EP0219959A2 - Gesteinsbohrer mit verschleissbeständigen Einsätzen - Google Patents

Gesteinsbohrer mit verschleissbeständigen Einsätzen Download PDF

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Publication number
EP0219959A2
EP0219959A2 EP86306897A EP86306897A EP0219959A2 EP 0219959 A2 EP0219959 A2 EP 0219959A2 EP 86306897 A EP86306897 A EP 86306897A EP 86306897 A EP86306897 A EP 86306897A EP 0219959 A2 EP0219959 A2 EP 0219959A2
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EP
European Patent Office
Prior art keywords
tungsten carbide
inserts
layer
rock bit
bit
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86306897A
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English (en)
French (fr)
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EP0219959A3 (en
EP0219959B1 (de
Inventor
David Richard Hall
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Smith International Inc
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Smith International Inc
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Publication date
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Publication of EP0219959A3 publication Critical patent/EP0219959A3/en
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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56—Button-type inserts
    • E21B10/567—Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • E21B10/573—Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element
    • E21B10/5735—Interface between the substrate and the cutting element
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C26/00—Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/50—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of roller type
    • E21B10/52—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of roller type with chisel- or button-type inserts
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56—Button-type inserts
    • E21B10/567—Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • E21B10/5673—Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts having a non planar or non circular cutting face
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy

