Drill bit

Abstract

According to the drill bit, a plurality of main blades and auxiliary blades are connected to the crown of a drill bit body in a surrounding mode and are alternately arranged at intervals, and connection of cutting teeth and rotary cutting of the whole drill bit are facilitated. Rows of sharp round teeth and round teeth are arranged on the main blades, and the sharp round teeth improve the capability of penetrating into the stratum and improve the cutting efficiency. The exposed height of the circular teeth is lower than that of the sharp round teeth, and the circular teeth are located behind the sharp round teeth in the rotating cutting direction of the sharp round teeth. And when the sharp round teeth are greatly abraded, cutting is assisted. The machine speed is prevented from being greatly reduced, and the single-trip footage of the drill bit is effectively improved. The rotating teeth on the auxiliary blades are connected with the auxiliary blades through the connecting parts, and the rotating parts rotationally connected with the connecting parts can be used for cutting. And the pressure intensity at the cutting position is improved, and the stratum penetration capacity is improved. The service life of the drill bit is prolonged while the cutting efficiency is improved through cutting of different cutting teeth. The problems that when a compact and high-hardness rock stratum is drilled, the drilling efficiency is low, and the service life is short are solved to a certain extent.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas drilling tools, and in particular to a drill bit. Background Art

[0002] The drill bit is the most important rock-breaking tool in the drilling process, which is directly related to the drilling machine's drilling speed, drilling cycle and drilling cost. PDC drill bits have the advantages of strong formation adaptability, fast drilling speed and low cost. They are more and more widely used and gradually replace roller drill bits. Although PDC drill bits are widely used, only when the selected drill bit type has a good compatibility with the lithology of the drilled formation, can the drilling efficiency be greatly improved, the service life of the drill bit be increased, and the drilling cost can be greatly reduced.

[0003] In the prior art, a drill bit includes a drill body, blades, and a plurality of cutting teeth. The blades are fixed to the crown of the drill body, and the cutting teeth are fixed to and protrude from the blades. The cutting teeth are usually a plurality of conventional cutting teeth with the same structure. For denser and harder rock formations, this type of drill bit is difficult to penetrate into the rock formation during use, and has poor drillability, and the drill bit is severely worn during use. For example, for horizontal wells developed in dense sandstone gas, the drilling efficiency is low, the wear rate is high, and the life is short, making it difficult to achieve the goal of "one-trip drilling" of the horizontal section. Summary of the invention

[0004] The present application aims to at least to some extent solve the problem of low drilling efficiency and short drilling life when drilling dense and hard rock formations. To this end, the present application provides a drill bit. It includes:

[0005] a drill body having a crown;

[0006] A plurality of main blades and a plurality of auxiliary blades are connected to the crown and are alternately spaced around the crown;

[0007] A plurality of sharp round teeth and a plurality of circular teeth are connected to the main blade in a row, the exposed height of the circular teeth is lower than the sharp round teeth, and in the rotational cutting direction of the sharp round teeth, the circular teeth are located behind the sharp round teeth;

[0008] A plurality of rotating teeth are connected to the auxiliary blade wing at intervals and have an exposed height higher than the pointed round teeth. The rotating teeth include a connecting portion connected to the auxiliary blade wing and a rotating portion rotatably connected to the connecting portion, and the rotating portion is used for cutting.

[0009] In some embodiments provided by the present application, the pointed round tooth includes a tooth root portion connected to the main blade wing, and a cutting portion connected to the tooth root portion for cutting, the cross-sectional area of ​​the cutting portion is smaller than the cross-sectional area of ​​the tooth root portion, and the pointed round tooth further includes:

[0010] A plurality of transition slopes are connected to transition the cutting portion and the tooth root portion, and the plurality of transition slopes are distributed at intervals around the tooth root portion.

[0011] In some embodiments provided in the present application, the tooth root portion is columnar, the cutting portion is located at one end of the tooth root portion away from the main blade, and is a centrally divergent structure, and the cutting portion points in the direction of the tooth root portion, and the cross-sectional area of ​​the cutting portion is reduced.

