Self-sharpening high-efficiency pdc bit

Abstract

The utility model discloses a self-sharpening high -efficient PDC drill bit in the field of well drilling tool, including drill head body and install on the drill head body drill head crown, the drill head crown top is provided with a plurality of blade wing, and is provided with a plurality of drill water eyes between two adjacent blade wings, is provided with the nozzle in the drill water eye, and the rake face of each blade wing is provided with a plurality of cutting tooth layers, and a plurality of cutting tooth layers are arranged and set up along the longitudinal direction of blade wing and present the stepped type, and each cutting tooth layer includes a plurality of cutting teeth, the drill head body includes the drill head female buckle and the drill head male buckle of integrative connection setting, the drill head female buckle is coaxial with the drill head crown and sets up, and the included angle between the central axis of drill head male buckle and the central axis of drill head crown is alpha. The utility model can effectively improve the service life and drilling efficiency of PDC drill bit.

Description

Technical Field

[0001] This utility model belongs to the field of drilling tool technology, and specifically relates to a self-sharpening high-efficiency PDC drill bit. Background Technology

[0002] In the fields of oil and gas drilling and mineral exploration, drill bits are key tools for breaking rocks during drilling operations, and they are a significant factor affecting drilling speed, efficiency, and cost. PDC (Polycrystalline Diamond Compact Bit) drill bits are a widely used drilling tool. PDC drill bits use polycrystalline diamond composite plates as cutting teeth, offering advantages such as high wear resistance, high drilling speed, and long service life.

[0003] Existing technology discloses an air-lift reverse circulation PDC drill bit, publication number: CN114718468A, application date: 2022-03-24. It includes a drill bit body, with a shackle groove on the lower outer wall, a central water hole at the lower center, and five drill bit water holes on the upper inner part. A cutter wing is mounted on the upper outer wall of the drill bit body, with gauge-protecting teeth installed in the lower part of the cutter wing, and PDC teeth fixedly mounted on the upper part of the cutter wing. Through the design of the drill bit body, a cuttings discharge channel is directly formed. Diamond composite sheets are embedded in the matrix, replacing the crushing action of rock breaking with shearing, resulting in more stable performance and faster mechanical advance. The drill bit water holes on the PDC drill bit body bring the rock cuttings generated during drilling to the surface. The direct formation of the cuttings discharge channel in the drill bit body avoids damage caused by secondary processing similar to that of roller cone drill bits, thus improving the service life of the drill bit. Its shortcomings are: after the single-row distributed cutting teeth wear down, the unworn cutting teeth have to bear a larger rock-breaking area, the contact area between the drill bit and the formation increases sharply, the mechanical drilling speed drops accordingly, affecting drilling efficiency, and when all the PDC cutting teeth in the area covered by the drill bit crown are worn down, the drill bit will soon experience circumferential cutting or core removal, and will be unable to continue drilling. Utility Model Content

[0004] The purpose of this invention is to provide a self-sharpening, high-efficiency PDC drill bit that can effectively improve the service life and drilling efficiency of PDC drill bits.

[0005] The purpose of this utility model is achieved as follows: A self-sharpening high-efficiency PDC drill bit includes a drill bit body and a drill bit crown mounted on the drill bit body. The top of the drill bit crown is provided with multiple blades, and a plurality of drill water holes are provided between two adjacent blades. A nozzle is provided in each drill water hole. The rake face of each blade is provided with multiple cutting tooth layers. The multiple cutting tooth layers are arranged in a stepped manner along the longitudinal direction of the blade. Each cutting tooth layer includes multiple cutting teeth. The drill bit body includes a drill bit female thread and a drill bit male thread integrally connected. The drill bit female thread is coaxially arranged with the drill bit crown. The angle between the central axis of the drill bit male thread and the central axis of the drill bit crown is α.

[0006] When this utility model is in use, the multi-layered cutting teeth arranged in a stepped pattern on the rotating drive blades cut the formation sequentially (the inner teeth are exposed after the outer teeth wear down). At the same time, high-pressure drilling fluid is sprayed from nozzles between adjacent blades to cool the cutting teeth and remove rock cuttings. The integrated drill bit body ensures the reliability of the connection with the drill bit crown. The male thread axis is designed with an angle between the male thread axis and the drill bit crown axis, so that the drill bit generates worm-like vibration due to the bending shaft during drilling, which improves the rock breaking efficiency and ultimately achieves the effect of continuous self-sharpening cutting and efficient rock breaking.

