A PDC drill bit with automatic tooth replacement downhole and replacement method

Abstract

The present invention relates to the technical field of drilling tools, and specifically discloses a PDC drill bit capable of automatically replacing teeth underground and a replacement method thereof. The drill bit comprises a drill bit body, wherein the outer wall of the drill bit body is provided with blades, and the blades are provided with cutting teeth; a mounting cavity is provided in the blades, and the mounting cavity is connected to the cavity in the drill bit body; the side walls of the blades are provided with multiple positioning grooves, which correspond one to one with the cutting teeth, and the inner walls of the positioning grooves are provided with positioning slots; the cutting teeth are installed in the positioning slots by a locking assembly; the locking assembly includes a positioning post, which can be inserted into or removed from the positioning slot; a replacement assembly is provided in the mounting cavity, and the replacement assembly includes a storage unit for collecting old cutting teeth, a storage unit for storing new cutting teeth, and a driving assembly for driving the old cutting teeth into the storage unit and fixing the new cutting teeth in the positioning slots. The present invention can realize automatic replacement of the cutting teeth of the PDC drill bit underground once, thereby reducing the frequency of drilling.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling tools, and in particular to a PDC drill bit capable of automatically replacing teeth downhole and a replacement method. Background Art

[0002] PDC drill bits are currently the most widely used downhole drilling tools, mainly used for drilling and breaking rocks, and some are also used in ground operations (such as mining, rescue, etc.).

[0003] The PDC drill bit mainly includes a drill body, one end of which is connected to the drill pipe through a connecting part, and the outer wall of the other end is provided with multiple blades, and a row of cutting teeth are provided on the blades. When drilling, the cutting teeth dig into the rock and soil to break the rock. The cutting teeth of the PDC drill bit are greatly worn out during use and need to be replaced regularly. The existing replacement method is to take the PDC drill bit out of the ground by drilling and manually replace it. For example, CN221032437U, a PDC drill bit with easy tooth replacement, CN220395616U, a PDC drill bit for oil drilling with easy tooth replacement, etc., both require the drill to take the PDC drill bit out of the ground to operate and replace the cutting teeth of the PDC drill bit.

[0004] During the drilling process, the PDC drill bit is lowered into the well along with the drill pipe and other drilling tools. When encountering complex formations, the service life of the PDC drill bit's cutting teeth will be significantly reduced. If the cutting teeth are replaced during drilling according to their service life, it will lead to frequent drilling and lowering, which is not only troublesome to operate and increase the construction period, but also other engineering problems may arise during the frequent drilling and lowering process.

[0005] If the PDC drill bit cutting teeth can be replaced only once downhole, the influence of the formation on drilling can be reduced. The cutting teeth of the PDC drill bit and other drilling tools can be replaced or maintained together with the drilling once, thus reducing the frequency of drilling. Summary of the Invention

[0006] The present invention aims to provide a PDC drill bit with automatic tooth replacement downhole and a replacement method, so as to realize automatic replacement of the cutting teeth of the PDC drill bit downhole once, thereby reducing the frequency of drilling.

[0007] The present invention is achieved through the following technical solutions:

[0008] A PDC drill bit with automatic tooth replacement downhole includes a drill bit body, a plurality of blades are provided on the outer wall of the drill bit body, and cutting teeth are provided on the blades; a mounting cavity is provided in the blades, and the mounting cavity is communicated with a cavity in the drill bit body;

[0009] The side wall of the blade is provided with a plurality of positioning slots, which correspond to the cutting teeth one by one, and the inner wall of the positioning slot is provided with a positioning slot;

[0010] The cutting teeth are detachably fixed in the positioning slot by a locking assembly in conjunction with external force; the locking assembly includes a positioning post, which can be inserted into or removed from the positioning slot;

[0011] A replacement assembly is provided in the installation cavity, which includes a storage unit for collecting old cutting teeth, a storage unit for storing new cutting teeth, and a driving assembly for driving the old cutting teeth into the storage unit and fixing the new cutting teeth in the positioning slot.

[0012] The existing process of replacing the teeth of a PDC drill bit requires the drill bit to be removed from the well and replaced manually on the ground. However, since the replacement frequency of the cutting teeth of a PDC drill bit is different from that of other drilling tools, when the cutting teeth of a PDC drill bit need to be replaced, other drilling tools do not necessarily need to be replaced. Based on this, the original intention of the present invention is to:

[0013] By redesigning the PDC drill bit, the cutting teeth can be automatically replaced once in the well, so that the cutting teeth and other drilling tools can be moved out of the well for replacement at the same frequency, ultimately reducing the frequency of drilling and drilling operations.