Definitions

  • This invention relates to rock bits for drilling oil wells or the like having polycrystalline diamond (PCD) tipped inserts for drilling a rock formation.
  • PCD polycrystalline diamond
  • Heavy duty rock bits are employed for drilling wells in subterranean formation for oil, gas, geothermal steam and the like.
  • Such bits have a body connected to a drill string and a plurality, typically three, of hollow cutter cones mounted on the body for drilling rock formations.
  • the cutter cones are mounted on steel journals or pins integral with the body at its lower end.
  • the drill string and bit body are rotated in the bore hole and each cone is caused to rotate on its respective journal as the cone contacts the bottom of the bore hole being drilled.
  • the total useful life of a rock bit in such severe environments is in the order of 20 to 200 hours for bits in sizes of about 6-1/2 to 12-1/4 inch diameter at depths of about 5000 to 20,000 feet. Useful lifetimes of about 65 to 150 hours are typical.
  • gage row The outermost row of inserts on each cone of a rock bit is known as the gage row. This row of inserts is subjected to the greatest wear since it travels furthest on the bottom of the hole, and the gage row inserts also tend to rub on the sidewall of the hole as the cones rotate on the drill bit body. As the gage row inserts wear, the diameter of the bore hole being drilled may decrease below the original gage of the rock bit. When the bit is worn out and removed, a bottom portion of the hole is usually under gage.
  • the rate of penetration of a rock bit into the rock formation being drilled is an important parameter for drilling. Clearly, it is desirable to maintain a high rate of drilling since this reduces the time required to drill the well, and such time is quite expensive because of the fixed costs involved in drilling.
  • the rate of penetration decreases when the inserts in the cones become worn and do not protrude from the cone surface to the same extent they did when drilling commences.
  • the worn inserts have an increased radius of curvature and increased contact area on the rock. It therefore takes greater force to penetrate and this may cause both bearing failure and gage row insert breakage. Drilling rate is continually observed by the driller and when the inserts are worn to the point that the rate of penetration is unacceptably low, the bit is replaced.
  • Wear resistance of conventional inserts of cemented tungsten carbide may be enhanced by increasing the propor­tion of tungsten carbide and decreasing the proportion of cobalt in the composite material. This increases the hardness and wear resistance of the cemented tungsten carbide but reduces its toughness so that the inserts are more susceptible to breakage than inserts with higher cobalt content.
  • the cobalt content of inserts for use in rock bits ranges from about 6% to 16% by weight cobalt.
  • particle size of the tungsten carbide phase is another factor that influences wear resistance and toughness.
  • Exemplary particle size in an insert is in the range of from three to seven microns. This particle size is an average particle size of a powder mixture that includes larger and smaller particles. For example, when the average particle size is five microns, there are submicron size particles present as well as particles as large as seven or eight microns. Generally speaking toughness increases with larger particle size and so does wear resistance.
  • a common grade of cemented tungsten carbide for rock bit inserts has an average tungsten carbide particle size of about six microns and contains about 10 to 14% by weight cobalt.
  • Toughness of the inserts is important in a rock bit since the inserts are subjected to impact loads as the cones rotate, as well as wear by rubbing against the rock formation. Breakage of inserts can be a substantial problem since it not only results in reduced drilling activity, but the fragments of a broken insert may damage other inserts. It is therefore desirable to provide inserts that are hard to resist wear and tough to resist breakage.
  • a rock bit is therefore provided in practice of this invention with a steel body having means at one end for connecting the bit to a drill string, and means at the opposite end for mounting roller cones for rotation around an axis transverse to the axis of the bit.
  • Each of the roller cones mounted on the body for rolling on the bottom of a bore hole being drilled includes a plurality of inserts for crushing rock at the bottom of the bore hole. At least a portion of those inserts comprise a cemented tungsten carbide body having a grip length embedded in the cone and a converging end portion protruding from the surface of the cone.
  • a layer containing polycrystalline diamond is provided on the converging end of such carbide bodies with a transition layer between the polycrystalline diamond layer and the carbide body.
  • the transition layer comprises a composite material containing diamond crystals and pre­cemented tungsten carbide particles.
  • An exemplary rock bit comprises a steel body 10 having three cutter cones 11 mounted on its lower end.
  • a threaded pin 12 is at the upper end of the body for assembly of the rock bit onto a drill string for drilling oil wells or the like.
  • a plurality of tungsten carbide inserts 13 are provided in the surfaces of the cutter cones for bearing on rock formation being drilled.
  • FIG. 2 is a fragmentary longitudinal cross section of the rock bit extending radially from the rotational axis 14 of the rock bit through one of the three legs on which the cutter cones 11 are mounted.
  • Each leg includes a journal pin 16 extending downwardly and radially inwardly of the rock bit body.
  • the journal pin includes a cylindrical bearing surface having a hard metal insert 17 on a lower portion of the journal pin.
  • the hard metal insert is typically a cobalt or iron base alloy welded in place in a groove on the journal leg and having a substantially greater hardness than the steel forming the journal pin and rock bit body.
  • An open groove 18 corresponding to the insert 17 is provided on the upper portion of the journal pin. Such a groove can, for example, extend around 60% or so of the circumference of the journal pin and the hard metal 17 can extend around the remaining 40% or so.
  • the journal pin also has a cylindrical nose 19 at its lower end.
  • Each cutter cone 11 is in the form of a hollow generally conical steel body having tungsten carbide inserts 13 pressed into holes on the external surface.
  • the outer row of inserts 20 on each cone is referred to as the gage row since these inserts drill at the gage or outer diameter of the bore hole.
  • Such tungsten carbide inserts provide the drilling action by engaging and crushing subterranean rock formation on the bottom of a bore hole being drilled as the rock bit is rotated.
  • the cavity in the cone contains a cylindrical bearing surface including an aluminum bronze insert 21 deposited in a groove in the steel of the cone or as a floating insert in a groove in the cone.
