Cutting tooth for crushing inter-tooth rock ridge and PDC (Polycrystalline Diamond Compact) drill bit comprising cutting tooth

Abstract

The invention discloses a cutting tooth for crushing inter-tooth rock ridges and a PDC drill bit comprising the cutting tooth, and relates to the technical field of drill bits, the cutting tooth comprises a hard alloy, a polycrystalline diamond composite layer for cutting and a polycrystalline diamond composite layer for impacting, and tungsten carbide is sintered into a whole. When the cutting teeth are installed, the symmetrical axis of the tooth surface is kept perpendicular to a tangent line of a certain point on the radial tooth distribution line, and the edge exposure height of the cutting teeth is larger than the tooth radius. A drill bit body of the PDC drill bit is provided with a plurality of blades, and conventional plane teeth are arranged on the blades. The cutting teeth for crushing the inter-tooth rock ridge are continuously arranged on the blades; front-row tooth positions and rear-row tooth positions are arranged on the blades, cutting teeth for crushing inter-tooth rock ridges are arranged on the front-row tooth positions, and conventional plane teeth are arranged on part of the front-row tooth positions and the rear-row tooth positions. According to the invention, near-drilling axial vibration impact energy and transverse vibration impact energy can be efficiently utilized to rapidly crush rock ridges between teeth, the utilization efficiency of drilling energy is improved, axial vibration and transverse vibration are reduced, the rock crushing efficiency is improved, and the drilling cost is saved.

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 of oil, natural gas and geothermal energy. Background Art

[0002] In the process of drilling oil and gas wells and geothermal energy wells, when drilling in soft and hard interlaced formations and hard plastic formations, downhole instrument failure, drill string breakage, premature drill bit failure and other problems often occur. These problems are mainly caused by strong lateral or axial vibrations near the drill end. These vibrations not only lead to premature drilling and low single-trip footage, but also reduce the effective utilization rate of drilling energy, seriously affecting the mechanical penetration rate and single-trip footage of PDC (polycrystalline diamond) drill bits in these formations.

[0003] In order to solve these problems, the existing technical means mainly include:

[0004] 1. Adjust the drill bit design depth: Control the near-drilling vibration by changing the depth between the front and rear teeth of the drill bit, the tooth material and other parameters. However, this method has a small design depth and may not be able to achieve fast drilling in non-difficult-to-drill layers.

[0005] 2. Develop a depth-adaptive PDC drill bit: This drill bit can automatically adjust the depth according to the drilling conditions, reduce near-drilling vibration, and improve drilling efficiency. Related research includes the report by Rodrigue W., Callais R., and Roy Chowdhury A. at the 2019 SPE / IADC International Drilling Conference.

[0006] 3. Micro-center PDC drill bit: This drill bit design can effectively reduce axial and lateral vibrations, especially for hard plastic formations, but may not be effective for other softer formations. Related research includes the report by Azar M., White A., Segal S., et al. at the 2013 SPE / IADC Drilling Conference.

[0007] 4. Personalized spiral blade PDC drill bit: This drill bit destroys the inter-tooth rock ridges through stress concentration between adjacent teeth, reduces axial and lateral vibrations, and improves rock breaking efficiency. Related research was published by Zhaowei Wang, Xiangchao Shi, ShuaiChen, et al. in Geoenergy Science and Engineering in 2024.

[0008] However, these technical means have their own limitations. For example, under the condition of small design depth, the personalized spiral blade PDC drill bit may not be able to effectively destroy the inter-tooth rock ridge by relying solely on the stress concentration between adjacent teeth, which reduces its general applicability. Therefore, in order to further improve the function of PDC drill bits in reducing near-drilling axial and lateral vibrations under different design parameters, it is necessary to develop cutting teeth specifically for inter-tooth rock ridges and PDC drill bits containing such cutting teeth to enhance their adaptability and efficiency in soft-hard interlaced 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 including the same to solve the above problems. Summary of the invention

[0010] The object of the present invention is to provide a cutting tooth for breaking rock ridges between 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 rock ridges between teeth can be flexibly placed on the inner cone part, nose part and shoulder part of the drill bit, so as to personalize the vibration reduction capacity of the whole drill bit in the axial and lateral directions, thereby improving the drill bit life and footage capacity under the premise of minimizing the sacrifice of machine speed.

