Abstract: A hybrid drill bit having both roller cones and fixed blades is disclosed. The cutting elements on the fixed blades form a continuous cutting profile from the perimeter of the bit body to the axial center. The roller cone cutting elements overlap with the fixed cutting elements in the nose and shoulder sections of the cutting profile between the axial center and the perimeter. The roller cone cutting elements crush and pre-fracture formation in the weak and highly stressed nose and shoulder sections.

Abstract: A drill bit, insert and method useful for subterranean drilling, or forming boreholes in subterranean formations is provided. More particularly, a more efficient cutting structure and method is provided in the central portion of a PDC drill bit. The present invention provides a drill bit, insert and method having a central cutting portion with a more normalized angle of attack. The drill bit of the present invention provides for various attack angles much closer to the optimum side rake.

Abstract: A drill bit having a bit body includes a blade face surface on at least one blade extending longitudinally and radially outward over a face of the bit body. The blade face surface of the at least one blade includes a contact zone and a sweep zone. The sweep zone rotationally trails the contact zone with respect to a direction of intended bit rotation about a longitudinal axis of the bit body provides reduce rubbing contact when engaging with a subterranean formation.

Abstract: An earth-boring bit comprising a bit body configured at its upper extent for connection into a drillstring. A selected number of fixed blades extend downward from the bit body and a selected number of rolling cutters are mounted for rotation on the bit body. A plurality of rolling-cutter cutting elements are arranged on each rolling cutter and a plurality of fixed-blade cutting elements are arranged on each fixed blade. The selected number of fixed blades exceeds the selected number of rolling cutters by at least one.

Abstract: A cutter for a drill bit used in a geological formation includes a shaped ultra hard working surface. The cutter with the shaped working surface is mounted on a drill bit to provide desired cutting characteristics. The shaped working surface provides varied cutting characteristics depending upon the shape, and the characteristics can vary depending upon the depth of the cut.

Abstract: An earth-boring tool includes a bit body having a face on which two different types of cutters are disposed, the first type being cutting elements suitable for drilling at least one subterranean formation and the second type suitable for drilling through at least one elastomeric component of a casing string, as well as a casing shoe and cement. Methods of drilling with an earth-boring tool include engaging and drilling an elastomeric component using at least one abrasive cutting structure.

Abstract: A rotary drag bit includes a primary cutter row comprising at least one primary cutter, and at least two additional cutters configured relative to one another. In one embodiment, the cutters are backup cutters of a backup cutter group located in respective first and second trailing cutter rows, oriented relative to one another, and positioned to substantially follow the at least one primary cutter. The rotary drag bit life is extended by the backup cutter group, making the bit more durable and extending the life of the cutters. In other of the embodiments, the cutters are configured to selectively engage a subterranean formation material being drilled, providing improved bit life and reduced stress upon the cutters. Still other embodiments of rotary drag bits include backup cutter configurations having different backrake angles and siderake angles, including methods therefor.

Abstract: A modified cutting element that includes a base portion, an ultrahard layer disposed on the base portion, and at least one modified region disposed adjacent to a cutting face of the cutter. In certain applications, the ultrahard layer includes thermally stable polycrystalline diamond.

Abstract: A drill bit is disclosed that in one aspect may include a bit body having a plurality of blade profiles thereon, a first plurality of cutting elements disposed on each blade such that at least one cutting element on a first section of each blade profile is offset relative to at least one cutting element on a second section of each blade profile so as to increase lateral stability of the drill relative to the drill bit without an offset.

Abstract: An improved drill bit comprises a bit body, a plurality of blades disposed on the bit body, a first plurality of cutting elements disposed on the blades, such that the first plurality of cutting elements define a first cutter profile, and a second plurality of cutting elements disposed on the blades, such that the second plurality of cutting elements define a second cutter profile offset from the first cutter profile. The first plurality of cutting elements may, or may not, be greater in number than the second plurality of cutting elements. The cutting elements of the first plurality may, or may not, be greater in size than the cutting elements of the second plurality. The second cutter profile may be offset inwardly or outwardly from the first cutter profile. The second cutter profile may run along a cone section, a nose section, and/or a shoulder section of the bit.