[0012] In some embodiments provided in the present application, there is a gap between two adjacent pointed circular teeth, and the gap is opposite to the circular teeth located behind the pointed circular teeth.

[0013] In some embodiments provided in the present application, the connecting portion and the rotating portion are both rotating bodies, the rotating portion surrounds the connecting portion and rotates with the connecting portion, and the rotating tooth further includes:

[0014] An annular groove is provided on the rotating portion and surrounds the axis of the connecting portion.

[0015] In some embodiments provided in the present application, the back tilt angle of the pointed round teeth is smaller than the back tilt angle of the circular teeth.

[0016] In some embodiments provided in the present application, the length of the main blade wing is greater than the length of the auxiliary blade wing, and the width of the main blade wing is greater than the thickness of the auxiliary blade wing.

[0017] In some embodiments provided in the present application, the drill bit body is further provided with a gauge protection portion, and the drill bit further comprises:

[0018] A plurality of shock absorbing teeth are connected to the connection between the gauge protection part and the main blade wing and the auxiliary blade wing, and the end surface of the shock absorbing teeth is flush with the gauge protection surface of the gauge protection part.

[0019] In some embodiments provided in the present application, the width of the gauge protection portion close to the crown is greater than the width of the gauge protection portion away from the crown.

[0020] In some embodiments provided in the present application, the main blade is provided with a semicircular groove between two adjacent cutting teeth for passing mud, and the cutting teeth include the pointed round teeth and the circular teeth.

[0021] The embodiments of the present application have at least the following beneficial effects:

[0022] A plurality of main blades and auxiliary blades are connected around the crown of the drill bit body and arranged alternately at intervals, which is convenient for the connection of the cutting teeth and the rotational cutting of the drill bit as a whole. The main blade is provided with rows of sharp round teeth and circular teeth. The cross-sectional area of ​​the part used for cutting by the sharp round teeth is smaller. Compared with the traditional circular teeth, the force-bearing area can be reduced, and the ability to cut into the formation is improved by point impact. The exposed height of the circular teeth connected to the same main blade is lower than that of the sharp round teeth, and in the rotational cutting direction of the sharp round teeth, the circular teeth are located behind the sharp round teeth. The circular teeth located behind the sharp round teeth will not affect the ability of the sharp round teeth to cut into the bottom layer. The exposed height is lower than that of the sharp round teeth, and it can also ensure that the sharp round teeth can be assisted in cutting when the wear of the sharp round teeth is large. Avoid a large reduction in machine speed and effectively improve the single-pass footage of the drill bit. The rotating teeth arranged on the auxiliary blade are connected to the auxiliary blade through a connecting part, and the rotating part rotatably connected to the connecting part can be used for cutting. The rotating part of the rotating teeth higher than the sharp round teeth will also rotate and cut when the drill bit is used. The rotating teeth will wear evenly. This structure can increase the pressure at the cutting point and improve the ability to cut into the formation. The sharp round teeth can improve the ability to cut into the formation and the cutting ability. The circular teeth with low exposure height can assist in cutting when the sharp round teeth are consumed more, and extend the overall cutting life. The rotating teeth can assist in cutting and increase the cutting ability. The rotating part rotates for cutting. Each position of the rotating part that cuts off the bottom layer can be used for cutting, which is beneficial to extend the service life of the drill bit as a whole. The sharp round teeth and circular teeth are located on the main blade, and the rotating teeth are located on the auxiliary blade. The cutting teeth arranged on each blade are more reasonable, and the cutting rate is higher. The sharp round teeth, circular teeth and rotating teeth are all cutting teeth of the drill bit. The overall composite cutting can improve the cutting efficiency while extending the service life of the drill bit, which is beneficial to improve the drilling efficiency and service life. To a certain extent, it solves the problem of low drilling efficiency and short service life when drilling dense and hard rock formations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A front view of a drill bit provided for this application.

[0024] Figure 2 A top view of a drill bit provided in this application.

[0025] Figure 3 A schematic diagram of the structure of a pointed round tooth provided in this application.

[0026] Figure 4 A side view of a sharp round tooth provided in this application.

