Drill bit with self-adaptive telescopic blades

Abstract

According to the drill bit with the self-adaptive telescopic blades, the telescopic blades are arranged at the positions, located at rear row teeth, of at least part of main cutting blades, the first ends of the telescopic blades are connected with telescopic cutting teeth, and the second ends of the telescopic blades are connected with hydraulic power mechanisms; the hydraulic power mechanism controls the axial movement stroke of the telescopic blades along the drill bit body by adjusting the displacement of drilling fluid in the drill bit fluid main channel according to the hardness degree of a stratum. When the telescopic blades axially move by the maximum stroke, the telescopic cutting teeth outwards protrude out of the main cutting teeth in the axial direction, and when the telescopic blades axially move by the minimum stroke, the telescopic cutting teeth inwards protrude out of the main cutting teeth in the axial direction. The drill bit with the self-adaptive telescopic blades can balance the drilling efficiency in soft and hard staggered complex stratums and improve the average mechanical drilling speed of the whole well section, and has the advantages that the stability, the impact resistance and the capacity of penetrating through the soft and hard staggered complex stratums of the drill bit are enhanced.

Description

Technical Field

[0001] This invention relates to the field of oil drilling technology, and more particularly to a drill bit with adaptive retractable blades. Background Technology

[0002] Drilling is a crucial part of oil and gas exploration and development. Drill bits are an indispensable tool in the geological drilling industry. The proper selection of drill bits has a significant impact on oil drilling quality, drilling speed, and drilling costs. Overall, drill bit-related costs account for a considerable portion of total drilling costs; therefore, extending drill bit life and improving drill bit efficiency are among the primary tasks in drilling projects. This is especially true for deep formations with high rock hardness, strong abrasiveness, high anisotropy, and large differences in formation hardness indices, posing challenges to drill bit selection. PDC drill bits are a new type of drilling tool developed with the advancement of composite materials. These drill bits offer long service life and significantly improved drilling efficiency. However, the performance of polycrystalline diamond composite blades (PDC cutting blades) limits the application range of PDC drill bits; PDC cutting blades are only suitable for high-efficiency drilling in soft to medium-hard formations.

[0003] Extensive research has been conducted on drill bit technology for hard formations, abrasive formations, and difficult-to-drill heterogeneous formations in deep drilling, resulting in the development of novel PDC cutting blades. The improvements to the new PDC cutting blades include the following aspects: First, improved working performance and lifespan indicators (e.g., wear ratio, surface roughness, impact resistance) and technological performance indicators (e.g., thermal stability) of the composite blade itself; second, altered the structure of the composite blade, such as thickening the composite blade and developing composite blades with non-planar intersecting surface structures; third, modified the shape of the composite blade, such as wedge-shaped teeth, rectangular teeth, and ball-head teeth. These improvements enable PDC drill bits to adapt to hard formations, abrasive formations, and difficult-to-drill heterogeneous formations.

[0004] During drilling, the lithology varies significantly between different well sections, typically requiring different drill bits and increasing drilling costs. Furthermore, PDC drill bits suffer from severe impact damage failure, low mechanical drilling rate, and poor stability during drilling in complex formations with alternating soft and hard surfaces.

[0005] Therefore, based on years of experience and practice in related industries, the inventor proposes a drill bit with adaptive retractable blades to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a drill bit with adaptive retractable blades, which solves the technical problems in the prior art, such as the need for different drill bits for different well sections, severe impact damage and failure of PDC drill bits, low mechanical drilling rate and poor stability during drilling in complex formations with alternating soft and hard surfaces. The drill bit with adaptive retractable blades of this invention can balance drilling efficiency in complex formations with alternating soft and hard surfaces, improve the average mechanical drilling rate of the entire well section, and has the advantages of enhanced drill bit stability, impact resistance and ability to traverse complex formations with alternating soft and hard surfaces.

[0007] The objective of this invention is achieved as follows: a drill bit with adaptive retractable blades, comprising a drill bit body, wherein a plurality of main cutting blades and a nozzle are provided on the drill bit body, and each of the main cutting blades is provided with a plurality of main cutting teeth; a main fluid channel for the drill bit is provided within the drill bit body, and the nozzle is connected to the main fluid channel for the drill bit.