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 for drilling at least one subterranean formation and the second type being cutting elements for drilling through a casing bit disposed at an end of a casing or liner string and cementing equipment or other components. 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: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gave curve such that its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: A PDC bit includes a plurality of blades including primary blades and secondary blades. The included primary blades are set with PDC cutters in accordance with a “single set” methodology. The included secondary blades, however, are set with PDC cutters using a type of “plural set” methodology such that the radial positions of cutters on a secondary blade match the radial positions of cutters on a single set primary which is immediately preceding that secondary blade. Plural secondary blades can be positioned to follow a single primary blade, and the cutters on those plural secondary blades will have radial positions matching the cutters of the immediately preceding single set primary blade.

Abstract: A drill bit has cutting elements with multiple cutting surface geometries that are positioned so that their cutting profiles overlap, but do not completely contain or engulf one another. The different cutting surface geometries and the specific overlap create a zone of high density in the middle regions of the cutting profiles and low density in the periphery, resulting in a cutting profile that becomes sharper with increasing wear. Such an arrangement is more effective and stable as the drill bit encounters hard and abrasive formation materials. Moreover, cutting elements with larger axial volumes may be combined with cutting elements having smaller axial volumes, resulting in an even more effective drill bit in terms of durability and ability to drill efficiently in hard and abrasive formations.

Abstract: A drill bit is provided that employs a plurality of discrete, post-like, abrasive, particulate-impregnated cutting structures extending upwardly from the bit face. The cutting structures may be disposed on abrasive, particulate-impregnated blades that also define a plurality of fluid passages on the bit face. One or more of the cutting structures may include outermost ends that exhibit a cross-sectional geometry that is elongated in a direction along a defined axis. The cutting structures may be oriented such that the defined axis is neither coplanar with, nor parallel to, an intended rotational path of the at least one discrete cutting structure during operation of the bit. In one embodiment, the cutting structure is oriented such that the defined axis is at an acute angle relative to a tangent of the intended rotational path for the associated cutting structure. Other or different features may include, for example, additional, differently configured cutting elements.

Abstract: A method for designing a roller cone drill bit having a plurality of cutting elements in a row. The method includes defining a pitch pattern for the plurality of cutting elements such that a first group of adjacent cutting elements are arranged in a first pitch and a second group of adjacent cutting elements are arranged in a second pitch in the row, wherein the first group of adjacent cutting elements have a different extension length than the second group of adjacent cutting elements, evaluating the pitch pattern of the plurality of cutting elements in the row, and modifying at least one of the plurality of cutting elements based on the evaluating of the pitch pattern of the plurality of cutting elements.

Abstract: A drill bit having fixed Polycrystalline Diamond Compact cutters is used to drill a borehole having a core stump therein. A plurality of additional fixed Polycrystalline Diamond Compact cutters are disposed in the dome of the bit and are usable to concentrate stresses in the top end of the core stump to facilitate the cutting down of the core stump.

Abstract: A drilling tool including at least two cutting elements (e.g., redundant or upon a selected profile region) sized, positioned, and configured thereon so as to contact or encounter a change in at least one drilling characteristic of a subterranean formation along an anticipated drilling path prior to other cutting elements thereon encountering same is disclosed. Methods of designing a drilling tool are also disclosed including placing such cutting elements upon the cutting element profile in relation to a predicted boundary surface along an anticipated drilling path. Methods of operating a drilling tool so as to initially contact a boundary surface between two differing regions of a subterranean formation drilled with at least two cutting elements is disclosed. The cutting elements configured on drilling tools and methods of the present invention may be designed for limiting lateral force or generating a lateral force having a desired direction during drilling associated therewith.

Abstract: The present invention provides a cutting element having a cylindrical body having a canted end face on which is formed an ultra hard material layer and to a bit incorporating such cutting element. One or a plurality of transition layers may be provided between the ultra hard material layer and the cutting element body.

