Patent Application
20120285101
This invention relates generally to abrasive wear components and, more particularly, to high energy treated polycrystalline diamond compact (“PDC”), cubic boron nitride (“CBN”) cutter, and other similar type cutter substrates and the methods of manufacturing such items.
Typically, down hole tools including, but not limited to drill bits and reamers, have a plurality of blades that have a plurality of cutters or inserts coupled to each of the blades. These plurality of cutters may include, but is not limited to, tungsten carbide inserts, PDC cutters, CBN cutters, and thermally stable polycrystalline diamond cutters. PDC cutters are fabricated by pressing a diamond layer onto a tungsten carbide substrate, or similar substrate, to create a highly wear resistant layer or cutter face. Similarly, CBN cutters are fabricated in the same manner except that a CBN layer is pressed in lieu of a diamond layer.
The substrate is typically formed by combining grains of a metallic material, such as tungsten carbide, with a binder material, such as cobalt, to form a composite material. This composite material is pressed into a desired shape and heated, sometimes under pressure, such that the binder material liquefies and cements the grains of abrasive material together. The cemented abrasive component is then allowed to cool and ground into shape to form the substrate. Higher concentrations of cobalt increases the toughness, but decreases the hardness or abrasion resistance.
As the down hole tool is rotated, the cutters scrape against the bottom and sides of the borehole to cut away rock. As the rate of penetration of the down hole tool increases, the effective life of these cutters is substantially decreased because the cutters become cracked and occasionally are violently torn from the blade. Thus, there is a need for fabricating cutters with greater hardness and toughness traits so that their effective life may increase.
With respect to tungsten carbide inserts, High Energy Tumbling, as disclosed in U.S. Pat. No. 7,258,833 (the “'833 Patent”) issued to Rainey et al. on Aug. 21, 2007, has been used successfully to treat the tungsten carbide inserts in a way that work hardens the outer surface of the inserts while maintaining the core toughness of the inserts. This treatment creates inserts that are more resistant to both fracture breakage and to abrasive wear than untreated inserts. This process also acts to screen out inserts with significant but indiscernible flaws that would otherwise be used and fail prematurely.
With respect to PDC cutters, CBN cutters, and other similar type cutters, these cutters fail through breakage of the substrate at a rate estimated to be about 4% to about 8% of the time. Thus, PDC cutters, CBN cutters, and other similar type cutters having a highly wear resistant cutter face also may benefit from a surface treatment of the substrate equivalent to the High Energy Tumbling process to reduce the failure rate from substrate breakage suffered when in use. However, since the diamond layer of PDC cutters and the CBN layer of CBN cutters are extremely brittle, the High Energy Tumbling process would damage the layer thereby destroying the usefulness of the cutters, especially in drilling applications. Thus, the High Energy Tumbling process does not provide an effective method for treating PDC cutters, CBN cutters, and other similar type cutters when the entire fabricated cutter with the wear resistant layer is subjected to the process.
Additionally, treating the substrates in the High Energy Tumbling process prior to pressing the diamond layer or CBN layer is not a viable option because the benefits of the treatment would be substantially reversed during the High Pressure High Temperature press that is typically used to press the wear resistant layer to the substrate. Thus, the High Energy Tumbling process does not provide an effective method for treating the substrates of PDC cutters, CBN cutters, and other similar type cutters prior to pressing the diamond layer or CBN layer.
In view of the foregoing discussion, need is apparent in the art for improving the PDC cutters and the CBN cutters so that the life of the cutters are increased. Additionally, a need is apparent for providing effective surface treatment of the substrates for PDC cutters, CBN cutters, and other similar type cutters similar to that accomplished by the High Energy Tumbling process for tungsten carbide inserts, but accomplished in such a manner that the brittle diamond layer of the PDC cutter and the CBN layer of the CBN cutter are not damaged by the process. A technology addressing one or more such needs, or some other related shortcoming in the field, would benefit down hole drilling, for example creating boreholes more effectively and more profitably. This technology is included within the current invention.