[0008] At least a portion of the main cutting blades are provided with telescopic blades located at the rear row of teeth, which can extend and retract along the axial direction of the drill bit body. Each telescopic blade has a first end and a second end along the axial direction of the drill bit body. The first end of the telescopic blade is connected to a telescopic cutting tooth, and the second end is connected to a hydraulic power mechanism. The hydraulic power mechanism controls the axial movement of the telescopic blades along the drill bit body by adjusting the drilling fluid discharge rate in the main fluid channel of the drill bit according to the hardness of the formation. When the telescopic blade moves to its maximum axial movement, the telescopic cutting tooth protrudes outward along the axial direction from the main cutting tooth; when the telescopic blade moves to its minimum axial movement, the telescopic cutting tooth is concave inward along the axial direction from the main cutting tooth. A pressure sensing unit is provided on the main cutting blades behind the main cutting tooth. This pressure sensing unit detects the hardness of the formation and feeds back to the drilling fluid discharge control unit via a downhole mud pulse generator to achieve adaptive adjustment of the drilling fluid discharge rate.

[0009] In a preferred embodiment of the present invention, a receiving groove is provided on the drill bit body, and the telescopic cutter blade is slidably and sealingly fitted into the receiving groove along the axial direction of the drill bit body. A hydraulic chamber is formed between the second end of the telescopic cutter blade and the bottom of the receiving groove. The hydraulic power mechanism includes the hydraulic chamber, and the hydraulic chamber is connected to the main fluid channel of the drill bit through a one-way valve control circuit. The hydraulic power mechanism controls the axial movement and extension of the telescopic cutter blade by controlling the liquid pressure in the hydraulic chamber.

[0010] In a preferred embodiment of the present invention, the one-way valve control circuit includes a hydraulic control channel, the first end of which is connected to the main fluid channel of the drill bit, and the second end of which is connected to the hydraulic chamber; a one-way valve is provided in the hydraulic control channel to allow drilling fluid to flow from the main fluid channel of the drill bit to the telescopic cutter blade.

[0011] In a preferred embodiment of the present invention, the one-way valve control circuit further includes at least one fluid distribution channel, the first end of the fluid distribution channel being connected to the hydraulic control channel located downstream of the outlet of the one-way valve, and the second end of the fluid distribution channel being connected to the hydraulic chamber.

[0012] In a preferred embodiment of the present invention, the one-way valve includes a valve cylinder, a valve seat, and a valve body. At least one first sealing unit is provided between the outer wall of the valve cylinder and the inner wall of the hydraulic control channel. The valve body can be seated on the valve seat and can leave the valve seat under the action of drilling fluid. At least one second sealing unit is provided between the valve body and the valve seat.

[0013] In a preferred embodiment of the present invention, a water inlet is provided on at least one side of the telescopic blade on the main cutting blade, the water inlet being able to connect the hydraulic chamber and the ground.

[0014] In a preferred embodiment of the present invention, the telescopic blade includes a telescopic body capable of radial extension and retraction, the bottom of the telescopic body is provided with a first step portion, the inner wall of the receiving groove is provided with a second step portion, and the first step portion can be locked onto the second step portion to limit the telescopic blade.

[0015] In a preferred embodiment of the present invention, the telescopic cutting teeth are polycrystalline diamond cutting teeth.

[0016] In a preferred embodiment of the present invention, the included angles between the plurality of nozzles and the axial direction of the drill bit body are set differently.

[0017] In a preferred embodiment of the present invention, a sleeve short section is connected to the drill bit body, and a hollow threaded short section is connected to the sleeve short section. The inner cavities of the threaded short section and the sleeve short section are in communication with the main fluid channel of the drill bit, and the threaded short section is used to connect to the upper drill rod.

