A PDC bit with double sequence of large and small teeth

Abstract

The present application relates to the technical field of drilling equipment, and discloses a PDC drill bit with double-order distribution of large and small teeth, which comprises a drill bit body, a main blade, a secondary blade, a first main cutting tooth and a second main cutting tooth, and at least two main blades are uniformly distributed on the upper end of the drill bit body in a circumferential direction. The present application has reasonable and compact structure, the distribution order of the main cutting tooth is opposite to that of the secondary cutting tooth, so that the cutting amount and cutting force of the main cutting tooth and the secondary cutting tooth can be balanced respectively, which is beneficial to the workload balance and life balance of the cutting tooth, the main cutting tooth and the secondary cutting tooth are alternately arranged, the advantages of the main cutting tooth and the secondary cutting tooth are complementary, the superiority of the double-order distribution is maximally exerted, and the PDC drill bit has good stability, durability and high mechanical drilling speed in difficult strata, so that the stratum adaptability of the drill bit can be obviously improved, the soft stratum and the hard stratum can be drilled, and the ability of the drill bit to drill through the interlayer can be enhanced.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, and is a PDC drill bit with a dual-sequence tooth arrangement of large and small teeth. Background Technology

[0002] Polycrystalline diamond compact (PDC) drill bits are among the most widely used rock-breaking tools in oil and gas drilling. PDC drill bits are typically designed with a wing-like structure, with PDC teeth arranged on the wing crowns of the drill bit body, forming hydraulic chip removal channels between the wings. PDC teeth are composed of a polycrystalline diamond layer and a cemented carbide base. The polycrystalline diamond layer possesses the high hardness and wear resistance of diamond, but also exhibits some brittleness. PDC teeth are generally cylindrical. During rock breaking, the PDC teeth are driven into the formation by drill pressure, and the rotation of the drill bit body further scrapes and breaks the rock. Generally, the smaller the PDC tooth size (referring to the diameter of the cylinder), the easier it is to penetrate the formation. However, smaller PDC tooth sizes result in a smaller amount of rock broken during scraping, and the tooth coverage area is also smaller. Therefore, when drilling in softer formations, larger PDC teeth are generally used to increase the amount of rock cut and broken by the PDC teeth, thereby improving the drilling efficiency in soft formations; when drilling in hard formations, smaller PDC teeth are generally used to enhance the ability and depth of the PDC teeth to penetrate the formation, thereby increasing the drilling speed.

[0003] Because the polycrystalline diamond layer of PDC (polycrystalline diamond) teeth has a certain degree of brittleness, larger PDC teeth have a higher diamond content and greater wear height than smaller PDC teeth, but their impact resistance is weaker. When drilling in harder formations, the PDC teeth struggle to penetrate due to the hardness of the formation, resulting in significant impact damage. Therefore, smaller PDC teeth are generally chosen for hard formations. However, smaller PDC teeth have a lower wear height, lower diamond content, and a relatively shorter wear life. This presents a dilemma in selecting PDC teeth for hard formations.

[0004] Drill bits often do not drill through formations with relatively uniform lithology. Sometimes, they must traverse multiple formations of varying hardness and lithology, such as formations with frequent alternations of hard and soft materials, soft (or hard) interlayers, and heterogeneous formations. Because PDC (partition-controlled die) teeth have a certain degree of brittleness, their formation adaptability is relatively poor. Changes in formation can lead to damage to the PDC teeth or a decrease in drilling speed. Drill bits using a single-size PDC tooth are often unsuitable for rapid, long-life, and efficient drilling in formations with alternating hard and soft materials, interlayers, or heterogeneous formations. Summary of the Invention

[0005] This invention provides a PDC drill bit with a dual-sequence tooth arrangement of large and small teeth, which overcomes the shortcomings of the prior art and can effectively solve the problems of low drilling speed and long well construction cycle in existing deep and difficult-to-drill formations.

