Sawtooth type PDC drill bit

Abstract

The utility model discloses a sawtooth type PDC drill bit which comprises a connector, and threads are arranged at the left end of the connector. A drill bit body is arranged at the right end of the connector and provided with cutting teeth, a nozzle is arranged in the middle of the right side of the connector, the right side of the nozzle penetrates through the drill bit body, a gauge protection face is arranged on the drill bit body and provided with a shackle device groove position, and the top of a thread is connected to the bottom of a connecting column. The thread adopts 3.650-6TPIV040RPIN3 / 4 'TPFINCL, and the end surface of the tail end of the thread is arranged in an inclined manner; five sets of sawtooth bodies are arranged on the right side of the connector, and the five sets of sawtooth bodies are evenly arranged on the drill bit body in a 34-degree mode. A drill bit body adopts a shallow inner cone, and an outer cone adopts a short parabola crown outline. According to the sawtooth type PDC drill bit, the drill bit body is installed, the overall length of the drill bit body is reduced, then loss caused by media in the transmission process of torsional impact loads can be reduced, and then the drilling efficiency of the drill bit body is improved.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas drilling engineering technology, specifically a sawtooth PDC drill bit. Background Technology

[0002] Serrated PDC drill bits offer multiple advantages in drilling operations, including high-efficiency cutting, strong adaptability, good stability, long service life, and good directional control. These advantages make serrated PDC drill bits an indispensable drilling tool in fields such as oil, gas, and groundwater exploration.

[0003] The existing matrix drill bit body is made by loading tungsten carbide powder of different particle sizes and impregnation metal materials of different proportions into a well-designed graphite mold and then impregnating and sintering it at high temperature without pressure. The sawtooth PDC drill bit produced in this way will suffer losses due to torsional impact loads, resulting in a poor service life.

[0004] To address the aforementioned shortcomings, the deep-sea drilling directional PDC drill bit with publication number CN211230252U employs two rows of cutting teeth on its cutter wing crown, resulting in a compact structure. The cylindrical PDC cutting teeth are conventional cutting teeth, while the conical PDC cutting teeth are positioned slightly higher than the cylindrical PDC cutting teeth. This ensures directional operation during drilling in deep-sea sedimentary rocks, reduces the counter-torque effect of torque acting on the sedimentary rock layer on the PDC drill bit, thereby reducing the drill bit wear rate and increasing the drill bit's service life.

[0005] In the actual use of the PDC drill bit, although the conical PDC cutting teeth can reduce the damage caused by torque, the drill bit is relatively long. As a result, the torsional impact load will be lost during transmission due to the presence of the medium. The farther the transmission distance, the greater the loss, which leads to poor drilling efficiency.

[0006] Therefore, we proposed a sawtooth PDC drill bit that can effectively solve the above problems. Utility Model Content

[0007] The purpose of this invention is to provide a serrated PDC drill bit to solve the problem mentioned in the background art that the drill bits on the market are too long, which leads to the loss of torsional impact load during transmission due to the presence of the medium. The longer the transmission distance, the greater the loss, thus resulting in poor drilling efficiency.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a sawtooth PDC drill bit, including a connector, wherein the left end of the connector is provided with a thread;

[0009] The invention is characterized in that the right end of the connector is provided with a drill bit body, and the drill bit body has cutting teeth, and the middle of the right side of the connector is provided with a nozzle, the right side of the nozzle penetrates the drill bit body, and the drill bit body is provided with a gauge protection surface, and the gauge protection surface has a shackle slot, and the top of the thread is connected to the bottom of the connecting post.

[0010] Preferably, the thread is 3.650-6TPIV040RPIN3 / 4”TPFINCL, and the end face of the thread is inclined.

[0011] Preferably, the right side of the connector is provided with a sawtooth body, and there are five sets of sawtooth bodies, and the five sets of sawtooth bodies are evenly arranged on the drill bit body at a 34-degree angle.

[0012] Preferably, the drill bit body adopts a shallow inner cone and an outer cone with a short parabolic crown profile, and the shoulder shape of the drill bit body is continuously transitioned.

[0013] Preferably, the distance between the right end of the drill bit body and the left end of the connector is shortened by 98 mm, and the drill bit body adopts a steel body design structure with 5 helical blades and 7 water holes.

[0014] Preferably, the cutting teeth are polished and contain a PDC composite sheet with a diameter of 16 mm and a length of 13 mm as the main cutting element, and the cutting teeth also contain a polished PDC composite sheet with a diameter of 13 mm and a length of 8 mm as the auxiliary cutting element. There is a height difference between the main cutting element and the auxiliary cutting element on the cutting teeth.

