Patent Application
20250237112
Not applicable.
The present disclosure relates generally to earth-boring bits used to drill boreholes for the ultimate recovery of oil, gas, or minerals. More particularly, the present disclosure relates to matrix compositions for the bodies of fixed cutter drill bits and methods for manufacturing such fixed cutter drill bits.
An earth-boring drill bit is typically mounted on the lower end of a drill string and is rotated by rotating the drill string at the surface or by actuation of downhole motors or turbines, or by both methods. With weight applied to the drill string, the rotating drill bit engages the earthen formation and proceeds to form a borehole along a predetermined path toward a target zone. The borehole thus created has a diameter generally equal to the diameter or “gage” of the drill bit.
Fixed cutter bits, also known as rotary drag bits, are one type of drill bit commonly used to drill boreholes. Fixed cutter bit designs include a bit body having a plurality of blades angularly spaced about a bit face. The blades generally project radially outward along the bit face and form flow channels therebetween. Cutter elements are typically grouped and mounted on the blades. The configuration or layout of the cutter elements on the blades may vary widely, depending on a number of factors.
The bit body including the blades is typically made of steel or a metal matrix. Fixed cutter drill bits having steel bodies are often referred to as “steel bodied bits,” whereas fixed cutter drill bits having metal matrix bodies are often referred to as “matrix bits.” Metal matrix bit bodies are formed of tungsten carbide (WC) particles dispersed within a metal or metal alloy. In particular, a WC powder is mixed with a metal powder, and then poured into a graphite mold of the bit body design. Copper alloy metal ingots are poured on top of the mixed powder in the mold, and the mold is heated in a furnace to allow the copper alloy to flow and migrate into the interstitial spaces between the mixed powder particles. The mixture in the mold is then allowed to cool and solidify into the bit body. Cutter elements are then mounted to the blades of the bit body to form the matrix drill bit. For most conventional metal matrix bit bodies, the WC particles have sizes ranging from 60 mesh (250 microns) to 325 mesh (44 microns), and the bit bodies typically have a Transverse rupture strength (TRS) less than 165 ksi (according to ASTM B406 Test), moderate to poor erosion resistance, and a Charpy Impact Toughness (un-notched) of about 2.8 to 3.2 ft-lbs (ASTM E23 standard).
The cutter elements disposed on the several blades of a fixed cutter bit are typically formed of extremely hard materials and include a layer of polycrystalline diamond (“PCD”) material. In the typical fixed cutter bit, each cutter element includes an elongate and generally cylindrical support member that is received and secured in a pocket formed in the surface of one of the several blades. In addition, each cutter element typically has a hard cutting layer of polycrystalline diamond or other superabrasive material such as cubic boron nitride, thermally stable diamond, polycrystalline cubic boron nitride, or ultrahard tungsten carbide (meaning a tungsten carbide material having a wear-resistance that is greater than the wear-resistance of the material forming the substrate), as well as mixtures or combinations of these materials. The cutting layer is mounted to one end of the corresponding support member, which is typically formed of tungsten carbide.
While the bit is rotated, drilling fluid is pumped through the drill string and directed out of the face of the drill bit. The fixed cutter bit typically includes nozzles or fixed ports spaced about the bit face that serve to inject drilling fluid into the passageways between the several blades. The drilling fluid exiting the face of the bit through nozzles or ports performs several functions. In particular, the drilling fluid removes formation cuttings (e.g., rock chips) from the cutting structure of the drill bit. Otherwise, accumulation of formation cuttings on the cutting structure may reduce or prevent the penetration of the drill bit into the formation. In addition, the drilling fluid sweeps away and removes formation cuttings from the bottom of the hole. Failure to remove formation materials from the bottom of the hole may result in subsequent passes by cutting structure to essentially re-cut the same materials, thereby reducing the effective cutting rate and potentially increasing wear on the cutting surfaces of the cutter elements. The drilling fluid flushes the cuttings removed from the bit face and from the bottom of the hole radially outward, and then up the annulus between the drill string and the borehole sidewall to the surface. Still further, the drilling fluid removes heat, caused by contact with the formation, from the cutter elements to prolong cutter element life.
