A cutting tooth for breaking down a ledge between teeth and a PDC drill bit comprising the same

Abstract

The application discloses a cutting tooth for breaking inter-tooth rock ridge and a PDC drill bit comprising the same, and relates to the technical field of drill bits. The cutting tooth comprises hard alloy, a polycrystalline diamond composite layer for cutting and a polycrystalline diamond composite layer for impact, and is sintered into one body by using tungsten carbide. When the cutting tooth is installed, the tooth surface symmetry axis is kept in a vertical relationship with the tangent of a point on the radial tooth arrangement line, and the cutting tooth blade height is greater than the tooth radius. The drill bit body of the PDC drill bit is provided with a plurality of blades, the blades are provided with conventional plane teeth, the cutting tooth for breaking inter-tooth rock ridge is continuously arranged on the blades, the blades are provided with front teeth positions and rear teeth positions, the cutting tooth for breaking inter-tooth rock ridge is arranged in the front teeth positions, and the conventional plane teeth are arranged in part of the front teeth positions and the rear teeth positions. The application can efficiently utilize the near-drill axial vibration impact energy and the transverse vibration impact energy to quickly break the inter-tooth rock ridge, improve the drilling energy utilization efficiency, reduce the axial vibration and the transverse vibration, improve the rock breaking efficiency, and save the drilling cost.

Description

Technical Field

[0001] The present invention relates to the technical field of drill bits, and in particular to a cutting tooth for breaking rock ridges between teeth and a PDC drill bit comprising the same, which can be used for drilling oil, natural gas and geothermal energy. Background Art

[0002] During oil and gas well construction and geothermal drilling, problems such as downhole instrument failure, drill string breakage, and premature drill bit failure often occur when drilling in interlaced soft and hard formations or hard-plastic formations. These problems are primarily caused by intense lateral or axial vibrations near the drill tip. These vibrations not only lead to premature drilling and low single-pass footage, but also reduce the effective utilization of drilling energy, severely impacting the mechanical penetration rate and single-pass footage of PDC (polycrystalline diamond) drill bits in these formations.

[0003] To solve these problems, existing technical means mainly include:

[0004] 1. Adjusting the drill bit's designed draft: By changing the drill bit's draft depth, tooth material, and other parameters, near-drilling vibration can be controlled. However, this method results in a smaller draft and may not allow for rapid drilling in difficult-to-drill layers.

[0005] 2. Development of a depth-adaptive PDC drill bit: This drill bit automatically adjusts its depth based on drilling conditions, reducing near-hole vibration and improving drilling efficiency. Related research includes a presentation by Rodrigue W., Callais R., and Roy Chowdhury A. at the 2019 SPE / IADC International Drilling Conference.

[0006] 3. Micro-center PDC drill bits: This bit design effectively reduces axial and lateral vibration and is particularly suitable for hard-plastic formations, but may not be as effective in softer formations. Related research includes a presentation by Azar M., White A., Segal S., et al. at the 2013 SPE / IADC Drilling Conference.

[0007] 4. Customized Spiral Blade PDC Drill Bit: This drill bit destroys inter-tooth rock ridges by concentrating stress between adjacent teeth, reducing axial and lateral vibration and improving rock breaking efficiency. Related research by Zhaowei Wang, Xiangchao Shi, Shuai Chen, et al. was published in Geoenergy Science and Engineering in 2024.

[0008] However, each of these technical approaches has limitations. For example, under conditions of small design depth, personalized spiral blade PDC drill bits may not be able to effectively destroy inter-tooth ridges solely by relying on stress concentration between adjacent teeth, reducing their universal applicability. Therefore, to further improve the PDC drill bit's ability to reduce near-drilling axial and lateral vibration under different design parameters, it is necessary to develop cutters specifically targeting inter-tooth ridges and PDC drill bits containing such cutters to enhance their adaptability and efficiency in soft-hard mixed formations and hard-plastic formations.

