Cutting elements and drill bits

Abstract

The present invention provides a cutting element and a drill bit. The cutting element comprises: a cylindrical base; a superhard material layer fixed to the cylindrical base, the top of the superhard material layer having a working surface, with a chamfer formed between the outer side of the superhard material layer and the working surface; at least one cutting tooth, formed by cutting at the periphery of the superhard material layer so that the orthographic projection of the cutting tooth on the base lies within the outer circle of the projection surface of the base; and a cutting ridge located on the working surface and corresponding one-to-one with each cutting tooth. The present invention solves the problems of low cutting efficiency and inability to break chips in the cutting element of a drill bit in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum exploration, and in particular to a cutting element and a drill bit. Background Art

[0002] To drill a wellbore for oil and gas extraction or other applications, a drill bit is typically attached to the lower end of a drill pipe assembly, with the ends of the drill pipe sections connected to each other to form a drill string. Rotating the drill string above ground engages the formation, driving the drill bit. This action, through abrasion, fracturing, or shearing, causes the drill bit to penetrate the formation material, forming a wellbore along a predetermined trajectory toward the target formation. Many different types of drill bits have been developed and found to be very useful in drilling these wellbores.

[0003] The cutting elements arranged on the blades of a drill bit are typically formed from extremely hard materials. In a typical drill bit, each cutting element consists of a tungsten carbide substrate of a certain length, usually cylindrical, which is placed and fixed in a groove formed on the surface of the blade. Conventional cutting elements usually include a layer of superhard material such as polycrystalline diamond (PCD) or other extremely wear-resistant materials such as heat-stable diamond or polycrystalline cubic boron nitride.

[0004] During drilling, cutting elements are desired that can withstand high loads, thereby extending the operating life of the drill bit. Cutters that can effectively cut according to the designed speed and load conditions and control the contact area in varying formations are also desired. Furthermore, cutting elements with chip-breaking properties are also desired.

[0005] As can be seen from the above, the existing technology has the problem that the cutting element of the drill bit has low cutting efficiency and cannot break chips. Summary of the Invention

[0006] The main purpose of the present invention is to provide a cutting element and a drill bit to solve the problems of low cutting efficiency and inability to break chips in the cutting element of the drill bit in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a cutting element, comprising: a substrate, which is cylindrical; a superhard material layer fixed on the substrate, the top of the superhard material layer having a working surface, and a chamfer formed between the outer side surface of the superhard material layer and the working surface; a cutting tooth, wherein there is at least one cutting tooth, and the cutting tooth is cut and formed at the periphery of the superhard material layer so that the positive projection of the cutting tooth on the substrate is located within the outer circle of the projection surface of the substrate; a cutting ridge, wherein the cutting ridge is located on the working surface and corresponds one-to-one to the cutting tooth.

[0008] Furthermore, the periphery of the superhard material layer has a plurality of recessed areas, and a cutting tooth is provided between two adjacent recessed areas.

[0009] Furthermore, a plurality of recessed areas are spaced apart along the circumference of the superhard material layer, and the recessed areas extend downward along the height direction of the superhard material layer.

[0010] Furthermore, the cutting teeth are round, pointed or saw-toothed.

[0011] Furthermore, the number of the cutting teeth is 1 to 20.

[0012] Furthermore, a plurality of recessed areas form the outer boundary of the superhard material layer, and the recessed areas start from the working surface, extend in a direction perpendicular to the working surface, and gradually end at the outer side surface of the substrate.

[0013] Furthermore, the angle between the outer side surface of the superhard material layer and the chamfer is 30 degrees to 60 degrees.

[0014] Furthermore, the working surface is a curved surface.

[0015] Furthermore, the working surface includes a plurality of area surfaces, and the number of the area surfaces is equal to the number of the recessed areas.

[0016] Furthermore, the center of the working surface is higher than, lower than or equal to the edge of the working surface.

[0017] Further, the cutting ridge includes a first ridge, and the first ridge is located between two adjacent regional surfaces.

[0018] Furthermore, the first ridge is a straight line or a curve, and the first ridge connects the center of the working surface and the symmetry center of the cutting tooth.