[0007] Compared with existing technologies, the beneficial effects of this utility model are as follows: the cutting teeth on the rake face of the cutter wing are arranged in a stepped manner along the longitudinal direction, forming multiple cutting units with different heights. This allows the outer cutting teeth to preferentially contact the formation and gradually wear down, while the inner cutting teeth can be exposed and engaged in cutting in sequence, achieving a "self-sharpening" function. Compared with the traditional single-plane or uniformly heighted cutting tooth arrangement, the stepped structure effectively extends the overall effective cutting cycle of the drill bit, avoiding the problem of a sudden drop in the overall performance of the drill bit due to the rapid wear and failure of the outer teeth. Each cutting tooth layer contains multiple cutting teeth, and the stepped arrangement makes the cutting depth and force distribution of different layers of teeth more uniform. The outer teeth bear the initial cutting, and the inner teeth gradually take over the force as they wear down. The instantaneous load on a single tooth is dispersed, reducing the risk of local overload wear and significantly extending the overall life of the cutting teeth. Due to the presence of the curved shaft, the drill bit generates worm-like vibration during rotary drilling, improving the efficiency of breaking hard and dense rock. In addition, the worm-like vibration caused by the curved shaft causes the drill bit to oscillate laterally / axially, which dynamically changes the gap between the cutter blades and the bottom of the well and disturbs the cuttings bed, forming a pumping effect and fluid turbulence, enhancing the ability to carry cuttings into the annulus. On the other hand, it causes the cutting teeth to periodically detach from the formation contact, allowing the drilling fluid to directly impact the tooth surface and form a circumferential vortex, significantly improving the heat exchange efficiency between the cooling medium and the cutting teeth, thereby simultaneously enhancing the cuttings removal and drilling fluid cooling effects.

[0008] As a further improvement of this utility model, the bottom outer periphery of the drill bit crown is provided with an external thread, the drill bit female thread is provided with a cavity for accommodating the bottom of the drill bit crown, the inner wall of the cavity is provided with an internal thread that mates with the external thread, and the drill bit male thread is a conical structure with an external thread on its outer periphery.

[0009] As a further improvement of this utility model, the drill bit male thread has a hollow interior forming a water inlet chamber with openings at both ends. The drill bit crown has a resonant cavity communicating with the water inlet chamber and a flow divider cavity communicating with the resonant cavity along its own axis. The flow divider cavity is connected to the drill bit water eye through a flow channel.

[0010] As a further improvement of this utility model, the upper and lower ends of the water inlet chamber are respectively provided with an expanding conical hole and a contracting conical hole, and the inner diameter of the resonant cavity is larger than the inner diameter of the water inlet chamber.

[0011] As a further improvement of this utility model, a conical expansion cavity is provided at the connection between the resonant cavity and the shunt cavity, and the inner diameter of the shunt cavity is larger than the inner diameter of the resonant cavity.

[0012] As a further improvement of this utility model, the end face of the drill bit crown corresponding to the drill bit nut is provided with a shoulder.

[0013] As a further improvement of this utility model, each of the blades has at least two rows of cutting teeth on its front face.

[0014] As a further improvement of this utility model, multiple cutting teeth in the cutting tooth layer are arranged in a single row in a staggered manner according to the principle of equal cutting.

[0015] As a further improvement of this utility model, the material, shape and size of each cutting tooth in each cutting tooth layer may be the same or different.

[0016] As a further improvement of this utility model, the wear rate of the blade along its longitudinal direction in each region is consistent with the wear rate of the cutting tooth layer. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure along direction A in Embodiment 1 of this utility model.

[0018] Figure 2 for Figure 1 Sectional view at point BB.

[0019] Figure 3 for Figure 1 Sectional view at point CC.

[0020] Among them, 1 is the drill bit body, 101 is the female drill bit thread, 102 is the male drill bit thread, 103 is the water inlet chamber, 104 is the enlarged conical hole, 105 is the contracted conical hole, 2 is the drill bit crown, 201 is the cutter wing, 202 is the drill bit water eye, 203 is the cutting tooth layer, 204 is the resonant cavity, 205 is the flow splitting cavity, 206 is the flow channel, 207 is the shoulder, and 208 is the conical enlarged cavity. Detailed Implementation Example

[0021] like Figure 1-3 As shown, a self-sharpening high-efficiency PDC drill bit includes a drill body 1 and a drill crown 2 mounted on the drill body 1. The drill crown 2 has five blades 201 on its top and external threads on its bottom outer periphery. Both the blades 201 and the drill crown 2 are made of steel and are integrally formed; in other embodiments, they can also be independently machined and then assembled. A drill water eye 202 is provided between two adjacent blades 201, and a nozzle is provided inside the drill water eye 202. Each blade 201 has three cutting tooth layers 203 on its rake face, and the three cutting tooth layers 203 are arranged longitudinally along the blade 201. The drill bit features a stepped arrangement; each cutting tooth layer 203 includes multiple cutting teeth. In actual use, by optimizing the material of the blade 201, the geometric parameters of the cutting teeth (such as controlling their exposure height, adjusting the tooth rake angle or side tilt angle), and the overall mechanical distribution, the wear rate of the blade 201 along its longitudinal direction is consistent with the wear rate of the cutting tooth layer 203 during long-term drilling. This ensures that the cutting teeth are always properly supported by the blade 201 and that the blade 201 is effectively utilized by the cutting teeth, thus guaranteeing a good fit between the blade 201 and the cutting tooth layer 203, thereby ensuring the drilling effect of the drill bit.