[0011] To achieve the above-mentioned purpose, in one aspect, the present invention provides a cutting tooth for crushing rock ridges between teeth, which is arranged in the front 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 impact. The cemented carbide, the polycrystalline diamond composite layer for cutting, and the polycrystalline diamond composite layer for impact are sintered into one with tungsten carbide; the cross-sections of the cemented carbide, the polycrystalline diamond composite layer for cutting, and the polycrystalline diamond composite layer for impact are composite polygon A, composite polygon B, and composite polygon C, respectively, which satisfy the Boolean sum relationship of "B=A+C".

[0012] In some optional embodiments of the present invention, the cutting teeth are arranged in the inner cone part, nose part and shoulder part of the front tooth position of the PDC drill bit, and the symmetric axis of the tooth surface is kept perpendicular to the tangent line of a certain point on the radial tooth line, and the cutting tooth edge height is greater than half of the tooth diameter of the cutting tooth. The distribution position and number of the cutting teeth for breaking the rock ridge between the teeth are determined according to the strength of the lateral vibration and axial vibration near the drill end.

[0013] In some optional embodiments of the present invention, the composite polygon A is composed of arcs Arc It is composed of two straight lines H5 and two straight lines H4, and the straight lines H4 and H5 are respectively parallel and perpendicular to the tooth surface symmetry axis L1.

[0014] In some optional embodiments of the present invention, 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 from both ends; arc R1 is tangent to the circumscribed circle of composite polygon B, and the tangent point is P1; 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.

[0015] In some optional implementations of the present invention, on the same plane, the composite polygon A and the composite polygon C are subjected to Boolean sum to obtain the composite polygon B.

[0016] In some optional embodiments of the present invention, the diameter of the circumscribed circle of the composite polygon B is the tooth diameter D of the cutting tooth.

[0017] 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.

[0018] In some optional embodiments of the present invention, the composite polygon A, composite polygon B, and composite polygon C satisfy the following geometric relationship: distance H6 The perimeter of ≥ π D / 2; the length of straight line H5 and the length of H3 are between 1.5-4 mm.

[0019] On the other hand, the present invention further provides a PDC drill bit, comprising a cutting tooth for breaking rock ridges between teeth as described in any one of the above items, the PDC drill bit comprising:

[0020] Drill bit body;

[0021] cutting teeth mounted on the drill body;

[0022] The cutting teeth are any of the cutting teeth for breaking inter-tooth ridges as described above.

[0023] 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 part of the front row of tooth positions and all the rows of tooth positions.

[0024] ​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 drilling pressure in various parts of the drill bit, helping to optimize the cutting performance of the drill bit.

[0025] Optionally, the cutting teeth are arranged on the front row of teeth corresponding to the inner cone part, the nose part and the shoulder part.

[0026] 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 rock ridge are arranged at the rear tooth positions corresponding to the nose portion and the shoulder portion;

[0027] When the near-drilling axial vibration is relatively light and the lateral vibration is relatively severe, the cutting teeth for breaking the inter-tooth rock ridge are arranged at the front tooth positions corresponding to the inner cone part and the nose part;

[0028] When both the near-drilling axial vibration and the lateral vibration are relatively serious, the cutting teeth for breaking the inter-tooth rock ridge are arranged on the front tooth positions corresponding to the inner cone part, the nose part and the shoulder part.

[0029] Optionally, the cutting teeth for breaking inter-tooth ridges arranged on the front tooth positions corresponding to the inner cone part, the nose part and the shoulder part can concentrate the axial or lateral vibration impact energy on the unconfined or confined inter-tooth ridges to quickly break the inter-tooth ridges. The cutting teeth for breaking inter-tooth ridges arranged on the inner cone part mainly use the lateral vibration impact energy to break the inter-tooth ridges, the cutting teeth for breaking inter-tooth ridges arranged on the nose part mainly use the lateral and axial vibration impact energy to break the inter-tooth ridges, and the cutting teeth for breaking inter-tooth ridges arranged on the shoulder part mainly use the axial vibration impact energy to break the inter-tooth ridges.