The foregoing and other features and aspects of the invention will be best understood with reference to the following description of certain exemplary embodiments of the invention, when read in conjunction with the accompanying drawings, wherein:
The substrate 110 is fabricated from a composite material that is typically formed from a mixture of a metallic material 136, such as tungsten carbide, and a binder material 138, such as cobalt. The metallic material 136 and the binder material 138 have been pressed together, thereby liquefying the binder material 138 and cementing the grains of the metallic material 136 together. Prior to applying a treatment on the substrate 110, which may be a high energy treatment, the composite material typically has the binder material 138 uniformly dispersed throughout the metallic material 136.
Upon applying the treatment to the substrate 110, the cutter is transformed into the high energy treated cutter 100, which is shown in
In the embodiment shown in
The wear resistant layer 130 is made from hard cutting elements, such as natural or synthetic diamonds. The cutters made from synthetic diamonds are generally known as polycrystalline diamond compact cutters (PDCs). Other materials, including, but not limited to, cubic boron nitride (CBN) and thermally stable polycrystalline diamond (TSP), may be used for the wear resistant layer 130 without departing from the scope and spirit of the exemplary embodiment.
Although the method 200 has been illustrated in certain steps, some of the steps may be performed in a different order without departing from the scope and spirit of the exemplary embodiment. Additionally, some steps may be combined into a single step or divided into multiple steps without departing from the scope and spirit of the exemplary embodiment.
Method 200 may be performed according to at least two embodiments. The first embodiment is a cascading high energy treatment embodiment.
With reference to the cascading high energy treatment embodiment,
At step 220, protection is provided around the wear resistant layer.
The first protective cover 350 may be made of any material capable of providing protection to the wear resistant layer 330 and still withstand the impact forces generated during a pre-determined time period of the high energy treatment. These materials include, but are not limited to, rubber, any type of elastomer, polyurethane, a soft metal, for example copper, inside a steel crimp cap, and epoxy. The first protective cover 350 may be coupled around the wear resistance layer 330 by its own adherence to the wear resistance layer 330 or by using a bonding agent, for example glue, to couple the first protective cover 350 around the wear resistance layer 330. One example of a glue used to couple the first protective cover 350 to the wear resistance layer 330 is Bakerlok®. However, other types of bonding agents may be used without departing from the scope and spirit of the exemplary embodiment.
At step 230, a high energy treatment is applied to the at least one cutter to form at least one high energy treated cutter, wherein the substrate is exposed to the high energy treatment and the wear resistant layer is protected from exposure to the high energy treatment. According to the cascading high energy treatment embodiment, the high energy treatment is performed within a cascading machine 400 as shown in
Although the process has been illustrated in certain steps, some of the steps may be performed in a different order without departing from the scope and spirit of the exemplary embodiment. Additionally, some steps may be combined into a single step or divided into multiple steps without departing from the scope and spirit of the exemplary embodiment.
The compressive stresses that result from this process increase the toughness and hardness of the cutters by increasing the threshold level of stress necessary to fracture or deform the substrates. This higher threshold prevents or reduces the likelihood of chipping, cracking, and/or fracture of the substrates. Moreover, the increased surface hardness also increases the wear resistance of the substrates.
Under the high-energy conditions in particular embodiments, cascading machine 400 may be operated at a speed of approximately 100 to greater than 300 RPM. The exact speed within this range may be chosen according to the mass of the individual cutters being cascaded such that the kinetic energy of the cutters within the at least one rotatable drum 410 is maximized without damaging the cutters. Cutters having a smaller mass are cascaded at higher speeds, while cutters having a larger mass are cascaded at lower speeds. With this in mind, the optimal time and optimal speed for the high-energy process will vary depending on the material grade, size, density, geometry, and desired finish of the component being cascaded.
By cascading cutters, having a substrate and a wear resistant layer coupled to the top surface of the substrate, in a high-energy cascading machine, such as cascading machine 400, particular embodiments offer the ability to increase the toughness, or resistance to fracture, of the substrate. This is due to the fact that the cascading motion of the cutters inside the at least one rotatable drum 410 and the high rotational speeds generate numerous forceful collisions between the cutters within the barrels. These forceful collisions plastically deform the binder near the surfaces of the substrate, inducing residual compressive stresses along the surfaces of the substrate. These residual compressive stresses along the surface of each substrate increase the threshold stress required to fracture the substrate, increasing the substrate's toughness. The residual compressive stresses that result from the high-energy cascading also serve to increase the surface hardness, or resistance to deformation, of the substrate for a similar reason. Additionally, the cascading process actually induces an increasing hardness profile in the substrate, meaning the hardness of the substrate is higher at the perimeter of the substrate than at the center of the substrate.
