Impact-resistant multi-cutting-edge diamond compact

Abstract

The present application relates to a kind of anti-impact multi-cutting edge diamond composite sheet, including cylindrical cemented carbide substrate and diamond composite layer, the diamond composite layer is arranged at one end of cemented carbide substrate, both are associated into an organic whole, it is characterized in that the diamond composite layer end face edge is provided with 2 or more than 2 different chamfers, to form different cutting edges, at least there is a strong attack cutting edge, anti-impact cutting edge is arranged in the two sides of strong attack cutting edge, there is flow guide cavity in the middle of diamond composite layer end face.The same composite sheet of the present application has different attack ability and anti-impact ability in different edge, strong attack cutting edge has higher cutting efficiency, it has stronger lateral anti-impact ability in the two sides, so that composite sheet has better cutting performance and side anti-impact ability in gravel formation, prolongs the service life of composite sheet.

Description

Technical Field

[0001] This invention relates to an impact-resistant multi-cutting-edge diamond composite sheet, used as a cutting element in diamond drill bits, belonging to the field of oil drilling tool technology. Background Technology

[0002] Since the 1980s, diamond drill bits have been widely used in oil and gas drilling projects. Diamond drill bits mainly consist of a drill body and cutting elements. Based on their cutting elements, diamond drill bits are divided into three categories: PDC (polycrystalline diamond) drill bits, TSP (thermally stabilized polycrystalline diamond) drill bits, and natural diamond drill bits. PDC drill bits are mainly used for drilling in soft to medium-hard formations. With continuous technological advancements, the application range of PDC drill bits has become increasingly wider, offering good economic value. TSP drill bits are mainly used for drilling in medium-hard to extremely hard formations. Currently, deep well operations are gradually increasing in oil and gas drilling projects, and the formations encountered are becoming increasingly complex.

[0003] Diamond composite sheets consist of a cylindrical cemented carbide matrix and a diamond composite layer. The chamfered edges of the diamond composite layer form the cutting edge of the composite sheet. During drilling, different areas encounter different formations, requiring varying degrees of aggression and impact resistance from the composite sheet. In gravel formations, the normal cutting surface of the diamond composite sheet often wears normally, while the sidewalls suffer more severe chipping and failure, leading to overall composite sheet failure. These phenomena indicate that the required impact resistance differs between the cutting surface and the sidewalls of the diamond composite sheet. Existing composite sheet cutting edge chamfers are all single circumferential chamfer structures, which are insufficient to meet the drilling requirements of complex formations. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an impact-resistant multi-cutting diamond composite sheet that addresses the shortcomings of the prior art. It not only has strong cutting surface aggression but also strong side impact resistance, long service life, and can adapt to the drilling needs of complex formations.

[0005] The technical solution adopted by the present invention to solve the above-mentioned problems is as follows: it includes a cylindrical cemented carbide substrate and a diamond composite layer, wherein the diamond composite layer is disposed at one end of the cemented carbide substrate and the two are connected as one unit. The characteristic is that the edge of the end face of the diamond composite layer is provided with two or more different chamfers to form different cutting edges, at least one aggressive cutting edge exists, and impact-resistant cutting edges are provided on both sides of the aggressive cutting edge. A flow guiding cavity is provided in the middle of the end face of the diamond composite layer.

[0006] According to the above technical solution, the edge of the diamond composite layer end face has 2 to 4 different chamfers to form 2 to 4 different cutting edges; the chamfered slope is one or more of the following: inclined chamfer, bent chamfer, curved chamfer.

[0007] According to the above technical solution, the angle between the slope of the beveled chamfer and the end plane of the diamond composite layer is 20-70°, the end plane of the diamond composite layer is perpendicular to the axis of the cylindrical cemented carbide substrate, and the bend chamfer is a combination of two types of beveled chamfers, with the angle of the outer beveled chamfer being greater than the angle of the inner beveled chamfer.

[0008] According to the above technical solution, the surface chamfer is a circular arc chamfer with different radii of curvature.