[0019] Furthermore, two adjacent regional surfaces are both planar or curved structures.

[0020] Furthermore, the included angle between two adjacent regional surfaces intersecting at the first ridge is 100 degrees to 179.5 degrees.

[0021] Furthermore, the cutting ridge further includes a second ridge, and the second ridge is located on the area surface between two adjacent first ridges.

[0022] Furthermore, the second ridge is a straight line or a curve, and the second ridge connects the center of the working surface and the symmetry center of adjacent cutting teeth.

[0023] Furthermore, the included angle between two adjacent regional surfaces intersecting at the second ridge is 180.5 degrees to 260 degrees.

[0024] Further, the radius of the cutting tooth is 10% to 100% of the radius of the cutting element.

[0025] According to another aspect of the present invention, a drill bit is provided, comprising the above-mentioned cutting element.

[0026] According to the technical solution of the present invention, the cutting element includes a base, a superhard material layer fixed on a cylindrical base, cutting teeth and a cutting ridge. The base is cylindrical, the top of the superhard material layer has a working surface, a chamfer is formed between the outer side surface of the superhard material layer and the working surface, there is at least one cutting tooth, and the cutting tooth is cut and formed at the periphery of the superhard material layer so that the positive projection of the cutting tooth on the base is located within the outer circle of the projection surface of the base. The cutting ridge is located on the working surface and corresponds one-to-one to the cutting tooth, so that the cutting element can withstand high loads during drilling and has a chip breaking function, solving the problem of low cutting efficiency and inability to break chips of the cutting element of the drill bit in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 shows a perspective view of a drill bit in one embodiment of the present invention;

[0029] Figure 2 shows a perspective view of a conventional cutting element;

[0030] Figure 3 A schematic diagram showing a conventional cutting element cutting rock;

[0031] Figure 4 Shown Figure 3 Schematic diagram of cutting elements generating rock chips;

[0032] Figure 5 shows a perspective view of a cutting element in one embodiment of the present invention;

[0033] Figure 6 Shown Figure 5 A top view of

[0034] Figure 7 Shown Figure 5 The main view;

[0035] Figure 8 Shown Figure 5 An angled cross-sectional view of a cutting element;

[0036] Figure 9 Shown Figure 5 A cross-sectional view of the cutting element at another angle;

[0037] Figure 10 A schematic diagram showing a cutting element cutting rock in a specific embodiment of the present invention;

[0038] Figure 11 Shown Figure 8 Schematic diagram of the cutting elements generating and breaking rock chips.

[0039] The above drawings include the following reference numerals:

[0040] 3. Drill bit body; 4. Blade; 5. Cutting element; 502. Superhard material layer; 503. Working surface; 504. Base; 505. Outer surface; 507. Chamfer; 516. Cutting tooth; 517. Recessed area; 523. Area surface; 530. First ridge; 534. Second ridge; 410. Formation; 412. Contact surface; 413. Rock cuttings. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0043] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0044] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0045] In order to solve the problem of low cutting efficiency and inability to break chips in the cutting element of the drill bit in the prior art, the present invention provides a cutting element and a drill bit. Specifically, the drill bit described below includes the following cutting element.

[0046] like Figure 1 As shown, the drill bit comprises a drill body 3 and a plurality of blades 4. The blades 4 protrude radially outward from the drill body 3, forming flow channels therebetween. Cutting elements 5 are grouped and mounted on the blades 4 in a radially extending arrangement. The structure and layout of the cutting elements 5 on the blades 4 vary widely, depending on factors such as the formation being drilled.

[0047] like Figure 2As shown, the cutting element 5 includes a superhard material layer 502 and a substrate 504. The top of the superhard material layer 502 has a working surface 503, and a chamfer 507 is formed between the outer side surface of the cemented carbide substrate 504 and the working surface 503. It should be noted that at least a portion of the chamfer 507 may function as the working surface 503, which contacts the ground during drilling operations. According to known technology, Figure 2 Flat-top cutting elements with a superhard material layer 502 are generally the most common and easiest to manufacture using existing technology.