  • the aluminum bronze insert 21 in the cone engages the hard metal insert 17 on the leg and provides the main bearing surface for the cone on the bit body.
  • a nose button 22 is between the end of the cavity in the cone and the nose 19, and carries the principal thrust loads of the cone on the journal pin.
  • a bushing 23 surrounds the nose and provides additional bearing surface between the cone and journal pin.
  • a plurality of bearing balls 24 are fitted into complementary ball races in the cone and on the journal pin. These balls are inserted through a ball passage 26 which extends through the journal pin between the bearing races and the exterior of the rock bit.
  • a cone is first fitted on the journal pin and then the bearing balls 24 are inserted through the ball passage. the balls carry any thrust loads tending to remove the cone from the journal pin and thereby retain the cone on the journal pin.
  • the balls are retained in the races by a ball retainer 27 inserted through the ball passage 26 after the balls are in place.
  • a plug 28 is then welded into the end of the ball passage to keep the ball retainer in place.
  • the bearing surfaces between the journal pin and cone are lubricated by a grease which fills the regions adjacent the bearing surfaces plus various passages and a grease reservoir.
  • the grease reservoir comprises a cavity 29 in the rock bit body which is connected to the ball passage 26 by a lubricant passage 31.
  • Grease also fills the portion of the ball passage adjacent the ball retainer, the open groove 18 on the upper side of the journal pin and a diagonally extending passage 32 therebetween. Grease is retained in the bearing structure by a resilient seal in the form of an O-ring 33 between the cone and journal pin.
  • a pressure compensation subassembly is included in the grease reservoir 29.
  • This subassembly comprises a metal cup 34 with an opening 36 at its inner end.
  • a flexible rubber bellows 37 extends into the cup from its outer end. The bellows is held in place by a cap 38 having a vent passage 39 therethrough.
  • the pressure compensation subassembly is held in the grease reservoir by a snap ring 41.
  • the bellows has a boss 42 at its inner end which can seat against the cap 38 at one end of the displacement of the bellows for sealing the vent passage 39.
  • the end of the bellows can also seat against the cup 34 at the other end of its stroke, thereby sealing the opening 36.
  • At least a portion of the cutting structure of the rock bit comprises tungsten carbide inserts that are tipped with polycrystalline diamond.
  • An exemplary insert is illustrated in longitudinal cross section in FIG. 3. Such an insert has a cylindrical grip length 46 extending along a major portion of the insert.
  • a converging portion 47 which may have any of a variety of shapes depending on the desired cutting structure.
  • the converging portion may be referred to as a projectile shape or basically a cone with a rounded end. It may be a chisel shape which is like a cone with converging flats cut on opposite sides and a rounded end.
  • the converging portion may be hemispherical or any of a variety of other shapes known in the art.
  • Such an insert is press fitted or brazed into the roller cone.
  • Each one of the cones has a plurality of flat bottomed holes in circumferential rows on its outer surface.
  • An exemplary hole has a diameter about 0.13 millimeters smaller than the diameter of the grip 46 of an exemplary insert. The insert is pressed into the hole in the steel cone with many thousand pounds of force. This press fit of the insert into the cone tightly secures the insert in place and prevents it from being dislodged during drilling.
  • the converging portion of the insert illustrated in FIG. 3, has an outer layer 48 for engaging rock when the insert is used in a rock bit, and an inner layer 49 between the outer layer and the main cemented tungsten carbide body of the insert.
  • the outer layer in an exemplary embodiment comprises polycrystalline diamond (PCD) with a thickness of 125 microns.
  • the inner layer has a thickness of 380 microns and comprises a composite material of polycrystalline diamond and precemented tungsten carbide, such as disclosed in U. S. Patent No. 4,525,178.
  • PCD polycrystalline diamond
  • the term polycrystalline diamond, along with its abbreviation "PCD" refers to the material produced by subjecting individual diamond crystals to sufficiently high pressure and high temperature that intercrystalline bonding occurs between adjacent diamond crystals.
  • Exemplary minimum temperature is about 1300°C and an exemplary minimum pressure is about 35 kilobars.
  • the minimum sufficient temperature and pressure in a given embodiment may depend on other parameters such as the presence of a catalytic material, such as cobalt, with the diamond crystals. Generally such a catalyst/binder material is used to assure intercrystalline bonding at a selected time, temperature and pressure of processing.
  • PCD refers to the polycrystalline diamond including residual cobalt. Sometimes PCD is referred to in the art as "sintered diamond".
  • the outer layer of PCD is made from a mixture of diamond crystals and cobalt powder, with 13% by weight or 6% by volume of cobalt in the total mixture.
  • the catalyst metal is present in the range of from one to ten percent by volume.
  • About 65% of the diamond crystals are in the range of four to eight microns.
  • the other 35% of the diamond crystals are in the range of one-half to one micron.
  • the diamond crystals may be either naturally occurring diamonds or synthetic diamonds produced by a high temperature, high pressure process.
  • the diamond crystal size can range upwardly from sub­micron sizes. Preferably they range up to about twenty microns. Preferably a mix of sizes is used for dense packing.
  • the cobalt content can be in the range of from one to fifteen percent by volume, preferably less than about ten percent by volume. In some embodiments other catalyst metals such as iron or nickel may be used.
  • the raw materials for making the PCD layer are preferably milled together for a sufficient time to thoroughly coat the diamond particles with cobalt. Milling in a ball mill lined with cemented tungsten carbide and using cemented tungsten carbide balls is preferred to avoid contamination of the diamond. An attritor or planetary mill may be used if desired. Such milling should be sufficiently energetic to "smear" the cobalt but should avoid appreciable comminution of the diamond particles. One or two days of ball milling is appropriate.
  • Intercrystalline bonding between adjacent diamonds occurs and a unitary solid polycrystalline diamond article is formed when the milled materials are subjected to high temperature and a sufficient pressure that diamond is thermodynamically stable.
  • the intermediate composite layer is formed of a mixture of diamond crystals, cobalt, and precemented tungsten carbide particles.