[0009] According to the above technical solution, the axial height of the chamfer is 0.2 to 3 mm, or the radial depth of the chamfer on one side is 0.2 to 5 mm.

[0010] According to the above technical solution, the different chamfers are arranged circumferentially and connected end to end, with each chamfer corresponding to a central angle.

[0011] According to the above technical solution, the end face of the diamond composite layer is a plane, a concave surface, or a convex surface.

[0012] According to the above technical solution, the aggressive cutting edge is a chamfered surface with a single-sided radial depth of less than or equal to 0.4 mm and an included angle of 45°, or a chamfered surface with a single-sided radial depth of greater than 0.4 mm and an included angle of less than 30°, or a bend chamfered surface with a single-sided radial depth of greater than 0.4 mm and an included angle of less than 30°. The central angle corresponding to the chamfer of each aggressive cutting edge is 50 to 70°.

[0013] According to the above technical solution, the impact-resistant cutting edge is a chamfered surface with a single-sided radial depth of 0.5 to 2 mm and an included angle of 45° or greater, or a circular arc chamfer with a radius of curvature of 0.5 to 2 mm.

[0014] According to the above technical solution, the guiding cavity includes an upwardly opening concave cavity and a guiding groove that extends and contracts towards the edge of the end face and upward.

[0015] According to the above technical solution, the intersection surface of the flow guiding cavity and the end face of the composite layer is prismatic or triangular, and the flow guiding groove of the flow guiding cavity points to the aggressive cutting edge.

[0016] According to the above technical solution, the radial cross-section of the diamond composite layer is the same as the radial cross-section of the cemented carbide matrix, which is circular, elliptical, or regular polygonal.

[0017] According to the above technical solution, the bonding surface between the cemented carbide substrate and the diamond composite layer is a plane, a concave-convex surface, a grooved surface, an annular grooved surface, or other shapes.

[0018] According to the above technical solution, the diamond composite layer is a polycrystalline diamond composite layer or a thermally stable polycrystalline diamond composite layer.

[0019] The beneficial effects of this invention are as follows: 1. By setting different chamfers on the edge of the diamond composite layer end face, multiple cutting edges are formed in the circumferential direction of the diamond composite sheet end face. This allows different edges of the same composite sheet to have different attack capabilities and impact resistance. The cutting edge with strong attack capability has high cutting efficiency, and its two sides have strong lateral impact resistance, giving the composite sheet good cutting performance and lateral impact resistance in gravel formations, thus extending the service life of the composite sheet. 2. Because the chamfers on the edge of the diamond composite layer end face form multiple cutting edges with different properties, the same diamond composite sheet can meet the drilling requirements of different formations. Reasonable placement of these edges on the diamond drill bit allows the diamond drill bit to adapt to the drilling requirements of complex formations. 3. A flow guide cavity is set in the middle of the diamond composite layer end face, which, with the help of water flow, provides a better cooling effect for the composite sheet during cutting, thereby improving the drilling rate and extending the service life of the composite sheet. Attached Figure Description

[0020] Figures 1 to 3 These are, respectively, a perspective view, a top view, and an AA rotated sectional view of Embodiment 1 of the present invention.

[0021] Figures 4 to 6 These are, respectively, a perspective view, a top view, and an AA-rotated sectional view of Embodiment 2 of the present invention.

[0022] Figures 7 to 9 These are, respectively, a perspective view, a top view, and an AA rotated sectional view of Embodiment 3 of the present invention.

[0023] Figure 10 This is a perspective view of Embodiment 4 of the present invention.

[0024] Figure 11 This is a perspective view of Embodiment 5 of the present invention.

[0025] Figure 12 This is a perspective view of Embodiment Six of the present invention. Detailed Implementation

[0026] The present invention will be further explained below with reference to the embodiments.