[0006] The technical solution of this invention is achieved through the following measures: A PDC drill bit with dual-sequence tooth arrangement of large and small teeth, comprising a drill bit body, main blades, secondary blades, first main cutting teeth, and second main cutting teeth. At least two main blades are evenly distributed along the circumference of the upper end of the drill bit body. The main blades are sequentially divided from the inside to the outside along the crown contour into a first inner cone section, a first nose section, a first shoulder section, a first outer cone section, and a first gauge section. Each main blade has several first main cutting teeth and first secondary cutting teeth alternately arranged from the inside to the outside on its first inner cone section, first nose section, first shoulder section, and first outer cone section. A secondary blade is fixed to the upper end of the drill bit body between each pair of adjacent main blades. The secondary blade is sequentially divided from the inside to the outside along the crown contour into a second inner cone section, a second nose section, a second outer cone section, and a second gauge section. The second shoulder, the second outer cone section, and the first diameter protection section, each of the second inner cone section, the second nose, the second shoulder, and the second outer cone section of each secondary blade are provided with several second main cutting teeth and second auxiliary cutting teeth alternately arranged from the inside to the outside. All the first inner cone sections and the first nose sections of the main blades and all the first inner cone sections and the first nose sections of the secondary blades form a tooth distribution surface. All the first main cutting teeth and the second main cutting teeth on the tooth distribution surface are main cutting teeth, and the main cutting teeth are distributed in a vortex shape. All the first auxiliary cutting teeth and the second auxiliary cutting teeth on the tooth distribution surface are auxiliary cutting teeth, and the auxiliary cutting teeth are distributed in a vortex shape with a rotation direction opposite to that of the main cutting teeth. Each main blade and the two adjacent secondary blades are connected to each other with a chip removal groove near the center of the upper end of the drill body.

[0007] The following are further optimizations and / or improvements to the above-mentioned technical solution:

[0008] The first and second main cutting teeth can both be cylindrical with the same diameter. The first and second auxiliary cutting teeth are also cylindrical with the same diameter. The diameter of the first auxiliary cutting tooth is smaller than that of the first main cutting tooth. The maximum height of the first main cutting tooth protruding from the main blade is the first distance. The maximum height of the first auxiliary cutting tooth protruding from the main blade is the second distance. The maximum height of the second main cutting tooth protruding from the auxiliary blade is the third distance. The maximum height of the second auxiliary cutting tooth protruding from the auxiliary blade is the fourth distance. The first, second, third, and fourth distances are all equal.

[0009] Each of the aforementioned first main cutting tooth end, first secondary cutting tooth end, second main cutting tooth end, and second secondary cutting tooth end may be provided with a composite layer.

[0010] The aforementioned at least one first primary cutting tooth, at least one first secondary cutting tooth, at least one second primary cutting tooth, or at least one second secondary cutting tooth may be located in the radial inner half region of the drill bit body.

[0011] The aforementioned at least one first primary cutting tooth, at least one first secondary cutting tooth, at least one second primary cutting tooth, or at least one second secondary cutting tooth may be located in the radial inner third region of the drill bit body.

[0012] The rake angle of each of the first primary cutting teeth is less than or equal to the rake angle of the first secondary cutting tooth adjacent to it and far from the center of the drill body, and the rake angle of each of the second primary cutting teeth is less than or equal to the rake angle of the second secondary cutting tooth adjacent to it and far from the center of the drill body.

[0013] Each of the main blades, from the cutting side, has a first nose and a first shoulder, and each of the secondary blades, from the cutting side, has a second nose and a second shoulder, spaced apart from the inside to the outside, with a number of auxiliary cutting teeth.

[0014] Each of the drill bit bodies at the position of each chip removal groove can be provided with at least one jet hole that is connected to the inside and outside at intervals, and a nozzle is fixedly installed in each jet hole.

[0015] The invention features a reasonable and compact structure. The arrangement of the main cutting teeth is opposite to that of the secondary cutting teeth, which makes it easier for the cutting amount and cutting force of the main and secondary cutting teeth to achieve a balance. This is beneficial for the balance of workload and lifespan of the cutting teeth. The alternating arrangement of the main and secondary cutting teeth allows their advantages to complement each other, maximizing the superiority of the dual-sequence tooth arrangement. Furthermore, it exhibits good stability, durability, and high mechanical drilling speed in difficult-to-drill formations, significantly improving the drill bit's formation adaptability. It can handle both soft and hard formations, and enhance the drill bit's ability to penetrate interlayers. Attached Figure Description

[0016] Appendix Figure 1 This is a top view of the structure of the present invention.

[0017] Appendix Figure 2 This is a three-dimensional structural diagram of the present invention.

[0018] Appendix Figure 3 This is a schematic diagram showing the tooth arrangement sequence of the main cutting teeth and the secondary cutting teeth in this invention.

[0019] Appendix Figure 4 This is a schematic diagram of the rake angle of the cutting teeth in this invention.