[0018] As described above, the drill bit with adaptive retractable blades of the present invention has the following beneficial effects:

[0019] In the drill bit with adaptive retractable blades of the present invention, by setting retractable blades and a hydraulic power mechanism, the extension length of the retractable blades at the rear row of teeth on the main cutting blade can be adjusted according to the hardness of the formation, and the exposed height of the retractable cutting teeth on the retractable blades can be adjusted. The adaptive adjustment of the retractable blades is achieved through the hydraulic power mechanism. With the help of adaptive drill bit technology, the cutting teeth at the rear row of teeth can be adjusted even without drilling, thereby improving the drill bit's durability.

[0020] The drill bit of this invention, featuring adaptive retractable cutter wings, can balance drilling efficiency in complex formations with alternating soft and hard surfaces, improving the average mechanical rate of penetration (MRP) throughout the well section. It also offers advantages such as enhanced drill bit stability, impact resistance, and the ability to traverse complex formations. Employing an intelligent hydraulic control mechanism, it utilizes data measured at or near the drill bit to automatically optimize and adjust based on the constantly changing dynamic environment, formation characteristics, drilling direction, and other practical conditions during construction. The axial extension and retraction of the main cutting blades are controlled via the retractable cutter wings, thereby improving the MRP, wellbore quality, and directional performance, extending drill bit life, and reducing drilling costs. Attached Figure Description

[0021] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

[0022] Figure 1 This is a schematic diagram of the overall structure of the drill bit with adaptive retractable blades according to the present invention.

[0023] Figure 2 This is a partial cross-sectional view of the drill bit with adaptive retractable blades of the present invention.

[0024] Figure 3 This is a schematic diagram of the drill bit body of the present invention.

[0025] Figure 4 This is a top view of the drill bit body of the present invention.

[0026] Figure 5 This is a schematic diagram of the telescopic blade of the present invention.

[0027] Figure 6 This is a schematic diagram of the one-way valve of the present invention installed in the hydraulic control channel.

[0028] Figure 7 This is a schematic diagram of the one-way valve of the present invention.

[0029] Figure 8 This is a schematic diagram of the telescopic blade of the present invention in its first state.

[0030] Figure 9 This is a schematic diagram of the telescopic blade of the present invention in its second state.

[0031] Figure 10 This is a schematic diagram of the telescopic blade of the present invention in the third state.

[0032] Figure 11 This is a schematic diagram showing the tooth height difference between the telescopic cutting teeth and the main cutting teeth when the telescopic blade is in the third state according to the present invention.

[0033] Figure 12 This is a schematic diagram of the telescopic cutting tooth of the present invention when the tooth shape is a concave tooth.

[0034] Figure 13 This is a schematic diagram of the telescopic cutting tooth of the present invention when the tooth shape is an axe-shaped tooth.

[0035] Figure 14 This is a schematic diagram of the telescopic cutting tooth of the present invention when the tooth shape is a triangular tooth.

[0036] In the picture:

[0037] 1. Drill bit body; 11. Main fluid channel of the drill bit;

[0038] 2. Main cutting blade; 21. Main cutting teeth;

[0039] 3. Nozzle;

[0040] 4. Telescopic blade; 41. Telescopic cutting teeth; 42. Telescopic body; 43. First step section;

[0041] 51. Hydraulic chamber; 52. Hydraulic control channel; 53. Check valve; 531. Valve cylinder; 532. Valve seat; 533. Valve body; 534. First sealing unit; 535. Second sealing unit; 54. Fluid flow distribution channel; 55. Water inlet;

[0042] 6. Sleeve short section;

[0043] 7. Threaded short section. Detailed Implementation

[0044] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0045] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] like Figures 1 to 14 As shown, the present invention provides a drill bit with adaptive retractable blades, including a drill bit body 1, a plurality of main cutting blades 2 and nozzles 3 are provided on the drill bit body 1, and a plurality of main cutting blades 2 are provided on each main cutting blade 2; a drill bit fluid main channel 11 is provided inside the drill bit body 1, and the nozzles 3 are connected to the drill bit fluid main channel 11.

