WO2016069712A1

WO2016069712A1 - Methods of manufacturing bit bodies

Info

Publication number: WO2016069712A1
Application number: PCT/US2015/057748
Authority: WO
Inventors: Ambalavanan SACHIDANANDAM; Mustafa S. RAMPURWALA
Original assignee: Smith International, Inc.
Priority date: 2014-10-31
Filing date: 2015-10-28
Publication date: 2016-05-06

Abstract

A method for manufacturing a drill bit includes coupling displacements to a mold with a series of attachment members, filling a cavity of the mold with a material, and heating the material to form a bit body of the drill bit. The method may also include removing the displacements to expose cutter pockets in the bit body and coupling cutting elements to the cutter pockets.

Description

METHODS OF MANUFACTURING BIT BODIES CROSS REFERENCE TO RELATED APPLICATION

[0001] This Application claims the benefit of and priority to U.S. Provisional Application 62/073,237 filed on October 31 , 2014, the entirety of which is incorporated herein by reference.

BACKGROUND

[0002] Systems for drilling boreholes into the earth for the recovery of hydrocarbons, such as oil and natural gas, typically include a drill bit mounted on the lower end of a drill string. The drill bit is configured to rotate and engage the earthen formation and thereby advance the drill bit into the formation to form a borehole. Common drill bits for use on borehole drilling systems include roller cone bits and fixed cutter bits (i.e., a drag bit). Roller cone bits include a series of cones configured to rotate relative to the drill string during a drilling operation. In contrast, fixed cutter bits typically include no moving parts. Fixed cutter bits may be used in either rotary drilling techniques or in percussion drilling techniques in which the drill bit is repeatedly raised and lowered to strike the earthen formation and thereby progressively increase the depth of the borehole.

[0003] Fixed cutter drill bits for use in subterranean drilling operations typically include a drill body and a plurality of cutting elements arranged on the drill body. Conventionally, the drill body is formed either by machining a billet material into the desired shape or by molding. Fine features of the drill bit, such as cutter pockets configured to receive and support the cutting elements, may be formed by positioning preformed displacements within a cavity of the mold prior to filling the cavity of the mold. However, such displacements are conventionally loosely fit or set into pockets within the mold, which permits the displacements to slide out of the proper position and/or may result in a technician improperly seating the displacements in the mold because visual inspection may be insufficient to reveal slight misalignments between the displacements and the mold. If the displacements are not properly positioned or seated within the mold, the cutter pockets and other fine features of the drill bit may be misplaced and/or improperly oriented on the drill body. Then, when the cutting elements are seated in the cutter pockets and attached to the drill bit body, the cutting elements will be misaligned on the drill body (e.g., the cutting elements may project farther out from the bit body than designed). This misalignment between the cutting elements and the drill body may negatively affect the drilling dynamics of the drill bit and cause premature wear and failure of the cutting elements and the bit body.

SUMMARY

[0004] The present disclosure is directed to various methods of manufacturing cutting tools. Such tools may be used in subterranean drilling or mining operations. In some embodiments, the method includes coupling a series of displacements to a mold with a series of attachment members, filling a cavity of the mold with a bit body material, and heating the bit body material to form a bit body of the drill bit. The method may further include removing the bit body from the mold and removing the series of displacements to expose a plurality of cutter pockets in the bit body. The method may also include coupling a series of cutting elements to the cutter pockets. The attachment members may be integrally formed in the displacements or integrally formed in the mold. Coupling the series of displacements to the mold may include press-fitting the attachment members into openings in the displacements and corresponding blind bores in the mold. The openings in the displacements may be either through holes or blind bores. The bit body material may include a matrix material and a metal binder and the attachment members may be formed from sand, graphite, ceramic, clay, or any combination thereof. An axis of each attachment member may define an angle from approximately 45 degrees to approximately 135 degrees relative to a longitudinal axis of each of the displacements. The method may include coupling an externally threaded tapered pin to one end of the bit body.