[0020] Appendix Figure 5 This is a schematic diagram of the radial coverage arrangement of the first main cutting tooth and the first auxiliary cutting tooth in this invention.

[0021] Appendix Figure 6 This is a schematic diagram of the radial coverage arrangement of the second main cutting tooth and the second auxiliary cutting tooth in this invention.

[0022] The codes in the attached diagram are as follows: 1 is the drill bit body, 2 is the main blade, 3 is the secondary blade, 4 is the first main cutting tooth, 5 is the second main cutting tooth, 6 is the first secondary cutting tooth, 7 is the second secondary cutting tooth, 8 is the composite layer, 9 is the auxiliary cutting tooth, 10 is the nozzle, 11 is the chip removal groove, and α is the forward tilt angle. Detailed Implementation

[0023] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0024] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0025] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0026] As attached Figure 1 , 2 As shown in Figures 3, 4, 5, and 6, this PDC drill bit with dual-sequence tooth arrangement includes a drill body 1, main blades 2, secondary blades 3, first main cutting teeth 4, and second main cutting teeth 5. At least two main blades 2 are evenly distributed along the circumference of the upper end of the drill body 1. The main blades 2 are divided sequentially from the inside to the outside along the crown profile into a first inner cone section, a first nose section, a first shoulder section, a first outer cone section, and a first gauge section. Each main blade 2 has several first main cutting teeth 4 and first secondary cutting teeth 6 alternately arranged from the inside to the outside on its first inner cone section, first nose section, first shoulder section, and first outer cone section. A secondary blade 3 is fixed to the upper end of the drill body 1 between each pair of adjacent main blades 2. The secondary blade 3 is divided sequentially from the inside to the outside along the crown profile into a second inner cone section, a second nose section, a second shoulder section, and a second gauge section. On the two outer conical sections and the first diameter protection section, each secondary blade 3 has several second main cutting teeth 5 and second auxiliary cutting teeth 7 arranged alternately from the inside to the outside on the second inner conical section, second nose, second shoulder and second outer conical section. The first inner conical section and first nose of all main blade 2 and the first inner conical section and first nose of all secondary blade 3 form a tooth distribution surface. All the first main cutting teeth 4 and second main cutting teeth 5 on the tooth distribution surface are main cutting teeth, and the main cutting teeth are distributed in a vortex shape. All the first auxiliary cutting teeth 6 and second auxiliary cutting teeth 7 on the tooth distribution surface are auxiliary cutting teeth, and the auxiliary cutting teeth are distributed in a vortex shape with the direction of rotation opposite to that of the main cutting teeth. Each main blade 2 and the two adjacent secondary blades 3 have a chip removal groove 11 that is interconnected near the center of the upper end of the drill body 1.

[0027] Depending on the requirements, the number of main cutting wings 2 and secondary cutting wings 3 can be four. The first main cutting tooth 4 and the first secondary cutting tooth 6 are embedded on the main cutting wing 2 near the cutting side, and the second main cutting tooth 5 and the second secondary cutting tooth 7 are embedded on the secondary cutting wing 3 near the cutting side. The tooth arrangement sequence refers to the order in which the cutting teeth are arranged in a plane perpendicular to the drill bit axis. The main cutting teeth are arranged clockwise on the crown of the drill bit, i.e., sequential tooth arrangement, such as... Figure 3 201→202→203→……; The secondary cutting teeth are arranged counterclockwise on the crown of the drill bit, i.e., reverse tooth arrangement, such as Figure 3 101→102→103→……. When the cutting teeth are arranged in a certain order, the cutting amount and cutting force distribution of the cutting teeth generally do not change abruptly. The arrangement sequence of the main cutting teeth is opposite to that of the secondary cutting teeth, which makes it easier for the cutting amount and cutting force of the main and secondary cutting teeth to reach a balance. This is beneficial to the balance of workload and life of the cutting teeth. The alternating arrangement of the main and secondary cutting teeth allows their advantages to complement each other, maximizing the superiority of the dual-sequence tooth arrangement, and providing good stability, durability, and high mechanical drilling speed in difficult-to-drill formations. When drilling into softer formations, the cutting teeth have a greater penetration depth, and the main cutting teeth fully utilize their advantage of large rock breaking volume to compensate for the insufficient rock breaking volume when using only secondary cutting teeth. When drilling into harder formations, the main cutting teeth have difficulty penetrating the formation, and the secondary cutting teeth utilize their advantage of strong penetration ability to compensate for the insufficient penetration ability when using only main cutting teeth. Therefore, the radial alternation of the main cutting teeth and the secondary cutting teeth can significantly improve the drill bit's adaptability to the formation, enabling it to drill into both soft and hard formations, and enhancing its ability to penetrate interlayers.