[0030] Compared with the prior art, the present invention at least discloses the following beneficial effects:

[0031] The present invention provides a cutting tooth for breaking rock ridges between teeth and a PDC drill bit including the cutting tooth, wherein the cutting tooth can be used for a conventional PDC drill bit or a spiral PDC drill bit, and the cutting tooth for breaking rock ridges between teeth is included in at least the inner cone portion, the nose portion or the shoulder portion of the drill blade. The new cutting tooth can form a high stress concentration area on the unconfined or confined rock ridges between teeth formed by the cutting polycrystalline diamond composite layer by means of the impact polycrystalline diamond composite layer, quickly and efficiently break the rock ridges formed between adjacent teeth on the same blade, reduce the lateral or axial vibration degree near the drill end, further improve the function of reducing the axial and lateral vibration near the drill end of a conventional PDC drill bit or a personalized spiral PDC drill bit under different design parameters, improve the utilization rate of drilling energy, reduce the probability of premature drilling, and ultimately reduce the drilling cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is a schematic diagram of the drill bit tooth arrangement method of the present invention;

[0034] Figure 2 A schematic diagram of a cutting tooth for breaking rock ridges between teeth according to the present invention;

[0035] Figure 3 A schematic diagram of the geometric features of a cutting tooth for breaking rock ridges between teeth according to the present invention;

[0036] Figure 4 It is a schematic diagram of the overall structure of the drill bit of the present invention;

[0037] Figure 5 A schematic diagram of a method for crushing inter-tooth rock ridges by a cutting tooth for crushing inter-tooth rock ridges according to the present invention;

[0038] Among them, 1. cemented carbide; 2. polycrystalline diamond composite layer for cutting; 3. polycrystalline diamond composite layer for impact; 4. inner cone part; 5. nose part; 6. shoulder part; 7. radial tooth line; 8. drill bit body; 9. blade; 10. nozzle; 11. front tooth position; 12. rear tooth position; 13. conventional plane tooth; 14. blade radial line; 15. rock ridge between teeth. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0040] In recent years, PDC drill bit technology has continued to advance, such as the composite drill bit developed by Baker Hughes that integrates a cone and a PDC drill bit. PDC drill bit, full name Polycrystalline Diamond Compactbit, is a drilling tool commonly used in the geological drilling industry. Conventional PDC drill bits consist of PDC cutting teeth, nozzles, matrix and drill bit body. PDC cutting teeth are made of a synthetic diamond layer combined with a tungsten carbide substrate to perform a precise cutting process. The cutting teeth of the PDC drill bit are circular in shape and are welded on a cylindrical cutting tool, which is then mounted on the drill bit body to form a PDC drill bit. The PDC drill bit rotates to make the PDC cutting teeth contact the rock and uses a shearing action to break the rock. This shearing method is more efficient than traditional crushing methods.

[0041] In response to the problems mentioned in the background technology, the existing technical means mainly reduce the axial or lateral near-drilling vibration, improve the rock breaking efficiency and increase the mechanical drilling speed by adjusting the designed draft between the front and rear rows of teeth of the drill bit, changing the tooth material of the front and rear rows of teeth, developing draft adaptive PDC drill bits, micro-core PDC drill bits, personalized spiral blade PDC drill bits and other means. Among the various existing technical means, the method of adjusting the designed draft often makes the designed draft smaller, which can meet the near-drilling vibration control requirements in a difficult-to-drill layer section. However, when the drill bit drills below the difficult-to-drill layer section, the designed draft designed for the difficult-to-drill layer section may prevent the drill bit from fully exerting its rapid drilling ability; the design of the micro-core drill bit can effectively reduce the near-drilling axial vibration and lateral vibration, but it only has a better effect on hard plastic formations, and cannot take into account other softer formations that may be encountered in a drilling trip; when the personalized spiral blade PDC drill bit drills into the formation, the teeth between the teeth are too small. The unconfined rock ridge can be destroyed by the stress concentration between adjacent teeth, thereby reducing the axial and lateral near-drilling vibrations. Although this can improve the rock breaking efficiency from the overall perspective of the drill bit, under the condition of a small design depth, the inter-tooth rock ridge cannot be effectively destroyed by relying solely on the inter-tooth stress concentration between adjacent teeth, which reduces the universal applicability of personalized spiral PDC drill bits. In order to further improve the function of conventional PDC drill bits and personalized spiral PDC drill bits to reduce the near-drilling axial and lateral vibrations under different design parameters, it is still necessary to develop cutting teeth for inter-tooth rock ridges and PDC drill bits containing such cutting teeth.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Example 1

[0044] Reference Figures 1 to 5As shown, embodiment 1 of the present invention provides a cutting tooth for crushing rock ridges between teeth, including a cemented carbide 1, a polycrystalline diamond composite layer 2 for cutting, and a polycrystalline diamond composite layer 3 for impact. 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.

