Patent Application
20250001553
The present invention relates generally to superabrasive materials and a method of making superabrasive materials, and more particularly, to impregnated diamond cutter with an improve rate of penetration (ROP).
Ultrahard diamond composite materials, typically in the form of abrasive compacts, are used extensively in cutting, milling, grinding, drilling and other abrasive operations, and also may be used as bearing surfaces and the like.
They generally contain a diamond phase, typically diamond particles, dispersed in a second phase matrix or binder phase. The matrix may be metallic or ceramic or a cermet. These particles may be bonded to each other by the binder during the high pressure and high temperature compact manufacturing process generally used, forming impregnated diamond cutters.
A known process issue encountered during HPHT synthesis which could not be optimized is the uneven distribution of diamond grains inside the diamond layer after HPHT sintering. This is because that the diamond feeds employed have multiple sizes ranging from nanometers to a few tens micrometers that caused inhomogeneous distribution during feed blending process, resulting in segregation of the diamond feeds. This would cause inconsistent cutting performance if existing in the PDC layer, leading to a premature failure during performance testing.
Therefore, there is a need to have impregnated diamond cutters to improve overall mechanical properties including wear resistance and toughness by modifying their constitutions.
In one embodiment, an impregnated diamond cutter may comprise a superabrasive volume has a plurality of diamond particles and a metal binder, wherein the metal binder comprises CoCuFeP.
In another embodiment, a method of making an impregnated diamond cutter may comprise steps of mixing a metal binder with a plurality of diamond particles in liquid such as isopropanol, to form a paste; extruding the paste into sausages that are rolled and dried into irregular granules; subjecting the irregular granules to a mold cavity which is under a first condition of temperature and pressure to form a green product; and subjecting the green product to a second condition of temperature and pressure suitable to produce the impregnated diamond cutter.
In yet another embodiment, a method of making an impregnated diamond cutter may comprise steps of mixing CoCuFeP as a metal binder with a plurality of diamond particles as a part of a diamond table; and subjecting the diamond table to a condition of temperature and pressure suitable to produce the impregnated diamond cutter.
Optionally in any embodiment, the metal binder may comprise an abrasive material.
Optionally in any embodiment, the abrasive material may comprise tungsten carbide (WC).
Optionally in any embodiment, the plurality of diamond particles may have a size ranging from about 500 μm to about 707 μm.
Optionally in any embodiment, the tungsten carbide has a size ranging from about 6 μm to about 30 μm.
Optionally in any embodiment, the tungsten carbide with a size ranging from about 1 μm to about 6 μm.
Optionally in any embodiment, the first conditions of temperature and pressure suitable for producing the green product are less than 250° C.
Optionally in any embodiment, the second conditions of temperature and pressure is under high pressure high temperature.
The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.
Before the description of the embodiment, terminology, methodology, systems, and materials are described; it is to be understood that this disclosure is not limited to the particular terminologies, methodologies, systems, and materials described, as these may vary. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions of embodiments only, and is not intended to limit the scope of embodiments. For example, as used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. In addition, the word “comprising” as used herein is intended to mean “including but not limited to.” Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as size, weight, reaction conditions and so forth used in the specification and claims are to the understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
As used herein, the term “about” means plus or minus 10% of the numerical value of the number with which it is being used. Therefore, about 50% means in the range of 45%-55%.
As used herein, the term “superabrasive particles” may refer to ultra-hard particles or superabrasive particles having a Knoop hardness of 3500 KHN or greater. The superabrasive particles may include diamond and cubic boron nitride, for example. The term “abrasive”, as used herein, refers to any material used to wear away softer materials.
The term “particle” or “particles”, as used herein, refers to a discrete body or bodies. A particle is also considered a crystal or a grain.
The term “impregnated diamond cutter”, as used herein, refers to a sintered product made using super abrasive particles, such as diamond feed or cubic boron nitride particles. The compact may include a support, such as a tungsten carbide support, or may not include a support. The “impregnated diamond cutter” is a broad term, which may include cutting element, cutters, or polycrystalline cubic boron nitride insert.
The term “cutter”, as used herein, means and includes any element of an earth-boring tool that is used to cut or otherwise disintegrate formation material when the earth-boring tool is used to form or enlarge a bore in the formation.
The term “earth-boring tool”, as used herein, means and includes any tool used to remove formation material and form a bore (e.g., a wellbore) through the formation by way of removing the formation material. Earth-boring tools include, for example, rotary drill bits (e.g., fixed-compact or “drag” bits and roller cone or “rock” bits), hybrid bits including both fixed compacts and roller elements, coring bits, percussion bits, bi-center bits, reamers (including expandable reamers and fixed-wing reamers), and other so-called “hole-opening” tools.
The term “feed” or “diamond feed”, as used herein, refers to any type of diamond particles, or diamond powder, used as a starting material in further synthesis of impregnated diamond cutter.
The term “superabrasive”, as used herein, refers to an abrasive possessing superior hardness and abrasion resistance. Diamond and cubic boron nitride are examples of superabrasives and have Knoop indentation hardness values of over 3500.