[0028] The PDC drill bit with dual-sequence tooth arrangement of large and small teeth can be further optimized and / or improved according to actual needs:

[0029] As attached Figure 1 , 2 As shown in Figures 4, 5, and 6, the first main cutting tooth 4 and the second main cutting tooth 5 are both cylindrical with the same diameter. The first secondary cutting tooth 6 and the second secondary cutting tooth 7 are both cylindrical with the same diameter. The diameter of the first secondary cutting tooth 6 is smaller than the diameter of the first main cutting tooth 4. The maximum height of the first main cutting tooth 4 protruding from the main blade 2 is the first distance. The maximum height of the first secondary cutting tooth 6 protruding from the main blade 2 is the second distance. The maximum height of the second main cutting tooth 5 protruding from the secondary blade 3 is the third distance. The maximum height of the second secondary cutting tooth 7 protruding from the secondary blade 3 is the fourth distance. The first distance, the second distance, the third distance, and the fourth distance are all equal.

[0030] The exposure height ratio refers to the ratio between the height of the cutting teeth exposed outside the drill bit body 1 and the diameter of the cutting teeth. Therefore, the first main cutting tooth 4 and the second main cutting tooth 5 have the same exposure height ratio, as do the first auxiliary cutting tooth 6 and the second auxiliary cutting tooth 7. The exposure height ratio of the first auxiliary cutting tooth 6 is greater than that of the first main cutting tooth 4. This allows for a smoother transition of the drill bit's cutting profile, preventing abnormal loading and failure of the cutting teeth. The use of cutting teeth of different sizes on the drill bit enhances its adaptability to different formations. When drilling in soft formations, the main cutting teeth increase the amount of rock broken by the drill bit, ensuring the drilling speed in soft formations. When drilling in hard formations, the auxiliary cutting teeth maintain the drill bit's invasiveness and aggressiveness, improving the rock-breaking efficiency in hard formations. Therefore, this drill bit balances drilling speed in soft formations with rock-breaking efficiency in hard formations, significantly improving its formation adaptability, especially in formations with alternating soft and hard surfaces. The secondary cutting teeth have strong impact resistance, thus enhancing the drill bit's impact resistance, drilling performance and service life in interlayers and heterogeneous formations. Simultaneously, the secondary cutting teeth easily penetrate the formation, embedding themselves into the rock, resulting in more stable operation of both the secondary cutting teeth and the drill bit, improving its working stability and extending its service life. Furthermore, the drill bit's smooth and stable cutting action makes its tool face easier to control, resulting in superior guiding ability.

[0031] As attached Figure 4 As shown, each of the ends of the first main cutting tooth 4, the first auxiliary cutting tooth 6, the second main cutting tooth 5, and the second auxiliary cutting tooth 7 is provided with a composite layer 8.

[0032] As required, composite layer 8 is a PDC layer. During use, the design of composite layer 8 can further meet the needs of drilling operations, reduce the wear of cutting teeth by rocks, and help reduce the problem of easy wear at high temperatures caused by excessive temperature of the tooth tip due to friction between the rock and the tip of the cutting teeth, thereby improving the wear resistance of the cutting teeth and further extending the service life of the invention.

[0033] As attached Figure 1 , 2 As shown in Figures 3, 5, and 6, at least one first primary cutting tooth 4, at least one first secondary cutting tooth 6, at least one second primary cutting tooth 5, or at least one second secondary cutting tooth 7 is located in the radial inner half region of the drill bit body 1.

[0034] Radial direction refers to the radius (diameter) direction of the drill bit body 1. The inner half of the radial region of the drill bit body 1 refers to the area from the center point of the drill bit body 1 outward along the radial direction to half the radius of the drill bit body 1. During use, this enhances the drill bit's ability to penetrate different formations and maximizes the advantages of the dual-sequence tooth arrangement.

[0035] As attached Figure 1 , 2 As shown in Figures 3, 5, and 6, at least one first primary cutting tooth 4, at least one first secondary cutting tooth 6, at least one second primary cutting tooth 5, or at least one second secondary cutting tooth 7 is located in the radial inner third region of the drill bit body 1.