[0009] In view of this, there is an urgent need for a cutting tooth for breaking the inter-tooth rock ridge and a PDC drill bit containing the same to solve the above problems. Summary of the Invention

[0010] The purpose of the present invention is to provide a cutting tooth for breaking the rock ridges between the teeth and a PDC drill bit containing the same, so as to solve the problems existing in the above-mentioned prior art. The new cutting teeth for breaking the rock ridges between the teeth can be flexibly placed in the inner cone part, nose part and shoulder part of the drill bit, so as to personalize the vibration reduction capacity of the entire drill bit in the axial and lateral directions, thereby improving the drill bit life and footage capacity while minimizing the sacrifice of machine speed.

[0011] To achieve the above objectives, in one aspect, the present invention provides a cutting tooth for breaking inter-tooth ridges, which is disposed in a front-row tooth position of a PDC drill bit and includes a cemented carbide, a polycrystalline diamond composite layer for cutting, and a polycrystalline diamond composite layer for impacting. The cemented carbide, the polycrystalline diamond composite layer for cutting, and the polycrystalline diamond composite layer for impacting are sintered into one piece using tungsten carbide; the cemented carbide and the polycrystalline diamond composite layer for impacting are located below the polycrystalline diamond composite layer for cutting; the cross-sections of the cemented carbide, the polycrystalline diamond composite layer for cutting, and the polycrystalline diamond composite layer for impacting are composite polygons A, B, and C, respectively; and composite polygon B is obtained by performing a Boolean sum of the composite polygons A and C on the same plane.

[0012] The composite polygon A consists of circular arcs , Arc , two straight lines H5, and two straight lines H4, straight lines H4 and H5 are parallel and perpendicular to the tooth surface symmetry axis L1 respectively; one end of a straight line H5 is connected to the arc One end of the arc and is connected to one end of a straight line H4, the other end of which is connected to the arc One end of another straight line H5 is connected to the arc The other end of the arc and is connected to one end of another straight line H4, and the other end of the other straight line H4 is connected to the arc The other end is connected;

[0013] The composite polygon C is composed of a straight line H7, a straight line H8, a straight line H9 and an arc R1, and the straight line H7 and the straight line H8 are tangent to the arc R1 at both ends; the arc R1 is tangent to the circumscribed circle of the composite polygon B, and the tangent point is P1; the ends of the straight line H7 and the straight line H8 are respectively connected to the two ends of the straight line H9.

[0014] In some optional embodiments of the present invention, the cutting teeth are arranged in the inner cone, nose, and shoulder portions of the front row of teeth of the PDC drill bit, with the tooth face symmetry axis perpendicular to a tangent line at a point on the radial tooth layout line, and the cutting edge height of the cutting teeth is greater than half the diameter of the cutting teeth. The distribution position and number of the cutting teeth for breaking the inter-tooth ridges are determined based on the intensity of the near-drill end lateral and axial vibrations.

[0015] In some optional embodiments of the present invention, the composite polygon A is stretched along the axial center line L2 by a length H2 to form a three-dimensional structure of cemented carbide, the composite polygon B is stretched along the axial center line L2 by a length H3 to form a three-dimensional structure of a polycrystalline diamond composite layer for cutting, and the composite polygon C is stretched along the axial center line L2 by a length H2 to form a three-dimensional structure of a polycrystalline diamond composite layer for impact.

[0016] In some optional embodiments of the present invention, the composite polygon A, composite polygon B, and composite polygon C satisfy the following geometric relationships: distance H6 The circumference is ≥πD / 2; the length of the straight line H5 is between 1.5-4mm; among them, the distance H6 is the vertical distance from the tangent point P1 of the arc R1 and the circumscribed circle of the composite polygon B to the tooth vertex P2, the cutting tooth diameter D is the circumscribed circle diameter of the composite polygon B, and H1 is the cutting tooth edge height.

