifted to surface, or may be allowed to fall downhole.

<FIG> is a perspective view of the downhole end of a bit <NUM>, according to some embodiments of the present disclosure. The bit <NUM> in <FIG> is an example of a fixed-cutter or drag bit, and includes a bit body <NUM>, and a plurality of blades <NUM> extending radially and azimuthally therefrom. One or more of the blades <NUM>-and potentially each blade <NUM>-may have a plurality of cutting elements <NUM> connected thereto. In some embodiments, at least one of the cutting elements <NUM> has a planar cutting face. A planar cutting face may be used to shear the downhole materials, and such a cutting element may be considered a shear cutting element. In other embodiments, at least one of the cutting elements <NUM> has a non-planar cutting face. A non-planar cutting face may shear, impact/gouge, or otherwise degrade the downhole materials. Examples of non-planar cutting elements (i.e., cutting elements having a non-planar cutting face) include cutting elements with conical, ridged, domed, saddle-shaped, chisel-shaped, or other non-planar cutting faces. In some embodiments, the bit <NUM> includes one or more stabilizer pads <NUM>. A stabilizer pad <NUM> may be located on a blade <NUM> or at other locations other than a blade <NUM>, such as on the bit body <NUM>.

In <FIG>, the bit <NUM> is coupled to a rotary steerable system ("RSS") <NUM> that may be used to steer the bit <NUM> when forming or enlarging a wellbore. The RSS <NUM> may include one or more steering devices <NUM> that are selectively actuatable to steer the bit <NUM>. In some embodiments, the steering device <NUM> includes one or more pistons <NUM> that are actuatable to move in a radially outward direction relative to a longitudinal axis <NUM> of the bit <NUM> and RSS <NUM>. The RSS <NUM> may apply a force at an angle relative to the drilling direction of the bit <NUM> to deflect the drilling direction. For instance, the pistons <NUM> may apply a force at an angle that is about perpendicular to the longitudinal axis <NUM>, or that is within <NUM>°, <NUM>°, or <NUM>° of being perpendicular to the longitudinal axis <NUM>. In some embodiments, the steering device <NUM> is or includes an actuatable surface or ramp that moves in a radial direction relative to the longitudinal axis <NUM>. The bit <NUM> and RSS <NUM> may rotate about the longitudinal axis <NUM>, and the one or more steering devices <NUM> may actuate in a timed manner with the rotation to steer the bit and form a directional wellbore, or to maintain a straight wellbore.

In some embodiments, a portion of the steering device <NUM> (e.g., a piston <NUM> or housing of the piston <NUM> is radially within an RSS body <NUM> when the steering device <NUM> is in a retracted position. In some embodiments, at least a portion of the steering device <NUM> (e.g., a piston <NUM> and/or a housing of the piston <NUM>) may protrude from an RSS body <NUM> when the steering device <NUM> is in an expanded or retracted position. In some embodiments, one or more portions of the RSS <NUM> may experience greater wear and/or impact during operation.

The cutting elements <NUM> of the bit <NUM> may experience different wear rates in different regions of the bit body <NUM> or blades <NUM>. In some embodiments, the cutting elements <NUM> of the bit <NUM> experience different wear rates at a cone region <NUM>, a nose region <NUM>, a shoulder region <NUM>, or a gage region <NUM> of the blades <NUM>. For example, the cutting elements <NUM> of the nose region <NUM> may experience higher wear rates than the cutting elements <NUM> of the gage region <NUM>. In other examples, the cutting elements <NUM> of the shoulder region <NUM> experience higher wear rates than the cutting elements <NUM> of the nose region <NUM>.

In some embodiments, the bit body <NUM>, the blades <NUM>, the RSS body <NUM>, or combinations thereof include one or more body materials. The bit <NUM> and/or the RSS <NUM> may be or include a second material that is harder and/or has higher wear or erosion resistance than the body material. Conventionally, the second material may be a hardfacing material that is manually applied to the bit body <NUM>, blades <NUM>, or RSS body <NUM>. Hardfacing may be applied to a steel bit to increase the wear and/or erosion resistance of certain areas on the bit and/or blades. Hardfacing is conventionally a manual process that melts hardfacing rods. The melted material is applied to the bit, and the material cools on the bit to have a final geometry. The hardfacing may be applied in layers. As a manual process, hardfacing is variable and may have defects that result in premature failure of the hardfacing and/or the hardfaced components at or near the defects. For example, the hardfacing may fail at boundaries, along compositional changes, at layers, or other inconsistencies in the hardfacing material. In other examples, the hardfacing delaminates from the bit and/or blades due to insufficient bond strengths between the hardfacing material and the bit and/or blades. In some embodiments of a cutting tool according to the present disclosure, one or more portions of a bit <NUM> and/or RSS <NUM> include gage protection or other inserts positioned in the bit and/or blades and affixed to the bit and/or blade. The inserts may have a higher wear and/or erosion resistance than adjacent bit material to prolong the operational lifetime of a tool that may not include hardfacing.

<FIG> is a perspective view of a crown another embodiment of a bit <NUM> with a bit body <NUM> that includes a plurality of blades. In some embodiments, the bit body <NUM> includes one or more primary blades <NUM>-<NUM> and one or more secondary blades <NUM>-<NUM>. In some embodiments, the primary blades <NUM>-<NUM> and secondary blades <NUM>-<NUM> both extend to the gage region <NUM> of the bit <NUM>, but the primary blades <NUM> extend radially inward to be nearer the longitudinal axis <NUM> of the bit <NUM> when compared to the secondary blades <NUM>. In some embodiments, tertiary blades are also included, which extend to the gage region, but are farther from the longitudinal axis <NUM> than are the secondary blades <NUM>-<NUM>.