[0014] Compared with the prior art, the present invention has the following three improvements:

[0015] 1) In the prior art, the cutting teeth of the PDC drill bit are fixed to the blade by adhesive combined with a heat treatment process. When the teeth need to be replaced, the solidified adhesive needs to be knocked off and then the cutting teeth are taken out. The cutting teeth of the present invention are detachable and are installed on the side walls of the blade. External force is mainly used to achieve the displacement of the cutting teeth in the positioning grooves on the blades. When the positioning column moves to the position corresponding to the positioning slot, the positioning column is pushed into the positioning slot under the action of the locking assembly. The positioning column and the positioning slot are engaged to limit the displacement of the cutting teeth, thereby achieving the fixation of the cutting teeth. When the cutting teeth need to be pulled out, they can be pulled out by external force (external force opposite to the pushing direction). The external force of the present invention includes the magnetic adsorption force generated by power or the power provided by other telescopic parts.

[0016] 2) The blade of the existing PDC drill bit is a solid structure set on the outer wall of the drill bit body. A row of mounting holes is set on one of the ridges of the blade, and the open ends of the mounting holes are set outward. The cutting teeth are installed through the open ends of the mounting holes. In order to realize the automatic replacement of cutting teeth underground, the present invention provides a mounting cavity for installing a replacement component in the blade, and the mounting cavity is connected to the cavity in the drill bit body to facilitate better installation of the replacement component.

[0017] 3) Compared with the prior art, the present invention adds a replacement component to realize automatic replacement of cutting teeth underground. The replacement component can be used to recover the old cutting teeth into the installation cavity and push the stored new cutting teeth into the positioning groove.

[0018] In summary, the present invention can realize automatic replacement of the cutting teeth of the PDC drill bit once underground, thereby reducing the frequency of drilling.

[0019] In a preferred embodiment, one end of the cutting tooth is a solid portion, and the other end is provided with a hollow portion;

[0020] The locking assembly is installed in the hollow part, and the locking assembly includes two adjusting rods, one end of the adjusting rod is hinged in the hollow part, and the other end is connected to the positioning column, and the two adjusting rods are connected by a third spring;

[0021] The side wall of the hollow portion is provided with a guide groove for passing the positioning column.

[0022] When the cutting teeth are fixed in the positioning grooves, the solid parts of the cutting teeth are fully or partially protruded from the blades, so as to be used for cutting into the rock and soil during the drilling process.

[0023] When the cutting tooth is inserted into the positioning groove, it is squeezed by the side wall of the positioning groove, and the positioning column will not protrude from the outer wall of the cutting tooth. When the cutting tooth moves the positioning column to the corresponding position of the positioning slot, the positioning column extends out of the guide slot and is embedded in the positioning slot under the action of the restoring force of the third spring, thereby fixing the cutting tooth.

[0024] In a preferred embodiment, a fifth magnetic block is provided at the other end of the adjusting rod. When power is turned on, there is an attractive force between the two fifth magnetic blocks.

[0025] The present invention can use the adsorption effect of the two fifth magnetic blocks to retract the positioning column. Compared with directly pulling out the cutting teeth by external force, it is easier to first use the adsorption effect of the two fifth magnetic blocks to retract the positioning column and then pull out the cutting teeth by external force.

[0026] In a preferred embodiment, the outer wall of the cutting tooth is provided with a hollow portion and a second magnetic block is provided; the inner wall of the blade is provided with a first magnetic block that cooperates with the second magnetic block on the outside of the positioning groove. When power is turned on, there is an attractive force between the first magnetic block and the second magnetic block. When the positioning column is embedded in the positioning slot, power is turned on to the first magnetic block to ensure that the first magnetic block and the second magnetic block are adsorbed and connected together.

[0027] When the positioning column is embedded in the positioning slot to fix the cutting tooth, the first magnetic block and the second magnetic block can be used for adsorption to improve the stability of the cutting tooth fixation.

[0028] In a preferred embodiment, a first spring is provided on the outer side of the positioning groove on the inner wall of the blade; when the first magnetic block and the second magnetic block are adsorbed together, the first spring is squeezed and compressed by the second magnetic block, and the restoring force of the first spring is used to realize the disassembly of the cutting tooth.