Embodiments of methods for manufacturing fixed cutter drill bits for drilling earthen formations are disclosed herein. The fixed cutter drill bits have a central axis and including a bit body, a plurality of circumferentially-spaced blades extending from the bit body, a plurality of cutter elements mounted to a cutter supporting surface of each blade. In one embodiment, the method comprises (a) preparing a powdered metal matrix mixture comprising 5.0 wt % to 20.0 wt % of a plurality of large size particles having mesh sizes ranging from 80 mesh to 200 mesh, at least 50.0 wt % of a plurality of medium size particles having mesh sizes ranging from 200 mesh to 325 mesh, and a plurality of small size particles having mesh sizes ranging from 325 mesh to 600 mesh. The plurality of large size particles consist essentially of a plurality of crushed cast tungsten carbide (WC) particles, a plurality of macrocrystalline WC particles, a plurality of spherical cast WC particles, a plurality of tungsten (W) particles, or a combination thereof. The plurality of medium size particles consist essentially of a plurality of spherical cast WC particles. The plurality of small size particles consist essentially of (i) a plurality of small size metal or metal alloy particles, and (ii) a plurality of small size macrocrystalline WC particles, a plurality of small size carburized WC particles, a plurality of small size spherical cast WC particles, a plurality of small size W particles, or a combination thereof. The powdered metal matrix mixture comprises 5.0 wt % to 20.0 wt % of the plurality of small size macrocrystalline WC particles, the plurality of small size carburized WC particles, the plurality of small size spherical cast WC particles, or the combination thereof. The powdered metal matrix mixture comprises 0.0 wt % to 10.0 wt % of the plurality of small size W particles and 0.0 wt % to 7.0 wt % of the plurality of small size metal or metal alloy particles. In addition, the method comprises (b) placing the powdered metal matrix mixture in a mold after (a). Further, the method comprises (c) positioning an infiltration alloy on top of the powdered metal matrix mixture in the mold after (b). Still further, the method comprises (d) heating the mold, the powdered metal matrix mixture in the mold, and the infiltration alloy after (c) to melt the metal or metal alloy particles and melt the infiltration alloy. Moreover, the method comprises (e) infiltrating the powdered metal matrix mixture with the melted metal or metal alloy and the melted infiltration alloy during (d). The method also comprises (f) cooling the mold, the melted metal or metal alloy, and the melted infiltration alloy to solidify the melted metal or metal alloy and solidify the melted infiltration alloy after (e) to form the bit body.
Embodiments of bit bodies for drill bits for drilling boreholes in earthen formations are disclosed herein. In one embodiment, a bit body for a drill bit for drilling a borehole in an earthen formation comprises 5.0 wt % to 20.0 wt % of a plurality of large size particles having mesh sizes ranging from 80 mesh to 200 mesh. The plurality of large size particles consist essentially of a plurality of crushed cast WC particles, a plurality of macrocrystalline WC particles, a plurality of spherical cast WC particles, a plurality of tungsten (W) particles, or a combination thereof. In addition, the bit body comprises at least 50 wt % of a plurality of medium size particles having mesh sizes ranging from 200 mesh to 325 mesh. The plurality of medium size particles consist essentially of a plurality of spherical cast WC particles. Further, the bit body comprises a plurality of small size particles having mesh sizes ranging from 325 mesh to 600 mesh. The plurality of small size particles consist essentially of (i) a plurality of small size metal or metal alloy particles, and (ii) a plurality of small size macrocrystalline WC particles, a plurality of small size carburized WC particles, a plurality of small size spherical cast WC particles, a plurality of small size W particles, or a combination thereof.
Embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical advantages of the invention in order that the detailed description of the invention that follows may be better understood. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. 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.
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.
Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” As used herein, the phrases “consist(s) of” and “consisting of” are used to refer to exclusive components of a composition, meaning only those expressly recited components are included in the composition; whereas the phrases “consist(s) essentially of” and “consisting essentially of” are used to refer to the primary components of a composition, meaning that only small or trace amounts of components other than the expressly recited components (e.g., impurities, byproducts, etc.) may be included in the composition. For example, a composition consisting of X and Y refers to a composition that only includes X and Y, and thus, does not include any other components; and a composition consisting essentially of X and Y refers to a composition that primarily comprises X and Y, but may include small or trace amounts of components other than X and Y. In embodiments described herein, any such small or trace amounts of components other than those expressly recited following the phrase “consist(s) essentially of” or “consisting essentially of” preferably represent less than 5.0 wt % of the composition, more preferably less than 4.0 wt % of the composition, even more preferably less than 3.0 wt % of the composition, and still more preferably less than 1.0wt % of the composition.
The term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a part), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. Still further, as used herein, the term “component” may be used to refer to a contiguous, single-piece or monolithic structure, part, or device. It is to be understood that a component may be used alone or as part of a larger system or assembly.
Any reference to up or down in the description and the claims is made for purposes of clarity, with “up”, “upper”, “upwardly”, “uphole”, or “upstream” meaning toward the surface of the borehole and with “down”, “lower”, “downwardly”, “downhole”, or “downstream” meaning toward the terminal end of the borehole, regardless of the borehole orientation. As used herein, the terms “approximately,” “about,” “substantially,” and the like mean within 10.0% (i.e., plus or minus 10%) of the recited value, and more preferably within 5.0% (i.e., plus or minus 5%) of the recited value. Thus, for example, a recited angle of “about 80.0 degrees” refers to an angle ranging from 72.0 degrees to 88.0 degrees, and preferably an angle ranging from 76.0 degrees to 84.0 degrees. Particle sizes and particle size distributions described herein are based on and in accordance with ASTM E11 Standard Sieves.
Without regard to the type of bit, the cost of drilling a borehole for recovery of hydrocarbons may be very high, and is proportional to the length of time it takes to drill to the desired depth and location. The time required to drill the well, in turn, is greatly affected by the number of times the drill bit must be changed before reaching the targeted formation. This is the case because each time the bit is changed, the entire string of drill pipe, which may be miles long, must be retrieved from the borehole, section by section. Once the drill string has been retrieved and the new bit installed, the bit must be lowered to the bottom of the borehole on the drill string, which again must be constructed section by section. This process, known as a “trip” of the drill string, requires considerable time, effort and expense. Accordingly, it is desirable to employ drill bits which will drill faster and longer.
During drilling operations, a drill bit is subjected to abrasive wear, impact loads, and thermal stresses. Consequently, drill bits may experience severe wear, corrosion, and physical damage while drilling. The length of time that a drill bit may be employed before it must be changed depends upon a variety of factors including the durability of the drill bit and its ability to maintain a high or acceptable ROP. For example, the bit body may be damaged due via impact with hard formations and rock. Sufficient damage to a drill bit may detrimentally reduce it cutting effectiveness and rate of penetration (ROP). In such cases, it may be necessary to trip the drill string to change the drill bit. For matrix body fixed cutter drill bits, the composition of the metal matrix defining the bit body impacts the mechanical properties including the strength, toughness, and erosion resistance of the drill bit, which in turn directly impact the durability of the drill bit. Accordingly, embodiments described herein are directed to matrix fixed cutter drill bits and metal matrix compositions for the bodies of fixed cutter drill bits that offer the potential to improve the strength, toughness, and erosion resistance of the drill bit, and hence, the overall durability of the drill bit as compared to conventional fixed cutter drill bits having bit bodies made of conventional compositions.
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Gage-facing surface 60 of gage pads 51 abut the sidewall of the borehole during drilling. The pads can help maintain the size of the borehole by a rubbing action when cutter elements 40 wear slightly under gage. Gage pads 51 also help stabilize bit 10 against vibration. In certain embodiments, gage pads 51 include flush-mounted or protruding cutter elements 51a embedded in the gage pads to resist pad wear and assist in reaming the bore hole side wall. Therefore, as used herein, the term “cutter element” is used to include at least the above-described forward-facing cutter elements 40 and flush or protruding elements 51a embedded in the gage pads, all of which may be made in accordance with the principles described herein.