In some embodiments, a bit <NUM> includes at least one primary blade <NUM>-<NUM>, secondary blade <NUM>-<NUM>, or tertiary blade (collectively, blades <NUM>), that includes one or more segments <NUM>-<NUM>, <NUM>-<NUM> (collectively segments <NUM>) coupled thereto. In some embodiments, the segments <NUM> are replaceable cutting element segments, and include one or more cutter pockets <NUM> therein. The segments <NUM> may define cutter pockets <NUM> that include a sidewall and optionally a base. In some embodiments, a cutting element <NUM> is positioned in the cutter pocket <NUM>. While shear cutting elements <NUM> are shown in <FIG>, the cutting element <NUM> may be any cutting element (e.g., a non-planar cutting element) described herein.

In some embodiments, a first segment <NUM>-<NUM> is coupled to a blade <NUM> (e.g., primary blade <NUM>-<NUM>). The first segment <NUM>-<NUM> may be connected to the blade <NUM> by one or more connection mechanisms. For example, the first segment <NUM>-<NUM> may be connected to the blade <NUM> by welding, brazing, an adhesive, mechanical fastener(s) (e.g., bolts, screws, pins, clips, clamps, or other mechanical fasteners), mechanical interlock (e.g., grooves, dovetails, posts, recesses, ridges, other surface features, or other mechanical interlocks), other mechanisms, or combinations thereof. In some embodiments, the first segment <NUM>-<NUM> is brazed or welded to the blade <NUM>. In other embodiments, the first segment <NUM>-<NUM> is at least partially coupled to the blade <NUM> with a mechanical interlock and partially with braze or weld.

In the same or other embodiments, a second segment <NUM>-<NUM> is coupled to the same blade <NUM> that has the first segment <NUM>-<NUM> coupled thereto. The second segment <NUM>-<NUM> may be coupled to the blade <NUM> by the same or different connection mechanism as the first segment <NUM>-<NUM>. For example, the forces experienced by the first segment <NUM>-<NUM> in a first portion of the blade <NUM> may be different that the forces experienced by the second segment <NUM>-<NUM> in a second portion of the blade <NUM>. In some examples, the forces applied during a cutting operation are, for instance, different at the nose or cone regions of the blade <NUM> (and at the first segment <NUM>-<NUM>) than at the shoulder region of the blade <NUM> (and at the second segment <NUM>-<NUM>). In some embodiments, different connection mechanisms are used at least partially due to the differing forces experienced during cutting operations.

In some embodiments, a segment <NUM> includes or is made of a segment material. The segment material may be different from a bit body material or a blade material. For example, the segment material may include a ceramic, carbide, diamond, or ultrahard material that is different than a ceramic, carbide, metal, metal alloy, or other material of the bit body or blade <NUM>. An "ultrahard material" is understood to refer to those materials known in the art to have a grain hardness of <NUM>,<NUM> HV (Vickers hardness in kg/mm2) or greater. Such ultra-hard materials can include those capable of demonstrating physical stability at temperatures above <NUM>, and for certain applications above <NUM>,<NUM>, that are formed from consolidated materials. In some embodiments, the ultrahard material has a hardness values above <NUM>,<NUM> HV. In other embodiments, the ultrahard material has a hardness value above <NUM>,<NUM> HV. In yet other embodiments, the ultrahard material has a hardness value greater than <NUM> HRa (Rockwell hardness A). In some examples, the segment material includes a carbide material (e.g., tungsten carbide, tantalum carbide, titanium carbide, etc.). According to some embodiments, a carbide material forming the segment(s) <NUM> is infiltrated and/or sintered, or a cemented carbide material. In some embodiments, the carbide material is sintered and cemented (e.g., a sintered tungsten carbide including a binder and formed by additive manufacturing). In yet other examples, the segment material includes ultrahard particles embedded in a matrix material.

In some embodiments, the bit body material and/or blade material is a material with a lower erosion and/or wear resistance than the segment material. In other embodiments, the bit body material and/or blade material is a material with higher toughness than the segment material. In some examples, the bit body material and/or blade material includes a steel alloy and the segment material includes a tungsten carbide. The steel alloy may have a higher toughness than the tungsten carbide, which is more brittle, and the tungsten carbide may provide greater wear and/or erosion resistance during cutting operations.

As the segments <NUM> may experience shear and/or compressive forces during cutting operations, the connection of the segments <NUM> with the blade <NUM>-<NUM>, <NUM>-<NUM> may include a variety of geometries and/or connection mechanisms. <FIG> is an exploded perspective view of the embodiment of a bit <NUM> in <FIG>, in which the segments <NUM> are connectable to a blade <NUM>. The blade <NUM> may be a primary blade <NUM>-<NUM> as shown in <FIG>, or a secondary or tertiary blade in other embodiments.

In some embodiments, a void or recess <NUM> is formed in the blade <NUM>, and configured to receive one or more of the segments <NUM>. For instance, in <FIG>, a recess <NUM> is formed in a rotationally leading face of the blade <NUM>, and the first segment <NUM>-<NUM> and the second segment <NUM>-<NUM> is positioned at least partially within the recess <NUM> and connected to the blade <NUM> at an interface.

In some embodiments, the interface includes one or more back surfaces <NUM> and one or more side surfaces <NUM>-<NUM>, <NUM>-<NUM>. A back surface <NUM> may provide support to a segment <NUM>. In particular, the back surface <NUM> may be formed in a blade <NUM> and configured to support a rear surface <NUM> of one or more of the segments <NUM>. The rear surface <NUM> of the segments <NUM> may be opposite the rotationally leading surface <NUM> of the segments <NUM>. The side surfaces <NUM>-<NUM>, <NUM>-<NUM> may provide support to the segments <NUM> along one or more longitudinal and/or radial surfaces of the segments <NUM>. The longitudinal and/or radial surfaces of the segments <NUM> may extend between the rear surface <NUM> and the rotationally leading surface <NUM> of a segment <NUM>. For example, the first side surface <NUM>-<NUM> may be oriented about normal to the longitudinal axis <NUM>, and during cutting operations, the first segment <NUM>-<NUM> may experience a longitudinal, compressive force from the formation and transmit that compressive force to the first side surface <NUM>-<NUM>, which extends radially along the blade <NUM>. The first side surface <NUM>-<NUM> may support the first segment <NUM>-<NUM> while receiving the compressive force. In other embodiments, the first side surface <NUM>-<NUM> is oriented at a different angle relative to the longitudinal axis <NUM>, or is curved or have some other contour, shape, or orientation.