[0045] In this embodiment, the cutting teeth for breaking the rock ridges between the teeth are arranged in the inner cone part 4, the nose part 5 and the shoulder part 6 in the front tooth position of the PDC drill bit. When installing the cutting teeth, it is necessary to keep the tooth surface symmetry axis L1 and the tangent line Ti at a certain point on the radial tooth arrangement line 7 in a vertical relationship, and the cutting tooth edge height H1 must be greater than half of the tooth diameter D of the cutting teeth.

[0046] Among them, the distribution position and distribution number of the cutting teeth for breaking the rock ridges between the teeth in this implementation are determined according to the strength of the lateral vibration and the axial vibration near the drill end.

[0047] 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, composite polygons B, and composite polygons C, respectively. When the composite polygons A, B, and C are translated to the same two-dimensional plane along the axial center line L2, they satisfy the Boolean sum relationship of "B = A + C". The diameter of the circumscribed circle of the composite polygon B is the cutting tooth diameter D. The composite polygon A is stretched along the axial center line L2 by a length of H2 to form the three-dimensional structure of the cemented carbide 1, the composite polygon B is stretched along the axial center line L2 by a length of H3 to form the three-dimensional structure of the cutting polycrystalline diamond composite layer 2, and the composite polygon C is stretched along the axial center line L2 by a length of H2 to form the three-dimensional structure of the impact polycrystalline diamond composite layer 3.

[0048] Further optimization scheme, the composite polygon A is composed of arcs Arc It is composed of 2 straight lines H5 and 2 straight lines H4, and the straight lines H4 and H5 are parallel and perpendicular to the tooth surface 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 from both ends, and arc R1 is tangent to the circumscribed circle of composite polygon B, and the tangent point is P1. On the same plane, the composite polygon A and the composite polygon C are Boolean summed to obtain composite polygon B. The 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 the distance H6.

[0049] Further optimization scheme, the necessary geometric relationships that need to be satisfied in the composite polygon A, composite polygon B, and composite polygon 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 the straight line H5 and the length H3 are between 1.5-4 mm.

[0050] The present embodiment discloses a structure and manufacturing method of a cutting tooth for crushing inter-tooth rock ridges, and the cutting tooth is used to crush rocks during drilling. The material is that the cutting tooth is composed of 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, composite polygons B, and composite polygons C, respectively. When these polygons are translated to the same two-dimensional plane along the axial center line L2, the Boolean sum relationship of "B = A + C" is satisfied. By stretching the composite polygons A, B, and C along the axial center line 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 rocks. By precisely controlling the geometric shape and size, the performance of the cutting tooth can be optimized to adapt to different drilling conditions.

[0051] Example 2

[0052] 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 comprises a drill bit body 8, a plurality of blades 9 and a plurality of nozzles 10 are arranged on the drill bit body 8, a front row of tooth positions 11 and a rear row of tooth positions 12 are arranged on the blades 9, and conventional plane teeth 13 are arranged on part of the front row of tooth positions 11 and all of the rear row of tooth positions 12;

[0053] 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 rock ridge are arranged on the rear tooth positions 12 corresponding to the inner cone part 4, the nose part 5 and the shoulder part 6.