[0015] Preferably, the back tilt angle of the cutting tooth gradually increases from 15° to 20°, and the side rotation angle of the cutting tooth is taken as an angle perpendicular to the normal of the spiral blade wing line.

[0016] Compared with the prior art, the beneficial effects of this utility model are: the sawtooth PDC drill bit has better efficiency and service life. By reducing the length of the drill bit body, drilling efficiency is improved, and the use of cutting teeth further extends the service life of the drill bit body. The specific details are as follows:

[0017] (1) A drill bit body is provided. By reducing the overall length of the drill bit body, the loss of torsional impact load due to the medium during transmission can be reduced, thereby improving the drilling efficiency of the drill bit body.

[0018] (2) It is equipped with cutting teeth. The smaller cutting angle is conducive to the cutting teeth entering the rock, resulting in higher rock breaking efficiency. The larger back slope angle is conducive to protecting the cutting teeth, thus improving the working life of the cutting teeth.

[0019] (3) It is equipped with threads, and the threads are made of 3.650-6TPIV040RPIN3 / 4”TPFINCL. The end face of the thread is inclined, which improves the sealing performance of the connection between the thread and the connecting post.

[0020] (4) It is equipped with cutting teeth. A saw tooth body is provided on the right side of the connector, and there are five sets of saw tooth bodies. The five sets of saw tooth bodies are evenly arranged on the drill bit body at 34 degrees, which can reduce the stress on the diameter, minimize the occurrence of vibration, and improve the stability of the drill bit body.

[0021] (5) The drill bit body is provided. The drill bit body adopts a shallow inner cone and a short parabolic crown profile for the outer cone. The continuous transition of the shoulder shape of the drill bit body is also provided, which enables the drill bit body to protect the cutting teeth, increase the drill bit body's ability to penetrate hard interlayers and enhance its diameter retention capability. Attached Figure Description

[0022] Figure 1 This is a front view structural diagram of the present invention;

[0023] Figure 2 This is a schematic diagram of the connection structure between the connector and the connecting post of this utility model;

[0024] Figure 3 This is a schematic diagram of the connection structure between the connector and the nozzle of this utility model;

[0025] Figure 4 This is a schematic diagram of the connection structure between the connector and the cutting teeth of this utility model;

[0026] Figure 5 This is a schematic diagram of the connection structure between the cutting teeth and the drill bit body of this utility model;

[0027] Figure 6 This is a schematic diagram of the angle structure of the drill bit body of this utility model.

[0028] In the diagram: 1. Connector; 2. Thread; 3. Drill bit body; 4. Gauge protection surface; 5. Nozzle; 6. Shackle slot; 7. Cutting teeth; 701. Main cutting element; 702. Auxiliary cutting element; 8. Connecting post; 9. Sawtooth body. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] Example 1: A serrated PDC drill bit solves the problem that existing drill bits are too long, leading to losses of torsional impact loads during transmission due to the presence of the medium. The longer the transmission distance, the greater the loss, resulting in poor drilling efficiency. The drill bit body 3 improves drilling stability, thereby increasing drilling efficiency. The following is disclosed:

[0031] The left end of the connector 1 is provided with thread 2; the right end of the connector 1 is provided with drill body 3, and the drill body 3 has cutting teeth 7, and the middle right side of the connector 1 is provided with nozzle 5, the right side of nozzle 5 penetrates the drill body 3, and the drill body 3 is provided with gauge protection surface 4, and the right side of gauge protection surface 4 has a shackle slot 6, the top of thread 2 is connected to the bottom of connecting post 8, the distance between the right end of the drill body 3 and the left end of the connector 1 is shortened by 98MM, and the drill body 3 adopts a steel body design structure with 5 helical blades and 7 water holes, the thread 2 adopts 3.650-6TPIV040RPIN3 / 4”TPFINCL, and the end face of thread 2 is inclined.

[0032] refer to Figure 1 and Figure 2 This shortens the distance from the connecting post 8 to the drill bit body 3 by approximately 98mm, reducing the loss of torsional impact loads transmitted to the drill bit body 3. This avoids losses caused by the presence of the medium during the transmission of torsional impact loads during the use of the drill bit body 3, and more effectively reduces the adhesion of cuttings and mud to the drill bit, forming "mud bags." This protects the drill bit, extends the service life of the drill bit body 3, increases drilling speed, and improves the sealing performance of the thread 2 connection. The sawtooth body 9 structure uses a 5-tooth structure, each tooth at a 34-degree angle, evenly distributed, resulting in a tensile strength of 1213000N for the drill bit body 3. With a torque of 23.78T and a torsional strength of 50.7KN.M, the calculated safety factor of this structure is greater than 2, meeting the safety requirements. The drill bit body 3 adopts a steel drill bit design structure with 5 helical blades and 7 water holes. The helical blades can reduce the stress on the diameter, minimize vibration, and improve the stability of the drill bit. The helical blades can reduce the swirling effect of the drill bit body 3. The helical blade structure disperses the cutting force generated by the cutting teeth 7 when cutting the formation and pointing towards the well wall, reducing the contact stress between the helical blades and the well wall, thus reducing the number of swirling movements of the drill bit body 3.