[0027] Example 1 Figures 1 to 3As shown, the device includes a cylindrical cemented carbide substrate 102 and a diamond composite layer 101. The diamond composite layer is disposed at one end of the cemented carbide substrate. The diamond composite layer is a polycrystalline diamond composite layer. The diamond composite layer and the cemented carbide substrate are bonded together by ultra-high temperature and high pressure sintering. The end 108 of the diamond composite layer is flat. The edge of the end face of the diamond composite layer is provided with four chamfers 103, 104, 105, and 106. Among them, two chamfers 103 and 105 have the same structure, which are 45-degree bevel chamfers with an axial height of 0.3 mm. The central angle corresponding to each chamfer is... Each chamfer occupies 60° (Л / 3), forming a strong, aggressive cutting edge. The other two chamfers, 104 and 106, have the same structure: 45-degree beveled chamfers with an axial height of 1mm. The central angle corresponding to each chamfer is 120° (2Л / 3), forming an impact-resistant cutting edge. A flow guide cavity 107 is provided in the middle of the diamond composite layer end face. This flow guide cavity includes an upwardly opening concave cavity and a flow channel extending towards the edge and upwards of the end face. The intersection of the flow guide cavity and the composite layer end face 108 is prismatic. The two flow channels (acute angles less than 90°) of the flow guide cavity point towards the strong, aggressive cutting edge. In this embodiment, the chamfers are arranged circumferentially and connected end-to-end, with a smooth transition between each chamfer. The radial cross-section of the diamond composite sheet is circular with a diameter of 15.8mm and a cylindrical height of 13.2mm.

[0028] Example 2 Figures 4 to 6 As shown, the difference between this embodiment and Embodiment 1 lies in the following: the two chamfers 203 and 205 have the same structure, being beveled chamfers with an axial height of 0.8 mm and an included angle α of 22.5°. The central angle corresponding to each chamfer is 60° (Л / 3), forming a strong, aggressive cutting edge. The other two chamfers 204 and 206 have the same structure, being beveled chamfers with an axial height of 1 mm and an included angle β of 45°. The central angle corresponding to each chamfer is 120° (2Л / 3), forming an impact-resistant cutting edge. Other structures, including the flow guide cavity 207, are the same as in Embodiment 1.

[0029] Example 3 Figures 7 to 9 As shown, the difference between this embodiment and Embodiment 2 lies in the fact that the structures of the two chamfers 303 and 305 are identical. The inner chamfer has an axial height of 0.8 mm and an included angle θ of 20°, while the outer chamfer has an axial height of 0.2 mm and an included angle δ of 45 degrees. Each chamfer corresponds to a central angle of 60° (Л / 3), forming a highly aggressive cutting edge. Other structures, including the structures of the other two chamfers 304 and 306 and the flow guide cavity 307, are the same as in Embodiment 2.

[0030] Example 4 Figure 10As shown, the difference between this embodiment and Embodiment 3 lies in that the bend chamfer 403 forming the aggressive cutting edge is only one, consisting of an inner bevel chamfer with an axial height of 0.8 mm and an included angle θ of 20°, and an outer bevel chamfer with an axial height of 0.2 mm and an included angle δ of 45 degrees. The central angle corresponding to the chamfer is 60° (Л / 3), forming one aggressive cutting edge. The remaining circumferential edges are all bevel chamfers 404 with an axial height of 1 mm and an included angle of 45 degrees, forming an impact-resistant cutting edge. The other structures are the same as in Embodiment 3.

[0031] Example 5 Figure 11 As shown, the difference between this embodiment and Embodiment 3 lies in the fact that it has three chamfers 503, 505, and 507 with the same structure. These are bends with an inner bevel chamfer having an axial height of 0.8 mm and an included angle θ of 20°, and an outer bevel chamfer having an axial height of 0.2 mm and an included angle δ of 45°. Each chamfer corresponds to a central angle of 60° (π / 3), forming three aggressive cutting edges. Between these three bends, three identical bevel chamfers 504, 506, and 508 are respectively arranged, each with an axial height of 1 mm and an included angle of 45°. Each chamfer corresponds to a central angle of 60° (π / 3), forming impact-resistant cutting edges. Correspondingly, the intersection of the flow guide cavity 509 and the composite layer end face 510 forms an equilateral triangle. The three flow channels of the flow guide cavity (acute angles less than 90°) point to the three aggressive cutting edges. Other structures are the same as in Embodiment 3.