[0048] During drilling, the working surface 503 contacts the formation and is subjected to peak (high-amplitude) pressures generated by normal loads, as well as shear and impact loads applied to the working surface 503 during drilling. Because the cutting elements 5 are typically inserted into the scraper drill bit at a certain back rake angle, peak stresses acting on the working surface 503 alone or in combination with other factors, such as residual thermal stress, can cause cracks to form and propagate within the surface or interior of the superhard material layer 502 of the cutting element 5. Cracks of sufficient length may cause a sufficiently large piece of superhard material to be detached, rendering the cutting element 5 ineffective or causing the cutting element 5 to fail. When this occurs, drilling operations may have to be stopped to remove the scraper drill bit and replace the ineffective or failed cutting element 5.

[0049] like Figures 3 and 4 As shown, conventional cutting elements use flat cutting edges to cut the formation 410, with the contact surface being contact surface 412 and the cutting depth being L. During the drilling process, the superhard material layer 502 cuts the rock while resisting strong impacts from the rock. Because the working surface of the superhard material layer 502 lacks the flexibility to reduce the contact area, when drilling into formations with a high gravel content or hard formations, the cutting elements are easily damaged by impacts, resulting in damage to the cutting surface. On the other hand, when drilling into shale, mudstone or other formations, the rock cuttings generated by the diamond composite blade cutting can easily form long strips of rock cuttings 413. Due to the large size of such rock cuttings, they are easily adhered to the blades 4 and the drill bit body 3, forming mud bags. As a result, the cutting working surface of the drill blades is wrapped and cannot continue to work, ultimately resulting in a reduction in the mechanical drilling rate, no drilling footage, or other problems.

[0050] like Figures 5 to 7As shown, the cutting element 5 is essentially in the form of a cylinder. That is, the substrate 504 is cylindrical. The cutting element 5 includes a superhard material layer 502 bonded to the substrate 504. The manufacturing process of the cutting element 5 can use a cemented carbide body as the substrate 504, in which tungsten carbide particles are bonded together with cobalt. During the sintering process, superhard material powder (such as diamond or cubic boron nitride) is placed on the cemented carbide body, and the mixture is subjected to high pressure under high temperature conditions. Under this pressure environment, the superhard material particles are thermodynamically stable. This condition causes the superhard material particles to recrystallize, forming the superhard material layer 502 directly on the upper surface of the substrate 504. In this embodiment, the superhard material layer 502 is a polycrystalline diamond or polycrystalline cubic boron nitride layer. The top of the superhard material layer 502 has a working surface 503, and a chamfer 507 is formed between the outer side surface 505 of the superhard material layer 502 and the working surface 503. The angle between the sidewall of the base 504 and the chamfer 507 is about 45 degrees. At least a portion of the outer side surface 505 and the chamfer 507 can also serve as the working surface 503.

[0051] In this embodiment, the angle between the outer side surface 505 of the superhard material layer 502 and the chamfer 507 is 30 degrees to 60 degrees.

[0052] To withstand high loads during drilling and provide chip breaking characteristics, the cutting element 5 is provided with multiple cutting points or edges. The cutting element 5 is fabricated so that two or more cutting edges are incorporated into the outer circumference of the superhard material layer 502. As is known in the industry, the two or more cutting edges can be formed into the outer circumference through machining methods.

[0053] like Figure 5 As shown, the cutting element 5 includes a cutting tooth 516. There is at least one cutting tooth 516, and the cutting tooth 516 is cut and formed at the periphery of the superhard material layer 502 so that the orthographic projection of the cutting tooth 516 on the substrate 504 is located within the outer circle of the projection surface of the substrate 504. The periphery of the superhard material layer 502 has multiple recessed areas 517, with one cutting tooth 516 located between two adjacent recessed areas 517. If at least one recessed area 517 is machined into the superhard material layer 502, two or more cutting edges can form the outer circumference of the superhard material layer 502. Therefore, it is also possible to form a cutting tooth 516 between two recessed areas 517. The cutting tooth 516 may be a flat, elongated triangular ridge protruding from the outer circumference of the superhard material layer 502. The cutting tooth 516 may also be round, pointed, serrated, or other desired shapes. The recessed area 517 can form the periphery or edge of a conventional cutting element. The recessed area 517 may extend along the entire side of the cutting element or along the height of the cutting element or may extend entirely or partially along the side of the superhard material layer of the cutting tooth.