[0027] Figure 5 A schematic diagram of the structure of a rotating tooth provided in this application.

[0028] Figure 6 A partial cross-sectional view of a rotating tooth provided in the present application.

[0029] Figure 7 A schematic diagram of the back tilt angle of a circular tooth provided in this application.

[0030] Explanation of the reference numerals: 1. drill body; 11. crown; 12. gauge protection part; 13. joint; 2. main blade; 21. body; 22. ball holder; 23. semicircular groove; 3. auxiliary blade; 4. pointed round teeth; 41. tooth root; 42. cutting part; 43. transition slope; 5. circular teeth; 6. rotating teeth; 61. connecting part; 62. rotating part; 63. annular groove; 64. rotating body; α, back tilt angle; 7. damping teeth; 8. gauge protection teeth; 9. chip removal groove; 10. nozzle. DETAILED DESCRIPTION

[0031] In order to enable technicians in the technical field to which the present application belongs to understand the present application more clearly, the technical solution of the present application is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0032] Figure 1 A front view of a drill bit provided for this application, Figure 2 A top view of a drill bit provided in this application, referring to Figure 1 and Figure 2 In the embodiment of the present application, the drill bit includes a drill bit body 1, a plurality of main blades 2, auxiliary blades 3, pointed round teeth 4, circular teeth 5 and rotating teeth 6.

[0033] The drill body 1 is provided with a crown 11 .

[0034] The plurality of primary blades 2 and the plurality of secondary blades 3 are connected to the crown 11 and are alternately spaced and distributed around the crown 11 .

[0035] A plurality of sharp round teeth 4 and a plurality of circular teeth 5 are connected to the main blade 2 in a row, the exposed height of the circular teeth 5 is lower than that of the sharp round teeth 4, and in the rotational cutting direction of the sharp round teeth 4, the circular teeth 5 are located behind the sharp round teeth 4.

[0036] A plurality of rotating teeth 6 are connected to the auxiliary blade wing 3 at intervals, and the exposed height is higher than the sharp round teeth 4. The rotating teeth 6 include a connecting portion 61 connected to the auxiliary blade wing 3, and a rotating portion 62 rotatably connected to the connecting portion 61, and the rotating portion 62 is used for cutting.

[0037] A plurality of main blades 2 and auxiliary blades 3 are connected around the crown 11 of the drill bit body 1 and are arranged alternately and at intervals, which is convenient for the connection of the cutting teeth and the rotational cutting of the drill bit as a whole. The main blade wing 2 is provided with rows of sharp round teeth 4 and circular teeth 5. The cross-sectional area of ​​the part where the sharp round teeth 4 are used for cutting is smaller. Compared with the traditional circular teeth 5, the force-bearing area can be reduced, and the ability to cut into the formation can be improved by using point impact. The exposed height of the circular teeth 5 connected to the same main blade wing 2 is lower than that of the sharp round teeth 4, and in the rotational cutting direction of the sharp round teeth 4, the circular teeth 5 are located behind the sharp round teeth 4. The circular teeth 5 located behind the sharp round teeth 4 will not affect the ability of the sharp round teeth 4 to cut into the bottom layer. The exposed height is lower than that of the sharp round teeth 4, and it can also ensure that the sharp round teeth 4 can be assisted in cutting when the wear of the sharp round teeth 4 is large. Avoid a large reduction in machine speed and effectively improve the single-pass footage of the drill bit. The rotating teeth 6 arranged on the auxiliary blade wing 3 are connected to the auxiliary blade wing 3 through the connecting portion 61, and the rotating portion 62 rotatably connected to the connecting portion 61 can be used for cutting. The rotating part 62 of the rotating teeth 6, which is higher than the sharp round teeth 4, will also rotate and cut when the drill bit is in use. The rotating teeth 6 will wear evenly, and this structure can increase the pressure at the cutting point and improve the ability to cut into the formation. The sharp round teeth 4 improve the ability to cut into the formation, which can improve the cutting ability. The circular teeth 5 with a low exposed height can assist in cutting when the sharp round teeth 4 are consumed more, and extend the overall cutting life. The rotating teeth 6 can assist in cutting and increase the cutting ability, and the rotating part 62 rotates for cutting. Each position of the rotating part 62 that is cut with the bottom layer can be used for cutting, which is beneficial to extend the service life of the drill bit as a whole. The sharp round teeth 4 and the circular teeth 5 are located on the main blade 2, and the rotating teeth 6 are located on the auxiliary blade 3. The cutting teeth arranged on each blade are more reasonable, and the cutting rate is higher. The rotating teeth 6 can participate in cutting the rock as a whole, achieve uniform wear, reduce local transition wear, increase the service life of the drill bit, and effectively increase the single-trip footage of the drill bit. The sharp round teeth 4, the circular teeth 5 and the rotating teeth 6 are all cutting teeth of the drill bit. The overall composite cutting can improve the cutting efficiency and extend the service life of the drill bit, which is beneficial to improve the drilling efficiency and service life. To a certain extent, it solves the problem of low drilling efficiency and short service life when drilling dense and hard rock formations.