[0005] The present disclosure is also directed to various embodiments of a mold for manufacturing a drill bit having a series of blades and a series of cutter pockets defined in each of the blades. In some embodiments, the mold defines a cavity corresponding to an outer shape of the drill bit, a series of depressions corresponding to an outer shape of the blades, and a series of attachment members extending from an inner surface of the mold. The attachment members are configured to position and secure a series of displacements in the cavity. The displacements correspond to the cutter pockets in the bit body. The mold may include a series of arcuate notches defined in the cavity. The arcuate notches are configured to receive the series of displacements. Each attachment member may be a blind bore configured to receive a pin coupled to each of the displacements or a projection configured to engage an opening in each of the displacements. The openings in the displacements may be either through holes or blind bores. The projections may be any suitable shape, such as cylindrical. The mold may also include a series of displacements configured to form the cutter pockets in the drill bit. The displacements are coupled to the mold by the series of attachment members. Each of the displacements may define any suitable angle relative to a respective one of the attachment members, such as from approximately 45 degrees to approximately 135 degrees.

[0006] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in limiting the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features and advantages of embodiments of the present disclosure will become more apparent by reference to the following detailed description when considered in conjunction with the following drawings. In the drawings, like reference numerals are used throughout the figures to reference like features and components. The figures are not necessarily drawn to scale.

[0008] FIG. 1 is a perspective view of a fixed cutter drill bit according to one embodiment of the present disclosure;

[0009] FIG. 2 is a perspective view of a mold used during one method of manufacturing the fixed cutter drill bit of FIG. 1; and

[0010] FIG. 3 is a cross-sectional view of the mold illustrated in FIG. 2 and a plurality of displacements coupled to the mold according to one method of manufacturing the fixed cutter drill bit of FIG. 1.

DETAILED DESCRIPTION

[0011] The present disclosure is directed to various methods for manufacturing cutting tools. Such tools could be used during subterranean mining and drilling operations. In particular, the present disclosure is directed to various methods for properly aligning cutting elements on the cutting tools by properly aligning and securing displacements within a mold during a process of forming the cutting tool. The cutting tools may be any kind of cutting tool suitable for the intended application, such as, for instance, fixed cutter bits (e.g., drag bits or percussion bits), rotary drill bits, or reamers.

[0012] With reference now to FIG. 1 , a fixed cutter drill bit 100 manufactured according to various methods of the present disclosure is illustrated. The drill bit 100 includes a dome-shaped bit body 101, a cylindrical shank 102 extending from one end of the bit body 101, and a tapered pin 103 extending from a side of the shank 102 opposite the bit body 101. The tapered pin 103 includes external threads 104 for coupling the drill bit 100 to a drill string assembly configured to rotatably advance the drill bit 100 into a subterranean formation to form a borehole. The shank 102 defines a pair of opposing flats or notches 105 configured to be engaged by a suitable tool for making or breaking the connection between the drill bit 100 and the drill string.

[0013] With continued reference to the embodiment illustrated in FIG. 1 , the drill bit 100 also includes a plurality of blades or fins 106 circumferentially disposed around the bit body 101 and extending outward from an outer bit face 107 of the bit body 101. Although in the illustrated embodiment the drill bit 100 includes six blades 106, in one or more alternate embodiments, the drill bit 100 may include any other suitable number of blades 106, such as, for instance, from two to ten blades 106, depending on the composition of the earthen formations the drill bit 100 is intended to cut through and the intended operations conditions of the drill bit 100 (e.g., rotational drill speed). Additionally, although in the illustrated embodiment the blades 106 are uniformly spaced apart around the bit body 101 (e.g., adjacent blades 106 are spaced apart by approximately 60 degrees), in one or more alternate embodiments, the blades 106 may be non-uniformly spaced around the bit body 101. In each of the blades 106, a plurality of cutter pockets 108 are defined. The cutter pockets 108 are configured to accept and support a plurality of cutting elements 109 therein. In FIG. 1, one of the cutting elements 109 is omitted to clearly reveal one of the cutter pockets 108. Additionally, in the illustrated embodiment, each of the blades 106 is a primary blade that extends radially from proximal a central axis 110 of the bit body 101 toward the shank 102. In one or more alternate embodiments, the drill bit 100 may include one or more secondary blades that extend radially from a point spaced apart from the central axis 110 toward the shank 102 (e.g., the drill bit 100 may include one or more secondary blades that do not extend the same extent or length along the bit body 101 as the primary blades 106). In one more alternate embodiments, the cutting elements 109 may be incorporated into any other suitable type of tool, such as a rotary bit or a reamer.