Additionally, in some embodiments of the cascading high energy treatment, the latent and the sub-surface defects that were previously difficult or impossible to detect using typical visual inspection techniques can now be identified. Examples of these defects include sub-surface voids and surface cracks that were difficult to detect prior to cascading. By subjecting the substrate to the high energy treatment, these defects are magnified such that they can be identified prior to using the cutters in their intended applications, saving both time and money spent replacing the cutters at a later time.
With reference to the spray high energy treatment embodiment,
At step 220, protection is provided around the wear resistant layer.
Referring to
Although this embodiment shows that the at least one recess 520 has a depth equal to the thickness of the wear resistant layer 534, the depth of the at least one recess 520 may be slightly larger than the thickness of the wear resistant layer 534. For example, the depth of the at least one recess 520 may be up to 25 thousandths of an inch greater than the thickness of the wear resistant layer 534. In another example, the depth of the at least one recess 520 may be up to 50 thousandths of an inch greater than the thickness of the wear resistant layer 534. Additionally, according to another example, the depth of the at least one recess 520 may be up to 100 thousandths of an inch greater than the thickness of the wear resistant layer 534. The benefits of having the depth of the at least one recess 520 to be slightly greater than the thickness of the wear resistant layer 534 has been described above with respect to the first protective cover 350 of the cascading high energy treatment embodiment.
The at least one recess 520 is shown to have a circular shape. Although this embodiment shows the at least one recess 520 being a circular shape, the at least one recess 520 may be any geometric shape, including but not limited to square, oval, and rectangular, so long as the at least one recess 520 has the same shape as the wear resistant layer 534 without departing from the scope and spirit of the exemplary embodiment. Additionally, the size of the at least one recess 520 is slightly larger than the size of the wear resistant layer 534 provided that a tight tolerance exists between the wear resistant layer 534 and the at least one recess 520.
As seen in
Additionally, although the tray table 500 has been illustrated as being circular in shape, the tray table 500 may be shaped into any other geometric shape without departing from the scope and spirit of the exemplary embodiment. The tray table 500 may also be convexedly shaped, wherein the center of the tray table 500 is raised above the perimeter of the tray table and the surface gradually slopes downward from the center of the tray table 500 to the perimeter of the tray table 500. This shape for the tray table 500 may facilitate the recycling or removal of a high energy media stream, which will be discussed in further detail below. Alternatively, the tray table 500 may be substantially planar without departing from the scope and spirit of the exemplary embodiment.
Referring now to
In this embodiment, the cutter 530 may be secured to the tray table 500 by at least one of the following methods. The wear resistant layer 534 may be bonded using a bonding agent within the at least one recess 520. As previously mentioned, one example of a bonding agent is glue, which may be Bakerlok®, for example. Alternatively, the wear resistant layer 534 may be secured to the tray table 500 by applying a weight to the substrate 532 when the cutter 530 has been placed within the at least one recess 520. Alternatively, the wear resistant layer 534 may be secured to the tray table 500 by applying a pulling force to the bottom of the wear resistant layer 534 when the cutter 530 has been placed within the at least one recess 520. One example of applying a pulling force is to apply a vacuum to the bottom side of the tray table 500. Although three exemplary methods have been illustrated for securing the wear resistant layer 534 to the at least one recess 520, these methods may be used alone or in combination with one another without departing from the scope and spirit of the exemplary embodiment. Additionally, although three exemplary methods have been illustrated for securing the wear resistant layer 534 to the at least one recess 520, alternative methods for securing the wear resistant layer 534 to the at least one recess 520 may be used without departing from the scope and spirit of the exemplary embodiment.
Referring now to
In this embodiment, the cutter 530 may be secured to the tray table 500 by at least one of the following methods. The wear resistant layer 534 may be bonded using a bonding agent within the at least one recess 520. As previously mentioned, one example of a bonding agent is glue, which may be Bakerlok®, for example. Alternatively, the wear resistant layer 534 may be secured to the tray table 500 by applying a weight to the substrate 532 when the cutter 530 has been placed within the at least one recess 520. Although two exemplary methods have been illustrated for securing the wear resistant layer 534 to the at least one recess 520, these methods may be used alone or in combination with one another without departing from the scope and spirit of the exemplary embodiment. Additionally, although two exemplary methods have been illustrated for securing the wear resistant layer 534 to the at least one recess 520, alternative methods for securing the wear resistant layer 534 to the at least one recess 520 may be used without departing from the scope and spirit of the exemplary embodiment.