  • the precemented tungsten carbide is made by blending tungsten carbide powder and cobalt powder in a ball mill or the like. The blended powders are compacted and sintered near the melting point of cobalt. The resultant compact is comminuted to the desired particle size for use in making the composite material of the inner layer. In an exemplary embodiment a grit size of -325 U. S. mesh (about 44 microns) is used in the composite material of the inner layer.
  • the precemented tungsten carbide grit can have a variety of tungsten carbide particle sizes and shapes, and various cobalt contents.
  • the cobalt content can be in the range of from five to sixteen percent by weight and the tungsten carbide particles are preferably in the range of from four to fifteen microns. In an exemplary embodiment the particle size is six microns and the cobalt content is fourteen percent by weight.
  • the inner layer between the layer of polycrystalline diamond and the cemented tungsten carbide substrate is made from a mixture of forty percent by volume of the aforementioned diamond powder (containing six percent by volume cobalt) and sixty percent by volume precemented tungsten carbide grit. If desired, additional cobalt can be included depending on the cobalt content of the cemented tungsten carbide.
  • the diamond crystals and cobalt powder are ball milled together as hereinabove described. After initial milling cemented tungsten carbide grit is added, with or without additional cobalt, and the mixture is further milled for thoroughly blending and smearing the mixture.
  • diamond and cobalt powders may be ball milled together for up to a day before addition of tungsten carbide grit. This mixture is then ball milled for another one or two days. Forty-eight hours in an exemplary ball milling time.
  • the blended powders for making the layers on the insert are sintered and bonded to a rock bit insert blank 51 in an assembly of the type illustrated in FIG. 5.
  • the insert being formed in the embodiment illustrated in FIG. 5 has layers somewhat different from those in the embodiment of FIG. 3 as hereinafter described, but the manufacturing technique is the same.
  • the insert blank 51 comprises a cylindrical cemented tungsten carbide body having a converging portion at one end.
  • the converging portion has the geometry of the completed insert, less the thickness of the layers to be formed thereon.
  • the assembly is formed in a deep drawn metal cup which preferably has double walls.
  • the inner cup is zirconium sheet having a thickness of 50 to 125 microns.
  • the outer cup 53 is molybdenum with a thickness of 250 microns.
  • a zirconium sheet 54 and molybdenum sheet 55 close the assembly at the top.
  • the zirconium "can” thus formed protects material within it from the effects of nitrogen and oxygen.
  • the molybdenum can protects the zirconium from water which is often present during the high pressure, high temperature pressing cycle used to form the rock bit insert.
  • blended diamond powder including cobalt may be placed in the cup and spread into a thin layer by rotation and pressing with an object having the same shape as the insert blank when the blank is axisymmetric. If a chisel insert is being made, the powder can be spread with a generally conical tool. Powder to make the outer layer is spread first, then powder to make the inner layer may be spread on the outer layer. Finally the insert blank is put in place and the metal sheets are added to close the top of the assembly. A small amount of paraffin wax may be included in the blended powders to aid distribution and retention of the powder in thin layers. Alternatively layers can be built up on the end of the insert blank before insertion into the cup.
  • sufficient wax may be included with the powders to form self-supporting "caps" of blended powder to be placed on the insert blank or in the cups. After assembly is made by one of such techniques, it is preferable to press the assembly through a die to swage the cups tightly against their contents.
  • One or more of such assemblies is then placed in a conventional high pressure cell for pressing in a belt press or cubic press.
  • a variety of known cell configurations are suitable.
  • An exemplary cell has a graphite heater tube surrounding such an assembly and insulated from it by salt or pyrophyllite for sealing the cell and transmitting pressure.
  • Such a cell, including one or more such assemblies for forming a rock bit insert, is placed in a high pressure belt or cubic press and sufficient pressure is applied that diamond is thermodynamically stable at the temperatures involved in the sintering process. In an exemplary embodiment, a pressure of 50 kilobars is used.
  • the grip of the completed insert may be diamond ground to a cylinder of the desired size for fitting in a hole in the cone of a rock bit.
  • the composite layer of diamond crystals and precemented carbide particles is, of course, sintered by the high temperature and pressure and is no longer in the form of discrete particles that could be separated from each other.
  • each cemented tungsten carbide insert blank was made with six micron tungsten carbide particles and 14% by weight cobalt.
  • the inner layer had a thickness of 380 microns and was formed from 40% by volume of a diamond-cobalt mixture with 6% by volume cobalt, and 60% by volume of -325 mesh precemented tungsten carbide grit.
  • the outer layer was PCD with a nominal thickness of 125 microns. There was some uneveness in forming the outer layer and in some areas it is believed that the layer was as thin as 75 microns.
  • the other inserts (other than the gage inserts) in the cutting structure on the rock bit were conventional tungsten carbide inserts made with six micron tungsten carbide powder and 14% cobalt.
  • One of the bits was used to drill from a depth of 1514 feet to a depth of 4094 feet or a total footage of 2580 feet.
  • the bit was used for forty-five and one-quarter hours for an average penetration rate of 57 feet per hour.
  • the weight on the bit was in the range of from 15,000 to 50,000 pounds (6800 to 22,700 kilograms) and the bit was rotated at speeds in the range of from 67 to 106 RPM.
  • the maximum WR of the bit was 425 which is a little below average for the field being drilled. WR refers to the weight on the bit times the rotational speed divided by the bit gage diameter.
  • This run may be compared with runs with conventional bits in seven nearby wells drilled with the same drilling rig at roughly comparable depths.
  • An average run lasted 54 hours and drilled a depth of 2848 feet for a rate of penetration of about 53 feet per hour.
  • the bit with diamond tipped inserts in the gage row on each cone was run at an above average penetration rate, but the run time and depth drilled were a little below average.