[0036] The radial inner half region of the drill bit body 1 refers to the area extending outward from the center point of the drill bit body 1 along its radius to one-third of its radius. During use, the larger the area covered by the main and secondary cutting teeth, the better the drill bit's adaptability in complex geological formations, enhancing its ability to penetrate different formations and maximizing the advantages of a dual-sequence tooth arrangement.

[0037] As attached Figure 1 , 2 As shown in Figure 4, the pitch angle α of each first main cutting tooth 4 is less than or equal to the pitch angle α of the first auxiliary cutting tooth 6 adjacent to it and far from the center of the drill body 1, and the pitch angle α of each second main cutting tooth 5 is less than or equal to the pitch angle α of the second auxiliary cutting tooth 7 adjacent to it and far from the center of the drill body 1.

[0038] The rake angle α refers to the normal to the drill bit cutting profile at the radial position point of the cutting tooth on the cutting surface of the cutting tooth (the normal to the cutting profile is attached). Figure 5 The angle between the vertical centerline and the centerline of the drill bit; the drill bit cutting profile refers to the radial profile formed by the tooth tips of the main cutting teeth on the drill bit (the radial profile is an auxiliary line). Figure 5 and attached Figure 6 The radial position of the cutting teeth (as shown in the curve) refers to the position of the point of tangency between the tip of the cutting tooth and the cutting profile of the drill bit on the drill bit radius. During use, a smaller inclination angle α results in a stronger ability to penetrate the formation. The first main cutting tooth 4 and the second main cutting tooth 5 have a smaller ability to penetrate the formation than the first auxiliary cutting tooth 6 and the second auxiliary cutting tooth 7. However, the first main cutting tooth 4 and the second main cutting tooth 5 can compensate for their insufficient ability to penetrate the formation, thus improving the overall formation penetration performance and rock-breaking efficiency of the drill bit.

[0039] As attached Figure 1 , 2 As shown, each main blade 2 has a first nose and first shoulder away from the cutting side, and each secondary blade 3 has a second nose and second shoulder away from the cutting side, each with several auxiliary cutting teeth 9 spaced from the inside to the outside.

[0040] During use, the rear row of auxiliary cutting teeth 9 on the drill bit participates in cutting and breaking rocks, reducing the overall wear rate and increasing the life of the drill bit. The rear row of auxiliary cutting teeth 9 can limit the penetration depth of the main cutting teeth and secondary cutting teeth, help the main cutting teeth and secondary cutting teeth bear part of the impact load, reduce drill bit vibration and the probability of composite layer 8 cracking, protect the sharpness of the main cutting teeth and secondary cutting teeth of the drill bit, and improve the mechanical drilling speed of the drill bit during drilling.

[0041] As attached Figure 1 , 2 As shown, at least one jet hole with internal and external communication is provided at the upper end of the drill body 1 corresponding to each chip removal groove 11 position, and a nozzle 10 is fixedly installed in each jet hole.

[0042] During use, this setting can prevent rock cuttings from accumulating in the cuttings removal groove 11, thereby optimizing the hydraulic rock breaking and drill bit cuttings removal effects and reducing the risk of mud buildup on the drill bit body 1.