In the same or other embodiments, the second side surface <NUM>-<NUM> defining the recess <NUM> is oriented at an angle to the longitudinal axis <NUM> to provide support in the radial direction to the second segment <NUM>-<NUM>. For example, during cutting operations, the second segment <NUM>-<NUM> may experience a compressive force optionally in both the longitudinal direction (in the direction of the longitudinal axis <NUM>) and in a radial direction (normal to and toward the longitudinal axis <NUM>). The second side surface <NUM>-<NUM> may extend in both radial and longitudinal directions and support the second segment <NUM>-<NUM> while receiving the longitudinal and radial compressive force. In some embodiments, the second side surface <NUM> extends longitudinally to be parallel to the longitudinal axis <NUM>, is perpendicular to the longitudinal axis <NUM>, is be curved, or has some other contour, shape, or orientation. Thus, the first and second side surfaces <NUM>-<NUM>, <NUM>-<NUM> may be planar or non-planar.

In some embodiments, the back surface <NUM> supports the rear surface <NUM> of a segment <NUM> as the bit <NUM> rotates in the rotational direction (so that the leading surface <NUM> rotationally leads the rear surface <NUM>) about the longitudinal axis <NUM>. Shear, frictional, or other forces on the blades <NUM> from the formation or other downhole material may oppose the direction of movement of the bit <NUM>-including the segments <NUM>-during cutting operations. The back surface <NUM> defining the recess <NUM> may provide a compressive support against the shear and other forces from the formation. In some embodiments, the back surface <NUM> is planar, curved, or otherwise configured. In at least some embodiments, the back surface <NUM> is angled toward the rotational direction such that shear force applied to the segment <NUM>-<NUM>, <NUM>-<NUM> is partially directed toward the bit body. For instance, the downhole end portion of the back surface <NUM> (i.e., the portion nearest the top of the blade <NUM>) may be inclined toward (and nearer) the rotationally leading face of the blade <NUM>. In other embodiments, the uphole end portion of the back surface <NUM> is inclined toward the rotationally leading face of the blade <NUM>.

In some embodiments, the segments <NUM> are connected at the interface with the recess (and at the back surface <NUM> and/or side surfaces <NUM>) with a connection mechanism. In <FIG>, the connection mechanism includes mechanical interlocking features <NUM>. In some embodiments, the mechanical interlocking features <NUM> include complementary recesses and posts. For instance, one or more recesses may be formed in the blades <NUM> and one or more complementary posts in the segments <NUM>, or one or more recesses may be formed in the segments <NUM> and one or more posts in the blades <NUM>. In another one or more embodiments, recesses are formed in each of the segments <NUM> and in the blades <NUM>, and one or more complementary posts are formed separately and inserted into the recesses in both the segments <NUM> and the blades <NUM>. In other embodiments, the mechanical interlocking features <NUM> include dovetails, tapered dovetails, ridges, grooves, or other surface features that limit and/or prevent the movement of a segment <NUM> relative to the blade <NUM> in one or more directions.

In some embodiments, the mechanical interlocking features <NUM> are positioned in a side surface <NUM> defining the recess <NUM>. In the same or other embodiments, one or more mechanical interlocking features <NUM> are positioned in the back surface <NUM> defining the recess <NUM>. In at least one embodiment, mechanical interlocking features <NUM> are positioned in both the side surfaces <NUM> and the back surface(s) <NUM> defining the recess <NUM>. For example, a dovetail feature in the back surface <NUM> may allow a segment <NUM> to slide along the dovetail, and potentially until a post engages with a recess in a side surface <NUM>. In some embodiments, mechanical interlocking features <NUM> or other surface features assist in aligning a segment <NUM> with a location within the recess <NUM>. In some examples, mechanical interlocking features <NUM> limit and/or prevent movement of a segment <NUM> relative to the blade <NUM>-<NUM> during a brazing, welding, or other attachment process. In other examples, a first segment <NUM>-<NUM> and a second segment <NUM>-<NUM> have different mechanical interlocking features <NUM>, or have different shapes, to preventing incorrect placement and installation of the segments <NUM>.

In some embodiments, at least a portion of the side surfaces <NUM> is planar. A planar side surface <NUM> may provide a stronger connection between the interface of the recess <NUM> and the replaceable segments <NUM>. For example, the planar side surface <NUM> adjacent the segments <NUM> of the embodiment shown in <FIG> allows for more reliable brazing of the first segment <NUM>-<NUM> to the blade <NUM> and of the second segment <NUM>-<NUM> to the blade <NUM>. In other embodiments, a planar side surface <NUM> reduces or eliminates stress concentrations within the corresponding side surface <NUM>. In some embodiments, there is a discontinuous angle between a first side surface <NUM>-<NUM> and a second side surface <NUM>-<NUM>.

<FIG> is an exploded view of another embodiment of a bit <NUM> having a segment <NUM> positioned in a recess <NUM> in a blade <NUM>. Although the blade <NUM> is shown as a secondary blade, the segment <NUM> may be used in connection with a primary, tertiary, or other blade. In some embodiments, at least part of an interface defined by a recess <NUM> within the blade <NUM> and the segment <NUM> is curved. For instance, a full or partial portion of a side surface <NUM> may be curved or otherwise non-planar. In other examples, a portion of the side surface <NUM> is curved and another portion of the side surface <NUM> is planar.

In some embodiments, a curved portion of the side surface <NUM> has a radius of curvature in a range having an upper value, a lower value, or upper and lower values including any of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or any values therebetween. For example, the curved portion of the side surface <NUM> may have a radius of curvature greater than <NUM>. In other examples, the curved portion of the side surface <NUM> has a radius of curvature less than <NUM>. In yet other examples, the curved portion of the side surface <NUM> has a radius of curvature between <NUM> and <NUM>. In further examples, the curved portion of the side surface <NUM> has a radius of curvature between <NUM> and <NUM>. In yet further examples, the curved portion of the side surface <NUM> has a radius of curvature <NUM>. In still other embodiments, the radius of curvature of the side surface <NUM> is less than <NUM> or greater than <NUM>. Additionally, the radius of curvature of the side surface <NUM> may vary or may be constant.

