Abstract: Thermally stable diamond bonded materials and compacts include a diamond body having a thermally stable region and a PCD region, and a substrate integrally joined to the body. The thermally stable region has a microstructure comprising a plurality of diamond grains bonded together by a reaction with a reactant material. The PCD region extends from the thermally stable region and has a microstructure of bonded together diamond grains and a metal solvent catalyst disposed interstitially between the bonded diamond grains. The compact is formed by subjecting the diamond grains, reactant material, and metal solvent catalyst to a first temperature and pressure condition to form the thermally stable region, and then to a second higher temperature condition to both form the PCD region and bond the body to a desired substrate.

Abstract: A drill bit having a plurality of cutters on its lower surface, each of which can having a plurality of PDC cutter elements disposed thereon. The cutting surface on each of the cutters is mounted in in an orientation that allows drilling of oversize boreholes which enables the drill bit to be turned more easily to facilitate the boreholes being drilled on a smaller radius. The placement of the cutters on each of the blades enables the drill bit to drill both vertically and laterally.

Abstract: A polycrystalline diamond compact useful for wear, cutting, drilling, drawing and like applications is provided with a first diamond region remote from the working surface which has a metallic catalyzing material and a second diamond region adjacent to or including the working surface containing a non-metallic catalyst and the method of making such a compact is provided. This compact is particularly useful in high temperature operations, such as hard rock drilling because of the improved thermal stability at the working surface.

Abstract: A rotary drill bit or other drilling tool for drilling or reaming through subterranean formation and comprising a body comprising a distal end and gage areas near a proximal end thereof and comprising longitudinally upward extensions of a plurality of blades or legs. A longitudinally trailing, radially inwardly extending surface is associated with at least some gage pads or legs at the longitudinally trailing ends thereof. Protective structures in the form of superabrasive elements comprising a plurality of thermally stable polycrystalline diamonds, or so-called “TSPs” (thermally stable products) are secured to a trailing surface of at least one gage pad. PDC elements may be employed in combination with the TSPs. Non-diamond structures may also be employed, in lieu of or in conjunction with diamond structures, particularly if drilling of ferrous metal casing components is contemplated.

Abstract: Thermally stable ultra-hard polycrystalline materials and compacts comprise an ultra-hard polycrystalline body that wholly or partially comprises one or more thermally stable ultra-hard polycrystalline region. A substrate can be attached to the body. The thermally stable ultra-hard polycrystalline region can be positioned along all or a portion of an outside surface of the body, or can be positioned beneath a body surface. The thermally stable ultra-hard polycrystalline region can be provided in the form of a single element or in the form of a number of elements. The thermally stable ultra-hard polycrystalline region can be formed from precursor material, such as diamond and/or cubic boron nitride, with an alkali metal catalyst material. The mixture can be sintered by high pressure/high temperature process.

Abstract: The invention concerns a drill bit (1) with stationary cutting structure, comprising a tool body (2) and several blades (3), which consist of a metal matrix impregnated with abrasive particles, and which are fixed to the tool body while extending forward therefrom, said blades (3) forming jointly a front cutting surface (7), and having radial channels (4) for drilling fluid which mutually separate the blades (3) and are open outwards. The invention is characterized in that it further comprises, through at least one radial fluid channel (2) arranged between two said blades (3), at least one bridge (6, 6?, 6?) which connects said two blades, by being arranged between the tool body (2) and said front cutting surface (7).

Abstract: A drill bit that includes a body having a lower end face for engaging a rock formation, the end face having a plurality of raised ribs extending from the face of the bit body and separated by a plurality of channels therebetween; and at least one of the plurality of ribs having a cutting portion of the at least one rib comprising a first diamond impregnated matrix material and at least a portion of a gage surface region thereof comprising a second diamond impregnated matrix material, the gage surface region backed by a third matrix material is disclosed.