[0038] It should be noted that the rotational cutting direction refers to the cutting direction of the cutting teeth on the drill bit on the formation when the drill bit rotates, which is usually counterclockwise or clockwise. The sharp round teeth 4, the circular teeth 5 and the rotating teeth 6 are all the cutting teeth of the drill bit in this application, and the main blade wing 2 and the auxiliary blade wing 3 are all the blade wings of the drill bit. This application does not limit this.

[0039] In some embodiments provided in this application, the drill bit may be a polycrystalline diamond composite drill bit, which has a better cutting effect. In some embodiments provided in this application, the drill bit may also be other drill bits, which is not limited in this application.

[0040] Figure 3 A schematic diagram of the structure of a pointed round tooth provided in this application. Figure 4 A side view of a sharp round tooth provided in this application. Figure 3 and Figure 4 In some embodiments provided in the present application, the sharp round tooth 4 includes a tooth root portion 41 connected to the main blade 2, and a cutting portion 42 connected to the tooth root portion 41 for cutting, and the cross-sectional area of ​​the cutting portion 42 is smaller than the cross-sectional area of ​​the tooth root portion 41. The sharp round tooth 4 also includes a plurality of transition slopes 43.

[0041] The plurality of transition inclined surfaces 43 connect the transition cutting portion 42 and the tooth root portion 41 , and the plurality of transition inclined surfaces 43 are distributed at intervals around the tooth root portion 41 .

[0042] The cross-sectional area of ​​the cutting portion 42 of the sharp round teeth 4 is smaller than the cross-sectional area of ​​the tooth root portion 41, and a plurality of transition slopes 43 are connected between the cutting portion 42 and the tooth root portion 41, which can increase the point impact of the sharp round teeth 4 while ensuring the overall cutting strength and cutting life of the sharp round teeth 4. This improves the overall cutting ability and service life of the drill bit. Under the same drilling pressure, the transition slope 43 can increase the pressure of the sharp round teeth 4 at this location, making it easier to penetrate into the formation.

[0043] In some embodiments provided in the present application, the tooth root portion 41 is columnar, the cutting portion 42 is located at one end of the tooth root portion 41 away from the main blade 2, and is a centrally divergent structure, and the cutting portion 42 points in the direction of the tooth root portion 41, and the cross-sectional area of ​​the cutting portion 42 is reduced.

[0044] The columnar tooth root 41 can be easily connected to the blade. The cutting portion 42 is a central divergent structure, and the cutting portion 42 points in the direction of the tooth root 41, and the cross-sectional area of ​​the cutting portion 42 is reduced. The cutting portion 42 itself has a relatively good ability to cut into the formation. The cutting ability of the sharp round teeth 4 is improved to improve the cutting ability of the drill bit as a whole.

[0045] It should be noted that the central divergent structure is a structure that diverges from one point to the surroundings in a plane. The center of the central divergent structure may be on the axis of the columnar tooth root 41. The cutting ability and strength of the sharp round teeth 4 can be guaranteed.