  • the reason for the somewhat low total depth drilled was that the bit was run into a particularly difficult rock formation of dolomite with sandstone stringers at an excessive speed and weight, and the gage row inserts were broken. Breakage of the inserts was detected at the ground surface and drilling with that bit was ended. It is estimated that 15 to 20 feet of hole after breakage of the inserts was under gage and needed reaming. In exemplary comparable holes, the length of hole needing reaming can range from zero to about 150 feet.
  • the second experimental bit went in the hole at 1511 feet depth and was withdrawn at 3687 feet, for a total footage drilled of 2176 feet.
  • the drilling time was 33 hours and the average rate of penetration was 66 feet per hour.
  • the weight on the bit ranged from 15,000 to 55,000 pounds (6800 to 25,000 kilograms) and the speed was in the range of from 78 to 120 RPM.
  • the maximum WR of the bit was above average for the rock formation being drilled, namely 545.
  • the second experimental bit was pulled from the hole before there was any indication at the ground surface that the bit was dull, damaged or worn. Inspection of the bit showed that there was no perceptible wear on the diamond tipped gage row inserts. A few gage row inserts had minor chipping of the diamond layer. Under these same drilling conditions, appreciable wear would be observed on standard cemented tungsten carbide gage row inserts. It also appears that there was less wear on the cemented tungsten carbide inserts inwardly from the gage row than would be observed in a standard bit having cemented tungsten carbide inserts in the gage row. Almost no wear was seen on the carbide inserts of the test bit. In most bits the inner inserts are so badly worn that the rate of penetration decreases markedly.
  • gage row inserts not only maintains the full gage of the hole but also affords some protection for tungsten carbide inserts inwardly from the gage row. This may occur since the weight on the bit is more uniformly distributed on the inserts in the absence of gage row wear and the other inserts are not overloaded. Wear resistant gage row inserts may have an additional benefit by protecting the bearings used to mount the cones on the rock bit body. When the bit wears and cuts under gage, or when reaming an under gage hole, there may be an undue load on the cone bearings. Such "pinching" of the bit may contribute to premature bearing failure. Thus, an embodiment of rock bit with gage row inserts tipped with PCD and other inserts of cemented metal carbide is suitable for practice of this invention.
  • FIG. 4 illustrates another embodiment of rock bit insert tipped with polycrystalline diamond as provided in practice of this invention.
  • This insert has a conventional cemented tungsten carbide blank 57 with a cylindrical grip 58 and a converging end on the portion of the insert that protrudes beyond the surface of the cone in which it is pressed.
  • the inner layer is overlain by an intermediate layer 60 that is 250 microns thick. This in turn is overlain by an outer layer 61 that is 125 microns thick.
  • the outer layer 61 is PCD as hereinabove described.
  • the intermediate layer is formed of a mixture of 60% by volume PCD (including 6% by volume cobalt) and 40% by volume precemented tungsten carbide.
  • the inner layer is formed of a mixture of 40% by volume PCD and 60% by volume precemented tungsten carbide.
  • the volume percentages may differ slightly from the proportions in the original mixture due to interactions. For example, some of the diamond may dissolve in the cobalt phase, thereby slightly reducing the volume proportion of diamond in the PCD and composite.
  • the intermediate layer 60 near the PCD layer has a relatively higher proportion of PCD and lower proportion of cemented carbide than the inner layer 59, thereby providing a transition between the outer layer and cemented carbide blank in two steps instead of the single step in the embodiment hereinabove described and illustrated in FIG. 3.
  • FIG. 5 illustrates still another embodiment of insert as provided in practice of this invention.
  • the converging portion of the insert blank 51 has an outer layer 63 of polycrystalline diamond.
  • This outer PCD layer is separated from the blank by an inner layer 64 having a gradual transition of properties between the PCD layer and the cemented carbide blank.
  • Such a transition layer has a high proportion of PCD (e.g., 80% or more by volume) and low proportion of cemented tungsten carbide adjacent to the outer PCD layer 63.
  • the polycrystalline diamond content adjacent to the blank may be 20% by volume and the precemented tungsten carbide content may be 80% by volume.
  • a gradual transition in proportion of diamond in the transition layer provides, in effect, a very large number of steps in mechanical properties between the outer PCD layer and the cemented tungsten carbide substrate.
  • the transition layer provides a transition in a variety of important properties of the PCD layer and carbide substrate. It compensates for differences in coefficient of thermal expansion and modulus of elasticity. It has a sonic velocity intermediate between the PCD and carbide which means that a stress wave travelling through the insert has less stress concentration at the interface.
  • a transition layer of diamond crystals and precemented tungsten carbide particles is significantly different from a mere mixture of diamond, cobalt and carbide powders. It is believed that the precemented carbide particles act as a plurality of "mini-anvils" that provide a pressure distribution in the layer very different from the pressure distribution in a mix of powders, resulting in better compaction.
  • the precemented carbide has less shrinkage than a powder mixture, improving the rheology of pressing. Further, the distribution of carbide in the composite is rather different from a powder; an analogy could be use of steel reinforcing bar in concrete as compared with powdered steel. Significantly different properties can result from the difference in distribution.
  • the outer PCD layer has a thickness of about 125 microns and thicker layers can be employed if desired.
  • the PCD layer can be in the range of 75 to 600 microns thick. Surprisingly, however, since the PCD is extremely resistant to erosion by rock formations being drilled, a layer only 125 microns thick is adequate for a long life rock bit.
  • the thickness of the transition layer, or layers can range from 100 microns to 3 millimeters or more. Other proportions of PCD and precemented carbide particles in the transition layers may also be used as desired.
  • these layers can range from 5 to 95% by volume polycrystalline diamond and from 95 to 5% precemented tungsten carbide.
  • additional cobalt may be included in the mixture for good sintering of the transition layer.
  • Other metal carbides such as tantalum carbide or titanium carbide may be suitable in some embodiments.
EP86306897A 1985-10-18 1986-09-05 Gesteinsbohrer mit verschleissbeständigen Einsätzen Expired - Lifetime EP0219959B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US78912085A 1985-10-18 1985-10-18
US789120 1985-10-18