[0032] Example 6 Figure 12 As shown, the difference between this embodiment and Embodiment 3 lies in the presence of two parallel and symmetrical flow guiding cavities 607 and 608 on both sides of the middle of the diamond composite layer end face. Each flow guiding cavity includes an upwardly opening concave cavity and a flow-guiding groove extending towards the edge and upwards of the end face. The intersection of the flow guiding cavity and the end face 609 of the composite layer forms a flattened prism shape. The flow-guiding groove (acute angle less than 90°) points towards a strong cutting edge. Other structural features include two bend chamfered surfaces 603 and 605, and two inclined chamfered surfaces 604 and 606, the same as in Embodiment 3.

Claims

1. An impact-resistant multi-cutting-edge diamond composite sheet, comprising a cylindrical cemented carbide substrate and a diamond composite layer, wherein the diamond composite layer is disposed at one end of the cemented carbide substrate, and the two are integrally connected, characterized in that... The diamond composite layer end face edge is provided with two or more different chamfers to form different cutting edges. These cutting edges are arc-shaped cutting edges in the radial section, with at least one highly aggressive cutting edge. Impact-resistant cutting edges are provided on both sides of the highly aggressive cutting edge. A flow guide cavity is provided in the middle of the diamond composite layer end face. The diamond composite layer end face edge has 2 to 4 different chamfers to form 2 to 4 different cutting edges. The chamfered surface is a slope chamfer, a bent surface chamfer, or a curved surface. One or more types of chamfers; the aggressive high-cutting edge is a chamfer with a single-sided radial depth of 0.4~0.3mm and an included angle of 45°, or a chamfer with a single-sided radial depth greater than 0.4mm and an included angle less than 30°, or a bend chamfer with a single-sided radial depth greater than 0.4mm and an included angle less than 30°, wherein the central angle corresponding to the chamfer of each aggressive high-cutting edge is 50~70°; the guide cavity includes an upwardly opening concave cavity and a guide groove extending and contracting towards the end face edge and upward.

2. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 1, characterized in that... The angle between the beveled surface of the beveled face and the end plane of the diamond composite layer is 20~70°. The end plane of the diamond composite layer is perpendicular to the axis of the cylindrical cemented carbide substrate. The bend face bevel is a combination of two types of beveled face bevels, with the angle of the outer beveled face bevel being greater than that of the inner beveled face bevel.

3. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 1, characterized in that... The aforementioned surface chamfer is a circular arc chamfer with different radii of curvature.

4. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 2 or 3, characterized in that... The axial height of the chamfer is 0.2~3mm, or the radial depth of the chamfer on one side is 0.2~5mm.

5. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 1 or 2, characterized in that... The different chamfers are arranged circumferentially and connected end to end, with each chamfer corresponding to a central angle.

6. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 1, characterized in that... The diamond composite layer has a flat, concave, or convex end face.

7. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 1 or 2, characterized in that... The impact-resistant cutting edge is a chamfered surface with a radial depth of 0.5~2mm on one side and an included angle of 45° or greater, or a circular arc chamfer with a radius of curvature of 0.5~2mm.

8. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 2, characterized in that... The intersection of the flow guiding cavity and the end face of the composite layer is prismatic or triangular, and the flow guiding groove of the flow guiding cavity points to the aggressive cutting edge.

9. The impact-resistant multi-cutting-edge diamond composite sheet according to claim 1 or 2, characterized in that... The radial cross-section of the diamond composite layer is the same as that of the cemented carbide substrate, and is circular, elliptical, or regular polygonal; the bonding surface between the cemented carbide substrate and the diamond composite layer is a plane, a concave-convex surface, a groove surface, or an annular groove surface.

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