Abstract: Superabrasive inserts are disclosed. More particularly, a superabrasive insert may comprise a superabrasive layer bonded to a substrate at an interface. Further, the superabrasive layer may include a central substantially planar surface, a peripheral side surface, and an arcuate peripheral surface extending between the central substantially planar surface and the peripheral side surface. In one embodiment, the arcuate peripheral surface may comprise a lateral extent and an extension depth, wherein a ratio of the lateral extent to the extension depth is at least about 1.5. In another embodiment, an arcuate peripheral surface may comprise a substantially circular arc, wherein the substantially planar surface is tangent to the substantially circular arc and a tangent reference line to the substantially circular arc forms an angle of at least about 10° with the peripheral side surface. Subterranean drilling tools (e.g., drill bits) including at least one superabrasive insert are disclosed.

Abstract: Embodiments relate to methods of fabricating PCD materials by subjecting a mixture that exhibits a broad diamond particle size distribution to a HPHT process, PCD materials so-formed, and PDCs including a polycrystalline diamond table comprising such PCD materials. In an embodiment, a method includes subjecting a mixture to heat and pressure sufficient to form a PCD material. The mixture comprises a plurality of diamond particles exhibiting a diamond particle size distribution characterized, in part, by a parameter ? that is less than about 1.0, where ? = x 6 · ? , x is the average particle size of the diamond particle size distribution, and ? is the standard deviation of the diamond particle size distribution.

Abstract: A tool has a sintered body of diamond or diamond-like particles in a metal matrix bonded to a cemented metal carbide substrate at a non-planar interface. A working surface has at least one region fir enough away from the non-planar interface that during high pressure, high temperature processing a restricted amount of metal from the substrate reaches the region, the amount comprising 5 to 0.1 percent of the region by volume, resulting in the region having a high density of superhard particles.

Abstract: Embodiments of the invention can provide cryogenic treatment processes for diamond abrasive tools. One process in accordance with an embodiment of this invention can include introducing an abrasive tool into a cycling chamber, wherein the tool has a temperature of about ambient temperature; and introducing at least one cryogenic material into the chamber, wherein the internal temperature of the chamber or tool can be controlled by adjusting the flow rate of the at least one cryogenic material. The process can result in a strengthened and toughened abrasive tool. The process can be repeated multiple times.

Abstract: PCD materials comprise a diamond body having bonded diamond crystals and interstitial regions disposed among the crystals. The diamond body is formed from diamond grains and a catalyst material at high pressure/high temperature conditions. The diamond grains have an average particle size of about 0.03 mm or greater. At least a portion of the diamond body has a high diamond volume content of greater than about 93 percent by volume. The entire diamond body can comprise high volume content diamond or a region of the diamond body can comprise the high volume content diamond. The diamond body includes a working surface, a first region substantially free of the catalyst material, and a second region that includes the catalyst material. At least a portion of the first region extends from the working surface to depth of from about 0.01 to about 0.1 mm.

Abstract: A drill bit includes a plurality of continuous segments impregnated with diamond that are each mounted to form a corresponding blade. The regions between the blades define a plurality of fluid passages on the bit face. The blades extend radially outwardly to the gage. The continuous segments may be either straight or spiral in design. Furthermore, the design of the segments supports varying one or more of: diamond content, width, back rake angle and/or relief angle along a length of the segment.

Abstract: A drill bit including at least one stress-relieved cutting element, wherein the at least one cutting element is mounted on the drill bit, wherein the stress-relieved cutting element includes a substrate, at least one transition layer disposed upon the substrate and a polycrystalline diamond layer having a thickness of at least 0.008 inches disposed upon the at least one transition layer.

Abstract: In one aspect of the present invention, an insert comprises a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate. The diamond body comprises a substantially conical shape with conical side wall terminating at an apex. The diamond body comprises a first region with a metallic catalyst dispersed through interstices between the diamond grains and a second region proximate the apex with the characteristic of higher thermal stability than the first region.