Abstract: A method of optimizing drill bit design and an optimized drill bit for drilling a well into an earth formation comprising a bit body; a number of blades spaced around the bit body, each blade having a curved outer edge and a forward face; a first row of cutter pockets recessed into the face along the outer edge of each blade; a second group of cutter pockets recessed into the face of each blade offset from the first row; and a plurality of cutting elements, each cutting element being brazed into a different one of the cutter pockets.

Abstract: A method of optimizing drill bit design and an optimized drill bit for drilling a well into an earth formation comprising a bit body; a number of blades spaced around the bit body, each blade having a curved outer edge and a forward face; a first row of cutter pockets recessed into the face along the outer edge of each blade; a second group of cutter pockets recessed into the face of each blade offset from the first row; and a plurality of cutting elements, each cutting element being brazed into a different one of the cutter pockets.

Abstract: A rolling cone drill bit includes at least one cutter element comprising a base portion and a cutting portion extending from the base portion. The cutting portion includes a cutting surface with an apex defining an extension height and at least one rib extending from the apex toward the base portion. In addition, the at least one rib has a convex outer surface in profile view.

Abstract: A drill bit for cutting a borehole through an earthen formation comprises a bit body having a bit axis. In addition, the drill bit comprises a rolling cone cutter mounted on the bit body and adapted for rotation about a cone axis. Further, the drill bit comprises an insert having a base portion secured in the rolling cone cutter and having a cutting portion extending therefrom, the insert having an initial impact direction. The cutting portion of the insert has a cutting surface comprising a planar surface defining an extension height. Moreover, the cutting portion of the insert comprises an indentation extending at least partially through the upper planar surface, the indentation including a forward facing formation engaging surface and a lower surface defining a depth of the indentation.

Abstract: A drill bit has cutting elements with multiple cutting surface geometries that are positioned so that their cutting profiles overlap, but do not completely contain or engulf one another. The different cutting surface geometries and the specific overlap create a zone of high density in the middle regions of the cutting profiles and low density in the periphery, resulting in a cutting profile that becomes sharper with increasing wear. Such an arrangement is more effective and stable as the drill bit encounters hard and abrasive formation materials. Moreover, cutting elements with larger axial volumes may be combined with cutting elements having smaller axial volumes, resulting in an even more effective drill bit in terms of durability and ability to drill efficiently in hard and abrasive formations.

Abstract: A method for optimizing drill bit design and an optimized drill bit for drilling a well in an earth formation, wherein, in one embodiment, the optimized drill bit comprises a bit body with a plurality blades spaced along the bit body, each blade having a curved outer edge, a substantially flat forward face, and a number of insert pockets milled into each blade. A cutter insert is preferably secured into each insert pocket. The inserts are selected to give a desired cutter orientation, which is preferably independent of the orientation of the insert. Finally, a cutter is preferably secured at least partially within each cutter insert. The insert pockets may be formed by a cylindrical flat ended mill oriented substantially orthogonal to an outer edge of the blade, thereby creating the insert pockets with two substantially flat sidewalls, a curved endwall, and a substantially flat bottom.

Abstract: A drill bit configured having eight blades thereon with secondary cutters on four blades using opposed kerfing for the secondary cutters located on four of the blades.

Abstract: A drill bit, insert and method useful for subterranean drilling, or forming boreholes in subterranean formations is provided. More particularly, a more efficient cutting structure and method is provided in the central portion of a PDC drill bit. The present invention provides a drill bit, insert and method having a central cutting portion with a more normalized angle of attack. The drill bit of the present invention provides for various attack angles much closer to the optimum side rake.

Abstract: A rolling cone drill bit includes a cutter element having a cutting portion with a chisel crest and a pilot portion extending beyond the chisel crest. The pilot portion includes a cutting surface that may be generally conical, or form a second chisel crest. The cutting tip of the pilot portion is supported by buttress portions which emerge from and extend beyond the flanks of the chisel crest to provide additional strength and support for the material of the pilot portion that extends beyond the height of the chisel crest.