[0017] On the other hand, the present invention further provides a PDC drill bit comprising any of the above-mentioned cutting teeth for breaking inter-tooth ridges, the PDC drill bit comprising:

[0018] Drill bit body;

[0019] cutting teeth mounted on the drill bit body;

[0020] The cutting teeth are any of the cutting teeth for crushing inter-tooth ridges described above.

[0021] Optionally, a plurality of blades are provided on the drill body, and a front row of tooth positions and a rear row of tooth positions are provided on the blades, and conventional plane teeth are installed on some of the front row of tooth positions and all of the rear row of tooth positions.

[0022] ​Optionally, the drill bit body also includes a plurality of nozzles, which help to extend the service life of the drill bit through effective cooling and cleaning. The layout and design of the nozzles can affect the distribution of the bit pressure in various parts of the drill bit, helping to optimize the cutting performance of the drill bit.

[0023] Optionally, when the near-drilling axial vibration is relatively severe and the lateral vibration is relatively light, the cutting teeth for breaking the inter-tooth ridge are arranged at the rear tooth positions corresponding to the nose portion and the shoulder portion;

[0024] When the axial vibration near the drill bit is relatively light and the lateral vibration is relatively severe, the cutting teeth for breaking the inter-tooth ridge are arranged on the front tooth positions corresponding to the inner cone portion and the nose portion;

[0025] When both the near-drilling axial vibration and the lateral vibration are relatively severe, the cutting teeth for breaking the inter-tooth ridge are arranged on the front tooth positions corresponding to the inner cone portion, the nose portion and the shoulder portion.

[0026] Optionally, the cutting teeth for crushing inter-tooth ridges, located on the front tooth positions corresponding to the inner cone, nose, and shoulder portions, can concentrate axial or lateral vibration impact energy on unconfined or confined inter-tooth ridges, rapidly crushing the inter-tooth ridges. The cutting teeth for crushing inter-tooth ridges located on the inner cone portion primarily utilize lateral vibration impact energy to crush the inter-tooth ridges, the cutting teeth for crushing inter-tooth ridges located on the nose portion primarily utilize lateral and axial vibration impact energy to crush the inter-tooth ridges, and the cutting teeth for crushing inter-tooth ridges located on the shoulder portion primarily utilize axial vibration impact energy to crush the inter-tooth ridges.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] The frequency converter is faster and more rapid than that of conventional PDC drill bits, and the new type of PDC drill bit with high speed rotating shafts has a great impact on the drill bit life cycle, which is why it is so important to pay close attention to the drill bit operation procedures. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0030] Figure 1 A schematic diagram of the tooth distribution mode of the drill bit of the present application;

[0031] Figure 2 A schematic diagram of the cutting tooth for breaking the rock ridge between teeth of the present application;

[0032] Figure 3 A schematic diagram of the geometric characteristics of the cutting tooth for breaking the rock ridge between teeth of the present application;

[0033] Figure 4 A schematic diagram of the overall structure of the drill bit of the present application;

[0034] Figure 5 A schematic diagram of the mode of breaking the rock ridge between teeth of the cutting tooth for breaking the rock ridge between teeth of the present application;

[0035] In the figure, 1 is hard alloy, 2 is cutting polycrystalline diamond composite layer, 3 is impact polycrystalline diamond composite layer, 4 is inner cone part, 5 is nose part, 6 is shoulder part, 7 is radial tooth distribution line, 8 is drill bit body, 9 is blade, 10 is nozzle, 11 is front row tooth position, 12 is rear row tooth position, 13 is conventional flat tooth, 14 is blade radial line, and 15 is rock ridge between teeth. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0037] In recent years, PDC bit technology has been continuously improved, such as the composite bit developed by Baker Hughes, which integrates the roller and the PDC bit. The PDC bit, full name Polycrystalline Diamond Compact bit, is a commonly used drilling tool in the geological drilling industry. The PDC bit of the conventional technology is composed of PDC cutting teeth, nozzles, matrix and bit body. The PDC cutting teeth are combined by a synthetic diamond layer and a tungsten carbide substrate to perform an accurate cutting process. The cutting teeth of the PDC bit are circular in shape, are embedded and welded on the cylindrical cutting tool, and then the cutting tool is embedded on the bit body to form the PDC bit. The PDC bit makes the PDC cutting teeth contact with the rock through rotation, and breaks the rock by shearing action, which is more efficient than the traditional crushing method.