[0048] like Figure 1 , Figure 2 As shown, at least a portion of the main cutting blade 2 is provided with a telescopic blade 4 that can extend and retract along the axial direction of the drill bit body at a position located at the rear row of teeth (the main cutting teeth 21 are located at the front row in the cutting direction, and the cutting teeth located behind them are the rear row of teeth). The telescopic blade 4 has a first end and a second end along the axial direction of the drill bit body 1. The first end of the telescopic blade 4 is connected to the telescopic cutting tooth 41, and the second end of the telescopic blade 4 is connected to a hydraulic power mechanism. The hydraulic power mechanism adjusts the drilling fluid in the main fluid channel of the drill bit according to the hardness of the formation. The displacement size controls the axial movement of the telescopic cutter blade along the drill bit body; when the telescopic cutter blade 4 moves to its maximum axial movement, the telescopic cutting tooth 41 protrudes outward along the axial direction from the main cutting tooth 21, and when the telescopic cutter blade 4 moves to its minimum axial movement, the telescopic cutting tooth 41 is recessed inward along the axial direction from the main cutting tooth 21; a pressure sensing unit is installed on the main cutting blade 2 behind the main cutting tooth (front row of cutting teeth), the pressure sensing unit is used to detect the hardness of the formation and feeds it back to the drilling fluid displacement control unit through the downhole mud pulse generator to achieve adaptive adjustment of the drilling fluid displacement.

[0049] Under the same drilling pressure, in soft formations, the main cutting teeth 21 (front row teeth) on the main cutting blade 2 penetrate the formation to a greater depth, and the pressure surface of the telescopic cutting teeth 41 (located at the rear row teeth position) on the telescopic blade 4 increases. The telescopic blade is in a retracted state, and the telescopic cutting teeth 41 are retracted inside the main cutting blade 2, which does not affect the cutting amount of the main cutting teeth 21 on the main cutting blade 2 during drilling in soft formations. In hard formations, the drill bit penetrates the formation to a smaller depth, and the pressure surface of the telescopic cutting teeth 41 on the telescopic blade 4 decreases, and they are in an extended state, which limits the cutting amount of the main cutting teeth 21 on the main cutting blade 2, stabilizes the torque, and prevents swirl.

[0050] When moving from soft to hard formation, the telescopic blades extend to bear part of the drilling pressure and torque, creating a pre-fracture effect on the rock. This protects the main cutting blade 2, preventing the main cutting teeth 21 from failing or being damaged, which would affect subsequent drilling. When moving from hard to soft formation, the telescopic blades retract, without affecting the cutting amount of the main cutting blade 2 during drilling in soft formation, thus improving cutting efficiency and extending the life of the drill bit.

[0051] In the drill bit with adaptive retractable blades of the present invention, by setting retractable blades 4 and a hydraulic power mechanism, the extension length of the retractable blades at the rear row of teeth on the main cutting blades can be adjusted according to the hardness of the formation, and the exposed height of the retractable cutting teeth on the retractable blades can be adjusted. The adaptive adjustment of the retractable blades is achieved through the hydraulic power mechanism. With the help of adaptive drill bit technology, the cutting teeth at the rear row of teeth can be adjusted even without drilling, thereby improving the drill bit's durability.

[0052] The drill bit of this invention, featuring adaptive retractable cutter wings, can balance drilling efficiency in complex formations with alternating soft and hard surfaces, improving the average mechanical rate of penetration (MRP) throughout the well section. It also offers advantages such as enhanced drill bit stability, impact resistance, and the ability to traverse complex formations. Employing an intelligent hydraulic control mechanism, it utilizes data measured at or near the drill bit to automatically optimize and adjust based on the constantly changing dynamic environment, formation characteristics, drilling direction, and other practical conditions during construction. The axial extension and retraction of the main cutting blades are controlled via the retractable cutter wings, thereby improving the MRP, wellbore quality, and directional performance, extending drill bit life, and reducing drilling costs.