Bit body 12 is made of a metal matrix composition in accordance with principles described herein. The metal matrix composition of bit body 12 includes tungsten carbide (WC) particles and optionally tungsten (W) particles dispersed within a metal or metal alloy. As will be described in more detail below, the metal or metal alloy is formed from metal or metal alloy particles including, without limitation, nickel (Ni) particles, iron (Fe) particles, steel alloy particles, or combinations thereof. The WC particles, the optional W particles (if any), and the metal or metal alloy particles used to form the metal matrix composition of bit body 12 have particular size distributions and geometries as described hereinbelow.
Referring now to
It should be appreciated that the foregoing recited ranges for the wt % of each size of particles in the powdered metal matrix mixture (i.e., large size particles, medium size particles, and small size particles) may vary from the foregoing ranges by up to +/−5.0 wt % or alternatively up to +/−2.0 wt % as a small percentage of large size particles may fall slightly outside the 80 mesh (177 microns) to 200 mesh (74 microns) range, a small percentage of medium size particles may fall slightly outside the 200 mesh (74 microns) to 325 mesh (44 microns) range, and a small percentage of the small size particles may fall slightly outside the 325 mesh (44 microns) to 600 mesh (16 microns) range.
Referring still to
In block 105, the mold, the powdered metal matrix mixture in the mold, and the infiltration alloy are heated in a furnace to melt the infiltration alloy and the metal or metal alloy in the powdered metal matrix mixture, and allow the melted infiltration alloy and the metal or metal alloy in the powdered metal matrix mixture to flow and migrate into the interstitial spaces between the WC particles (and optional W particles). Next, the mold and mixture therein (i.e., WC particles and optional W particles distributed in the liquified infiltration alloy and metal or metal alloy) is allowed to cool and solidify into bit body 12 in block 106. Then, in block 107, bit body 12 is removed from the mold, and in block 108, the drill bit 10 is completed by mounting cutter elements 40 to blades 42, 52, removing the stem on the end of the bit body 12 after it cools, and attaching the pin 14 to the end of the bit body 12.
In one exemplary embodiment, referred to herein as “Composition FO19,” the powdered metal matrix mixture prepared in block 102 and used to form bit body 12 via method 100 includes 10.0 wt % of crushed cast WC particles having sizes ranging from 100 mesh to 200 mesh (i.e., the large size particles), 76.0 wt % of spherical cast WC particles having sizes ranging from 200 mesh to 325 mesh (i.e., the medium size particles), 10 wt % of macrocrystalline WC particles having sizes ranging from 325 mesh to 600 mesh (i.e., the small size particles), and 4.0 wt % of Ni particles having sizes ranging from 325 mesh to 600 mesh (i.e., the small size particles). In another exemplary embodiment, referred to herein as “Composition FN88,” the powdered metal matrix mixture prepared in block 102 and used to form bit body 12 via method 100 includes 5.0 wt % of crushed cast WC particles having sizes ranging from 100 mesh to 200 mesh (i.e., the large size particles), 5.0 wt % of macrocrystalline WC particles having sizes ranging from 100 mesh to 200 mesh (i.e., the large size particles), 76.0 wt % of spherical cast WC particles having sizes ranging from 200 mesh to 325 mesh (i.e., the medium size particles), 10.0 wt % of macrocrystalline WC particles having sizes ranging from 325 mesh to 600 mesh (i.e., the small size particles), and 4.0 wt % of Ni particles having sizes ranging from 325 mesh to 600 mesh (i.e., the small size particles).