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EP0219959A2 true EP0219959A2 (de) 1987-04-29
EP0219959A3 EP0219959A3 (en) 1988-10-19
EP0219959B1 EP0219959B1 (de) 1992-04-29

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JP (1) JPS62111093A (de)
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Cited By (20)

* Cited by examiner, † Cited by third party
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EP0315330A2 (de) * 1987-11-03 1989-05-10 Camco Drilling Group Limited Herstellung von Rotationsbohrmeisseln
GB2273306A (en) * 1992-12-10 1994-06-15 Camco Drilling Group Ltd Improvements in or relating to cutting elements for rotary drill bits
GB2282833A (en) * 1993-09-20 1995-04-19 Smith International Drill bit inserts enhanced with polycrystalline diamond
US5487436A (en) * 1993-01-21 1996-01-30 Camco Drilling Group Limited Cutter assemblies for rotary drill bits
WO1997030263A1 (en) * 1996-02-15 1997-08-21 Baker Hughes Incorporated Polycrystalline diamond cutter with enhanced durability and increased wear life
EP0794314A1 (de) * 1996-03-06 1997-09-10 General Electric Company Abrasives Schneidelement und Bohrmeissel
WO1999009292A1 (en) * 1997-08-18 1999-02-25 Sandvik Ab (Publ) Partially enhanced drill bit
EP0890705A3 (de) * 1997-07-09 1999-05-06 Baker Hughes Incorporated Bohrmeissel mit Schneidelementen mit einer Schneidfläche aus nanokristallinem Diamant
US5924501A (en) * 1996-02-15 1999-07-20 Baker Hughes Incorporated Predominantly diamond cutting structures for earth boring
WO2011017592A2 (en) * 2009-08-07 2011-02-10 Smith International, Inc. Diamond transition layer construction with improved thickness ratio
WO2011017590A2 (en) * 2009-08-07 2011-02-10 Smith International, Inc. Polycrystalline diamond material with high toughness and high wear resistance
US8573330B2 (en) 2009-08-07 2013-11-05 Smith International, Inc. Highly wear resistant diamond insert with improved transition structure
WO2014039542A1 (en) * 2012-09-04 2014-03-13 Superior Drilling Products, Llc Low-friction, abrasion resistant replaceable bearing surface
US9187962B2 (en) 2011-04-26 2015-11-17 Smith International, Inc. Methods of attaching rolling cutters in fixed cutter bits using sleeve, compression spring, and/or pin(s)/ball(s)
US9488229B2 (en) 2012-09-04 2016-11-08 Extreme Technologies, Llc Low-friction, abrasion resistant replaceable bearing surface
US9739092B2 (en) 2011-04-08 2017-08-22 Extreme Technologies, Llc Method and apparatus for reaming well bore surfaces nearer the center of drift
US9739097B2 (en) 2011-04-26 2017-08-22 Smith International, Inc. Polycrystalline diamond compact cutters with conic shaped end
US10626922B2 (en) * 2012-09-04 2020-04-21 Extreme Technologies, Llc Low-friction, abrasion resistant replaceable bearing surface
US11111739B2 (en) 2017-09-09 2021-09-07 Extreme Technologies, Llc Well bore conditioner and stabilizer
US11408230B2 (en) 2017-10-10 2022-08-09 Extreme Technologies, Llc Wellbore reaming systems and devices