Abstract: A cutting element assembly for use on a rotary drill bit for forming a borehole in a subterranean formation. A cutting element includes a substrate having a base member affixed to a back surface of the substrate is disclosed, wherein the base member includes a recess configured to secure the base member to a rotary drill bit. An inner member may be positioned within the recess of the base member. Also, a structural element may be coupled to the inner member or to the base member. A rotary drill bit may include a cutting element assembly. In addition, a method of securing a cutting element to a rotary drill bit may include providing a base member affixed to a cutting element and positioning the base member within a recess of the rotary drill bit.

Abstract: Cutting elements are provided having substrates including end surfaces. TSP material layers extend over only a portion of the end surfaces or extend into the substrates below the end surfaces. Bits incorporating such cutting elements are also provided.

Abstract: Thermally-stable polycrystalline diamond materials of this invention comprise a first phase including a plurality of bonded together diamond crystals, and a second phase including a reaction product formed between a binder/catalyst material and a material reactive with the binder/catalyst material. The reaction product is disposed within interstitial regions of the polycrystalline diamond material that exists between the bonded diamond crystals. The first and second phases are formed during a single high pressure/high temperature process condition. The reaction product has a coefficient of thermal expansion that is relatively closer to that of the bonded together diamond crystals than that of the binder/catalyst material, thereby providing an improved degree of thermal stability to the polycrystalline diamond material.

Abstract: Superabrasive elements, methods of fabricating such elements, and applications utilizing such elements. In one embodiment, a superabrasive element includes a mass of polycrystalline diamond including ultra-dispersed diamond grain structures present in an amount greater than zero weight percent and less than about 75 weight percent of the mass of polycrystalline diamond. Various structures and apparatuses that utilize the superabrasive elements, such as polycrystalline diamond compacts (PDCs) and drill bits are disclosed. Methods of manufacture are also disclosed.

Abstract: Cutting elements include an ultra-hard body, e.g., comprising diamond, that is attached to substrate, e.g., comprising a cermet. An interface exists between the body and the substrate, and an angle of departure as measured between the interface and a free edge of the cutting element within one or both of the body and substrate, is less than about 90 degrees to provide a desired stress reduction along the interface. The angle of departure can be from about 3 to 87 degrees. The desired reduced angle of departure is provided by a surface feature disposed along an outer side surface of the cutting element adjacent a free edge of the interface. The surface feature can in the form of a groove disposed circumferentially around the body and/or substrate outer side surface, that is configured to provide the desired reduced angle of departure within the body and/or substrate.

Abstract: Diamond-bonded constructions include a diamond-bonded body having a thermally stable region extending a distance below a diamond-bonded body surface. The thermally stable region comprises a matrix phase of bonded-together diamond crystals, and interstitial regions comprising a reaction product. The reaction product is formed by reaction between the diamond crystals and a reactive material. The reactant is a carbide former and the reaction product is a carbide. The diamond-bonded body includes a further diamond region extending from the thermally stable region that comprises the matrix phase and a Group VIII metal disposed within interstitial regions of the matrix phase. The thermally stable region is substantially free of a catalyst material used to initially form the diamond-bonded body. The diamond-bonded body may include a material layer formed from the reaction product that is disposed on a surface of the diamond-bonded body thermally stable region.

Abstract: Ultra-hard composite constructions comprise an ultra-hard body having a plurality of diamond crystals bonded to one another by a carbide reaction product. A reactant material is selected from materials that are strong carbide formers to form a carbide reaction product with diamond at HPHT conditions. The body includes a high-density diamond region positioned along a surface portion of the body and that is substantially exclusively diamond, and that has a diamond volume content of 95 to 99 percent or more. The high-density diamond region can form a working surface of the composite construction. A substrate can be attached to the body, thereby forming a compact, and can include metallic materials, ceramic materials, carbides, nitrides, cermets, and mixtures thereof. An intermediate layer can be interposed between the body and the substrate depending on the substrate and/or method of attaching the same.