[0022] Specifically, the drill body 1 includes a drill bit female thread 101 and a drill bit male thread 102 integrally connected. The drill bit female thread 101 is coaxially connected to the drill bit crown 2, and the angle between the central axis of the drill bit male thread 102 and the central axis of the drill bit crown 2 is α. The drill bit female thread 101 is provided with a cavity for accommodating the bottom of the drill bit crown 2, and the inner wall of the cavity is provided with an internal thread that mates with the external thread of the drill bit female thread 101. The drill bit male thread 102 has a conical structure and an external thread on its outer periphery for fixed connection with a power tool.

[0023] The drill bit crown 2 is provided with a shoulder 207 on the end face corresponding to the drill bit female thread 101. By increasing the contact area, the load of the drill bit crown 2 is transferred to the drill bit body 1 more evenly, reducing the risk of the drill bit crown 2 cracking due to excessive local stress.

[0024] The drill bit male thread 102 has a hollow interior forming a water inlet chamber 103 with openings at both ends. The upper and lower ends of the water inlet chamber 103 are respectively provided with an expanding conical hole 104 and a contracting conical hole 105. The drill bit crown 2 has a resonant cavity 204 connected to the water inlet chamber 103 and a flow divider cavity 205 connected to the resonant cavity 204, arranged along its own axis. The flow divider cavity 205 is connected to the drill bit water inlet 202 through a flow channel 206. The inner diameter of the resonant cavity 204 is larger than the inner diameter of the water inlet chamber 103. The contracting conical hole 105, by gradually reducing the cross-sectional area of ​​the flow channel, further accelerates the laminar flow output from the expanding conical hole 104, allowing the fluid to enter the resonant cavity 204 at a higher velocity. The higher inlet velocity enhances the resonance. The fluid inertial force within cavity 204 provides more power for the subsequent resonance effect, ultimately enhancing the intensity of the nozzle jet. The enlarged conical orifice 104 gradually expands the cross-sectional area of ​​the flow channel, converting the kinetic energy of the high-speed fluid into pressure energy. Simultaneously, it reduces the velocity gradient, decreases the frictional resistance between the fluid and the cavity wall, and prevents energy dissipation caused by water impacting the inner wall of the resonant cavity 204. A conical expanding cavity 208 is provided at the connection between the resonant cavity 204 and the diversion cavity 205. The inner diameter of the diversion cavity 205 is larger than that of the resonant cavity 204. The gradually changing cross-section of the conical expanding cavity 208 can prolong the residence time of the fluid in the cavity, making the inlet pressure of the diversion cavity 205 tend to stabilize, providing a basis for subsequent uniform flow diversion. Example

[0025] The difference between this embodiment and Embodiment 1 is that: multiple cutting teeth in the cutting tooth layer 203 are arranged in a single row in a staggered manner according to the principle of equal cutting. The principle of equal cutting means that the key parameters such as cutting load, cutting depth, and cutting force borne by each cutting tooth during rock breaking are kept consistent, so as to avoid premature failure due to excessive load of individual teeth or underutilization of teeth due to insufficient load. The single row in a staggered manner means that in the same longitudinal arrangement area of ​​the same blade 201, multiple cutting teeth are not arranged equidistantly and aligned along a straight line, but are arranged in an asymmetrical layout of "high and low staggered" or "front and back staggered" by offsetting the longitudinal position or circumferential angle, so as to enhance the self-sharpening performance and attack performance of the drill bit and increase the ability of the drill bit cutting teeth to penetrate the formation. Example

[0026] The difference between this embodiment and Embodiment 1 is that the material, shape and size of each cutting tooth in each cutting tooth layer 203 may be the same or different. By "differentiated parameter matching", it can achieve precise adaptation to complex formations, dynamic loads and cutting environments, which can improve the targeted rock breaking efficiency, reduce the risk of local failure of cutting teeth and extend the overall life of the drill bit.