[0014] With continued reference to the embodiment illustrated in FIG. 1, each of the cutting elements 109 includes an ultra-hard cutting layer 111 coupled to a substrate 112. The substrate 112 is configured to facilitate attachment of the cutting element 109 in the cutter pockets 108 of the bit body 101, such as by brazing or any other suitable process. Additionally, in the illustrated embodiment, each of the ultra-hard cutting layers 111 is cylindrical and includes a working surface 113, an interface surface 114 opposite the working surface 113, a sidewall 115 extending between the working surface 113 and the interface surface 114, and a cutting edge 116 defined where the working surface 113 meets the sidewall 115. The cutting edge 116 is the portion of the cutting element 109 that is configured to engage the earthen formation during a subterranean drilling or mining operation. The interface surface 114 is the portion of the ultra-hard cutting layer 111 that abuts the substrate 112 when the ultra-hard cutting layer 111 is coupled to the substrate 112 to form the cutting element 109. Although the ultra-hard cutting layers 111 in the illustrated embodiment are cylindrical, in one or more alternate embodiments, the ultra-hard cutting layers 111 may have any other suitable shape depending upon the intended application of the drill bit 100 into which the ultra-hard cutting layers 111 are incorporated. Additionally, although the ultra-hard cutting layers 111 in the illustrated embodiment each include a planar working surface 113 and interface surface 114, in one or more alternate embodiments, the working surfaces 113 and interface surfaces 114 of the ultra-hard cutting layers 111 may each be non-planar. For instance, the interface surfaces 114 of the ultra-hard cutting layers 111 may include one or more features configured to join the ultra-hard cutting layer 111 to the substrate 112, such as, for instance, depressions (e.g., grooves or channels) or projections (e.g., ribs) configured to engage corresponding features on the substrate 112, and the working surface 113 may be generally pointed (e.g., conical), may include a crest or ridge extending across the diameter of the cutter, or any other non-planar working surface 113 may be used. Additionally, in one or more embodiments, an intermediate layer may be disposed between the substrate 112 and the ultra-hard cutting layer 111.

[0015] The substrates 112 may be formed from any material suitable to facilitate attachment of the cutting elements 109 to the bit body 101, such as, for instance, cemented tungsten carbide. In one embodiment, the ultra-hard cutting layers 111 each comprise a polycrystalline diamond ("PCD") material. In one or more embodiments, the ultra-hard cutting layers 111 may comprise any suitable kind of thermally stable polycrystalline diamond ("TSP") material, such as, for instance, non-metal catalyst PCD, binderless PCD, or leached PCD. In an alternate embodiment, the ultra- hard cutting layers 111 may be thermally stable polycrystalline cubic boron nitride (PCBN). The ultra-hard cutting layer 111 may be coupled to the substrate 112 by any suitable process or mechanism, such as, for instance, brazing, high-pressure high-temperature (HPHT) sintering, mechanical fastening, or any combination thereof.