At step 230, a high energy treatment is applied to the at least one cutter to form at least one high energy treated cutter, wherein the substrate is exposed to the high energy treatment and the wear resistant layer is protected from exposure to the high energy treatment. According to the spray high energy treatment embodiment, the high energy treatment is performed within a cabinet 610 as shown in
In one embodiment, the spray high energy treatment system 600 comprises the cabinet 610 having a high energy treatment region 620 and a drip region 660, a slurry reservoir tank 670, and a slurry reservoir tank pump 675. The slurry reservoir tank 670 and the slurry reservoir tank pump 675 are optional and are used only when desiring recycling of a high energy media stream 632.
The cabinet 610 is configured to have a right circular cylindrical shape that is fabricated from a metal, metal alloy, or any other material capable of withstanding the operating conditions taking place within the cabinet 610. Although the cabinet 610 is configured to have a right circular cylindrical shape according to an exemplary embodiment, other embodiments may have the cabinet 610 configured into an alternative geometric shape, including, but not limited to, a rectangular shape or square shape, without departing from the scope and spirit of the exemplary embodiment. The cabinet 610 may be enclosed at the top or open at the top as shown in
The high energy treatment region 620 comprises at least one spray nozzle 630, and a tray table 500. In certain other embodiments, the high energy treatment region 620 may also comprise a seal 650. According to this embodiment, the at least one spray nozzle 630 is gooseneck-shaped and is fabricated from a metal, metal alloy, or any other material capable of withstanding the operating conditions taking place within the at least one spray nozzle 630. The at least one spray nozzle 630 is designed to have a plurality of spray holes (not shown) spaced and sized to allow for a uniform spraying of a high energy media stream 632 onto at least a portion of the tray table 500. In one embodiment, there is at least one spray nozzle 630 that is movable with no stationary spray nozzles. The at least one moveable spray nozzle 630 may be movable in a longitudinal horizontal direction, a latitudinal horizontal direction, a vertical direction, or a combination of any one of these directions, either one direction at a time or multiple directions simultaneously. In accordance with another embodiment, there may be at least one spray nozzle 630 that is movable and at least one spray nozzle 630 that is stationary. In accordance with another embodiment, there may be at least one spray nozzle 630 that is stationary and no moveable spray nozzles. The at least one spray nozzle 630 may be positioned so that the high energy media stream 632 is directed at an angle towards the tray table 500. This configuration allows the high energy media stream 632 to provide high energy treatment to a greater area of the substrate 532 of the cutters 530 that have been positioned within the at least one recess 520 of the tray table 500, especially providing the ability of treating the portion of the substrate immediately adjacent to the wear resistant layer 534. In some embodiments, the movable spray nozzle may be designed to have movement so that it provides coverage to the entire surface of the tray table 500 in the longitudinal horizontal direction, the latitudinal horizontal direction, or in both of these directions.
The high energy media stream 632 comprises a plurality of shot material 634. The shot material 634 may include, but is not limited to, crushed tungsten carbide, steel, metallic blast media, ceramic, or any combination of these materials. Other materials capable of providing impact forces on the substrate 532 may also be used as shot material 634 without departing from the scope and spirit of the exemplary embodiment. The shot material 634, as seen in
The tray table 500 and the seal 650 separate the high energy treatment region 620 and the drip region 660 from one another. The tray table 500 has been described above in detail and is similar to the tray table used herein. The tray table 500 is rotatable, either in a clockwise direction or in a counter-clockwise direction, in some embodiments, while the tray table 500 is stationary in other embodiments. Additionally, the tray table 500, whether rotatable or stationary, may vibrate so that movement of the shot material 634 across the tray table 500 may be facilitated. In some embodiments, the rotation of the tray table 500 may be performed manually, for example, a handle to rotate the tray table 500, or performed automatically. According to embodiments using the rotatable tray table 500, a plurality of spray nozzles 630 may be used, wherein some or all of the spray nozzles are stationary. Alternatively, some or all of the spray nozzles 630 may be movable in these embodiments. Additionally, there may be only one spray nozzle 630 that is movable such that it is capable of providing all exposed substrates 532 with uniform coverage to the high energy media stream 632. According to the embodiments using the stationary tray table 500, a plurality of spray nozzles 630 may be used, wherein some or all of the spray nozzles are stationary. Alternatively, some or all of the spray nozzles 630 may be movable in these embodiments. Moreover, there may be only one spray nozzle 630 that is movable such that it is capable of providing all exposed substrates 532 with uniform coverage to the high energy media stream 632.