Embodiments of the powder metal matrix mixtures described above are used to form bit body 12 via the casting method 100. It should be appreciated that in block 104 of method 100, the metal or metal alloy particles melt, and then flow and migrate into the interstitial spaces between the WC particles (and optional W particles). However, the WC particles and optional W particles do not melt in block 104. Thus, the WC particles and optional W particles in cast bit body 12 and drill bit 10 generally maintain the same size and geometry distributions as the WC particles and optional W particles had in the powder metal matrix mixture prepared in block 102; whereas the metal or metal alloy particles in the powdered metal matrix mixture prepared in block 102 melt in block 104 become generally amorphous in the cast bit body 12 and drill bit 10. Thus, the metal or metal alloy particles do not maintain the same size and geometry distribution as the metal or metal alloy particles had in the powdered metal matrix mixture prepared in block 102 after melting in block 104. However, it should be appreciated that despite the melting of the metal or metal alloy particles in block 104 of method 100, the wt % of WC particles, the wt % of the optional W particles, and the wt % of the metal or metal alloy in the powdered metal matrix mixture prepared in block 102 and in the cast bit body 12 remain constant, respectively, before and after block 104. Thus, in embodiments described herein, bit body 12 has a composition (after block 104 and casting) including 5.0 wt % to 20.0 wt % of the large size particles, alternatively 8.0 wt % to 12.0 wt % of the large size particles, and alternatively about 10 wt % of the large size particles; and at least 50 wt % of the medium size particles, alternatively at least 70 wt % of the medium size particles, and alternatively at least 80 wt % of the medium size particles. As previously described, the large size particles consist of or consist essentially of crushed cast WC particles, macrocrystalline WC particles, tungsten (W) particles, or combinations thereof; and the medium size particles consist of or consist essentially of spherical cast WC particles. The balance of the composition of bit body 12 (after block 104 and casting) includes the amorphous metal or metal alloy, small size particles of macrocrystalline WC, small size particles carburized WC particles, small size W particles, or combinations thereof. Due to the uniform mixing of the powder mixture used to form bit body 12, the composition of bit body 12 and the distribution of WC particles and optional W particles within bit body 12 are generally uniform throughout bit body 12.
Embodiments of bit bodies made and having compositions as disclosed herein offer the potential for enhanced mechanical properties such as strength, toughness, and erosion resistance. As previously described, most conventional metal matrix bit bodies typically exhibit a Transverse rupture strength (TRS) less than 165 ksi (according to ASTM B406 Test), moderate to poor erosion resistance, and a Charpy Impact Toughness (un-notched) of about 2.8 to 3.2 ft-lbs. In contrast, embodiments of bit bodies made and having compositions as disclosed herein (e.g., bit body 12) exhibit a TRS greater than 190 ksi (according to ASTM B406 Test), moderate to good erosion resistance, and a Charpy Impact Toughness (un-notched) of about 7.0 ft-lbs (ASTM E23 standard).
A plurality of bit bodies having conventional compositions, a bit body having Composition FO19 as previously described, and a bit body having Composition FN88 as previously described were tested in identical manners to determine and compare the TRS Strength of the bit bodies (according to ASTM B406 Test) and the Erosion Resistance of the bit bodies (quantified by the erosion volume loss based on application of the same abrasion wear test including a uniform mixture of water and an abrasive grit such as sand or garnet bombarded onto the compositions at a constant velocity). The conventional compositions that were tested generally had 0.0 wt % spherical cast WC, and employed various mixtures of crushed cast WC and macrocrystalline WC, with additions of 2.0 wt % to 7.0 wt % of iron and/or nickel having particle sizes less than 200 mesh (74 microns). The conventional compositions tested included 20.0 wt % to 100.0 wt % of crushed cast WC (with the balance being macrocrystalline WC). The crushed cast WC particles and macrocrystalline WC particles in the conventional compositions had a wide distribution of sizes ranging from 60 mesh (250 microns) to 400 mesh (37 microns).Referring now to
While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.
This application claims benefit of U.S. provisional patent application Ser. No. 63/623,790 filed Jan. 22, 2024, and entitled “Drill Bits for Drilling Subterranean Boreholes and Methods for Making Same,” which is hereby incorporated herein by reference in its entirety for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63623790 | Jan 2024 | US |