[0053] Furthermore, such as Figure 1 , Figure 2 As shown, a receiving groove is provided on the drill bit body 1, and the telescopic blade 4 can be slidably and sealed in the receiving groove along the axial direction of the drill bit body 1. The second end of the telescopic blade 4 and the bottom of the receiving groove can form a hydraulic chamber. The hydraulic power mechanism includes a hydraulic chamber 51, which is connected to the main fluid channel 11 of the drill bit through a one-way valve control circuit. The hydraulic power mechanism controls the axial movement and extension of the telescopic blade 4 by controlling the liquid pressure in the hydraulic chamber, that is, changing the exposed height of the telescopic blade 4 to ensure the stability of the drill bit during the cutting process.

[0054] Furthermore, such as Figure 1 , Figure 2 As shown, the one-way valve control circuit includes a hydraulic control channel 52, the first end of which is connected to the drill bit fluid main channel 11, and the second end of which is connected to the hydraulic chamber 51; a one-way valve 53 is provided in the hydraulic control channel 52 to allow drilling fluid to flow from the drill bit fluid main channel 11 to the telescopic cutter wing 4.

[0055] Furthermore, such as Figure 1 , Figure 2As shown, the one-way valve control circuit also includes at least one fluid distribution channel 54. The first end of the fluid distribution channel 54 is connected to the hydraulic control channel 52, which is located downstream of the outlet of the one-way valve 53. The second end of the fluid distribution channel 54 is connected to the hydraulic chamber 51.

[0056] Furthermore, such as Figure 6 , Figure 7 As shown, the one-way valve 53 includes a valve cylinder 531, a valve seat 532, and a valve body 533. At least one first sealing unit 534 is provided between the outer wall of the valve cylinder 531 and the inner wall of the hydraulic control channel 52. The valve body 533 can be seated on the valve seat 532 and can leave the valve seat 532 under the action of drilling fluid. At least one second sealing unit 535 is provided between the valve body 533 and the valve seat 532.

[0057] In this embodiment, there are two first sealing units 534, which are arranged vertically and alternately between the outer wall of the valve cylinder 531 and the inner wall of the hydraulic control channel 52. One second sealing unit 535 is arranged between the valve body 533 and the valve seat 532. Both the first sealing unit 534 and the second sealing unit 535 are sealing rings.

[0058] Furthermore, such as Figure 4 As shown, a water inlet 55 is provided on at least one side of the telescopic blade 4 on the main cutting blade 2. The water inlet 55 connects the hydraulic chamber 51 and the formation. When moving from a hard formation to a soft formation, the one-way valve 53 can be closed by reducing the drilling fluid discharge rate during operation. The drilling fluid in the bottom cavity (hydraulic chamber 51) of the telescopic blade can be discharged through the water inlet 55, thereby realizing the retraction of the telescopic blade 4.

[0059] Furthermore, such as Figure 5 As shown, the telescopic cutter wing 4 includes a telescopic body 42 that can extend and retract along the axial direction of the drill bit body. A first step portion 43 is provided at the bottom of the telescopic body 42, and a second step portion is provided on the inner wall of the receiving groove. The first step portion 43 can be locked onto the second step portion to limit the telescopic cutter wing 4. That is, the first step portion 43 and the second step portion are used to control the maximum exposed height of the telescopic cutter wing.

[0060] In this embodiment, the telescopic body 42 is a telescopic block, and a base is provided at the bottom of the block. The base and the block form a first step 43.

[0061] Furthermore, the telescopic cutting tooth 41 is a polycrystalline diamond cutting tooth, which can switch different tooth shapes to adapt to different formations according to formation requirements. The telescopic cutting tooth 41 includes, but is not limited to, concave teeth (such as...). Figure 12 (as shown), conical teeth, axe-shaped teeth (such as...) Figure 13 As shown), triangular teeth (such as...) Figure 14 (as shown in the image) etc.

[0062] Furthermore, the multiple nozzles 3 are set at different angles to the axial direction of the drill bit body 1, which can prevent the front side of the cutting teeth from being covered by mud when the drill bit is drilling, thus ensuring the stability of drilling and improving the efficiency of cuttings transport.

[0063] In this embodiment, there are 9 nozzles 3, which are arranged at intervals along the circumference of the drill bit body 1, with each nozzle 3 located between adjacent blades.

