Abstract: A layer of diamond formed by chemical vapor deposition (CVD) is brazed to a drill bit body to form a cutting element thereon. The ability to withstand high temperatures permits the cutting elements to be brazed using alloys requiring much higher temperatures than those used in connection with brazing convention PDC cutting elements. In an infiltrated bit, a CVD cutting element formed by chemical vapor deposition is placed in a bit mold which is thereafter filled with infiltration powder and placed in a furnace with temperature in excess of 1100.degree. Centigrade. The CVD cutting element may also be mounted on a slug or stud via brazing and the slug or stud in turn mounted on or infiltrated into the bit body or brazed thereto.

Abstract: A diamond cutting element for use on an earth boring drill bit, such as a drag bit. The cutting element is cooled with drilling fluid via a plurality of internal channels having outlets adjacent the peripheral cutting edge of the diamond cutting element.

Abstract: A drill bit, and a cutter for a drill bit, are provided, wherein the cutter will encounter the formation with cutting surfaces of differing rake angles to optimize cutting efficiency. In most circumstances, the cooperating cutters will have differing, positive, and negative or neutral rakes. Cutters of differing rakes may be cooperatively paired on a drill bit such that the portion of a formation which is affected by the action of one cutter may be similarly affected by the operation of the other cutter.

Abstract: Drill bit cutter structure and means of mounting said cutter structure relative to a drill bit for drilling earth formations is described in which the cutter structure provides diverse rotational orientation of the cutting element about at least one axis relative to the drill bit. The cutter structure generally includes a bearing surface associated with the drill bit, a supporting member articulable with the bearing surface to provide diverse orientation thereof, and a cutting element secured to said supporting member.

Abstract: A drill bit includes a generally cylindrical central blank and a matrix portion mounted on the lower end of the blank which includes the crown and gage of the drill bit. Exceptionally deep junk slots are defined in the matrix portion. The lower end of the blank includes a radially inwardly tapering portion having matrix material formed thereover which defines an upper end of the junk slot. The matrix material is formed from powdered matrix material and a ductile filler which provides a matrix with a relatively high ductility. Also disclosed is a steel bit constructed in accordance with the present invention.

Abstract: A multidirectional drill bit cutter comprising a cylindrical stud having a layer of polycrystalline diamond formed thereabout. In one embodiment the stud is fortified with diamond grit and diamond rods to reduce stud wear and to reduce the depth of cut taken by the polycrystalline diamond cutting element formed about the stud. In another aspect of the invention, an earth-boring drilling system having a pair of flat profile bits utilizes multidirectional cutters in a manner which causes them to cut from a plurality of different directions.

Abstract: A cutter for a rotating drag bit which has a cutting face formed from a plurality of polycrystalline diamond compact (PCD) elements. The elements can be of varying thickness and/or varying hardness to provide a cutting edge having a nonuniform wear pattern. Also provided is a cutter which includes two layers of PCD elements. The PCD elements can be of varying thickness and/or hardness to provide a cutter which presents a cutting edge having a wear ratio which varies with cutter wear. Also provided is an impact cutter having a cutting surface formed from one or more layers of PCD elements.

Abstract: A drill bit and method in which polycrystalline diamond cutters mounted on a bit crown cut formation chips akin to the manner in which a grater cuts cheese. Chips in impermeable or plastic formations are extruded by the cutters into cavities internal to the bit via slots adjacent each cutter. Drilling fluid circulates internally of the bit from the drill string and into the annulus above that portion of the bit bearing cutters. In one embodiment, the portion of the bit body upon which the crown is formed is made of an elastomer which is pressurized into sealing engagement with the bottom of the borehole thereby further sealing freshly cut formation from drilling fluid.

Abstract: A drag-type drill bit for boring an earth formation having a plurality of cutting elements formed thereon. Each cutting element includes a cutting surface having a cutting edge formed thereon. During boring, the cutting edge is embedded into an earth formation so that the formation is received against a portion of the cutting surface. As the cutting surface advances against the formation, a chip forms. The chip has a first surface directed generally toward the cutting surface and a second surface directed generally in the direction of cutting element travel. A number of different embodiments are disclosed which include means formed on and in the cutting surface for communicating drilling fluid pressure via slots or discontinuities to a location on the cutting surface relatively close to the cutting edge.

Abstract: A rotary drill bit for drilling earth formations is provided and includes a bit shank, a hard metal matrix secured to a blank and cutting elements on the exterior face thereof. The matrix includes a displacement material having a different composition than the matrix material within the matrix. The displacement material is preferably less expensive than the matrix material and also has different material properties. The resulting bit may be custom-engineered for toughness, ductility, and impact resistance.

Abstract: A drill bit offering improved steerability. Drill bits include gage sections which are adapted to facilitate deflection of the bits within a borehole to facilitate navigational or directional drilling. The gage portions of the bit may be arranged in an arcuate path around a portion of the periphery of the bit. Also, the bit portions may be spaced and adapted to serve, at least in part, as fulcrums, to facilitate deflection of the bit and the bringing of gage cutting portions of the bit in contact with the sidewalls of the borehole.

Abstract: A coring apparatus which includes a drill bit and a receiving member. The drill bit includes discrete cutting elements for cutting the outer dimension of the core. The receiving member is adapted to lie proximate to the discrete cutting surfaces and to receive the core as it leaves the cutting surfaces. Additionally, drilling fluid is directed away from the cut core.

Abstract: An improved diamond drill bit is provided which has a diamond film cutting surface. The drill bit comprises a body member and a plurality of cutting members, each including a diamond cutting face formed from a diamond substrate coated with a diamond film.

Abstract: An improved bit and method for cutting plastic and sticky rock formations, which tend to cause bit balling, is provided by a drag bit having a cutting face formed of a plurality of generally radially extending open arched blades. Each arched blade is provided with a cutting face and defines a cavity beneath the arched to the bit body. In a preferred embodiment, the cutting elements on the arched blade are a plurality of synthetic polycrystalline diamonds which are cut, sized and shaped to comformally fit with each other so as to present a substantially diamond-only surface as a cutting surface of the bit. Hydraulic nozzles are defined in the bit body beneath and azimuthally behind the arches formed by each blade. The nozzles direct hydraulic flow across the cavity under the arch and across each portion of the cutting face on the arch.

Abstract: A replaceable stud cutter for use in matrix drag bit is provided by furnacing a ductile metallic receptacle within the body of the drag bit as it is fabricated. The metal receptacle is characterized by having a receiving cavity defined therein and by including various mechanisms such as grooves or flares which facilitate retention of the metallic receptacle within the matrix body. The lowermost portion of the receptacle within the matrix body may also be shaped or tapered to allow dense packing of the receptacle adjacent to other receptacles along a given radial line on the bit face. A replaceable cutter is brazed, adhesively bonded and/or mechanically locked within the receiving cavity defined in the metal receptacle. When the replaceable cutter becomes worn through normal use, the mechanical locking elements can be drilled out, the brazing melted or adhesive dissolved to allow insertion of a new replacement cutter without causing any damage or alteration either to the receptacle, matrix body or bit face.

Abstract: A drill bit is provided which includes cutting elements cooperatively arranged with apertures in the bit to define flow paths for hydraulic flow proximate each cutting element. Cutting elements are preferably arranged in cutting pads which generally surround the apertures, such that hydraulic flow is forced to flow across the entire surface of the cutting pad. The dimensions of the cutting pad may be varied so as to control the hydraulic flow.