[0033] Example 2: A serrated PDC drill bit solves the problem of poor lifespan of existing serrated PDC drill bits by using a height difference setting for the cutting teeth 7, thereby improving the service life of the cutting teeth 7. The following is disclosed:

[0034] The right side of the connector 1 is provided with a sawtooth body 9, and there are five sets of sawtooth bodies 9. The five sets of sawtooth bodies 9 are evenly arranged on the drill bit body 3 at a 34-degree angle. The drill bit body 3 adopts a shallow inner cone and an outer cone with a short parabolic crown profile. The shoulder shape of the drill bit body 3 is continuously transitioned. The cutting teeth 7 are polished. The cutting teeth 7 contain a PDC composite sheet with a diameter of 16mm and a length of 13mm as the main cutting element 701. The cutting teeth 7 also contain a polished PDC composite sheet with a diameter of 13mm and a length of 8mm as the auxiliary cutting element 702. There is a height difference between the main cutting element 701 and the auxiliary cutting element 702 on the cutting teeth 7.

[0035] refer to Figures 1 to 6 The drill bit body 3 adopts a dual-protection cutting structure. A 16mm diameter, 13mm long PDC composite sheet is used as the main cutting element 701, with highly polished tooth surfaces to reduce friction that causes rock cuttings to adhere to the cutting tooth surface 7, thus improving rock cuttings transport, reducing torque, and minimizing the possibility of mud buildup. A 13mm diameter, 8mm long polished PDC composite sheet is selected as the auxiliary cutting element 702. The main and auxiliary teeth are arranged with a certain height difference, which is beneficial to the dynamic stability of the drill bit body 3, reduces the rotation of the drill bit body 3, and thus reduces impact damage to the PDC teeth. The function of the auxiliary cutting element 702 is to prevent the drill bit body 3 from penetrating... When the interlayer is soft or hard, the main cutting element 701 is assisted in bearing the impact load, thereby reducing the impact load on the main cutting element 701. The drill body 3 has undergone tooth layout optimization design to achieve the goal of the wear ratio or cutting volume of each cutting tooth 7 being basically equal. Furthermore, a lateral force balance design is adopted. The drill body 3 is designed with cutting teeth 7 extending outward from the center of the drill bit, with the back angle gradually increasing from 15° to 20°. The side rotation angle of the cutting tooth 7 is taken as an angle perpendicular to the normal of the spiral blade wing line, which not only reduces the reverse torque but also maintains the advantage of high mechanical drilling speed. The utilization of the auxiliary cutting element 702 improves the service life of the drill body 3 and the working stability of the drill body 3.

[0036] Example 3: A serrated PDC drill bit solves the problem that the existing nozzle 5 easily damages the cutting blades. By adjusting the azimuth angle of the nozzle 5, damage to the cutting blades can be avoided. The following is disclosed:

[0037] The back tilt angle of the cutting tooth 7 gradually increases from 15° to 20°, and the side rotation angle of the cutting tooth 7 is taken as the angle perpendicular to the normal of the spiral blade wing line;

[0038] refer to Figures 1 to 6The drill bit body 3 is designed with a shallow inner cone and a short parabolic crown profile for the outer cone. The continuous transition of the parabolic shoulder shape of the drill bit body 3 can eliminate concentrated point loads and increase the projection density of the cutting teeth 7 from the nose to the gauge section of the drill bit body 3. This is beneficial for protecting the cutting teeth 7, increasing the drill bit body 3's ability to penetrate hard interlayers, and strengthening its gauge retention capability. The short parabolic outer cone can reduce the contact area between the drill bit body 3 and the well wall, thereby reducing the friction between the drill bit body 3 and the well wall and reducing the vortex of the drill bit body 3 caused by friction with the well wall. The shallow inner cone and short parabolic outer crown shape improve the directional response sensitivity of the drill bit body 3, making it more suitable for directional drilling. Furthermore, adjusting the azimuth angle of the nozzle 5 so that the jet of the nozzle 5 avoids the drill bit blades as much as possible and points towards the larger chip removal groove can reduce the erosion of the cutting teeth 7 and blades by hydraulic energy.