Abstract: Diamond-impregnated cutting tools including fibers and drilling systems incorporating such tools are described. The cutting tools contain a diamond-impregnated cutting portion that contains fibers made from carbon, glass, ceramic, polymer, and the like. The fibers may be used to both control the tensile strength and the erosion rate of the matrix to optimize the cutting performance of the tools. Additionally, the fibers may also weaken the structure and allow higher modulus binders to be used for the cutting tools at a lower cost, allowing the amount of fibers to be tailored to retain the diamonds in the cutting portion for the desired amount. As the cutting portion erodes, the fibers may also increase the lubricity at the face of the cutting portion. Using the fibers allows the cutting tools to last longer and make them safer and more economical because they need to be replaced less often.

Abstract: A drill bit comprises a bit body and a plurality of cutting blades extending radially from the bit body, the plurality of cutting blades further comprising cutting elements disposed thereon. The drill bit also comprises a plurality of utility blades extending radially from the bit body, the plurality of utility blades being free of cutting elements.

Abstract: In one aspect of the present invention, a high-impact resistant pick has a superhard material bonded to a cemented metal carbide substrate at a non-planar interface. The cemented metal carbide substrate is bonded to a front end of a cemented metal carbide bolster. A bore formed in a base end of the carbide bolster is generally opposed to the front end. A steel body has a steel shaft fitted into the bore of the bolster at an interface. A shank adapted for connection to a driving mechanism extends from the steel body opposite the shaft. A washer is disposed intermediate the base end of the carbide bolster and a shelf of the steel body.

Abstract: A cutting element for an earth boring bit, wherein the PDC layer of the cutting element has a flat on a periphery thereof terminating longitudinally at en edge spaced from of the cutting face of the PDC layer. A chamfer adjacent the cutting face desirably has a length that exceeds its depth. Embodiments include a chamfer along the entire circumference of the cutting element, multiple step-wise, radially adjacent chamfers, and multiple circumferentially spaced portions of the uppermost radius of the PDC layer of the cutting element that each includes a chamfer with an associated flat. An embodiment including a flat terminating at a radial edge with the cutting face of a PDC layer is also disclosed, as are drill bits incorporating embodiments of the cutting elements of the invention and a method of forming the cutting elements.

Abstract: An abrasive-impregnated cutting structure for use in drilling a subterranean formation is disclosed. The abrasive-impregnated cutting structure may comprise a plurality of abrasive particles dispersed within a substantially continuous matrix, wherein the abrasive-impregnated cutting structure exhibits an anisotropic wear resistance. One or more of the amount, average size, composition, properties, shape, quality, strength, and concentration of the abrasive particles may vary within the abrasive-impregnated cutting structure. Anisotropic wear resistance may relate to a selected direction, such as, for example, one or more of an expected direction of engagement of the abrasive-impregnated cutting structure with the subterranean formation and an anticipated wear direction. Anisotropic wear resistance of an abrasive-impregnated cutting structure may be configured for forming or retaining a formation-engaging leading edge thereof.

Abstract: PCD materials comprise a diamond body having bonded diamond crystals and interstitial regions disposed among the crystals. The diamond body is formed from diamond grains and a catalyst material at high pressure/high temperature conditions. The diamond grains have an average particle size of about 0.03 mm or greater. At least a portion of the diamond body has a high diamond volume content of greater than about 93 percent by volume. The entire diamond body can comprise high volume content diamond or a region of the diamond body can comprise the high volume content diamond. The diamond body includes a working surface, a first region substantially free of the catalyst material, and a second region that includes the catalyst material. At least a portion of the first region extends from the working surface to depth of from about 0.01 to about 0.1 mm.