The terms “diamond particle” or “particles” or “diamond powder”, which is a plurality of a large number of single crystal or polycrystalline diamond particles, are used synonymously in the instant application and have the same meaning as “particle” defined above.
In a particular case, a polycrystalline diamond composite compact comprises a plurality of crystalline diamond grains, which are not bound to each other, but instead are bound together by foreign bonding materials such as a binder, e.g. borides, nitrides, carbides, bonded diamond material.
Impregnated diamond cutters may be fabricated in different ways and the examples discussed herein do not limit a variety of different types of diamond composites and Impregnated diamond cutters which may be produced according to an embodiment.
The invention discloses an application of diamond granules with CoCuFeP as a metal binder in fabrication of impregnated diamond cutters. The present embodiment provides a way to wet the diamond by the binder CoCuFeP in order to increase bonding between diamond particles and tungsten carbide during the HPHT synthesis. Moreover, the same idea can also improve the uniformity of diamond feeds blending, resulting in a uniform distribution of broad sized diamond grains.
An impregnated diamond cutter 10 in accordance with an embodiment is shown in
In one embodiment, the impregnated diamond cutter 10 may be a standalone cutter without a substrate. In another embodiment, the impregnated diamond cutter 10 may include a substrate. The superabrasive volume 11 may be formed by a plurality of diamond particles 12 and a matrix material 14. The matrix material 14 may include an abrasive material and a metal binder. The abrasive material may further include a carbide, such as tungsten carbide (WC), silicon carbide (SiC), silicon nitride, etc. The diamond particles bonded in part by the metal binder. The metal binder may include a metal alloy, such as CoCuFeP, for example.
In one embodiment, the plurality of diamond particles have a size ranging from about 500 μm to about 707 μm. In one embodiment, the tungsten carbide has a size ranging from about 6 μm to about 30 μm. In another embodiment, the tungsten carbide with a size ranging from about 1 μm to about 6 μm.
In one embodiment, the substrate 20 may be cemented cobalt tungsten carbide, while the superabrasive volume 12 may be formed from a polycrystalline ultra-hard material, such as polycrystalline diamond or diamond crystals bonded by a foreign material. In one embodiment, metal binder may comprise CoCuFeP.
Although in accordance with an embodiment, the alloy, such as CoCuFeP is used in combination with the tungsten carbide, it is possible for other alloys to be employed. The alloy selected must be capable of wetting the surface of the diamond particles. Such alloys typically have a relatively low melting temperature. When using such alloys within the powdered metal matrix, upon applying heat, the alloys prepares the surfaces of the diamond particles so that the surfaces have a greater affinity for the matrix material. Once the surfaces of the diamond particles have so prepared, upon solidifying the metal matrix securely retains the diamond particles.
The amounts of tungsten carbide and CoCuFeP alloy used in the mixture vary depending upon the particular use intended for the drill bit. Since the tungsten carbide is more abrasive and provides for a higher degree of hardness, a greater quantity of that compound is used for more abrasive rock formations. On the other hand, where the drill is to be used in softer rock formations, a greater quantity of the CoCuFeP alloy can be employed.
In general, a powdered metal matrix includes between about 15% to about 50% by weight of a metal alloy having a relatively low melting temperature and capable of properly preparing the surface of the diamond particles (in the preferred embodiment the CoCuFeP alloy), 10% to 50% tungsten carbide. The ratio between tungsten (WC) to the metal binder may be from about 30% to about 70%. In one embodiment, diamond particles may be about 25 volume percent, tungsten carbide about 52 volume percent, metal binder about 23 volume percent. Volume percentage of diamond particles, WC, and metal binder can be varied depending on the properties to be sought for. In general, the iron powder may be employed since it has good infiltration characteristics and serves to improve the soldering or fusing characteristics of the powdered metal matrix.
The impregnated diamond cutter are known for their toughness and durability, which allow them to be an effective cutter in demanding applications. Although one type of impregnated diamond cutter 10 has been described, other types of impregnated diamond cutters 10 may be utilized. For example, in one embodiment, impregnated diamond cutter 10 may have a chamfer (not shown) around an outer peripheral of the top surface 21. The chamfer may have a vertical height of about 0.5 mm or 1 mm, for example, and an angle of about 45° degrees, for example, which may provide a particularly strong and fracture resistant tool component.
Diamond distributed in a hard matrix may be progressively exposed as surface diamonds are worn and shed to maintain adequate rate of penetration. In the design of an impregnated cutter, two competing processes must be balanced. If the embedded diamonds are exposed too quickly, the life of the cutter is shortened. If the embedded diamonds are exposed too slowly, the overall rate of penetration will be reduced. An important parameter is what matrix material is used to retain the diamond.
With the impregnated diamond cutters, as the metal matrix wears away, new diamonds are exposed with such diamonds providing new cutting surfaces. Ideally, the diamonds should be evenly dispersed within the metal matrix so that as the matrix wears, there are always new diamond cutting surfaces being exposed.