[0038] In view of the problems mentioned in the background art, the prior art mainly reduces the axial or lateral near-bit vibration, improves the rock breaking efficiency and increases the rate of penetration by adjusting the design depth between the front and rear rows of teeth, changing the front and rear rows of teeth, developing a depth-adaptive PDC bit, a micro-core PDC bit, and a personalized spiral blade PDC bit. Among the existing various technical means, the method of adjusting the design depth makes the design depth relatively small, which can meet the near-bit vibration control requirements in a difficult drilling section, but when the bit drills into the section below the difficult drilling section, the design depth designed for the difficult drilling section may not fully develop the rapid drilling capacity of the bit. The design of the micro-core bit can effectively reduce the axial and lateral near-bit vibration, but it only has good effect on hard plastic strata and cannot take into account other relatively soft strata that may be encountered in one-trip drilling. When the personalized spiral blade PDC bit drills into the stratum, the side limit rock ridge between the teeth can be destroyed by the stress concentration between the adjacent teeth, thereby reducing the axial and lateral near-bit vibration. Although this can improve the rock breaking efficiency from the overall bit, under the condition of small design depth, the stress concentration between the adjacent teeth cannot effectively destroy the rock ridge between the teeth, which reduces the universal applicability of the personalized spiral PDC bit. In order to further improve the function of reducing the axial and lateral near-bit vibration of the conventional PDC bit and the personalized spiral PDC bit under different design parameters, it is still necessary to develop a cutting tooth for the rock ridge between the teeth and a PDC bit containing the cutting tooth.

[0039] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0040] Example 1

[0041] Reference Figures 1 to 5As shown, embodiment 1 of the present invention provides a cutting tooth for crushing inter-tooth rock ridges, comprising a cemented carbide 1, a polycrystalline diamond composite layer 2 for cutting, and a polycrystalline diamond composite layer 3 for impact, wherein the cemented carbide 1, the polycrystalline diamond composite layer 2 for cutting, and the polycrystalline diamond composite layer 3 for impact are sintered into one with tungsten carbide.

[0042] In this embodiment, the cutting teeth for breaking the inter-tooth ridge are arranged in the inner cone portion 4, nose portion 5 and shoulder portion 6 in the front tooth position of the PDC drill bit. When installing the cutting teeth, the tooth surface symmetry axis L1 must be kept perpendicular to the tangent line Ti at a certain point on the radial tooth layout line 7, and the cutting tooth edge height H1 must be greater than half of the cutting tooth diameter D.

[0043] The distribution position and number of the cutting teeth for crushing the rock ridges between the teeth in this embodiment are determined according to the strength of the lateral vibration and the axial vibration near the drill end.

[0044] In a further optimization scheme, the cross-sections of the cemented carbide 1, the cutting polycrystalline diamond composite layer 2, and the impact polycrystalline diamond composite layer 3 are composite polygons A, B, and C, respectively. When the composite polygons A, B, and C are translated onto the same two-dimensional plane along the axial centerline L2, they satisfy the Boolean sum relationship of "B = A + C." The circumscribed circle diameter of the composite polygon B is the cutting tooth diameter D. Stretching the composite polygon A along the axial centerline L2 by a length H2 forms the three-dimensional structure of the cemented carbide 1. Stretching the composite polygon B along the axial centerline L2 by a length H3 forms the three-dimensional structure of the cutting polycrystalline diamond composite layer 2. Stretching the composite polygon C along the axial centerline L2 by a length H2 forms the three-dimensional structure of the impact polycrystalline diamond composite layer 3.