[0054] In this embodiment, the number of the cutting teeth 516 is 1 to 20.

[0055] like Figure 5 As shown, substantially recessed regions 517 are formed around the sidewalls of the ultrahard material layer 502, with incisors 516 defined between each pair of adjacent recessed regions 517. The recessed regions 517 are spaced apart circumferentially around the ultrahard material layer 502 and extend downwardly along the height of the ultrahard material layer 502. Without changing the geometry of the recessed regions 517, they extend through the entire depth of the ultrahard material layer 502. In this embodiment, there are a total of ten recessed regions 517, defining the same number of incisors 516. While reference is made herein to the number and location of recessed regions 517, the present application is not limited to the specific arrangement described and illustrated, and it is understood that a wide range of changes and modifications may be made to the present application without departing from the scope of the present application. For example, if more than one incisor 516 is present in these embodiments, the incisors 516 may be of different sizes and shapes.

[0056] In this embodiment, the radius of the cutting tooth 516 is 10% to 100% of the radius of the cutting element 5 .

[0057] In this embodiment, recessed regions 517 are formed at an inwardly inclined angle around the outer circumference of the superhard material layer 502. Specifically, multiple recessed regions 517 form the outer boundary of the superhard material layer 502. The recessed regions 517 originate from the working surface 503, extend perpendicularly to the working surface 503, and gradually converge at the outer side surface of the substrate 504. Thus, the recessed regions 517 are not parallel to the central axis of the cutting element 5. The angle between the recessed regions 517 and the central axis of the cutting element 5 is between 15 and 45 degrees.

[0058] In this embodiment, the working surface 503 is a curved surface.

[0059] like Figure 5 As shown, the working surface 503 includes a plurality of area surfaces 523. The center of the working surface 503 is higher than the edge of the working surface 503. In this embodiment, the number of area surfaces 523 is equal to the number of recessed areas 517. The number of area surfaces 523 is also equal to the number of cutting teeth 516.

[0060] like Figure 5As shown, the area surface 523 includes cutting ridges. The cutting ridges include a first ridge 530 and a second ridge 534. The first ridge 530 is located between two adjacent area surfaces 523. The second ridge 534 is located on the area surface 523 between two adjacent first ridges 530. Furthermore, the first ridge 530 can be a straight line that slopes upward or downward from the central vertex to the edge, connecting the center of the working surface 503 and the symmetry center of the cutting tooth 516. In this way, each area surface 523 has a roughly triangular shape. The first ridge 530 is higher than the second ridge 534, so that the area surface 523 gradually slopes downward from the first ridge 530 to the second ridge 534.

[0061] In an optional embodiment, the center of the working surface 503 is lower than the edge of the working surface 503. Of course, the center of the working surface 503 may also be equal to the edge of the working surface 503, which can be selected according to actual needs.

[0062] like Figures 8 and 9 As shown, two adjacent regional surfaces 523 can be flat or curved. When the regional surfaces 523 are flat, the angle α between the two regional surfaces 523 intersecting at the first ridge 530 is 100 to 179.5 degrees. The second ridge 534 slopes downward from the central vertex to the periphery, and the angle β between adjacent regional surfaces 523 intersecting at the second ridge 534 is 180.5 to 260 degrees.

[0063] In some embodiments, the first ridge 530 is a straight line or curve connecting the center of the working surface 503 and the center of symmetry of the incisor 516. The second ridge 534 is a straight line or curve connecting the center of the working surface 503 and the center of symmetry of the adjacent incisor 516. The first ridge 530 is higher than the second ridge 534, and the regional surface 523 gradually slopes downward from the first ridge 530 to the second ridge 534.