In one embodiment, a method of making an impregnated diamond cutter, comprising steps of mixing CoCuFeP as a metal binder with a plurality of diamond particles as a part of a diamond table; and subjecting the diamond table to a condition of temperature and pressure suitable to produce the impregnated diamond cutter.
In another embodiment, a method of making an impregnated diamond cutter may comprise steps of mixing a metal binder with a plurality of diamond particles in liquid solution, such as isopropanol, to form a paste; extruding the paste into sausages that are rolled and dried into irregular granules; subjecting the irregular granules to a mold cavity which is under a first condition of temperature and pressure to form a green product; and subjecting the green product to a second condition of temperature and pressure suitable to produce the impregnated diamond cutter.
In general, the impregnated diamond cutters are made by placing the diamond particles within a carbon mold along with the various components of the metal matrix. In forming the impregnated diamond cutters, the diamond particles and the powder are mixed together and poured into a mold. In order to obtain better distribution of the diamonds, small quantities of the metallic powder and the diamond particles can be mixed and a plurality of such mixtures poured into the mold, a layer at a time, thereby obtaining a better distribution of the diamond particles. After the mold has been filled with the diamonds and the metallic powder so as to form the metal matrix, heat and pressure are applied.
In this embodiment, tungsten carbide (WC) particles of varying sizes are used in conjunction with CoCuFeP for the binder. Diamonds are mixed with matrix powder, binder, and liquid, such as propanol, into a paste, which is then loaded into a doser. The paste is extruded into short cylinders that are rolled and dried into irregular granules. The granules are packed into the desired areas of a mold, where they are subjected to a pre-compaction step using a cold press stage prior to hot pressing under an inert atmosphere.
As shown in Tables 1 and 2, the initial batch consisted of a 25/35 diamond mesh, most with a size distribution of ±5%. The distribution was varied to have a wider diamond size distribution in some formulas. The range of particulates is no larger than 707 μm and no smaller than 500 μm. The diamond volume percentage is varied between about 17.5% to about 27.5%. It is reported as diamond concentration, a 4× multiple of the volume percentage. The diamond granules are consistently distributed to allow a high concentration where the diamonds are not in close proximity. The diamond particle retention is increased as all portions of the diamond are encapsulated by the matrix, which in turn will increase the life of the cutter.
Selection of the matrix material must ensure processing temperatures that will not graphitize or oxidize the diamond. The matrix material must be adequately abrasion resistant so sharp diamonds are not released, impacting cutter life. Further, it must be hard to avoid localized yielding as diamonds push into the formation under high force. Tungsten carbide with a CoCuFeP binder meets these criteria. The size of the tungsten carbide particles range from fine (1-6 μm) to coarse (30-150 μm), and can be fused or spherically cast. Coarser grains are easier to infiltrate with a molten binder during the powder metallurgy processes, whereas fine grains have a higher packing density. Finer grains will have higher hardness, whereas coarser grains will have higher toughness.
A blending process is performed separate diamond grits from each other to avoid diamond clustering, which is considered the weak paint of the impregnated inserts for premature failure during drilling process.
Diamond granules are formed by mixing diamonds with matrix powder, a binder with liquid, such as isopropanol, into a paste. Coated diamond particles are surrounded by matrix powder and loaded into a doser. The paste is then extruded through a granulator into short “sausages” that are rolled and dried into irregular granules. The granules are meshed to the desired size and distribution.
The process for making diamond-impregnated matrix for bit bodies involves hand mixing of matrix powder with diamonds and a binder to make a paste. The doser weighs out the amount that will go into the mold. The paste is then packed into the desired areas of a mold. The pellets are transferred into a mold cavity, where they are subjected to a pre-compaction step under a cold press stage.
Palletizations allow an even distribution of diamond, protecting them during the heating cycles, and improves bonding. Well distributed diamonds result in a higher efficiency and longer lasting bit. Diamond clustering will lead to more diamonds being shed with an equal amount of matrix wear as a smaller area of matrix is holding more diamonds. Therefore, the cutter life will be shorter as diamonds are shed before they are blunt, and fresh diamonds are prematurely exposed.
Impregnated bits are typically formed into a solid body of matrix material formed by a number of powder metallurgy processes. Abrasive particles and a matrix powder are infiltrated with a molten binder material. Upon cooling, the bit body includes the binder and matrix material as well as the diamond particles suspended near and on the surface of the drill bit. The diamond can be either natural or synthetic diamond. Typically, the synthetic diamond used is a single crystal. Thermally stable polycrystalline diamond may also be used.
As shown in
In one embodiment, the impregnated diamond cutter can be made in a cylindrical forms (shown in
The average and standard deviation for samples S1-S8 and reference are presented in
The matrix hardness measured by Vickers microhardness is presented in
As shown in
While reference has been made to specific embodiments, it is apparent that other embodiments and variations can be devised by others skilled in the art without departing from their spirit and scope. The appended claims are intended to be construed to include all such embodiments and equivalent variations.