[0045] Further optimization scheme, the composite polygon A is composed of arcs , Arc , two straight lines H5, and two straight lines H4, where straight lines H4 and H5 are parallel and perpendicular to the tooth face symmetry axis L1, respectively. The composite polygon C is composed of straight lines H7, H8, H9, and arc R1, and straight lines H7 and H8 are tangent to arc R1 at both ends. Arc R1 is tangent to the circumscribed circle of composite polygon B, and the point of tangency is P1. On the same plane, the composite polygon A and composite polygon C are Boolean summed to obtain composite polygon B. Distance H6 is the vertical distance from the intersection point P1 of arc R1 and the circumscribed circle of composite polygon B to the tooth vertex P2. Based on the above definition, the intersection position of arc R1 and the circumscribed circle of composite polygon B can be determined by adjusting distance H6.

[0046] Further optimization scheme, the necessary geometric relationships that need to be satisfied in the composite polygons A, B and C are as follows: the distance H6 needs to satisfy the inequality relationship of "H6 The circumference must be ≥π D / 2; the length of straight line H5 and the length H3 must be between 1.5-4mm.

[0047] This embodiment discloses a structure and manufacturing method for a cutting tooth for crushing inter-tooth rock ridges, which is used to crush rocks during drilling. The material of the cutting tooth is a cemented carbide 1, a polycrystalline diamond composite layer 2 for cutting, and a polycrystalline diamond composite layer 3 for impact, which are sintered together by tungsten carbide. The cross-sections of the cutting tooth composed of cemented carbide 1, the polycrystalline diamond composite layer 2 for cutting, and the polycrystalline diamond composite layer 3 for impact are composite polygons A, B, and C, respectively. When these polygons are translated to the same two-dimensional plane along the axial centerline L2, they satisfy the Boolean sum relationship of "B=A+C". By stretching the composite polygons A, B, and C along the axial centerline L2, a corresponding three-dimensional structure is formed. This design is intended to improve the cutting efficiency and durability of the drill bit, especially when crushing hard rock. By precisely controlling the geometric shape and size, the performance of the cutting tooth can be optimized to adapt to different drilling conditions.

[0048] Example 2

[0049] Reference Figure 1 、 Figure 4 、 Figure 5 As shown, embodiment 2 of the present invention provides a PDC drill bit, comprising the cutting teeth for breaking inter-tooth ridges of embodiment 1, the PDC drill bit comprising a drill bit body 8, the drill bit body 8 being provided with a plurality of blades 9 and a plurality of nozzles 10, the blades 9 being provided with front-row tooth positions 11 and rear-row tooth positions 12, conventional flat teeth 13 being provided on some of the front-row tooth positions 11 and all of the rear-row tooth positions 12;

[0050] Further optimization scheme, such as Figure 1 As shown, the cutting tooth edge height H1 is formed between the blade radial line 14 and the radial tooth arrangement line 7. The cutting teeth for breaking the inter-tooth ridge are arranged on the rear tooth positions 12 corresponding to the inner cone portion 4, the nose portion 5 and the shoulder portion 6.

[0051] When it is known that the near-drilling axial vibration is more severe and the lateral vibration is lighter, the cutting teeth for breaking the inter-tooth ridge are set on the rear tooth positions 12 corresponding to the nose portion 5 and the shoulder portion 6, and the remaining rear tooth positions 12 are set as conventional flat teeth 13;

[0052] ​When it is known that the axial vibration near the drill bit is relatively light and the lateral vibration is relatively severe, the cutting teeth for breaking the inter-tooth ridge are set on the front tooth positions 11 corresponding to the inner cone portion 4 and the nose portion 5, and the remaining rear tooth positions 12 are set as conventional flat teeth 13;

[0053] When it is known that both the near-drilling axial vibration and the lateral vibration are relatively serious, the cutting teeth for breaking the inter-tooth ridge are set on the front tooth positions 11 corresponding to the inner cone part 4, the nose part 5 and the shoulder part 6, and the other front tooth positions 11 are set as conventional flat teeth 13; further optimization scheme,