[0043] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A PDC drill bit with dual-sequence tooth arrangement of large and small teeth, characterized in that... The drill bit includes a body, main blades, secondary blades, first main cutting teeth, and second main cutting teeth. At least two main blades are evenly distributed around the circumference of the upper end of the drill bit body. Each main blade, along its crown profile, is divided from the inside out into a first inner cone section, a first nose section, a first shoulder section, a first outer cone section, and a first gauge section. Each main blade's first inner cone section, first nose section, first shoulder section, and first outer cone section has several first main cutting teeth and first secondary cutting teeth alternately arranged from the inside out. A secondary blade is fixed to the upper end of the drill bit body between every two adjacent main blades. Each secondary blade, along its crown profile, is divided from the inside out into a second inner cone section, a second nose section, a second shoulder section, a second outer cone section, and a first gauge section. The second inner cone section, second nose, second shoulder, and second outer cone section of the secondary blade are each alternately provided with several second main cutting teeth and second auxiliary cutting teeth from the inside out. All the first inner cone sections and first nose sections of the main blades and all the first inner cone sections and first nose sections of the secondary blades form a tooth distribution surface. All the first main cutting teeth and second main cutting teeth on the tooth distribution surface are main cutting teeth, and the main cutting teeth are distributed in a vortex shape. All the first auxiliary cutting teeth and second auxiliary cutting teeth on the tooth distribution surface are auxiliary cutting teeth, and the auxiliary cutting teeth are distributed in a vortex shape with a rotation direction opposite to that of the main cutting teeth. Each main blade and the two adjacent secondary blades are connected to each other with a chip removal groove near the center of the upper end of the drill body. The first and second main cutting teeth are both cylindrical with the same diameter. The first and second auxiliary cutting teeth are also cylindrical with the same diameter. The diameter of the first auxiliary cutting tooth is smaller than that of the first main cutting tooth. The maximum height of the first main cutting tooth protruding from the main blade is the first distance. The maximum height of the first auxiliary cutting tooth protruding from the main blade is the second distance. The maximum height of the second main cutting tooth protruding from the auxiliary blade is the third distance. The maximum height of the second auxiliary cutting tooth protruding from the auxiliary blade is the fourth distance. The first distance, the second distance, the third distance, and the fourth distance are all equal. The main cutting teeth are arranged clockwise on the crown of the drill bit, in sequence, while the secondary cutting teeth are arranged counterclockwise on the crown of the drill bit, in reverse order.

2. The PDC drill bit with dual-sequence tooth arrangement of large and small teeth according to claim 1, characterized in that... Each of the first main cutting tooth tip, the first secondary cutting tooth tip, the second main cutting tooth tip, and the second secondary cutting tooth tip is provided with a composite layer.

3. The PDC drill bit with dual-sequence tooth arrangement according to claim 1 or 2, characterized in that... At least one first primary cutting tooth, or at least one first secondary cutting tooth, or at least one second primary cutting tooth, or at least one second secondary cutting tooth is located in the radial inner half of the drill bit body.

4. The PDC drill bit with dual-sequence tooth arrangement of large and small teeth according to claim 3, characterized in that... At least one first primary cutting tooth, or at least one first secondary cutting tooth, or at least one second primary cutting tooth, or at least one second secondary cutting tooth is located in the radial inner third region of the drill bit body.

5. The PDC drill bit with dual-sequence tooth arrangement according to claim 1, 2, or 4, characterized in that... The rake angle of each first primary cutting tooth is less than or equal to the rake angle of the first secondary cutting tooth adjacent to it and far from the center of the drill body, and the rake angle of each second primary cutting tooth is less than or equal to the rake angle of the second secondary cutting tooth adjacent to it and far from the center of the drill body.

6. The PDC drill bit with dual-sequence tooth arrangement of large and small teeth according to claim 3, characterized in that... The rake angle of each first primary cutting tooth is less than or equal to the rake angle of the first secondary cutting tooth adjacent to it and far from the center of the drill body, and the rake angle of each second primary cutting tooth is less than or equal to the rake angle of the second secondary cutting tooth adjacent to it and far from the center of the drill body.

7. The PDC drill bit with dual-sequence tooth arrangement according to claim 1, 2, 4, or 6, characterized in that... Each main blade's first nose and first shoulder, away from the cutting side, and each secondary blade's second nose and second shoulder, away from the cutting side, are provided with a number of auxiliary cutting teeth spaced from the inside to the outside; or / and, the upper end of the drill body corresponding to each chip removal groove position is provided with at least one jet hole that is connected internally and externally, and a nozzle is fixedly installed in each jet hole.

8. The PDC drill bit with dual-sequence tooth arrangement of large and small teeth according to claim 3, characterized in that... Each main blade's first nose and first shoulder, away from the cutting side, and each secondary blade's second nose and second shoulder, away from the cutting side, are provided with a number of auxiliary cutting teeth spaced from the inside to the outside; or / and, the upper end of the drill body corresponding to each chip removal groove position is provided with at least one jet hole that is connected internally and externally, and a nozzle is fixedly installed in each jet hole.

9. The PDC drill bit with dual-sequence tooth arrangement of large and small teeth according to claim 5, characterized in that... Each main blade's first nose and first shoulder, away from the cutting side, and each secondary blade's second nose and second shoulder, away from the cutting side, are provided with a number of auxiliary cutting teeth spaced from the inside to the outside; or / and, the upper end of the drill body corresponding to each chip removal groove position is provided with at least one jet hole that is connected internally and externally, and a nozzle is fixedly installed in each jet hole.

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