Families Citing this family (3)

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US8292006B2 (en) 2009-07-23 2012-10-23 Baker Hughes Incorporated Diamond-enhanced cutting elements, earth-boring tools employing diamond-enhanced cutting elements, and methods of making diamond-enhanced cutting elements
EP2462310A4 (de) 2009-08-07 2014-04-02 Smith International Verfahren zur formung eines wärmestabilen diamantschneideelements
WO2011017582A2 (en) 2009-08-07 2011-02-10 Smith International, Inc. Functionally graded polycrystalline diamond insert

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EP0054846A1 (de) * 1980-12-22 1982-06-30 General Electric Company Verschleissfeste Agglomerate aus Diamant und kubischem Bornitrid unter Verwendung von Schichten aus verschleissfesten Teilchen ausgewählter Korngrösse und Verfahren zu ihrer Herstellung
EP0111600A1 (de) * 1982-12-13 1984-06-27 Reed Rock Bit Company Schneidkörper
US4525178A (en) * 1984-04-16 1985-06-25 Megadiamond Industries, Inc. Composite polycrystalline diamond
FR2562451A1 (fr) * 1984-04-10 1985-10-11 Bruss Polt I Plaquette coupante composite pour l'usinage de pieces a grande resistance et procede de fabrication de cette plaquette
EP0196777A1 (de) * 1985-03-01 1986-10-08 Reed Tool Company Limited Schneideinsatz für Drehbohrmeissel

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EP0054846A1 (de) * 1980-12-22 1982-06-30 General Electric Company Verschleissfeste Agglomerate aus Diamant und kubischem Bornitrid unter Verwendung von Schichten aus verschleissfesten Teilchen ausgewählter Korngrösse und Verfahren zu ihrer Herstellung
EP0111600A1 (de) * 1982-12-13 1984-06-27 Reed Rock Bit Company Schneidkörper
FR2562451A1 (fr) * 1984-04-10 1985-10-11 Bruss Polt I Plaquette coupante composite pour l'usinage de pieces a grande resistance et procede de fabrication de cette plaquette
US4525178A (en) * 1984-04-16 1985-06-25 Megadiamond Industries, Inc. Composite polycrystalline diamond
US4525178B1 (de) * 1984-04-16 1990-03-27 Megadiamond Ind Inc
EP0196777A1 (de) * 1985-03-01 1986-10-08 Reed Tool Company Limited Schneideinsatz für Drehbohrmeissel