[0016] In the embodiment illustrated in FIG. 1, the drill bit 100 also defines a central longitudinal bore 117 and a plurality of fluid passages 118 in fluid communication with the central longitudinal bore 117. The drill bit 100 may also define a plurality of ports or nozzles 119 defined in the bit face 107 and in fluid communication with the fluid passages 118. Together, the central longitudinal bore 117, the fluid passages 118, and the nozzles 119 are configured to deliver drilling fluid from the drill string to the bit face 107 to flush away formation cuttings and to dissipate heat from the drill bit 100 during a drilling or mining operation. Additionally, in the illustrated embodiment, the drill bit 100 includes a plurality of fluid flow courses 120 defined between adjacent blades 106 to channel the flow of the drilling fluid and formation cuttings away from the drill bit 100. The drilling fluid is configured to direct the formation cuttings up through an annular gap defined between the drill string and the borehole formed by the drill bit 100 advancing into the earthen formation. [0017] With reference now to the embodiment illustrated in FIGS. 2 and 3, a method of manufacturing the drill bit 100 illustrated in FIG. 1 will now be described. In one embodiment, the method of manufacturing the drill bit 100 includes obtaining or manufacturing a mold 200 defining a cavity 201 corresponding to the desired shape and size of the bit body 101. The cavity 201 of the mold 200 defines a plurality of radially disposed depressions 202 corresponding to the number, shape, size, orientation, and arrangement of the blades 106 of the drill bit 100. In the illustrated embodiment, the cavity 201 of the mold 200 also defines a plurality of arcuate notches 203 in each of the radial depressions 202 and a blind bore 204 in each of the arcuate notches 203. The mold 200 may include any suitable number of arcuate notches 203 depending on the desired number of cutting elements 109 and the desired spacing between adjacent cutting elements 109 on the drill bit 100.

[0018] With reference now to FIG. 3, the method of manufacturing the drill bit 100 includes positioning a plurality of displacements 205 in the arcuate notches 203 of the mold 200. The displacements 205 are configured to form the cutter pockets 108 in the blades 106 of the drill bit 100 that are configured to receive and support the cutting elements 109. Additionally, in one embodiment, the shape and size of the displacements 205 may be selected depending on the desired corresponding shape and size of the cutting elements 109. The use of displacements 205 to form the cutter pockets 108 may facilitate the use of a single mold 200 to form drill bits 100 configured to support a variety of cutting elements 109 having different shapes and/or sizes by selecting the appropriately shaped and sized displacements 205 to position in the mold 200. For instance, a variety of displacements 205 having different shapes and sizes may be positioned into a single mold 200 depending on the desired shape and the size of the cutting elements 109 in the drill bit 100. High-tolerance and high-precision features may be formed within the displacements 205, rather than in the mold 200, which could be costly, time consuming, and/or cumbersome. [0019] With continued reference to FIG. 3, the displacements 205 may be aligned and secured within the arcuate notches 203 defined in the cavity 201 of the mold 200. In some embodiments, aligning and securing the displacements 205 within the mold 200 includes inserting an attachment member 206 (e.g., a rod or a pin) through an opening 207 in each of the displacements 205 and into the corresponding blind bore 204 in the mold 200. In the illustrated embodiment, the openings 207 in the displacements 205 are through holes, although in one or more alternate embodiments, the openings 207 may be blind holes. The attachment members 206 may have any suitable cross- sectional shape such as an axisymmetric cross-section or a non-axisymmetric cross-section. For example, the attachment members may any suitable cross-sectional geometric shape, such as a circular or oval cross-section. In some embodiments, the cross-section shape of the attachment members 206 may be a polygon, such as a square, rectangle, or triangle, to prevent or reduce rotation of the displacement 205 about an axis 208 of the attachment member 206, which could result in the formation of misaligned cutter pockets 108 in the bit body 101. In one embodiment, the shape and size of the openings 207 in the displacements 205 and the blind bores 204 in the mold 200 substantially correspond to the cross-sectional shape and size of the attachment members 206. In one embodiment, the attachment members 206 may be press-fit into both the openings 207 in the displacements 205 and the blind bores 204 in the mold 200, although in one or more alternate embodiments, the attachment members 206 may be coupled to the displacements 205 and the mold 200 by any other suitable process, such as, for instance, bonding. The engagement between attachment members 206 and the displacements 205 and the mold 200 is configured to ensure or promote proper positioning and alignment of the displacements 205 in the cavity 201 of the mold 200 such that the cutter pockets 108 are properly formed in the bit body 101. The proper formation of the cutter pockets 108 in the bity body 101 facilitates the proper positioning and alignment between the cutting elements 107 and the bit body 101. The displacements 205 may be made out of any suitable material, such as, for instance, sand, graphite, ceramics, clay, or any combinations thereof.