[0039] Working principle: When using this type of serrated PDC drill bit, first, refer to... Figure 1 and Figure 2 The distance between the connecting column 8 and the drill bit body 3 is shortened by about 98mm, resulting in less loss of torsional impact load transmitted to the drill bit body 3. It also more effectively reduces the adhesion of rock cuttings and mud to the drill bit to form "mud bags", protecting the drill bit and improving the service life of the drill bit body 3. The sawtooth body 9 structure adopts a 5-tooth structure, with each tooth at 34 degrees and evenly distributed to meet safety requirements. The drill bit body 3 adopts a steel body drill bit design structure with 5 helical blades and 7 water holes to improve the stability of the drill bit. The helical blades can reduce the rotation of the drill bit body 3 and reduce the contact stress between the helical blades and the well wall, thus reducing the number of rotational movements of the drill bit body 3.

[0040] refer to Figures 1 to 6 The drill bit body 3 adopts a dual-protection cutting structure. It uses a PDC composite plate with a diameter of 16mm and a length of 13mm as the main cutting element 701. The main and auxiliary teeth are arranged with a certain height difference, which is beneficial to the dynamic stability of the drill bit body 3, reduces the rotation of the drill bit body 3, and thus reduces the impact damage of the PDC teeth. The auxiliary cutting element 702 is designed to assist the main cutting teeth 7 in bearing the impact load when the drill bit body 3 passes through soft and hard interlayers, so as to achieve the goal of the wear ratio or cutting volume of each cutting tooth 7 being basically equal. It adopts a lateral force balance design, and the side rotation angle of the cutting tooth 7 is taken as the angle perpendicular to the normal of the spiral blade, which not only reduces the reverse torque, but also maintains the advantage of high mechanical drilling speed. The use of the auxiliary spare cutting teeth 7 improves the service life of the drill bit body 3 and the working stability of the drill bit body 3.

[0041] refer to Figures 1 to 6The drill bit body 3 is designed with a shallow inner cone and a short parabolic crown profile for the outer cone. The continuous transition of the parabolic shoulder shape of the drill bit body 3 can eliminate concentrated point loads, which is beneficial to protect the cutting teeth 7, increase the ability of the drill bit body 3 to penetrate hard interlayers and enhance the ability to maintain diameter, making it more suitable for directional drilling. In addition, the azimuth angle of the nozzle 5 is adjusted so that the jet of the nozzle 5 avoids the drill bit blades as much as possible and points to the larger chip removal groove, which can reduce the erosion of the cutting teeth 7 and blades by hydraulic energy.

[0042] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0043] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A serrated PDC bit, comprising a joint (1), the left end of the joint (1) being provided with a thread (2); characterized in that the right end of the joint (1) being provided with a bit body (3), and the bit body (3) containing cutting teeth (7), and the right middle part of the joint (1) being provided with a nozzle (5), the right side of the nozzle (5) penetrating through the bit body (3), and the bit body (3) being provided with a gage pad (4), and the right side of the gage pad (4) containing a back-off slot (6), the top of the thread (2) being connected to the bottom of a connecting column (8).

2. A sawtooth PDC bit according to claim 1 wherein: The thread (2) adopts 3.650-6TPI V040RPIN3 / 4”TPFINCL, and the end face of the thread (2) is inclined.

3. The sawtooth PDC bit of claim 1, wherein: The right side of the joint (1) is provided with a serrated body (9), and the serrated body (9) is provided with five groups, and the five groups of the serrated body (9) are uniformly arranged on the bit body (3) at 34 degrees.

4. The sawtooth PDC bit of claim 1 wherein: The bit body (3) adopts a shallow inner cone, and the outer cone adopts a short parabolic crown profile, and the continuity of the shoulder shape of the bit body (3) is transitionally arranged.

5. The sawtooth PDC bit of claim 1 wherein: The right end of the bit body (3) is shortened by 98MM from the left end of the joint (1), and the bit body (3) adopts a steel body design structure of 5 helical blades and 7 water eyes.

6. The sawtooth PDC bit of claim 1 wherein: The cutting tooth (7) is polished, and the cutting tooth (7) contains a PDC composite sheet with a diameter of 16mm and a length of 13mm as a main cutting element (701), and the cutting tooth (7) also contains a polished PDC composite sheet with a diameter of 13mm and a length of 8mm as an auxiliary cutting element (702), and the cutting tooth (7) contains a height difference between the main cutting element (701) and the auxiliary cutting element (702).

7. The sawtooth PDC bit of claim 1 wherein: The back rake angle of the cutting tooth (7) gradually increases from 15° to 20°, and the side turning angle of the cutting tooth (7) is the angle perpendicular to the normal line of the helical blade line.

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