[0054] like Figure 5 As shown, the cutting teeth for crushing inter-tooth ridges, which are arranged on the front tooth positions 11 corresponding to the inner cone portion 4, the nose portion 5, and the shoulder portion 6, can concentrate axial or lateral vibration impact energy on the unconfined or confined inter-tooth ridges 15, quickly crushing the inter-tooth ridges 15. The cutting teeth for crushing inter-tooth ridges, which are arranged on the inner cone portion 4, mainly use lateral vibration impact energy to crush the inter-tooth ridges 15. The cutting teeth for crushing inter-tooth ridges, which are arranged on the nose portion 5, mainly use lateral and axial vibration impact energy to crush the inter-tooth ridges 15. The cutting teeth for crushing inter-tooth ridges, which are arranged on the shoulder portion 6, mainly use axial vibration impact energy to crush the inter-tooth ridges 15. When the PDC drill bit is a conventional straight blade PDC drill bit, the inter-tooth ridges 15 are confined ridges. When the PDC drill bit is a customized spiral PDC drill bit, the inter-tooth ridges 15 are unconfined ridges.

[0055] Specifically: Each blade 9 is at least in the inner cone portion 4 (4 in the radial plane view) ), nose portion 5 (5 in radial plane view ), or shoulder 6 (6 in radial plane view ) has the cutting structure of the broken inter-tooth ridge, (the inner cone part 4, the nose part 5, and the shoulder part 6 are divided as shown in FIG. Figure 1 shown).

[0056] Reference Figure 1 and Figure 5 As shown, when it is known that the near-drilling axial vibration is relatively severe and the lateral vibration is relatively light, the cutting teeth for breaking the inter-tooth rock ridge are set on the rear tooth positions 12 corresponding to the nose portion 5 and the shoulder portion 6, and the inter-tooth rock ridge 15 is broken by axial impact energy. The remaining rear tooth positions 12 are set as conventional flat teeth 13, so as to reduce the near-drilling axial vibration at the expense of a small mechanical penetration rate.

[0057] Reference Figure 1 and Figure 5As shown, when it is known that the near-drilling axial vibration is relatively light and the lateral vibration is relatively severe, the cutting teeth for breaking the inter-tooth rock ridges are set on the front tooth positions 11 corresponding to the inner cone portion 4 and the nose portion 5, and the remaining rear tooth positions 12 are set as conventional flat teeth 13, and the lateral vibration energy is used to break the inter-tooth rock ridges 15, so as to reduce the near-drilling lateral vibration at the expense of a small mechanical penetration rate;

[0058] Reference Figure 1 and Figure 5 As shown, when it is known that both the near-drilling axial vibration and the lateral vibration are relatively severe, the cutting teeth for crushing the inter-tooth ridges are set on the front tooth positions 11 corresponding to the inner cone portion 4, the nose portion 5 and the shoulder portion 6, and the remaining front tooth positions 11 are set as conventional plane teeth 13, and the axial and lateral vibration energy is used to crush the inter-tooth ridges 15, so as to reduce the near-drilling axial and lateral vibrations at the expense of a small mechanical penetration rate.

[0059] Example 2 of the present invention discloses a PDC drill bit. Its design takes into account the vibration characteristics of the drilling process. By rationally distributing the cutting teeth, it optimizes drilling performance and reduces the impact of vibration on the drill bit and drilling results. This design helps improve drilling efficiency and safety, especially in complex geological conditions. It should be understood that by distributing the cutting teeth in different positions, near-hole axial and lateral vibration can be reduced, while sacrificing a relatively small amount of mechanical penetration rate, thereby improving drilling efficiency.

[0060] Any details not provided in the present invention are all conventional technical means well known to those skilled in the art.