Abstract: A cutter element for a drill bit includes a leading cutting surface and a trailing cutting surface. The leading surface includes a top surface and a front surface that meet in a radiused intersection forming a forward-facing, non-linear crest of non-uniform radius. The radius of the crest is smallest at the forward-most portion, and greater at each end. The crest has its largest radius at a location between its forward-most portion and one of its ends. The cutter element may be employed in the corner cutting portion of a rolling cone cutter in a drill bit, the cutter element being positioned such that the forward-most portion of the crest first engages the formation material, with the crest end having the largest radius being closest to the pin end of the bit.

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 for drilling at least one subterranean formation and the second type being cutting elements for drilling through a casing bit disposed at an end of a casing or liner string and cementing equipment or other components. 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: 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: In an embodiment, a drill bit for drilling a borehole comprises a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face. Further, the drill bit comprises a plurality of primary cutter elements mounted to the primary blade. The primary blade is free of backup cutter elements. Still further, the drill bit comprises a secondary blade extending radially along the bit face. Moreover, the drill bit comprises a plurality of primary cutter elements mounted to the secondary blade. In addition, the drill bit comprises a first plurality of backup cutter elements mounted to the secondary blade in a first backup row that trails the primary row. Further, the drill bit comprises a second plurality of backup cutter elements mounted to the secondary blade in a second backup row that trails the first backup row.

Abstract: An earth boring bit has an outer row of inserts located within extra deep holes. Each of the holes has a cylindrical sidewall with a depth greater than the length of the barrel of the insert mounted within. The difference in depth is at least equal to a distorted entry zone in the hole. A portion of the sidewall that includes the entry zone surrounds the cutting end, reducing the projection of the cutting end from the land.

Abstract: Cutter inserts for rotary drill bits include a cutter insert body having a cutter recess configured to receive a backup cutter therein. Rotary drill bits for drilling a subterranean formation include at least one such cutter insert affixed to a blade rotationally behind a cutter pocket for a primary cutter. Methods of manufacturing such drill bits include providing a bit body having a plurality of blades. A cutter insert is provided and secured within a cutter insert recess formed in the face of a blade. A backup cutter is secured within a cutter recess of the cutter insert.

Abstract: A solid hard material head for a percussion drilling tool rotatable about a rotational axis (A) in a rotational direction (?), includes at least one main bit and at least one auxiliary bit (5), circumferentially offset relative to the at least one main bit (3) and having an auxiliary cutting edge (6) formed, at least piecewise, as a circular arc section (7) spaced from the rotational axis (A) radially inwardly and inclined in a radial direction, and a straight outer section (8) extending radially outwardly with respect to the circular arc section (7) and inclined in the radial direction.

Abstract: A drill bit having cutting elements disposed on a roller cone surface in a non-linear pattern, wherein at least one of the cutting elements is asymmetrical to its axis of orientation. Also, a method for selecting and adjusting a cutting element orientation based on crater profile geometry which results in increased bottom hole coverage.

Abstract: A drill bit for drilling a borehole in earthen formations comprises a bit body including a cone region, a shoulder region, and a gage region. In addition the bit comprises a first primary blade and a second primary blade. Further, the bit comprises a plurality of primary cutter elements mounted to the first primary blade in different radial positions. Still further, the bit comprises a plurality of primary cutter elements mounted to the second primary blade in different radial positions. Moreover, a first primary cutter element of the plurality of primary cutter elements on the first primary blade and a first primary cutter element of the plurality of primary cutter elements on the second primary blade are each positioned in the cone region and are redundant. The shoulder region has a total cutter redundancy percentage that is less than a total cutter redundancy percentage in the cone region.

Abstract: A drill bit for drilling a borehole in earthen formations comprising a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face, the primary blade including a cutter-supporting surface that defines a blade profile in rotated profile view extending from the bit axis to an outer radius of the bit body. The blade profile is continuously contoured and includes a plurality of concave regions. Further, the drill bit comprises a plurality of cutter elements mounted to the cutter-supporting surface of the primary blade. Each cutter element on the primary blade has a forward-facing cutting face with a cutting edge adapted to penetrate and shear the earthen formation.