In some embodiments, a segment <NUM> is connected to the blade <NUM> with a mechanical fastener, either alone or in combination with other connection methods. For example, a segment <NUM> and blade <NUM> may include one or more mechanical fastener connection locations <NUM>. For example, a mechanical fastener connection location <NUM> may include a threaded hole (blind hole or through hole) to receive a threaded mechanical fastener, or an unthreaded through hole. In the same or other examples, a mechanical fastener connection location <NUM> includes a hole or recess with a shoulder (e.g., a countersunk bore having a first diameter and a larger second diameter with a step therebetween) to receive a nut, the head of a bolt, or other complimentary mechanical fastener. In at least one example, a mechanical fastener connection location <NUM> in a segment <NUM> has a shoulder to engage with a head of a threaded bolt, and a mechanical fastener connection location <NUM> in a blade <NUM> has a threaded bore to engage with threads of the threaded bolt. The threads may engage to allow the head of the bolt to compress the segment <NUM> toward the interface with the blade <NUM>.

<FIG> is a perspective exploded view another embodiment of a bit <NUM> with a modular or replaceable segment <NUM> configured to connect to a primary blade, a secondary blade, or some other blade <NUM>, using one or more mechanical fastener connections. The segment <NUM> may be compressed against a back surface <NUM> and/or side surface <NUM> by mechanical fasteners. In some embodiments, a resilient, energy absorption layer <NUM> is positioned between the segment <NUM> and the blade <NUM>. The resilient layer <NUM> may be any material that may deform under compression between the segment <NUM> and the blade <NUM>. For example, the resilient layer <NUM> may include an elastically compressible material, such as a spring steel, titanium alloy, other metal alloy, a polymer, a composite material, or other material, that may deform plastically or elastically. In some embodiments, the resilient layer has a bulk elastic modulus below <NUM> GPa. In other examples, the resilient layer <NUM> includes a geometry that allows for compression of the resilient layer <NUM>. For example, the resilient layer <NUM> may include a leaf spring geometry to apply a reactive force to the compression of a mechanical fastener.

According to some embodiments, mechanical fasteners may loosen during cutting operations due, at least partially, to vibrations incurred during cutting of the formation, casing, or other material. In some embodiments, a resilient layer <NUM> may limit and/or prevent the "walking out" of a mechanical fastener during cutting operations. In other embodiments, a resilient layer <NUM> may dampen the transmission of vibration from the segment <NUM> to the blade <NUM>, thereby reducing fatigue damage to the blade <NUM>. In the same or other embodiments, an elastic or inelastic resilient layer <NUM> may absorb impacts between the segment <NUM> and the blade <NUM>, reducing damage to the segment <NUM> and/or blade <NUM>. In further embodiments, a resilient layer <NUM> may provide a compliant layer between the segment <NUM> and the blade <NUM> that may reduce stress concentrations that arise from any mismatch between contact faces of the segment <NUM> and the blade <NUM>.

In other embodiments, a resilient or other layer is part of the segment. <FIG> is a side view of another embodiment of a segment <NUM> having two materials bonded to one another. The segment <NUM> may include a segment material and a substrate material that are metallurgically bonded or mechanically fastened. In some embodiments, a segment <NUM> is additively manufactured with a segment material layer <NUM> deposited on and bonded to a substrate material layer <NUM>. The substrate material layer <NUM> may be a metal alloy, such as steel, aluminum, titanium, or other metal alloy. In some embodiments, the substrate material is a weldable material. For example, a segment <NUM> with a steel substrate material layer <NUM> may be weldable to a weldable material (e.g. steel) of a blade of a bit or other cutting tool.

In some embodiments, the segment <NUM> includes one or more cutter pockets <NUM>, which have cutting elements <NUM> positioned therein. In some embodiments, the cutter pockets <NUM> are located at least partially in the segment material layer <NUM> of the segment <NUM>. In other embodiments, the cutter pocket <NUM> is located entirely in the segment material layer <NUM> of the segment <NUM>. In yet other embodiments, the cutter pocket <NUM> is located at least partially in the substrate material layer <NUM> of the segment <NUM>. In some embodiments, a thickness of the substrate material layer <NUM> is at least <NUM> in. (<NUM>), at least <NUM> in. (<NUM>), at least <NUM> in. (<NUM>), or at least <NUM> in. In other embodiments, the substrate material layer <NUM> is less than <NUM> in.

In some embodiments, a segment includes side and rear surfaces defining a cutter pocket within the segment. In other embodiments, a segment has a side surface extending fully and no rear surface, so that the cutter pocket extends fully through the segment from a first face to an opposing second face, such that the cutter pocket is open on both sides. In such embodiments, the blade defines at least a portion of the cutter pocket (e.g., a rear surface and/or a portion of one or more side surfaces), and the cutting element is at least partially connected directly to the blade of the bit, without the segment forming a purely indirect connection between the cutting element and the blade.

<FIG> is an exploded perspective view of an example embodiment of a bit <NUM> with cutter pockets <NUM> formed in a blade <NUM> (e.g., primary blade, secondary blade, tertiary blade, etc.) of the bit <NUM>, while a protective segment is positioned adjacent the cutter pockets <NUM> and the cutting elements <NUM>. In some embodiments, the protective segment includes a faceplate <NUM> that couples to a leading face of the blade <NUM> of the bit <NUM>. The faceplate <NUM> may be similar in some respects to segments described in relation to <FIG>. For example, a faceplate <NUM> may include a segment material, such as tungsten carbide. In other examples, a faceplate <NUM> includes a substrate material that is optionally a weldable material. In yet other examples, a faceplate <NUM> includes one or more mechanical fasteners or connection locations to facilitate coupling of the faceplate <NUM> to the blade <NUM>.