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A cutting tooth for breaking rock ridges between teeth, arranged in the front tooth position (11) of a PDC drill bit, characterized by: The invention comprises a cemented carbide (1), a polycrystalline diamond composite layer for cutting (2), and a polycrystalline diamond composite layer for impact (3), wherein the cemented carbide (1), the polycrystalline diamond composite layer for cutting (2), and the polycrystalline diamond composite layer for impact (3) are sintered into one body using tungsten carbide; the cemented carbide (1) and the polycrystalline diamond composite layer for impact (3) are located on the lower side of the polycrystalline diamond composite layer for cutting (2); the cross sections of the cemented carbide (1), the polycrystalline diamond composite layer for cutting (2), and the polycrystalline diamond composite layer for impact (3) are respectively a composite polygon A, a composite polygon B, and a composite polygon C; on the same plane, the composite polygon A and the composite polygon C are subjected to Boolean summation to obtain the composite polygon B; The composite polygon A consists of circular arcs , Arc , two straight lines H5, and two straight lines H4, straight lines H4 and H5 are parallel and perpendicular to the tooth surface symmetry axis L1 respectively; one end of a straight line H5 is connected to the arc One end of the arc and is connected to one end of a straight line H4, the other end of which is connected to the arc One end of another straight line H5 is connected to the arc The other end of the arc and is connected to one end of another straight line H4, and the other end of the other straight line H4 is connected to the arc The other end is connected; The composite polygon C is composed of a straight line H7, a straight line H8, a straight line H9 and an arc R1, and the straight line H7 and the straight line H8 are tangent to the arc R1 at both ends; the arc R1 is tangent to the circumscribed circle of the composite polygon B, and the tangent point is P1; the ends of the straight line H7 and the straight line H8 are respectively connected to the two ends of the straight line H9.

2. The cutting tooth for crushing inter-tooth ridges according to claim 1, characterized in that: The cutting teeth are arranged on the inner cone portion (4), the nose portion (5) and the shoulder portion (6) of the front tooth position (11) of the PDC drill bit, and the tooth face symmetry axis is kept perpendicular to the tangent line at a certain point on the radial tooth arrangement line (7), and the cutting tooth edge height is greater than half of the cutting tooth diameter.

3. The cutting tooth for crushing inter-tooth ridges according to claim 1, characterized in that: The composite polygon A, composite polygon B, and composite polygon C satisfy the following geometric relationship: distance H6 The circumference is ≥π D / 2; the length of the straight line H5 is between 1.5-4 mm; among them, the distance H6 is the vertical distance from the tangent point P1 of the arc R1 and the circumscribed circle of the composite polygon B to the tooth vertex P2, the cutting tooth diameter D is the circumscribed circle diameter of the composite polygon B, and H1 is the cutting tooth edge height.​ 4. A PDC drill bit, characterized by: The drill bit comprises a drill body (8) and cutting teeth mounted on the drill body (8), wherein the cutting teeth are the cutting teeth for crushing inter-tooth ridges according to any one of claims 1 to 3.

5. The PDC drill bit according to claim 4, characterized in that: The drill body (8) is provided with a plurality of blades (9), the blades (9) are provided with front-row tooth positions (11) and rear-row tooth positions (12), and conventional plane teeth (13) are installed on some of the front-row tooth positions (11) and all of the rear-row tooth positions.

6. The PDC drill bit according to claim 5, characterized in that: When the near-drilling axial vibration is relatively severe and the lateral vibration is relatively light, the cutting teeth for breaking the inter-tooth rock ridge are arranged on the rear tooth positions (12) corresponding to the nose portion (5) and the shoulder portion (6); When the near-drilling axial vibration is relatively light and the lateral vibration is relatively severe, the cutting teeth for crushing the inter-tooth rock ridge are arranged on the front tooth positions (11) corresponding to the inner cone portion (4) and the nose portion (5); When both the near-drilling axial vibration and the lateral vibration are relatively severe, the cutting teeth for breaking the inter-tooth rock ridge are arranged on the front tooth positions (11) corresponding to the inner cone portion (4), the nose portion (5) and the shoulder portion (6).

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