[0020] Additionally, although in the illustrated embodiment the attachment members 206 are separate components from the displacements 205 and the mold 200, in one or more alternate embodiments, the attachment members 206 may be integrally formed with either the displacements 205 or the mold 200. For instance, in one embodiment, the mold 200 may include a plurality of posts configured to be received in the openings 207 in the displacements 205. In another embodiment, the displacements 205 may each include an integral post configured to be received in the blind bores 204 in the mold 200. The attachment member 206 may be made out of any suitable material, such as, for instance, sand, graphite, ceramics, clay, or any combinations thereof. Additionally, in one embodiment, the attachment members 206 may be made out of the same material as the displacements 205, although in one or more alternate embodiments, the attachment members 206 and the displacements 205 may be made out of different materials.

[0021] In the embodiment illustrated in FIG. 3, the axis 208 of each attachment member 206 defines an angle a, such as for instance, from approximately 45 degrees to approximately 135 degrees, relative to a longitudinal axis 209 of the displacement 205 to which the attachment member 206 is coupled. In one or more alternate embodiments, the axis 208 of each attachment member 206 may define any other suitable angle a relative to the longitudinal axis 209 of the associated displacement 205, such as, for instance, approximately 45 degrees or less or greater than approximately 135 degrees. In some embodiments, the axis 208 of each attachment member 206 defines an obtuse angle a relative to the longitudinal axis 209 of the displacement 205, e.g., from greater than 90 degrees to 175 degrees.

[0022] In some embodiments, additional displacements may be inserted into the cavity of the mold 200 that correspond to any other features of the bit body 101, such as, for instance, displacements corresponding to the shapes and size of the central longitudinal bore 117 (e.g., a mandrel), the fluid passages 118, and/or the nozzles 119 of the bit body 101.

[0023] In some embodiments, a remainder of the cavity 201 of the mold 200 is filled with a bit body material 210 configured to form the bit body 101. The bit body material 210 may be any suitable material depending on the desired strength and durability of the bit body 101. In one embodiment, the bit body material 210 is composed of one or more matrix powders (e.g., tungsten carbide (WC) powder or tungsten (W) powder) and a binder material. In one embodiment, the binder material may be any suitable metal, such as, for instance, iron, cobalt, nickel, copper, manganese, zinc, tin, alloys thereof (e.g., nickel alloy), or any suitable combination thereof. The metal binder material may be provided either as a separate powder or as a solid body (e.g., a disc or slug of binder material) placed on top of the matrix powder. In another embodiment, the metal binder powder may be intermixed with the matrix powder. Additionally, in one or more embodiments, an organic solvent (e.g., alcohol) may be mixed with the metal binder powder and the matrix powder to form a slurry or a paste. Mixing the organic solvent into the matrix powder and the binder powder may facilitate ease of handling the bit body material 210 while filling the cavity 201 of the mold 200 with the bit body material 210. The organic solvent may be selected such that is does not affect the chemical characteristics of the matrix material. Additionally, a flux may be used as a chemical cleaning agent.