The faceplate <NUM> is positioned at an interface with the blade <NUM> within a recess <NUM> which may be formed in the leading surface of the blade <NUM>. While the faceplate <NUM> is shown positioned adjacent the leading face of a primary blade <NUM>, in other embodiments, the faceplate <NUM> is positioned adjacent other blades of the bit <NUM> (e.g. secondary blades), or on other surfaces of a blade (e.g., a top surface as shown in <FIG>). The recess <NUM> defines an interface including a back surface <NUM> and a side surface <NUM>. In some examples, at least a portion of the side surface <NUM> is curved or non-planar. In other examples, at least a portion of the side surface <NUM> is planar.

The back surface <NUM> of the interface between the faceplate <NUM> and the blade <NUM> has part of one or more cutter pockets <NUM> positioned therein. For example, a base, back, or rear surface of the cutter pocket <NUM> is at least partially within the blade <NUM>. At least some of a depth of the cutter pocket <NUM> is located in the blade <NUM>, so that the side surface of the cutter pocket <NUM> is at least partially formed by the blade <NUM> and at least partially by the faceplate <NUM>. The blade <NUM> and the faceplate <NUM> therefore cooperatively define the cutter pocket <NUM> when the faceplate <NUM> is positioned relative to the blade <NUM> to align respective portions of the cutter pocket <NUM>.

According to the invention, a cutting element <NUM> is positioned in the cutter pocket <NUM> and is connected to both the blade <NUM> and to the faceplate <NUM>. The cutting element <NUM> is brazed into the cutter pocket <NUM> such that the cutting element <NUM> is brazed to both the blade <NUM> and to the faceplate <NUM>.

In at least some embodiments, the faceplate <NUM> is pre-formed to replace hardfacing applied by conventionally welding/melting process. In this context, a "pre-formed" faceplate <NUM> has a shape suitable for application, adhesion, or coupling to a bit or other downhole tool, even in the absence of melting the material. Thus, in contrast to conventional hardfacing that is melted to be applied to the bit, the pre-formed faceplate <NUM> has a defined shape apart from the downhole tool that is generally similar to the shape of the faceplate <NUM> when coupled to the downhole tool. Additionally, while conventional hardfacing adheres to a downhole tool using material within the hardfacing itself, a pre-formed faceplate <NUM> may be attached by a separate material (e.g., braze, solder, etc.) or a separate mechanism (e.g., mechanical fasteners).

The faceplate <NUM> may be formed from carbide, ceramic, matrix, metal, metal alloy, or other materials having a higher abrasion or erosion resistance than materials forming the blade <NUM>. By way of example, a casting, infiltration, molding, additive manufacturing, sintering, machining, or other process, or a combination of the foregoing, may be used to produce faceplate <NUM> made at least partially, and potentially fully, of a sintered, cemented tungsten carbide material. The faceplate <NUM> may be coupled to a blade of a steel body bit. Due to the higher abrasion and erosion resistance of the sintered, cemented tungsten carbide material as compared to the steel material of the blade, the faceplate <NUM> may act as a pre-formed, and potentially replaceable material that may replace hardfacing material to protect areas of the blade of the bit <NUM> adjacent the cutting elements <NUM>. This may allow the operational life of the bit <NUM> to be extended as wear from contact with formation and other materials, and erosion from fluid flow from nozzles or a wellbore, may be reduced. As wear of the faceplate <NUM> increases beyond an acceptable level, the faceplate <NUM> may be removed and replaced. Optionally, the cutting elements <NUM> may also be removed; however, in at least some embodiments, one or more of the cutting elements <NUM> may remain coupled to the blade <NUM> while the faceplate <NUM> is removed, and optionally while a replacement faceplate <NUM> is attached. In at least some embodiments, the faceplate <NUM> is coupled to the blade <NUM> by brazing, welding, or mechanical fastening. The faceplate <NUM> may optionally be coupled with a braze material that is different than the braze material used for brazing the cutting elements <NUM>. In at least one embodiment, the braze material used to braze the faceplate <NUM> to the blade <NUM> has a higher melting temperature than the braze material used to braze the cutting elements <NUM> within the cutter pockets <NUM>.

<FIG> is a schematic, partial cross-section of another example of a blade <NUM> having multiple faceplates coupled to the blade <NUM>. In the embodiment shown in <FIG>, a first pre-formed faceplate <NUM>-<NUM> is shown as being coupled to a leading surface of the blade <NUM>, while a second pre-formed faceplate <NUM>-<NUM> is coupled to a top (or downhole or formation facing) surface of the blade <NUM>. The first pre-formed faceplate <NUM>-<NUM> may be similar to the faceplate <NUM> of <FIG>, and is optionally positioned within a recess in the leading face of the blade <NUM>. As shown in <FIG>, the first faceplate <NUM>-<NUM> may form at least a portion of a side surface of a cutter pocket <NUM> into which a cutting element <NUM> is positioned, while the blade <NUM> may also form a portion of the side surface of the cutter pocket <NUM>, as well as a base of the cutter pocket <NUM>.

In <FIG>, a second faceplate <NUM>-<NUM> is coupled to the blade <NUM> in a manner similar to the first faceplate <NUM>-<NUM>, except that the second faceplate <NUM>-<NUM> is located at the top surface of the blade <NUM>, and optionally adjacent the cutting element <NUM>. In the particular embodiment shown, the second faceplate <NUM>-<NUM> may cover at least a portion of the cutting element <NUM> to also define a portion of the cutter pocket <NUM>; however, such an embodiment is merely illustrative. In other embodiments, the second faceplate <NUM>-<NUM> is positioned rotationally behind the cutting element <NUM> on the blade <NUM>. The second faceplate <NUM>-<NUM> may provide increased abrasion or erosion resistance to the top, formation-facing surface of the blade <NUM> as drilling occurs. In some embodiments, the second faceplate <NUM>-<NUM> is positioned at least partially within a recess formed in the top surface of the blade <NUM>; however, in other embodiments, the second faceplate <NUM>-<NUM> is wholly within a recess, or may not be within any recess at all.