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0315330A3 (en) * 1987-11-03 1989-12-13 Reed Tool Company Limited Improvements in or relating to the manufacture of rotary drill bits
US4949598A (en) * 1987-11-03 1990-08-21 Reed Tool Company Limited Manufacture of rotary drill bits
EP0315330A2 (de) * 1987-11-03 1989-05-10 Camco Drilling Group Limited Herstellung von Rotationsbohrmeisseln
GB2273306B (en) * 1992-12-10 1996-12-18 Camco Drilling Group Ltd Improvements in or relating to cutting elements for rotary drill bits
GB2273306A (en) * 1992-12-10 1994-06-15 Camco Drilling Group Ltd Improvements in or relating to cutting elements for rotary drill bits
US5469927A (en) * 1992-12-10 1995-11-28 Camco International Inc. Cutting elements for rotary drill bits
US5487436A (en) * 1993-01-21 1996-01-30 Camco Drilling Group Limited Cutter assemblies for rotary drill bits
GB2282833B (en) * 1993-09-20 1997-03-12 Smith International Drill bit inserts enhanced with polycrystalline diamond
GB2282833A (en) * 1993-09-20 1995-04-19 Smith International Drill bit inserts enhanced with polycrystalline diamond
WO1997030263A1 (en) * 1996-02-15 1997-08-21 Baker Hughes Incorporated Polycrystalline diamond cutter with enhanced durability and increased wear life
US5706906A (en) * 1996-02-15 1998-01-13 Baker Hughes Incorporated Superabrasive cutting element with enhanced durability and increased wear life, and apparatus so equipped
US5924501A (en) * 1996-02-15 1999-07-20 Baker Hughes Incorporated Predominantly diamond cutting structures for earth boring
US6000483A (en) * 1996-02-15 1999-12-14 Baker Hughes Incorporated Superabrasive cutting element with enhanced durability and increased wear life, and apparatus so equipped
US6082223A (en) * 1996-02-15 2000-07-04 Baker Hughes Incorporated Predominantly diamond cutting structures for earth boring
EP0794314A1 (de) * 1996-03-06 1997-09-10 General Electric Company Abrasives Schneidelement und Bohrmeissel
EP0890705A3 (de) * 1997-07-09 1999-05-06 Baker Hughes Incorporated Bohrmeissel mit Schneidelementen mit einer Schneidfläche aus nanokristallinem Diamant
US5954147A (en) * 1997-07-09 1999-09-21 Baker Hughes Incorporated Earth boring bits with nanocrystalline diamond enhanced elements
WO1999009292A1 (en) * 1997-08-18 1999-02-25 Sandvik Ab (Publ) Partially enhanced drill bit
WO2011017592A2 (en) * 2009-08-07 2011-02-10 Smith International, Inc. Diamond transition layer construction with improved thickness ratio
US9447642B2 (en) 2009-08-07 2016-09-20 Smith International, Inc. Polycrystalline diamond material with high toughness and high wear resistance
WO2011017590A3 (en) * 2009-08-07 2011-05-12 Smith International, Inc. Polycrystalline diamond material with high toughness and high wear resistance
WO2011017592A3 (en) * 2009-08-07 2011-05-26 Smith International, Inc. Diamond transition layer construction with improved thickness ratio
CN102648328A (zh) * 2009-08-07 2012-08-22 史密斯国际有限公司 具有高的韧度和高的耐磨性的多晶金刚石材料
US8573330B2 (en) 2009-08-07 2013-11-05 Smith International, Inc. Highly wear resistant diamond insert with improved transition structure
US8579053B2 (en) 2009-08-07 2013-11-12 Smith International, Inc. Polycrystalline diamond material with high toughness and high wear resistance
US9470043B2 (en) 2009-08-07 2016-10-18 Smith International, Inc. Highly wear resistant diamond insert with improved transition structure
US8857541B2 (en) 2009-08-07 2014-10-14 Smith International, Inc. Diamond transition layer construction with improved thickness ratio
CN102648328B (zh) * 2009-08-07 2015-02-18 史密斯国际有限公司 具有高的韧度和高的耐磨性的多晶金刚石材料
WO2011017590A2 (en) * 2009-08-07 2011-02-10 Smith International, Inc. Polycrystalline diamond material with high toughness and high wear resistance
US9739092B2 (en) 2011-04-08 2017-08-22 Extreme Technologies, Llc Method and apparatus for reaming well bore surfaces nearer the center of drift
US10508497B2 (en) 2011-04-08 2019-12-17 Extreme Technologies, Llc Method and apparatus for reaming well bore surfaces nearer the center of drift
US11156035B2 (en) 2011-04-08 2021-10-26 Extreme Technologies, Llc Method and apparatus for reaming well bore surfaces nearer the center of drift
US9187962B2 (en) 2011-04-26 2015-11-17 Smith International, Inc. Methods of attaching rolling cutters in fixed cutter bits using sleeve, compression spring, and/or pin(s)/ball(s)
US9739097B2 (en) 2011-04-26 2017-08-22 Smith International, Inc. Polycrystalline diamond compact cutters with conic shaped end
WO2014039542A1 (en) * 2012-09-04 2014-03-13 Superior Drilling Products, Llc Low-friction, abrasion resistant replaceable bearing surface
US9488229B2 (en) 2012-09-04 2016-11-08 Extreme Technologies, Llc Low-friction, abrasion resistant replaceable bearing surface
US10626922B2 (en) * 2012-09-04 2020-04-21 Extreme Technologies, Llc Low-friction, abrasion resistant replaceable bearing surface
US11111739B2 (en) 2017-09-09 2021-09-07 Extreme Technologies, Llc Well bore conditioner and stabilizer
US11408230B2 (en) 2017-10-10 2022-08-09 Extreme Technologies, Llc Wellbore reaming systems and devices

Also Published As

Publication number Publication date
IE862386L (en) 1987-04-18
DE3685083D1 (de) 1992-06-04
CA1256096A (en) 1989-06-20
IE57504B1 (en) 1993-02-10
EP0219959A3 (en) 1988-10-19
JPS62111093A (ja) 1987-05-22
EP0219959B1 (de) 1992-04-29

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