Abstract: A cutting element and a method for forming a cutting element is described and shown. The cutting element includes a substrate, a TSP diamond layer, a metal interlayer between the substrate and the diamond layer, and a braze joint securing the diamond layer to the substrate. The thickness of the metal interlayer is determined according to a formula. The formula takes into account the thickness and modulus of elasticity of the metal interlayer and the thickness of the TSP diamond. This prevents the use of a too thin or too thick metal interlayer. A metal interlayer that is too thin is not capable of absorbing enough energy to prevent the TSP diamond from fracturing. A metal interlayer that is too thick may allow the TSP diamond to fracture by reason of bending stress. A coating may be provided between the TSP diamond layer and the metal interlayer. This coating serves as a thermal barrier and to control residual thermal stress.

Abstract: A cutting element for use with a drill bit includes a substrate having a longitudinal axis, a lateral surface substantially symmetric about the longitudinal axis and one or more key elements coupled to the lateral surface. The lateral surface lies between an insertion end and a cutting end of the substrate. The one or more key elements are substantially axially aligned with the longitudinal axis and configured to selectively rotationally locate the substrate in a pocket. A drill bit configured for retaining a cutting element having one or more key elements is also disclosed.

Abstract: In one aspect of the present invention, a roof bolt drill bit for use in underground mines comprises a bit body with a shank adapted for attachment to a driving mechanism. A working face disposed opposite the shank comprises a plurality of polycrystalline diamond cutting elements. Carbide bolsters are disposed intermediate the plurality of cutting elements and the bit body.

Abstract: The present invention provides a bit with cutting structures or inserts that include diamond particles, in which the diamond-impregnated inserts are surrounded by substantially diamond-free support members. The diamond-impregnated inserts are manufactured separately from the bit body. Once formed, the diamond-impregnated inserts are affixed to the substantially diamond-free support members on bit body by brazing or other means of attachment. The total thermal exposure of the diamond particles during manufacture in accordance with the present invention is significantly lower than the total manufacturing-related thermal exposure in previously known diamond-impregnated cutting structures. Furthermore, the substantially diamond-free support members allow the bit to continue cutting through a formation without an increased contact area, as experienced by bits with diamond-impregnated ribs. Thus, the operating life of the cutting structures, and therefore the life of the bit itself, is increased.

Abstract: In one aspect of the invention a rotary drag bit has a bit body intermediate a shank and a working surface. The working surface has a plurality of blades converging at a center of the working surface and diverging towards a gauge of the working surface. At least one blade has a cutting element with a carbide substrate bonded to a diamond working end with a pointed geometry. The diamond working end has a central axis which intersects an apex of the pointed geometry such that the axis is oriented within a 15 degree rake angle.

Abstract: A drill bit or milling tool includes a bit body on which a plurality of cutting elements are disposed. At least some of the plurality of cutting elements include a diamond table and a superabrasive material non-reactive with iron-based materials disposed over at least a portion of an exterior surface of the diamond table. The diamond table is suitable for drilling through a subterranean formation and the non-reactive superabrasive material is suitable for drilling through a casing or casing-associated component comprising an iron-based material and disposed within the subterranean formation. The diamond table may comprise a PDC and the non-reactive superabrasive material may comprise cubic boron nitride.

Abstract: Polycrystalline diamond constructions of this invention have a polycrystalline diamond body and a substrate attached thereto, wherein the diamond body has a material microstructure comprising a plurality of bonded-together diamond crystals forming a polycrystalline matrix phase, and second phase formed from different types of materials or sintering aids designed to reduce or eliminate the amount of free Group VIII elements therein. The use of such materials and the reduction and/or elimination of free Group VIII elements, in addition to graphitization, facilitates the sintering the construction at high pressure/high temperature conditions, e.g., greater than about 65 Kbar, to produce a construction having a high degree of thermal stability and/or thermal resistance when compared to conventional PCD materials. Polycrystalline diamond constructions of this invention are preferably configured as cutting elements that are disposed on drill bits used for drilling subterranean earthen formations.