<FIG> is an exploded view of another embodiment of a blade <NUM> with a faceplate coupled thereto. In some embodiments, the faceplate includes a plurality of faceplate segments <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> (collectively faceplate segments <NUM>) that are coupled to the blade <NUM>. In an example, a first faceplate <NUM>-<NUM> may be configured to be positioned adjacent to and/or protect a plurality of cutting elements <NUM>. The first faceplate <NUM>-<NUM> may be continuous across a distance adjacent to multiple cutting elements, and may reduce openings or edges that may be susceptible to increased erosion or wear rates. In other examples, at least one faceplate, such as the second faceplate segment <NUM>-<NUM> of <FIG>, is configured to be positioned adjacent to and/or protect a blade adjacent a single cutting element <NUM>. As should be appreciated in view of the disclosure herein, a faceplate segment <NUM> may be positioned adjacent to and/or protect a blade adjacent any number of cutting elements <NUM>, including partial portions of cutting elements <NUM>. Third faceplate segment <NUM>-<NUM>, for instance, may be positioned adjacent half of a cutting element <NUM>. Fourth faceplate segment <NUM>-<NUM> is shown as being positioned adjacent to and/or to protect a blade adjacent one and a half cutting elements <NUM>.

In some embodiments, having separate faceplates that are not connected to one another may allow for the relief of residual thermal or other mechanical stress in the faceplate. Allowing the second faceplate segment <NUM>-<NUM> to thermally expand or contract independently of the third faceplate segment <NUM>-<NUM> may reduce the likelihood of failure of the second faceplate segment <NUM>-<NUM> and/or third faceplate segment <NUM>-<NUM>. In other embodiments, having separate faceplates or faceplate segments that are not connected to one another may allow for the replacement or repair of individual faceplates as different regions of the blade <NUM> may experience different amounts of erosion or wear.

In some examples, the fourth faceplate segment <NUM>-<NUM> located on the nose region <NUM> of the blade <NUM> may experience a different wear/erosion rate than the second faceplate segment <NUM>-<NUM> located on the shoulder region <NUM> of the blade <NUM>. In other examples, the gage region <NUM> of the blade <NUM> may experience a substantially equal wear rate along a length of the gage <NUM>. In such examples, the gage region <NUM> may have a continuous first faceplate segment <NUM>-<NUM> such that there are no spaces or openings in the first faceplate segment <NUM>-<NUM> to increase operational lifetime of the gage region <NUM> with less risk of disproportionate wear/erosion on the first faceplate segment <NUM>-<NUM>.

In some embodiments, a faceplate has a different geometry based on the type of cutting element the faceplate protects. For example, a faceplate may have a first geometry when configured to protect a shear cutting element and another faceplate may have a second geometry when configured to protect a non-planar cutting element. A blade <NUM> with a plurality of faceplates may allow for one of more of the faceplates <NUM> to be changed, allowing the blade <NUM> and/or associated bit to be customized to the material to be degraded. A variety of faceplates and combinations of faceplate segments allow a single bit and/or blade design to be modular. In at least some embodiments, the faceplates or faceplate segments may provide pre-formed, hardened elements that replace hardfacing applied to one or more areas of the blade surface on a steel or other bit. As should be appreciated in view of the disclosure herein, the separable, modular segments of <FIG> may also be used in connection with faceplates used on regions other than a rotationally leading surface, including with a faceplate on a top surface of a blade as discussed with respect to <FIG>.

<FIG> is a side view of another embodiment of a bit <NUM> having a pre-formed, wear resistant insert <NUM> positioned in a gage region <NUM> of the bit <NUM>. The insert <NUM> may include a segment material as described herein. In some embodiments, the insert <NUM> is positioned in the blade <NUM> to provide increased wear resistance in comparison to a body material of the blade <NUM>. The insert <NUM> may be located in the blade in a void or recess, similar to the void or recess described in relation to <FIG>. The insert <NUM> may provide a surface without pockets, or without pockets for cutting elements (in contrast to the cutting element-bearing segments of the embodiments describe in relation to <FIG>) and/or be located on a non-cutting portion of the bit <NUM> (in contrast to the faceplate <NUM> located adjacent the cutting elements <NUM> in <FIG> and <FIG>). While embodiments include an insert <NUM> brazed into the blade <NUM>, in other embodiments, an insert <NUM> is connected to the blade <NUM> using welding, an adhesive, a mechanical fastener (such as a bolt, screw, pin, clip, clamp, or other mechanical fasteners), a mechanical interlock (such as grooves, dovetails, posts, recesses, ridges, other surface features, or other mechanical interlocks), other mechanisms disclosed herein or known in the art, or combinations thereof.

In other embodiments, pre-formed segments (including pre-formed hardened segments in lieu of hardfacing) are used in conjunction with cutting tools other than bits. For example, <FIG> is a side view of an embodiment of a downhole cutting tool <NUM> illustrative of an expandable milling tool or underreamer, with a plurality of segments <NUM>-<NUM>, <NUM>-<NUM>. A downhole cutting tool <NUM> may be used in milling applications to remove casing from a wellbore or other downhole environment, or in underreaming applications to degrade formation or cement. The downhole cutting tool <NUM> may have one or more cutting arms or blades <NUM>. In some embodiments, the blades <NUM> are selectively deployable at the intended location in the wellbore. The blades <NUM> may have a plurality of cutting elements <NUM> positioned on a radially outward portion of the blade <NUM>, which portion is configured to remove casing and/or formation. For example, a combination of different cutting elements <NUM> may be used on the blade <NUM> depending on the location on the blade <NUM>. In some examples, a first segment <NUM>-<NUM> carries and/or protects one or more cutting elements <NUM> that are configured to cut steel casing. In other examples, a second segment <NUM>-<NUM> carries and/or protects one or more cutting elements <NUM> configured to cut cement or earthen formation. In yet other examples, the blade <NUM> has one continuous segment that carries a plurality of types of cutting elements <NUM>, or a continuous segment or multiple segments carries a single type of cutting element <NUM>. In some embodiments, multiple types of cutting elements carried by the blade <NUM> include stabilizing or gage protection elements in addition to cutting elements.