[0027] Working principle: High-pressure drilling fluid first enters from the water inlet chamber 103 inside the drill bit body 1. When flowing through the resonant cavity 204, the energy distribution is optimized due to the fluid resonance effect. Then, it enters the distribution chamber 205 and is evenly distributed to each flow channel 206. Finally, it is sprayed to the bottom of the well in the form of a high-pressure pulse jet through the nozzle in the drill bit water eye 202, realizing the loosening and flushing of rock cuttings. At the same time, the drill bit rotates and advances along the axial direction. Multiple cutting tooth layers 203 on the front face of the cutter blade 201 participate in rock breaking in sequence along the longitudinal direction. The front row of cutting teeth first contacts the rock and completes the initial breaking. As the drilling progresses, the front row of teeth gradually becomes dull due to wear. The stacked cutting tooth layers 203 of the rear row are gradually exposed and take over the cutting function, forming a self-sharpening effect. This ensures that the contact area between the drill bit and the formation is stable and avoids a sharp drop in efficiency due to wear of a single row of teeth. During the cutting process, the high-pressure jet continuously flushes the bottom of the well, carrying the broken rock cuttings to the wellhead in a timely manner, preventing rock cuttings from accumulating and causing secondary wear on the cutting teeth.

[0028] The advantages of this invention are as follows: when the surface cutting teeth of the blade 201 lose their cutting ability due to wear, the lower cutting teeth will be automatically exposed and continue to undertake the rock breaking task, avoiding frequent drill bit replacement and significantly extending the service life of the drill bit; the multi-layer stepped cutting teeth act on the rock in sequence, reducing the load on a single cutting tooth and lowering the risk of tooth breakage; the resonant cavity 204 of this design generates pulse jets through fluid resonance, enhancing the loosening and carrying capacity of rock cuttings; the flow divider 205 ensures uniform water volume in each water hole, avoiding local erosion or insufficient cooling; the optimized flow channel 206 reduces water flow resistance and transfers the high-pressure water's efficient energy to the nozzle, significantly improving the bottom rock clearing effect while preventing drill bit overheating and failure.

[0029] This utility model is not limited to the above embodiments. Based on the technical solutions disclosed in this utility model, those skilled in the art can make some substitutions and modifications to some of the technical features without creative labor, and these substitutions and modifications are all within the protection scope of this utility model.

Claims

1. A self-sharpening high-efficiency PDC drill bit, characterized in that, The drill bit includes a drill body and a drill crown mounted on the drill body. The top of the drill crown is provided with multiple blades, and a number of drill water holes are provided between two adjacent blades. A nozzle is provided in each drill water hole. The rake face of each blade is provided with multiple cutting tooth layers. The multiple cutting tooth layers are arranged in a stepped manner along the longitudinal direction of the blade. Each cutting tooth layer includes multiple cutting teeth. The drill body includes a drill female thread and a drill male thread integrally connected. The drill female thread is coaxial with the drill crown. The angle between the central axis of the drill male thread and the central axis of the drill crown is α.

2. The self-sharpening high-efficiency PDC drill bit according to claim 1, characterized in that, The drill bit crown has an external thread on its outer periphery, and the drill bit female thread has a cavity for accommodating the bottom of the drill bit crown. The inner wall of the cavity has an internal thread that mates with the external thread. The drill bit male thread has a conical structure and an external thread on its outer periphery.

3. The self-sharpening high-efficiency PDC bit of claim 1, wherein, The drill bit has a hollow interior forming a water inlet chamber with openings at both ends. The drill bit crown has a resonant cavity connected to the water inlet chamber along its own axis, and a flow divider cavity connected to the resonant cavity. The flow divider cavity is connected to the drill bit water eye through a flow channel.

4. The self-sharpening high-performance PDC bit of claim 3, wherein, The upper and lower ends of the water inlet chamber are respectively provided with an expanding conical hole and a contracting conical hole, and the inner diameter of the resonant cavity is larger than the inner diameter of the water inlet chamber.

5. The self-sharpening high-efficiency PDC drill bit according to claim 3, characterized in that, A conical expansion cavity is provided at the connection between the resonant cavity and the shunt cavity, and the inner diameter of the shunt cavity is larger than the inner diameter of the resonant cavity.

6. The self-sharpening high-efficiency PDC drill bit according to claim 1, characterized in that, The end face of the drill bit crown corresponding to the drill bit nut is provided with a shoulder.

7. The self-sharpening high-efficiency PDC drill bit according to claim 1, characterized in that, Each blade has at least two rows of cutting teeth on its front face.

8. The self-sharpening high-efficiency PDC drill bit according to claim 1, characterized in that, The multiple cutting teeth within the cutting tooth layer are arranged in a single row in a staggered manner according to the principle of equal cutting.

9. The self-sharpening high-performance PDC bit of Claim 1, wherein, The material, shape, and size of each cutting tooth in each cutting tooth layer may be the same or different.

10. The self-sharpening high-efficiency PDC bit of claim 1, wherein, The wear rate of the blade along its longitudinal direction is consistent with the wear rate of the cutting tooth layer.

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