[0046] In certain embodiments provided in the present application, the pointed round teeth 4 may also be configured to have a pyramidal or other shapes at the top, and the present application does not impose any limitation on this.

[0047] In some embodiments provided by the present application, there is a gap between two adjacent sharp round teeth 4, and the gap is opposite to the circular teeth 5 located behind the sharp round teeth 4. The circular teeth 5 are opposite to the gap between the two sharp round teeth 4, so when the sharp round teeth 4 are cutting, the circular teeth 5 exposed from the gap can also play a certain cutting role. After the sharp round teeth 4 are further penetrated into the formation, the sharp round teeth 4 and the circular teeth 5 as a whole can improve the ability to damage the formation. This is conducive to improving cutting efficiency.

[0048] It should be noted that, even if no gap is provided between the sharp round teeth 4, or the gap between the circular teeth 5 and the sharp round teeth 4 is not in a relative state, the cutting ability of the drill bit relative to the traditional drill bit can also be improved.

[0049] Figure 5 A schematic diagram of the structure of a rotating tooth provided in this application. Figure 6 A partial cross-sectional view of a rotating tooth provided in the present application. Figure 6 and Figure 7 In some embodiments provided in the present application, the connecting portion 61 and the rotating portion 62 are both rotating bodies, the rotating portion 62 surrounds the connecting portion 61 and rotates with the connecting portion 61, and the rotating tooth 6 further includes an annular groove 63. The annular groove 63 is provided on the rotating portion 62 and surrounds the axis of the connecting portion 61.

[0050] The connecting part 61 and the rotating part 62 are both rotating bodies, which can facilitate the connection and cutting of the rotating teeth 6. The annular groove 63 added to the rotating part 62 can increase the surface area of ​​the rotating part 62, so that different parts contact the rock formation, improve the cooling effect of the rotating teeth 6, and avoid the unstable performance of the rotating teeth 6 caused by high temperature.

[0051] In some embodiments provided in the present application, the cross section of the annular groove 63 may be an inverted triangle, and the sharp corner of the inverted triangle may be in the shape of an arc transition, so as to facilitate chip removal.

[0052] In some embodiments provided by the present application, the rotational cooperation between the rotating part 62 and the connecting part 61 can be achieved by a rotating body 64, which is a part of the rotating tooth 6, and the rotating body 64 is located between the rotating part 62 and the connecting part 61. The rotating body 64 and the connecting part 61 can be a ring-shaped groove and a ring-shaped protrusion to achieve rotation. Or the peripheral wall of the connecting part 61 is provided with an annular groove, the rotating body 64 is sleeved in the annular groove, and the rotating part 62 is fixedly connected to the rotating body 64. This application does not limit this.

[0053] In some embodiments provided in the present application, the back rake angle α of the sharp round teeth 4 is smaller than the back rake angle α of the round teeth 5. When the drill bit is cutting, the cutting directions are the same, which is beneficial to improving the cutting efficiency.

[0054] In certain embodiments provided in the present application, the inclination angles α of the pointed round teeth 4, the circular teeth 5 and the rotating teeth 6 may also be set to be the same or other structures, and the present application does not impose any limitation on this.

[0055] Figure 7 A schematic diagram of the back tilt angle of a circular tooth provided in this application, Figure 7 The inclination angle of the circular tooth 5 can be seen in the figure. For the sake of ease of understanding, it is uniformly marked as α in the following.

[0056] In some embodiments provided in the present application, the main blade 2 is provided with sharp round teeth 4 and round teeth 5 staggered front and back, the sharp round teeth 4 are 13.2 mm thick, 15.88 mm in diameter, the thickness of the polycrystalline diamond layer is 3 mm, and the back rake angle αα of the sharp round teeth 4 is 13° to 15°. The back rake angle α refers to the angle between the cutting plane of the cutting tooth and the normal line, and the distribution spacing between the sharp round teeth 4 is 3.8 mm to 4.2 mm. Compared with traditional round teeth, the sharp round teeth 4 reduce the force-bearing area and use point impact to improve the ability to cut into the formation. The rear row of teeth are circular teeth 56, the thickness of the circular teeth 5 is 8mm, the diameter is 13.44mm, the thickness of the polycrystalline diamond layer is 2mm, the back inclination angle α of the circular teeth 5 is 15°~18°, the distribution spacing of the circular teeth 5 is 3.8mm~4.2mm, and the exposed height is reduced by 2.5mm relative to the sharp round teeth 4. The exposed height refers to the size of the cutting teeth exposed from the drill body 1, which does not affect the ability of the sharp round teeth 4 to cut into the formation, and can also ensure that when the front row of teeth is greatly worn, it can assist in cutting, avoid a large reduction in machine speed, and effectively increase the single-trip footage of the drill bit.