In some embodiments, a downhole cutting tool <NUM> experiences different wear rates in different locations on the blade <NUM> due, at least partially to different areas of the blade <NUM> interacting with different materials, carrying a higher burden for material removal, experiencing different vibrational/impact forces, or myriad other reasons. For example, the wear rate of the first segment <NUM>-<NUM> while cutting casing may be greater than the second segment <NUM>-<NUM> while cutting cement or earthen formation. In another example, the wear rate of the second segment <NUM>-<NUM> may be greater than the first segment <NUM>-<NUM> while both ream earthen formation. In at least one embodiment, it is beneficial to selectively replace or repair one of the segments <NUM>-<NUM>, <NUM>-<NUM> at a time.

Some embodiments of a cutting tool with a segment according to the present disclosure are manufactured according to a method such as illustrated in <FIG>. In some embodiments, a method <NUM> includes forming a blade from a body material at <NUM>. For example, the blade may be a bit blade, such as described in relation to <FIG>, or the blade may be a milling or reamer/underreamer blade, such as described in relation to <FIG>. The blade may be formed by a variety of methods, including but not limited to casting, machining, additive manufacturing, or combinations thereof. For example, a bit body may be cast with a blade protruding therefrom. In another example, a bit is machined with a blade integral with the bit body and protruding therefrom. In another example, a bit is cast or machined, and the blade is separately formed and welded or otherwise secured to the bit body. In yet another example, a bit body and blade are additively manufactured (collectively or separately). In at least some embodiments, forming the blade at <NUM> also includes a blade with a void or recess therein. For instance, the blade may be cast, machined, or additively manufactured with a recess configured to receive a corresponding pre-formed segment that has higher wear and/or erosion resistance than the material of the blade and/or bit body.

In some embodiments, a recess defines an interface including one or more side surfaces and/or back surfaces, as described herein. The interface may include planar surfaces. In other embodiments, the interface includes at least one surface that is fully or partially curved or non-planar. In yet other embodiments, the interface is entirely curved or non-planar surfaces. According to at least some embodiments, forming the blade at <NUM> includes forming full or partial cutter pockets.

The method <NUM> may further include forming a segment from a segment material at <NUM>. In some embodiments, the segment includes one or more full or partial cutter pockets. In other embodiments, the segment is a pre-formed, protective, hardened faceplate that forms at least a portion of a cutter pocket, while a base of the cutter pocket is formed by the blade. In yet other embodiments, the segment is an insert that lacks a cutter pocket and is positioned in the blade for increased wear resistance. Optionally, the segment is an insert with gage protection or stabilizing element pockets.

In some embodiments, forming the segment includes shaping the segment to have a shape complementary to the recess and interface with the blade to fill at least a portion of the recess. For example, the segment may complementarily fit the recess and mate with substantially the entire interface. In another example, the segment may complementarily fit a portion of the void and mate with less than the entire interface. In at least one example, the segment includes a plurality of segment portions that complementarily fit the void and mate with substantially the entire interface as a complete set of segment portions.

The segment may be formed of a segment material by a variety of methods, including but not limited to casting, machining, additive manufacturing, or combinations thereof. For example, a segment may be cast to have a complementary fit with at least a portion of the void. In another example, a segment is machined (e.g., in a green state) to complementarily fit at least a portion of the void. In yet another example, a segment is additively manufactured to have a complementary fit with at least a portion of the void. In at least one example, the segment is additively manufactured, cast, or molded to approximate final dimensions and machined to complementarily fit at least a portion of the void.

The method <NUM> may further include positioning the segment relative to a blade (e.g. in a recess or blade) at <NUM> and connecting the segment to the blade at <NUM>. In some embodiments, connecting the segment to the blade includes the use of by welding, brazing, adhesive, a mechanical fastener (such as a bolt, screw, pin, clip, clamp, or other mechanical fasteners), mechanical interlock (such as grooves, dovetails, posts, recesses, ridges, other surface features, or other mechanical interlocks), or combinations thereof. In some embodiments, the segment is brazed to the blade. In other embodiments, the segment is at least partially retained with a mechanical interlock with the blade and partially retained with a braze joint between the segment and the blade. For example, a layer of braze between the segment and the blade may be approximately <NUM> in. (<NUM>) in thickness.

In some embodiments, the segment and/or interface includes one or more surface features to space the segment and blade apart and create a gap into which the braze is positioned. For example, the segment may include one or more surface features that create a constant <NUM> in. (<NUM>) to <NUM> in. (<NUM>) gap between the blade and the segment. In some embodiments, the surface features provide a gap that is greater than or less than <NUM> in. For example, different brazes may flow more efficiently in a larger or smaller gap.

In the same or other embodiments, a segment is connected to the blade with a mechanical fastener and/or a resilient layer positioned between the segment and the blade, such as described in relation to <FIG>. In such embodiments, the resilient layer may provide vibration dampening and/or absorption to limit vibration damage to the segment, the blade, or the connection therebetween. In some embodiments, a segment is connected to the blade with by using a substrate of the segment. For instance, the segment may include a segment material bonded or otherwise coupled to a substrate material, as described herein in relation to <FIG>. The substrate material may be welded or brazed to a blade material, or may be coupled to the blade using mechanical fasteners.

According to the invention, the method <NUM> further includes positioning and connecting a cutting element in a cutter pocket of the segment and/or blade at <NUM>. A faceplate is connected to the blade (see <FIG>), and a cutting element is subsequently positioned in and connected to the cutter pocket formed by the blade and faceplate.