Abstract: A cutting structure that includes a plurality of encapsulated particles dispersed in a first matrix material, the encapsulated particles comprising: an abrasive grit encapsulated within a shell, wherein the shell comprises a second matrix material different from the first matrix material is disclosed.

Abstract: PCD constructions include a PCD body comprising a polycrystalline matrix region, a first region that includes a replacement material positioned remote from a body surface, and a second region that is substantially free of the replacement material and that extends a depth from the body surface. The PCD construction can further include a substrate that is attached to the body. The PCD body is formed by removing a solvent catalyst material used to form the body, replacing the removed solvent catalyst material with a replacement material, and then removing the replacement material from a region of the body to thereby form the second region. The replacement material can be introduced into the PCD body during a HPHT process, and the substrate may or may not be the source of the noncatalyzing material.

Abstract: This invention provides an improved cutting element for downhole cutting tools comprising a support element and a shearing element disposed on said support; a drill bit insert comprising a body and said cutting element disposed on said body; and a cutting tool, such as a hole opener or a reamer, comprising said cutting element and/or said drill bit insert. Also provided are methods for forming the said cutting element, drill bit insert and downhole cutting tools and a method for drilling mixed earth formation using the improved downhole cutting tools of the present invention.

Abstract: Polycrystalline diamond constructions include a diamond body comprising a matrix phase of bonded together diamond crystals formed at high pressure/high temperature conditions with a catalyst material. The sintered body is treated remove the catalyst material disposed within interstitial regions, rendering it substantially free of the catalyst material used to initially sinter the body. Accelerating techniques can be used to remove the catalyst material. The body includes an infiltrant material disposed within interstitial regions in a first region of the construction. The body includes a second region adjacent the working surface and that is substantially free of the infiltrant material. The infiltrant material can be a Group VIII material not used to initially sinter the diamond body. A metallic substrate is attached to the diamond body, and can be the same or different from a substrate used as a source of the catalyst material used to initially sinter the diamond body.

Abstract: A method of constructing an earth-boring, diamond-impregnated drill bit has a first step of coating diamond grit with tungsten to create tungsten-coated diamond particles. These coated particles are then encapsulated in a layer of carbide powder held by an organic green binder material. The encapsulated granules are then mixed along with a matrix material and placed in a mold. The matrix material includes a matrix binder and abrasive particles. The mixture is heated in the mold at atmospheric pressure to cause the matrix binder to melt and infiltrate the encapsulated granules and abrasive particles.

Abstract: A method of forming a thermally stable cutting element that includes disposing at least a portion of a polycrystalline abrasive body containing a catalyzing material to be leached into a leaching agent; and subjecting the polycrystalline abrasive object to an elevated temperature and pressure is disclosed. Thermally stable cutting elements and systems and other methods for forming thermally stable cutting elements are also disclosed.

Abstract: A rotary drag bit includes a primary cutter row comprising at least one primary cutter and a multiple backup cutter group. The multiple backup cutter group comprises a first and second trailing cutter row, each comprising at least one cutter positioned to follow the at least one primary cutter. The rotary drag bit life is extended by the multiple backup cutter groups making the bit more durable and extending the life of the cutters. Further, the cutters of the multiple backup cutter group are configured to selectively engage a subterranean formation material being drilled, providing improved bit life and reduced stress upon the cutters. Other embodiments of rotary drag bits are provided.

Abstract: A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a surface comprising a chamfer extending forwardly and inwardly from proximate a peripheral cutting edge at a first acute angle of orientation of greater than about 45° with respect to the longitudinal axis of the cutting element, and to no greater than a selected depth. The chamfer may be arcuate or planar, and of a dimension sufficient to ensure that a wear flat generated during use of the cutting element remains outside the inner boundary of the chamfer within the chamfer envelope, and small enough to maintain aggressive cutting characteristics for the cutter. Drill bits and drilling tools bearing the cutting elements are also disclosed.