[0054] When it is known that the near-drilling axial vibration is relatively serious 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, and the remaining rear tooth positions 12 are arranged as conventional flat teeth 13;

[0055] ​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 rock ridge are arranged 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 arranged as conventional plane teeth 13;

[0056] 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 rock 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 plane teeth 13; further optimizing the scheme,

[0057] like Figure 5 As shown, the cutting teeth for breaking the inter-tooth ridges 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 the axial or lateral vibration impact energy on the unconfined or confined inter-tooth ridges 15, and quickly break the inter-tooth ridges 15. The cutting teeth for breaking the inter-tooth ridges arranged on the inner cone portion 4 mainly use the lateral vibration impact energy to break the inter-tooth ridges 15, the cutting teeth for breaking the inter-tooth ridges arranged on the nose portion 5 mainly use the lateral and axial vibration impact energy to break the inter-tooth ridges 15, and the cutting teeth for breaking the inter-tooth ridges arranged on the shoulder portion 6 mainly use the axial vibration impact energy to break 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, and when the PDC drill bit is a personalized spiral PDC drill bit, the inter-tooth ridges 15 are unconfined ridges.

[0058] Specifically: Each blade 9 has at least one 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 rock ridge, (the inner cone part 4, the nose part 5, and the shoulder part 6 are divided as shown in Figure 1 shown).

[0059] Reference Figure 1 and Figure 5 As shown, when it is known that the axial vibration near the drill bit is relatively serious 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, and the inter-tooth rock ridge 15 is broken by the axial impact energy, and the remaining rear tooth positions 12 are arranged as conventional plane teeth 13, so as to reduce the axial vibration near the drill bit at the expense of a small mechanical drilling speed;

[0060] Reference Figure 1 and Figure 5As shown, 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 rock 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 plane teeth 13, and the lateral vibration energy is used to break the inter-tooth rock ridge 15, so as to reduce the near-drilling lateral vibration under the premise of sacrificing less mechanical drilling speed;

[0061] 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 serious, the cutting teeth for breaking the inter-tooth rock ridges 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 remaining front tooth positions 11 are set as conventional plane teeth 13, and the axial and lateral vibration energy is used to break the inter-tooth rock ridges 15, so as to reduce the near-drilling axial and lateral vibrations at the expense of less mechanical drilling speed.

[0062] Embodiment 2 of the present invention discloses a PDC drill bit, the design of which takes into account the vibration characteristics during the drilling process, optimizes the drilling performance by reasonably distributing the cutting teeth, and reduces the impact of vibration on the drill bit and the drilling effect. This design helps to improve the efficiency and safety of drilling, especially under complex geological conditions. It should be understood that by arranging the cutting teeth at different positions, the near-drilling axial and lateral vibrations can be reduced, thereby improving the drilling efficiency, while sacrificing less mechanical drilling speed.

[0063] The details not described in detail in the present invention are all conventional technical means well known to those skilled in the art.

[0064] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0065] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined 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 in that: 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 by using tungsten carbide; 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, satisfying the Boolean sum relationship of "B=A+C".

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

3. The cutting tooth for breaking the inter-tooth rock ridge according to claim 1, characterized in that: The composite polygon A consists of circular arcs Arc It is composed of two straight lines H5 and two straight lines H4, and the straight lines H4 and H5 are respectively parallel and perpendicular to the tooth surface symmetry axis L1.

4. The cutting tooth for breaking the rock ridge between teeth according to claim 3, characterized in that: 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 the composite polygon B, and the tangent point is P1; 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.

5. The cutting tooth for breaking the rock ridge between teeth according to claim 4, characterized in that: On the same plane, the composite polygon A and the composite polygon C are subjected to Boolean sum to obtain the composite polygon B.

6. The cutting tooth for breaking the rock ridge between teeth 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 perimeter of ≥ π D / 2; the length of straight line H5 and the length of H3 are between 1.5-4 mm.​ 7. A PDC drill bit, characterized in that: 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 breaking inter-tooth ridges according to any one of claims 1 to 6.

8. The PDC drill bit according to claim 7, characterized in that: The drill body (8) is provided with a plurality of blades (9), the blades (9) are provided with front row teeth (11) and rear row teeth (12), and conventional plane teeth (13) are installed on some of the front row teeth (11) and all the rows of teeth.

9. The PDC drill bit according to claim 8, characterized in that: The cutting teeth are arranged on the front tooth positions (11) corresponding to the inner cone portion (4), the nose portion (5) and the shoulder portion (6).

10. The PDC drill bit according to claim 9, characterized in that: When the near-drilling axial vibration is relatively serious 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 axial vibration near the drill bit is relatively light and the lateral vibration is 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) 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 part (4), the nose part (5) and the shoulder part (6).

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