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 rotary claw bit for drilling. The rotary claw bit includes a base plate having multiple lobes, the lobes having upper surfaces located in the same plane and lower surfaces located in the same plane. A plurality of bullet tooth attachment blocks are attached to the upper surface of each of the lobes. A bullet tooth having a hardened tip is removably attached within each of the attachment blocks. A pilot bit extends upwardly from the center of the base plate, the pilot bit having a tip that is located above the hardened tips of said bullet teeth. A tapered neck is attached to the lower surface of the base plate and adapted to be connected to a drilling string.

Abstract: A drill bit includes a bit body having a face on which two different types of cutters are disposed, the first type being cutting elements suitable for drilling at least one subterranean formation and the second type being at least one of an abrasive cutting structure and an abrasive cutting element suitable for drilling through a casing shoe, reamer shoe, casing bit, casing or liner string and cementing equipment or other components as well as cement Methods of forming earth-boring tools are also disclosed.

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: 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: A drag bit having cutting elements, wherein the cross section of the cutting elements is an oval shape, wherein in one embodiment the major axis is perpendicular to the surface of the drag bit blade. A method is also included, wherein the method comprises using a milling bit having an oval cross section that thereby produces pockets in the drag bit blades for receiving the oval shaped cutting elements. Use of the oval bit also results in a half oval formed at the closed end of the pocket.

Abstract: A bearing block is provided that may be used with a drag bit body or frame to limit depth of cut of cutters on a bit. The bearing block is designed so that it may be interchangeably replaced or repaired without necessitating alteration to a standardized bit frame. The interchangeable bearing block may be used to provide a target depth of cut (TDOC) and/or a selected contact or rubbing area to support weight on bit and limit depth of cut (DOC) for improving drilling performance of a bit. The interchangeable bearing block brings manufacturing selectability by providing a customizable product in terms of depth of cut selection and cutter penetration control for different formations, which is suitable for use with a common bit frame. A rotary drill bit assembly, a unitary cone insert bearing block for a drill bit, and a bit frame are also provided.

Abstract: A cutting element is provided including a substrate having a periphery and an interface surface. An ultra hard material layer is formed over the substrate and interfaces with the interface surface. The interface surface also includes a plurality of spaced apart projections formed inwardly and spaced apart from the periphery and arranged around an annular path, such that each projection includes a convex upper surface defining the projection as viewed in plan view. Each upper surface continuously and smoothly curves in the same direction when viewed along a plane through a diameter of the substrate. Bits incorporating such cutting elements are also provided.

Abstract: An improved cutter for fixed cutter drill bits includes a base portion with a longitudinal axis that extends through a center of the base portion and a cutting face which is generally centered with the base portion. The cutting face has a periphery edge geometry comprising a first arcuate segment and a second arcuate segment spaced apart and arranged opposite each other with linear edge segments disposed there between forming sides of the cutting face. The cutting face spans a maximum edge-to-edge dimension L in a first direction that corresponds to a major axis of the cutting face. The cutting face spans a maximum edge-to-edge dimension W in a second direction, which is perpendicular to the first direction, and W is less than L.

Abstract: A fixed cutter drill bit and a method for designing a fixed cutter drill bit includes simulating the fixed cutter drill bit drilling in an earth formation. A performance characteristic of the simulated fixed cutter drill bit is determined. A side rake angle distribution of the cutters is adjusted at least along a cone region of a blade of the fixed cutter drill bit to change the performance characteristic of the fixed cutter drill bit.

Abstract: Roller cone drill bits may be formed with cutting elements and cutting structures having cutting element profile angles selected to minimize cone wobble and improve life of associated bearings and seals. Normal force axes of the cutting elements may intersect with each other as a force center. Crest points of the cutting elements may be disposed on one or more circles extending from the associated force center.

Abstract: A fixed cutter rotary drill bit having gauge cutting elements at large back rake angles are disclosed. The gauge is located at the outer diameter side wall portion of the bit that extends from the cutting end. The gauge and its cutting components contact the side wall of the bore hole during drilling operations. The gauge cutting elements may be configured at a back rake angle in a range of about 40° to 70°.