[0057] In some embodiments provided in the present application, the length of the main blade wing 2 is greater than the length of the auxiliary blade wing 3, and the width of the main blade wing 2 is greater than the thickness of the auxiliary blade wing 3. This is beneficial to controlling the overall manufacturing cost of the drill bit, and the overall distribution position is relatively reasonable, ensuring that the distribution range of the sharp round teeth 4 and the circular teeth 5 on the main blade wing 2 is relatively large, and the number of the rotating teeth 6 on the auxiliary blade wing 3 is relatively small, ensuring that the cutting efficiency can be effectively improved.

[0058] In some embodiments provided in the present application, the main blade 2 is provided with a semicircular groove 23 between two adjacent cutting teeth for passing mud, and the cutting teeth include sharp round teeth 4 and round teeth 5. The semicircular groove 23 can reduce the resistance of the formation, facilitate the passage of mud, and improve the cleaning effect of the cutting teeth.

[0059] In some embodiments provided in the present application, the semicircular groove 23 may be located between two adjacent sharp round teeth 4, or between two adjacent round teeth 5, or between a sharp round tooth 4 and a round tooth 5. The present application does not limit this.

[0060] In some embodiments provided in the present application, the depth of the semicircular groove 23 can be 2-3 mm. This reduces resistance and facilitates the passage of mud. Figure 2, the semicircular groove 23 can also be arranged on the secondary blade wing 3. This application does not limit this.

[0061] In certain embodiments provided in the present application, a chip groove 9 may be formed between the primary blade wing 2 and the secondary blade wing 3, and a nozzle 10 of the drill bit may be disposed in the chip groove to flush and cool the cutting teeth.

[0062] In some embodiments provided in the present application, the drill bit includes three main blades 2 and two auxiliary blades 3. The position distribution is relatively reasonable, and the overall force balance of the drill bit is good.

[0063] In some embodiments provided in the present application, the drill bit body 1 can be connected to a joint 13; the drill bit body 1 and the joint 13 can be integrally formed. The drill bit body 1 can be connected to a device having a power mechanism through the joint 13. After the drill bit is lowered to the wellbore, the power mechanism can drive the drill bit to rotate and cut. The drill bit body 1, the blade and the joint 13 adopt an integrated structure, which shortens the overall height of the drill bit, improves the inclination efficiency, reduces the time for adjusting the well inclination, and improves the mechanical drilling speed.

[0064] In some embodiments provided in the present application, the drill bit body 1 is further provided with a gauge protection portion 12 , and the drill bit further includes a plurality of shock-absorbing teeth 7 .

[0065] A plurality of damping teeth 7 are connected to the connection between the gauge protection part 12 and the main blade wing 2 and the auxiliary blade wing 3, and the end surface of the damping teeth 7 is flush with the gauge protection surface of the gauge protection part 12. The damping teeth 7 can improve the contact point with the well wall, and when the drill bit vibrates due to the unbalanced effect, part of the unbalanced force is offset to reduce the frequency of the whirling vibration.

[0066] In some embodiments provided in the present application, the width of the gauge portion 12 close to the crown 11 is greater than the width of the gauge portion 12 away from the crown 11. This can prevent the lower portion of the gauge portion 12 from contacting the well wall, reducing the resistance of the drill bit during rotation and cutting.