Most importantly, the design and characteristics of the interaction between the at least one spray nozzle 630 and the tray table 500 should allow the exposed substrates 532 to have uniform exposure to the high energy media stream 632. Thus, in certain embodiments, one substrate 532 should not be exposed to excessive amounts of the high energy media stream 632, while another substrate 532 is not exposed to enough amounts of the high energy media stream 632. In some embodiments, each of the substrates 532 should be exposed to uniform exposure to the high energy media stream 632 to within plus or minus five percent exposure. In another embodiment, each of the substrates 532 should be exposed to uniform exposure to the high energy media stream 632 to within plus or minus ten percent exposure. According to one embodiment, the impact forces generated from the high energy media stream 632 is equivalent to the impact forces generated in the cascading high energy treatment embodiment. In another embodiment, the impact forces generated from the high energy media stream 632 is about plus or minus 20% of the impact forces generated in the cascading high energy treatment embodiment.
Although numerous embodiments exist that reflect the interaction between the at least one spray nozzle 630 and the tray table 500,
Referring back to
The drip region 660 is provided to collect the minimal portion of the high energy media stream 632 that may drip from the high energy treatment region 620. A minimal portion of the high media stream 632 is collected in the drip region 660 and is drained out of the cabinet 610 at some later desired time through one or more drain nozzles 662. Additionally, the drip region 660 may further comprise a drip slope 664 positioned at the bottom of the drip region 660. The drip slope 664 facilitates drainage of the drip region 660 by allowing the minimal portion of the high media stream 632 to collect adjacent to the one or more drain nozzles 662.
In certain embodiments, the substantial portion of the high energy media stream 632 is recycled back to the at least one spray nozzle 630 via the slurry reservoir tank 670 and the slurry reservoir tank pump 675. The high energy media stream 632 exits the cabinet 610 through cabinet discharge nozzle 612 and flows to the slurry reservoir tank 670 via a cabinet discharge line 614. The high energy media stream 632 collects within the slurry reservoir tank 670 and then flows to the slurry reservoir tank pump 675 via a slurry reservoir tank pump suction line 673. The slurry reservoir tank pump 675 then increases the pressure of the high energy media stream 632 and delivers the high energy media stream 632 to the at least one spray nozzle 630 via a slurry reservoir tank pump discharge line 677. Each of the cabinet discharge line 614, the slurry reservoir tank pump suction line 673, and the slurry reservoir tank pump discharge line 677 may be fabricated from a flexible hose, including but not limited to rubber, or from metal or metal alloy piping.
As previously mentioned, the cutters 530 may be secured within the at least one recess 520 via a weight, bonding agent, or a pulling force.
Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the scope of the invention.
This patent application is a divisional of and claims priority under U.S.C. §120 to U.S. patent application Ser. No. 12/555,947, entitled “High Energy Treatment of Cutter Substrates Having a Wear Resistant Layer,” filed Sep. 9, 2009; which claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 61/098,350, entitled “High Energy Treatment of Cutter Substrates Having a Wear Resistant Layer,” filed Sep. 19, 2008, the entirety of both being incorporated by reference herein. The present application is related to U.S. Pat. No. 7,258,833, entitled “High-Energy Cascading Of Abrasive Wear Components” and issued on Aug. 21, 2007, which is assigned to the assignee of the present non-provisional patent application. U.S. Pat. No. 7,258,833 is incorporated by reference in its entirety herein.
| Number | Date | Country | |
|---|---|---|---|
| 61098350 | Sep 2008 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12555947 | Sep 2009 | US |
| Child | 13560868 | US |