According to the invention, utilizing braze materials and joints to connect the segment to the blade and using braze materials and joints to connect the cutting element to the cutter, the faceplate is first connected to the blade and the cutting element is subsequently connected to the cutter pocket formed by the blade and faceplate. For instance, a first brazing may include a relatively higher temperature braze, for example, greater than <NUM>,<NUM> °F (<NUM>), and a second brazing may include a relatively lower temperature braze, for example, less than <NUM> °F (<NUM>). Performing the second braze at a lower temperature may limit and/or prevent damage to, or weakening of, the prior braze. In some embodiments, the melting temperature of the high temperature braze and low temperature braze is at least <NUM> °F (<NUM>) apart from one another to limit damage to the prior braze. Methods of brazing may therefore include performing a lower temperature braze process at a temperature that is at least <NUM> °F (<NUM>) lower than a high temperature braze process. In other embodiments, the high temperature braze and low temperature braze are performed at least <NUM> °F (<NUM>) apart from one another to limit damage to the prior braze. In some embodiments, a segment and/or cutting element is heated to the lower brazing temperature to selectively facilitate repair and/or replacement of the segment and/or cutting element connected by the low temperature braze.

While embodiments of segments have been described herein with and without cutter pockets or with a portion of a cutter pocket therein, the segment itself may additionally have a range of geometries relative to the blade. <FIG> is a side cross-sectional view of another embodiment of a bit <NUM>, according to the present disclosure. In some embodiments, a pre-formed, replaceable segment <NUM> is optionally hardened relative to a blade material, and connected to the blade <NUM>, which extends from a bit body <NUM>. A cutting element <NUM> may be positioned in and connected to the segment <NUM>. In some embodiments, a size of the segment <NUM> is defined by a vertical ratio and a horizontal ratio relative to a cutting tip <NUM> of the cutting element <NUM>. The cutting tip <NUM> may be the outermost point of the cutting element <NUM> from the bit body <NUM>, such that the cutting tip <NUM> is the first point of the cutting element <NUM> to contact the material being removed during cutting operations.

In some embodiments, the blade <NUM> has a blade height <NUM>-<NUM> and the segment <NUM> has a segment height <NUM>-<NUM>. The blade height <NUM>-<NUM> is measured from the bit body <NUM> to the cutting point <NUM>. The segment height <NUM>-<NUM> is measured from the point of the segment <NUM> closest to the bit body <NUM> to the cutting point <NUM>.

The vertical ratio is the ratio of the segment height <NUM>-<NUM> to blade height <NUM>-<NUM>. For example, a segment height <NUM>-<NUM> that is one half of the blade height <NUM>-<NUM> has a vertical ratio of <NUM>. In some embodiments, the vertical ratio is in a range having an upper value, a lower value, or upper and lower values including any of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or any values therebetween. For example, the vertical ratio may be greater than <NUM>. In other examples, the vertical ratio is between <NUM> and <NUM>. In yet other examples, the vertical ratio is between <NUM> and <NUM>. In further examples, the vertical ratio is between <NUM> and <NUM>. In at least one example, the vertical ratio is greater than <NUM>. In still other embodiments, the vertical ratio is less than <NUM> or even greater than <NUM> (e.g., where the segment is inset into the bit body and extends the full blade height <NUM>-<NUM>).

In some embodiments, the blade <NUM> has a blade width <NUM>-<NUM> and the segment <NUM> has a segment width <NUM>-<NUM>. The blade width <NUM>-<NUM> is measured from the rearmost point of the blade <NUM> to the cutting point <NUM>. The segment width <NUM>-<NUM> is measured from the rearmost point of the segment <NUM> to the cutting point <NUM>.

The horizontal ratio is the ratio of the segment width <NUM>-<NUM> to blade width <NUM>-<NUM>. For example, a segment width <NUM>-<NUM> that is one half of the blade width <NUM>-<NUM> has a horizontal ratio of <NUM>. In some embodiments, the horizontal ratio is in a range having an upper value, a lower value, or upper and lower values including any of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or any values therebetween. For example, the horizontal ratio may be greater than <NUM>. In other examples, the horizontal ratio is between <NUM> and <NUM>. In yet other examples, the horizontal ratio is between <NUM> and <NUM>. In further examples, the horizontal ratio is between <NUM> and <NUM>. In at least one example, the horizontal ratio is greater than <NUM>. In still other embodiments, the horizontal ratio is less than <NUM> or greater than <NUM> (e.g., where the segment over hangs the blade <NUM>). In <FIG>, the dashed lines on the base of the blade illustrate an example segment <NUM> having a horizontal ratio equal to <NUM>.

In at least one embodiment, a cutting tool according to the present disclosure has an increased operational lifetime relative to a conventional cutting tool. In some embodiments, a cutting tool with blades incorporating pre-formed, replaceable segments according to the present disclosure exhibits increased wear/erosion resistance relative to a conventional cutting tool. For instance, one or more segments may be located in places on the blade where wear and erosion are highest. When the segments wear, they may be removed and replaced to extend the operational life of the bit body and blades. For instance, phantom lines illustrate the use of example mechanical fasteners (e.g., complementary dovetail pins and sockets) that may be used in addition to, or instead of, braze, welding, or other fastening methods. In the same or other embodiments, a cutting tool with blades incorporating segments according to the present disclosure may allow for faster and/or easier repairs relative to conventional cutting tools in which the blades are integral with the body, or even in which the blades themselves are removable or replaceable.

Claim 1:
A downhole tool, comprising:
a rotatable body (<NUM>);
a blade (<NUM>) coupled to the body, the blade (<NUM>) including a recess (<NUM>) therein that defines an interface (<NUM>, <NUM>); and
a pre-formed faceplate (<NUM>) to replace hardfacing, the pre-formed faceplate (<NUM>) coupled to the blade (<NUM>) along at least a portion of the interface (<NUM>, <NUM>), the blade (<NUM>) and pre-formed faceplate (<NUM>) cooperatively defining a plurality of cutter pockets (<NUM>) partially within the pre-formed faceplate (<NUM>) and partially within the blade (<NUM>), wherein a base surface of each cutter pocket (<NUM>) is defined within the blade (<NUM>) and a side surface of each cutter pocket (<NUM>) is defined by the blade (<NUM>) and the faceplate (<NUM>); and
a plurality of cutting elements (<NUM>), each cutting element (<NUM>) brazed to both the blade (<NUM>) and to the faceplate (<NUM>) in a respective cutter pocket (<NUM>) of the plurality of cutter pockets (<NUM>).