Boring or penetrating the earth – Bit or bit element – Specific or diverse material
Reexamination Certificate
2000-03-30
2001-12-18
Schoeppel, Roger (Department: 3672)
Boring or penetrating the earth
Bit or bit element
Specific or diverse material
C175S431000, C175S432000
Reexamination Certificate
active
06330924
ABSTRACT:
FIELD OF INVENTION
This invention relates to superhard planar and/or convex drill bit elements useful in rotary and rolling-cone, earth-boring, bits for heel, gage, and cutting inserts for the oil, gas, geothermal, and mining industries. The heel, gage, and cutting inserts comprise a cylindrical metal-carbide substrate, or stud, onto which one or more layers of superhard material are bonded using a high-pressure/high temperature press apparatus. The substrate's perimeter is inclined, with one or more inclinations and circumscribed by one or more furrows or grooves, or is fluted, so as to permit the bonding of one or more layers of superhard material below the plane of the major interfacing surfaces, thereby reinforcing the perimeter, or cutting edge, of the element itself
As used in this patent: “superhard” or “superhard material” refers, without limitation, to one or more layers of natural or synthetic diamond, polycrystalline diamond, cubic boron nitride, diamond films, or thermally stable products. “Cylindrical” includes, without limitation, having a square, hexagonal, rectangular, diamond, conical, or hemispherical cross section shape. “Inclined” or “Inclinations” means chamfered, curved, rounded, fluted, radiused, tapered, or beveled, by means of grinding, cutting, shaping, preforming, or any other means known in the art. The “Plane of the Interface” refers to a line that is perpendicular to the major sides of the cutting element and defined by the bonded, adjacent surfaces of the superhard material and the substrate. “Substrate” means a cylindrical metal-carbide stud or post onto which the superhard material is bonded. “Non-Planar” means an interrupted surface comprising a pattern or profile of one or more grooves, ridges, furrows, shapes, or designs. “Heel insert or element” refers to a superhard insert positioned in the circumferential heel row of a rolling cone, or rotary cone, earth-boring bit. “Gage insert or element” refers to a superhard insert positioned in the gage row of either a rotary bit, which includes drag and shear bits, or a rolling cone, or rotary cone, earth boring bit so as to define and maintain the inside diameter, or gage, of the well bore as the bit drills the formation. “Cutting insert or element” refers to a superhard insert positioned on rotary and rolling cone, or rotary cone, earth boring bits so as to penetrate the formation being drilled as the bit rotates by means of cutting, abrading, and/or impacting the subsurface.
DESCRIPTION OF RELATED ART
Superhard cutting elements have been used in drill bits for the oil, gas, geothermal, and mining industries for more than a two decades. Superhard heel and gage elements have been used in drill bits for a much shorter time, but their use is known in the art today. Numerous means have been employed to strengthen the superhard surface of these elements to make them more resistant to premature failure usually manifested by edge chipping and delamination. The following prior art references not only teach the inventive techniques employed to toughen superhard elements, they also disclose the breath of the prior art pertaining to the present invention. It will be noted in the following prior art references that, unlike the elements in the present invention, the elements' superhard surfaces do not exhibit one or more inclinations having one or more circumscribing furrows or grooves, or flutes, along the surface that extends below the plane of their major interfacing surface between the superhard material and the substrate.
U.S. Pat. No. 5,172,778. This patent exhibits a superhard cutter with a serrated working surface intended to aid in chip removal and cooling of the superhard cutter's working face during cutting.
U.S. Pat. No. 5,238,074. This patent displays a cutter having a non-uniform working face of varying thickness and hardness so that the cutting edge has a wear ratio which varies with wear. The premise of this design was that it was desirable to have a cutter whose surface wore away at different rates during drilling. Thus, it was postulated, the wear rate would vary in a pre-selected fashion to optimize cutting through formations of varying hardness.
U.S. Pat. No. 5,351,772. The radial land configuration of this cutter's substrate on the interfacing surface with the superhard material was believed to redistribute the stresses along the interface, reduce their areas of concentration, and essentially interrupt the stress fields across the working surface of the cutter, thereby reducing the likelihood of edge fracturing and the propagation of fractures across the entire face of the cutter. It was also thought that the lands permitted the use of a thicker diamond table which would also reduce the risk of spalling and fracture. Despite the interrupted periphery of the substrate, the superhard material does not extend below the plane of the interface as defined in this disclosure.
U.S. Pat. No. 5,355,696. The innovations of this patent focus on its attempt to add support to the bond between the substrate and the superhard material surface by installing radially spaced-apart alternating channels and ridges. It was believed that such a configuration would strengthen the bond and consequently improve fracture and delamination resistance.
U.S. Pat. No. 5,373,908. This patent attempts to teach that by splitting the cutter and fashioning a chamfer along the split edge adjacent to the substrate and in a matching groove in the substrate itself, the stress concentrations along the face of the cutter will be reduced.
U.S. Pat. No. 5,435,403. This patent postulates that by thickening the diamond table of the cutter where it actually contacts the formation being drilled, and by having a multi-thickness diamond table, the cutter will produce a kerfing action during drilling as the thinner portions wear less than the thicker ones. Also, the thicker portions of the cutter were thought to stiffen the cutter so as to resist its tendency to flex upon initial contact with the formation. Such flex is thought to contribute significantly to fracture failure of the superhard material.
U.S. Pat. No. 5,120,327. In this patent the interfacing surfaces comprise a plurality of spaced apart ridges forming grooves there between. The ridges are spaced radially inwardly from an outer periphery of the substrate, whereby the diamond layer includes an annular ring portion completely surrounding the plurality of ridges to provide radial reinforcement against the formation and propagation of cracks tending to occur in the vicinity of the ridges. Despite the presence of two interfacing planes, it will be noted in this design that the diamond table does not extend below the plane lowest plane.
U.S. Pat. No. 5,437,343. In this example, the periphery of the superhard cutter's planar working surface is ground with a double chamfer, at different acute angles, in an effort to create a bearing surface which supports the cutter against the formation being drilled. This additional support is believed to aid in reducing edge fracture during the early stages of drilling when the edges of the cutters are most exposed to lateral stress and chipping. Even though the superhard cutting table has an inclined edge, the substrate's interfacing periphery has retained its right angle profile, and the diamond table does not extend below the substrate's interfacing surface.
U.S. Pat. No. 5,346,026. This disclosure teaches the use of gage inserts to maintain the gage of the bore hole using a rolling cone earth-boring bit.
U.S. Pat. No. 5,351,770. In this patent the use of superhard inserts in the heel row of a rotary cone bit is disclosed. The inserts are positioned in the circumferential heel row of the bit and serve to maintain the gage, or inside diameter, of the bore hole.
U.S. Pat. No. 5,467,836. Finally, in this patent's specification the use of superhard gage inserts in a rotary, or shear or drag, bit is disclosed. In this application, the inserts are interference fitted into sockets in the bit's surface proxi
LandOfFree
Superhard drill bit heel, gage, and cutting elements with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Superhard drill bit heel, gage, and cutting elements with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Superhard drill bit heel, gage, and cutting elements with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2558133