Abstract: In one aspect of the invention, a tool has a working portion with at least one impact tip brazed to a carbide extension. The carbide extension has a cavity formed in a base end and is adapted to interlock with a shank assembly of the cutting element assembly. The shank assembly has a locking mechanism adapted to interlock a first end of the shank assembly within the cavity. The locking mechanism has a radially extending catch formed in the first end of the shank assembly. The shank assembly has an outer surface at a second end of the shank assembly adapted to be press-fitted within a recess of a driving mechanism. The outer surface of the shank assembly has a coefficient of thermal expansion of 110 percent or more than a coefficient of thermal expansion of a material of the driving mechanism.

Abstract: A mortar removal drill bit system includes a toothed drill bit that includes an elongated rod that has a first end and a second end. A plurality of rectangular plates is attached to and extends laterally from the rod. Each of the plates has a distal edge with respect to the rod. Each of the distal edges is orientated parallel to a longitudinal axis of the rod. The first end of the rod is removably extendable into and attached to a drill.

Abstract: A cutter element is provided for use on a rotary drill bit of a drilling string to cut earthen formation and the like. The cutter element includes a cutting portion formed from cutting material adapted to cut into the earthen formation, and a substrate positioned adjacent the cutting portion. The cutting portion and the substrate form a body having a substantially planar front face, a longitudinal axis extending centrally through the front face and the substrate, and a circumferential surface extending inwardly form the front face and spaced outwardly from the longitudinal axis. The cutting portion includes a cutting face that provides at least a portion of the front face. The cutting portion extends longitudinally inward from the front face to a back surface engaging or inter-facing the substrate.

Abstract: Composite constructions comprise a plurality of granules that are arranged together in a randomly-oriented manner. The granules each comprise an ordered arrangement of a first material phase and a second material phase, wherein the first and second material phases are each continuous, and each occupy different and distinct regions of the granule. At least a portion of the first and second material phases of each granule are in contact with one another. The first material phase comprises a material selected from the group consisting of cermet materials, polycrystalline diamond, polycrystalline cubic boron nitride, and mixtures thereof. The second material phase comprises a material that is relatively softer, e.g., more ductile, than the first material phase.

Abstract: A cutting element for a downhole cutting tool including a support element, a shearing element disposed on said support, wherein the shearing element is disposed proximal to a leading edge of the downhole cutting tool, and a retaining element overlaying at least a portion of said shearing element is disclosed.

Abstract: A drill bit includes a bit body having a face on which two different types of cutting elements are disposed, the first type being cutting elements suitable for drilling at least one subterranean formation and the second type being cutting elements suitable for drilling through a casing bit disposed at an end of a casing or liner string and cementing equipment or other components, if such are disposed within the casing or liner string, as well as cement inside as well as exterior to the casing or liner string. The second type of cutting elements exhibits a relatively greater exposure than the first type of cutting elements, so as to engage the interior of the casing bit and, if present, cementing equipment components and cement to drill therethrough, after which the second type of cutting elements quickly wears upon engagement with the subterranean formation material exterior to the casing bit, and the first type of cutting elements continues to drill the subterranean formation.

Abstract: Thermally stable ultra-hard compact constructions comprise a polycrystalline diamond body substantially free of a catalyst material, and a substrate that is joined thereto. The substrate can be ceramic, metallic, cermet and combinations thereof, and can be joined to the body by a braze material or other material that forms an attachment bond at high pressure/high temperature conditions. The body and substrate are specially formed having complementary interfacing surface features to facilitate providing an improved degree of attachment therebetween. The complementary surface features can in the form of openings and projections, e.g., one of the body or substrate can comprise one or more openings, and the other of the body or substrate can comprise one or more projections, disposed within or extending from respective interfacing surfaces. The complementary surface features operate to resist unwanted delamination between the body and substrate, thereby extending effective service life of the construction.