[0024] In some embodiments, the bit body material 210 may be tightly packed in the cavity 201 of the mold 200 by any suitable process, such as, for instance, shaking the mold 200 to settle the bit body material 210 in the cavity 201 and/or pressing the bit body material 210 into the cavity 201 of the mold 200. In the illustrated embodiment, when the bit body material 210 is tightly packed into the cavity 201 of the mold 200, the bit body material 210 is tightly packed into the depressions 202 in the mold 200 corresponding to the blades 106 and tightly surrounds the displacements 205 defining the cutter pockets 108. [0025] In some embodiments, the cavity 201 of the mold 200 may be closed and the mold 200 and the bit body material 210 in the cavity 201 may be heated to a temperate equal to or exceeding the melting point of the binder material (i.e., the infiltration temperature of the binder material). In some embodiments, heating the mold 200 includes placing the mold 200 in a furnace generating temperatures from approximately 1000 °C to approximately 1800 °C depending on the melting point of the selected metal binder material. The mold 200 may be heated at or above the infiltration temperature of the binder material for a sufficient duration to cause the liquefied binder material to infiltrate into the matrix material. The liquefied binder material may be drawn through the matrix material due to capillary action. In an embodiment in which the matrix material and the binder material are mixed with an organic solvent to form a slurry, the organic solvent will burn off while heating the mold 200.

[0026] The mold 200 may be made out of any suitable heat resistant material capable of withstanding the high temperatures generated during the drill bit manufacturing process, such as, for instance, graphite, sand, or ceramics. The mold 200 may be made by any suitable process, such as, for instance, casting, machining, additive manufacturing techniques, and any combinations thereof.

[0027] The mold 200 may be cooled to a temperature below the infiltration temperature of the binder material (e.g., at room temperature), causing the binder material to solidify and bind the matrix particles together to form a solid body matrix in the desired size and shape of the bit body 101. After cooling, the bit body 101 may then be removed from the mold 200 and the displacements 205 and the attachment members 206 may be removed to expose the cutter pockets 108 in the bit body 101 that are configured to receive the cutting elements 109, as illustrated in FIG. 1. The displacements 205 and the attachment members 206 may be removed by any suitable processes. For instance, in an embodiment in which the displacements 205 and the attachment members 206 are formed from sand, the displacements 205 and the attachment members 206 may be removed by blowing out the displacements 205 and the attachment members 206. In one or more embodiments, the bit body 101 may include one or more post-processing procedures, for example, to achieve a desired shape, such as, by machining to achieve a final outer diameter.

[0028] A plurality of cutting elements 109 may then be seated in the cutter pockets 108 and attached to the bit body 201. The cutting elements 109 may be attached to the bit body 101 by any suitable process, such as, for instance, welding, brazing, mechanical fastening, or any combination thereof. As described above, aligning and securing the displacements 205 in the cavity 201 of the mold 200 (e.g., by inserting the attachment members 206 into the openings 207 in the displacements 205 and into the aligned blind bores 204 in the mold 200) ensures or promotes the proper location and orientation of the cutter pockets 108 in the bit body 201. Properly forming the cutter pockets 108 in the bit body 201 facilitates properly aligning and seating the cutting elements 109 in the cutter pockets 108 when coupling the cutting elements 109 to the bit body 101. Properly aligning and positioning the cutting elements 109 on the bit body 101 may improve cutting efficiency, cutting dynamics, and durability of the drill bit 100 compared to an otherwise comparable drill bit having misaligned cutting elements.

[0029] The bit body 101 may be coupled to the cylindrical shank 102 and the tapered pin 103 by any suitable process, such as, for instance, welding, brazing, mechanical fastening, or any combination thereof. The cylindrical shank 102 and the tapered pin 103 may be formed by any suitable processes, such as, for instance, machining or molding. In an alternate embodiment, the cylindrical shank 102 and the tapered pin 103 may be integrally and concurrently formed with the bit body 101 by selecting a mold 200 defining an interior cavity 201 corresponding to the exterior size and shape of the bit body 101, the cylindrical shank 102, and the tapered pin 103.