[0064] Furthermore, such as Figure 1 , Figure 2 As shown, a sleeve sub 6 is connected to the drill bit body 1, and a hollow threaded sub 7 is connected to the sleeve sub 6. The inner cavities of the threaded sub 7 and the sleeve sub 6 are connected to the main fluid channel 11 of the drill bit. The threaded sub 7 is used to connect to the upper drill rod (existing technology). The threaded sub 7 is provided with external threads, and the threaded sub 7 is connected to the upper drill rod through threads.

[0065] In this embodiment, the sleeve short section 6 and the threaded short section 7 are connected by welding, and have the same outer diameter as the drill bit body 1 and are concentrically connected.

[0066] Furthermore, the pressure sensing unit can be a pressure sensor, which is electrically connected to the drilling fluid discharge control unit. The drilling fluid discharge control unit adjusts the drilling fluid discharge based on the feedback from the pressure sensor, thereby achieving adaptive adjustment of the extension height of the telescopic cutter blade 4.

[0067] Example 1:

[0068] like Figure 1 , Figure 2 , Figure 3 As shown, in the drill bit with adaptive retractable blades of this embodiment, six blades are arranged on the drill bit body 1, and three retractable blades 4 are distributed at 120° intervals on the three main cutting blades 2.

[0069] The telescopic blade 4 has a first end and a second end along the axial direction of the drill bit body 1. The first end of the telescopic blade 4 is connected to a polycrystalline diamond cutting tooth, which can switch different tooth shapes as needed to adapt to different formations. The second end of the telescopic blade 4 and the bottom of the receiving groove can form a hydraulic chamber 51. The hydraulic chamber 51 is connected to the hydraulic control channel 52, and the hydraulic control channel 52 is equipped with a one-way valve 53, which can control the telescopic blade 4 (telescopic cutting tooth 41) to switch different states according to the hardness of the formation and by adjusting the drilling fluid discharge.

[0070] The one-way valve is located in the hydraulic control channel 52 (plunger water eye) which is connected to the cavity (hydraulic chamber 51) at the bottom of the three telescopic blades 4, and is connected to the main drill fluid channel 11 inside the drill bit body 1. By adjusting the drilling fluid discharge during the construction process, the exposed height of the telescopic blades 4 can be changed.

[0071] like Figure 4 As shown, each of the three telescopic blades 4 has three water inlets 55, for a total of nine water inlets 55. The water inlets 55 connect the hydraulic chamber 51 to the external stratum.

[0072] The telescopic cutter blade 4 and its telescopic cutting teeth 41 can switch between different states by adjusting the drilling fluid discharge rate according to the hardness of the formation.

[0073] In this embodiment, the telescopic blade has three states.

[0074] First state: such as Figure 8 As shown, during drilling in soft formations, the telescopic blade 4 is in a retracted state, which does not affect the cutting amount of the front row of teeth (main cutting teeth 21) of the main cutting blade during the drilling process in soft formations.

[0075] The second state: such as Figure 9 As shown, when drilling encounters low to medium hard strata, the telescopic cutter blade 4 is in its initial extended state, and the height of the telescopic cutting tooth 41 is slightly lower than the height of the main cutting tooth 21, which assists in breaking the rock. In this state, the height of the telescopic cutting tooth 41 is higher than the height of the telescopic cutting tooth 41 in the first state.

[0076] The third state: such as Figure 10 As shown, when encountering hard and difficult-to-drill formations, the telescopic cutting teeth 41 of the telescopic cutter blade 4 are flush with or slightly higher than the main cutting teeth 21 (e.g., Figure 11 As shown in the diagram, this pre-crushes the rock and protects the main cutting tooth 21 from damage. In this state, the height of the telescopic cutting tooth 41 is higher than that in the second state.

[0077] The telescopic blade 4 can switch between the first, second, and third states to achieve different effects.