[0064] During cutting using a cutting element, one, two, or more cutting points or edges may engage the material being cut, such as rock. Figures 10 and 11 As shown, the cutting element 5 uses a curved cutting edge to cut the formation 410. The contact surface is contact surface 412, and the cutting depth is L. The cutting element 5 in this application can reduce the overall contact area of ​​the cutting edge when cutting at the same cutting depth. The reduced contact area leads to reduced friction and reduced heat generation. For a given bit weight, the cutting teeth will sink deeper into the rock, resulting in better cutter stability and more efficient rock removal. Figure 3 Compared with the standard cutting area in Figure 8 The cutting area is reduced. This provides higher stress in the rock, resulting in improved efficiency in cutting hard formations.

[0065] During drilling, the cutting teeth 516 and the recessed areas 517 of the superhard material layer 502 alternately cut the rock, producing shorter rock chips 413 than those produced by continuous cutting using conventional cutting elements. The first ridges 530 separate the strips of rock chips, which are then cut into smaller pieces by the cutting elements. If concave, the top slopes away from the cutting surface, compared to standard crushing features, which further reduces friction and heat generation.

[0066] In this embodiment, both the first ridge 530 and the second ridge 534 can be used for rock cutting, and their configuration depends on the rock properties and drilling conditions.

[0067] The present application also provides a drill bit, comprising the above-mentioned cutting element 5.

[0068] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0069] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0070] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A cutting element, characterized in that: include: A base body, wherein the base body is cylindrical; A superhard material layer fixed on the substrate, wherein the top of the superhard material layer has a working surface, and a chamfer is formed between the outer side surface of the superhard material layer and the working surface; a cutting tooth, wherein the number of the cutting tooth is at least one, and the cutting tooth is formed by cutting at the periphery of the superhard material layer so that the orthographic projection of the cutting tooth on the substrate is located within the outer circle of the projection surface of the substrate; a cutting ridge, the cutting ridge being located on the working surface and corresponding one-to-one to the cutting teeth; The periphery of the superhard material layer has a plurality of recessed areas, and one cutting tooth is located between two adjacent recessed areas; A plurality of recessed areas form an outer boundary of the superhard material layer, wherein the recessed areas start from the working surface, extend in a direction perpendicular to the working surface, and gradually end at the outer side surface of the substrate; The working surface includes multiple regional surfaces, the number of which is equal to the number of the recessed areas. The cutting ridge includes a first ridge and a second ridge. The first ridge is located between two adjacent regional surfaces, and the second ridge is located on the regional surface between two adjacent first ridges. The first ridge is higher than the second ridge, so that the regional surface gradually tilts downward from the first ridge to the second ridge.

2. The cutting element according to claim 1, wherein The plurality of recessed areas are spaced apart along the circumference of the superhard material layer, and the recessed areas extend downward along the height direction of the superhard material layer.

3. The cutting element according to claim 1, wherein The cutting teeth are round, pointed or sawtooth-shaped.

4. The cutting element according to claim 1, wherein The number of the cutting teeth is 1 to 20.

5. The cutting element according to claim 1, wherein An angle between the outer side surface of the superhard material layer and the chamfer is 30 degrees to 60 degrees.

6. The cutting element according to claim 1, wherein The working surface is a curved surface.

7. The cutting element according to claim 1, wherein The center of the working surface is higher than, lower than or equal to the edge of the working surface.

8. The cutting element according to claim 1, wherein The first ridge is a straight line or a curve, and the first ridge connects the center of the working surface and the symmetry center of the cutting tooth.

9. The cutting element according to claim 1, wherein Two adjacent area surfaces are plane or curved structures.

10. The cutting element according to claim 9, characterized in that The included angle between two adjacent regional surfaces intersecting at the first ridge is 100 degrees to 179.5 degrees.

11. The cutting element according to claim 1, wherein The second ridge is a straight line or a curve, and the second ridge connects the center of the working surface and the symmetry center of the adjacent cutting teeth.

12. The cutting element according to claim 11, wherein The included angle between two adjacent regional surfaces intersecting at the second ridge is 180.5 degrees to 260 degrees.

13. The cutting element according to any one of claims 1 to 12, characterized in that The radius of the cutting tooth is 10% to 100% of the radius of the cutting element.

14. A drill bit, characterized in that: A cutting element comprising the cutting element of any one of claims 1 to 13.

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