[0030] It will be appreciated that the aforementioned tasks of aligning and securing a plurality of displacements within a mold, filling the mold with a material, heating the material to form the bit body, and coupling the cutting elements to the bit body may be performed to manufacture any other suitable kind of cutting tool, such as, for instance, a roller cone drill bit or a reamer, by selecting a mold and displacements having a size, shape, and configuration corresponding to the size, shape, and configuration of the desired cutting elements and cutting tool.

[0031] While this disclosure has been described in detail with particular references to embodiments thereof, the embodiments described herein are not intended to be exhaustive or to limit the scope of the invention to the exact forms disclosed. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of assembly and operation can be practiced without meaningfully departing from the principles, spirit, and scope of this invention. Additionally, as used herein, the term "substantially" and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Furthermore, as used herein, when a component is referred to as being "on" or "coupled to" another component, it can be directly on or attached to the other component or intervening components may be present therebetween.

[0032] In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not just structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke means-plus-function for any limitations of any of the claims herein, except for those in which the claim expressly uses the words 'means for' together with an associated function. Each addition, deletion, and modification to the embodiments that fall within the meaning and scope of the claims is to be embraced by the claims.

Claims

WHAT IS CLAIMED IS:

1. A method of manufacturing a drill bit for use in a drilling operation, the method comprising:

coupling a plurality of displacements to a mold with a plurality of attachment members;

filling a cavity of the mold with a bit body material; and

heating the bit body material to form a bit body of the drill bit.

2. The method of claim 1, further comprising:

removing the bit body from the mold; and

removing the plurality of displacements to expose a plurality of cutter pockets in the bit body.

3. The method of claim 2, further comprising coupling a plurality of cutting elements to the cutter pockets.

4. The method of claim 1, wherein the attachment members are integrally formed in the displacements.

5. The method of claim 1, wherein the attachment members are integrally formed in the mold.

6. The method of claim 1, wherein coupling the plurality of displacements to the mold comprises press-fitting the attachment members into openings in the displacements and corresponding blind bores in the mold.

7. The method of claim 6, wherein the openings in the displacements are through holes.

8. The method of claim 6, wherein the openings in the displacements are blind bores.

9. The method of claim 1 , wherein the bit body material comprises a matrix material and a metal binder.

10. The method of claim 1, wherein the attachment members comprise a material selected from the group of materials consisting of sand, graphite, ceramic, clay, and combinations thereof.

11. The method of claim 1, wherein an axis of each attachment member defines an angle from approximately 45 degrees to approximately 135 degrees relative to a longitudinal axis of each of the displacements.

12. The method of claim 1 , further comprising coupling an externally threaded tapered pin to one end of the bit body.

13. A mold for manufacturing a drill bit comprising a plurality of blades and a plurality of cutter pockets defined in the blades, the mold comprising:

a cavity defined in the mold corresponding to an outer shape of the drill bit;

a plurality of depressions defined in the mold corresponding to an outer shape of the blades; and a plurality of attachment members extending from an inner surface of the mold, the plurality of attachment members being configured to position and secure a plurality of displacements in the cavity, the displacements corresponding to the cutter pockets.

14. The mold of claim 13, further comprising a plurality of notches defined in the cavity configured to receive the plurality of displacements.

15. The mold of claim 13, wherein each of the plurality of attachment members comprises a blind bore configured to receive a pin coupled to each of the displacements.

16. The mold of claim 13, wherein each of the plurality of attachment members comprises a projection configured to engage an opening in each of the displacements.

17. The mold of claim 16, wherein the projection is cylindrical.

18. The mold of claim 16, wherein the opening in each of the displacements is a through hole.

19. The mold of claim 16, wherein a longitudinal axis of each of the plurality of displacements defines an angle relative to an axis of a respective one of the plurality of attachment members, the angle ranging from approximately 45 degrees to approximately 135 degrees.

20. The mold of claim 13, further comprising:

a plurality of displacements configured to form the plurality of cutter pockets in the drill bit coupled to the mold by the plurality of attachment members.