[0078] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A drill bit having self-adapting retractable blades, characterized by, The drill bit body is provided with a plurality of main cutting blade wings and nozzles, each of the main cutting blade wings is provided with a plurality of main cutting teeth; the drill bit body is provided with a drill bit fluid main channel, and the nozzles are communicated with the drill bit fluid main channel; At least part of the main cutting blade wings is provided with a retractable blade wing which can be extended and retracted along the axial direction of the drill bit body, the retractable blade wing has a first end and a second end along the axial direction of the drill bit body, the first end of the retractable blade wing is connected with a retractable cutting tooth, and the second end of the retractable blade wing is connected with a hydraulic power mechanism; the hydraulic power mechanism controls the axial movement stroke of the retractable blade wing along the drill bit body by adjusting the displacement of the drilling fluid in the drill bit fluid main channel according to the hardness of the stratum; when the retractable blade wing moves to the maximum stroke, the retractable cutting tooth protrudes outward along the axial direction of the main cutting tooth, and when the retractable blade wing moves to the minimum stroke, the retractable cutting tooth is recessed inward along the axial direction of the main cutting tooth; the main cutting blade wing is provided with a pressure sensing unit behind the main cutting tooth, and the pressure sensing unit is used for detecting the hardness of the stratum and feeding back to the drilling fluid displacement control part through the downhole mud pulse generator to realize the adaptive adjustment of the drilling fluid displacement.

2. The drill bit having self-adapting retractable blades of claim 1, wherein, The drill bit body is provided with a containing groove, the retractable blade wing is sealingly sleeved in the containing groove along the axial direction of the drill bit body, and a hydraulic chamber can be formed between the second end of the retractable blade wing and the groove bottom of the containing groove; the hydraulic power mechanism comprises the hydraulic chamber, the hydraulic chamber is connected with the drill bit fluid main channel through a one-way valve control circuit, and the hydraulic power mechanism controls the axial extension and retraction of the retractable blade wing by controlling the liquid pressure in the hydraulic chamber.

3. The drill bit having self-adapting retractable blades of claim 2, wherein, The one-way valve control circuit comprises a hydraulic control channel, a first end of the hydraulic control channel is communicated with the drill bit fluid main channel, and a second end of the hydraulic control channel is communicated with the hydraulic chamber; a one-way valve is arranged in the hydraulic control channel to allow the drilling fluid to flow from the drill bit fluid main channel to the retractable blade wing.

4. The drill bit having self-adapting retractable blades of claim 3, wherein, The one-way valve control circuit further comprises at least one liquid flow distribution channel, a first end of the liquid flow distribution channel is communicated with the hydraulic control channel downstream of the outlet of the one-way valve, and a second end of the liquid flow distribution channel is communicated with the hydraulic chamber.

5. The drill bit having self-adapting retractable blades of claim 3, wherein, The one-way valve comprises a valve cylinder, a valve seat and a valve body, at least one first sealing unit is arranged between the outer wall of the valve cylinder and the inner wall of the hydraulic control channel; the valve body can be seated on the valve seat and can be separated from the valve seat under the action of the drilling fluid, and at least one second sealing unit is arranged between the valve body and the valve seat.

6. The drill bit having self-adapting retractable blades of claim 2, wherein, A water eye is arranged on at least one side of the main cutting blade wing, and the water eye can communicate the hydraulic chamber with the stratum.

7. The drill bit having self-adapting retractable blades of claim 2, wherein, The retractable blade wing comprises a retractable body which can be radially extended and retracted, a first step portion is arranged at the bottom of the retractable body, a second step portion is arranged on the inner wall of the containing groove, and the first step portion can be clamped on the second step portion to limit the retractable blade wing.

8. The drill bit having self-adapting retractable blades of claim 1, wherein, The retractable cutting tooth is a polycrystalline diamond cutting tooth.

9. The drill bit having self-adapting retractable blades of claim 1, wherein, The angles between the plurality of nozzles and the axis of the drill bit body are different.

10. The drill bit having self-adapting retractable blades of claim 1, wherein, A sleeve segment is connected to the drill bit body, a hollow threaded segment is connected to the sleeve segment, the internal cavities of the threaded segment and the sleeve segment are in communication with the drill bit fluid main channel, and the threaded segment is used for connecting an upper drill rod.

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