[0067] In some embodiments provided in the present application, the width of the gauge guard portion 12 close to the crown 11 is the same as the wellbore size, and the width of the gauge guard portion 12 away from the crown 11 is 4 mm smaller than the width of the gauge guard portion 12 close to the crown 11, forming a stepped form, and gauge guard teeth 8 are provided on the gauge guard.

[0068] It should be noted that the width of the gauge-guarding portion 12 is a width perpendicular to the axial direction of the drill bit.

[0069] In some embodiments provided in the present application, the main blade 2 includes a main body 21 and a hemispherical ball holder 22 .

[0070] The body 21 is connected to the crown 11. The curved surface of the hemispherical ball holder 22 is connected to the body 21, and the flat surface is used to connect with the sharp round teeth 4 or the circular teeth 5. The ball holder 22 can be integrally formed with the drill body 1 to improve the support strength, reduce the deformation during the cutting process, and ensure the cutting efficiency.

[0071] It should be noted that the parallel or perpendicular mentioned in the present application is relative to the concept of absolute parallel or absolute perpendicular in geometry, and a deviation of 0 to 5° is allowed, and the present application does not impose any limitation on this.

[0072] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0073] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A drill bit, characterized in that: include: a drill body having a crown; A plurality of main blades and a plurality of auxiliary blades are connected to the crown and are alternately spaced around the crown; A plurality of sharp round teeth and a plurality of circular teeth are connected to the main blade in a row, the exposed height of the circular teeth is lower than the sharp round teeth, and in the rotational cutting direction of the sharp round teeth, the circular teeth are located behind the sharp round teeth; A plurality of rotating teeth are connected to the auxiliary blade wing at intervals and have an exposed height higher than the pointed round teeth. The rotating teeth include a connecting portion connected to the auxiliary blade wing and a rotating portion rotatably connected to the connecting portion, and the rotating portion is used for cutting.

2. The drill bit according to claim 1, characterized in that The pointed round tooth comprises a tooth root portion connected to the main blade wing, and a cutting portion connected to the tooth root portion and used for cutting, wherein the cross-sectional area of ​​the cutting portion is smaller than the cross-sectional area of ​​the tooth root portion, and the pointed round tooth further comprises: A plurality of transition slopes are connected to transition the cutting portion and the tooth root portion, and the plurality of transition slopes are distributed at intervals around the tooth root portion.

3. The drill bit according to claim 2, characterized in that The tooth root is columnar, the cutting portion is located at one end of the tooth root away from the main blade, and is a central divergent structure. The cutting portion points in the direction of the tooth root, and the cross-sectional area of ​​the cutting portion decreases.

4. The drill bit according to any one of claims 1 to 3, characterized in that: There is a gap between two adjacent pointed circular teeth, and the gap is opposite to the circular teeth located behind the pointed circular teeth.

5. The drill bit according to any one of claims 1 to 3, characterized in that: The connecting part and the rotating part are both rotating bodies, the rotating part surrounds the connecting part and rotates with the connecting part, and the rotating tooth further includes: An annular groove is provided on the rotating portion and surrounds the axis of the connecting portion.

6. The drill bit according to any one of claims 1 to 3, characterized in that: The back-rake angle of the pointed round teeth is smaller than the back-rake angle of the circular teeth.

7. The drill bit according to any one of claims 1 to 3, characterized in that: The length of the main blade wing is greater than the length of the auxiliary blade wing, and the width of the main blade wing is greater than the thickness of the auxiliary blade wing.

8. The drill bit according to any one of claims 1 to 3, characterized in that: The drill bit body is also provided with a gauge protection portion, and the drill bit further comprises: A plurality of shock absorbing teeth are connected to the connection between the gauge protection part and the main blade wing and the auxiliary blade wing, and the end surface of the shock absorbing teeth is flush with the gauge protection surface of the gauge protection part.

9. The drill bit according to claim 8, characterized in that The width of the gauge-guaranteed portion close to the crown is greater than the width of the gauge-guaranteed portion away from the crown.

10. The drill bit according to any one of claims 1 to 3, characterized in that: The main blade is provided with a semicircular groove between two adjacent cutting teeth for passing mud, and the cutting teeth include the pointed round teeth and the circular teeth.

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