[0029] Specifically, when the cutting tooth needs to be pulled out, the first magnetic block and the second magnetic block are powered off, the magnetic attraction effect between the two disappears, and the cutting tooth is moved out of the positioning groove under the action of the restoring force of the first spring, that is, the restoring force of the first spring provided in the present invention can act as an external force when pulling out the cutting tooth.

[0030] In a preferred embodiment, the end of the positioning post away from the adjustment rod is formed into an arc surface. The arc surface provides a certain guiding function, facilitating the insertion of the positioning post into the positioning slot. Moreover, compared to a flat surface, the arc surface has less friction with the inner wall of the positioning slot during the movement of the cutting tooth, thereby facilitating the movement of the cutting tooth within the positioning slot.

[0031] In a preferred embodiment, the replacement assembly includes a collecting plate and a storage plate; the collecting plate and the storage plate are arranged parallel to the side wall of the blade provided with the positioning slot, and the collecting plate is placed between the side wall and the storage plate;

[0032] The collecting plate is provided with a plurality of collecting slots, and a third magnetic block is provided at the bottom of the collecting slots, and the collecting slots correspond one to one with the positioning slots;

[0033] The storage plate is provided with a plurality of storage slots, each of which is provided with a fourth magnetic block and a second spring. A new cutting tooth is fixed in the storage slot by the fourth magnetic block, at which time the second spring is compressed; the storage slots correspond one to one with the positioning slots;

[0034] The driving assembly includes a second telescopic member, and the collecting plate and the storage plate are each connected to a second telescopic member. The collecting slot or the storage slot is moved to a position corresponding to the positioning slot through the second telescopic member.

[0035] The replacement assembly provided in the present invention can realize automatic replacement of the cutting teeth by operating the second telescopic member to turn on and off the power.

[0036] In a preferred embodiment, a second magnetic block is provided on the outer wall of the cutting tooth; when power is turned on, there is an attractive force between the second magnetic block and the third magnetic block; when power is turned on, there is an attractive force between the second magnetic block and the fourth magnetic block.

[0037] The present invention can utilize the magnetic attraction effect to fix the cutting teeth and recover and extract the cutting teeth by setting the second magnetic block, the third magnetic block and the fourth magnetic block. In addition, the magnetic attraction effect between the third magnetic block and the second magnetic block can be used as an external force to extract the cutting teeth.

[0038] In a preferred embodiment, the storage plate includes a sliding plate and a fixed plate;

[0039] The bottom of the sliding plate is slidably connected to the top of the fixed plate, and the storage slot is provided on the sliding plate;

[0040] A first telescopic member for pushing the sliding plate to move is arranged in the installation cavity.

[0041] The present invention can set the width of the blade to be larger, so that the collection plate, storage plate and first telescopic member can be installed in the installation cavity at the same time. The storage plate is set to include a sliding plate and a fixed plate. The collection plate can be lowered to avoid the collection plate blocking the displacement of the sliding plate. Then, the first telescopic member is used to push the sliding plate to move close to the positioning slot, thereby reducing the distance between the storage plate and the positioning slot, which is more conducive to pushing the cutting teeth stored in the storage plate into the positioning slot.

[0042] In a preferred embodiment, one end of the second telescopic member is connected to the collecting plate or the storage plate, and the other end is fixed in the cavity.

[0043] In a preferred embodiment, the replacement assembly includes a rotating receiving plate; a plurality of fixing slots are provided on the rotating receiving plate, new cutting teeth are fixed at intervals in the plurality of fixing slots, and the fixing slots where no cutting teeth are fixed are used to recycle old cutting teeth;

[0044] All the positioning slots on the blade are located on the same circumference, or at least a plurality of positioning slots are located on the same circumference;

[0045] The driving assembly includes a rotating shaft and a power assembly, and the power assembly is used to drive the rotating shaft to rotate; the rotating storage plate is connected to the rotating shaft through a connecting plate, and the rotating shaft is located in the cavity and at the center of the circle corresponding to the circumference of the multiple positioning slots.

[0046] The replacement component of the present invention can use a rotating storage plate to collect old cutting teeth in empty fixed grooves at the same time, and can push new cutting teeth stored in the fixed grooves into the positioning grooves for fixation. The operation is simple, and it is only necessary to rotate the rotating storage plate to respectively achieve one-to-one correspondence between the empty fixed grooves or the fixed grooves loaded with new cutting teeth and the positioning grooves.

[0047] In a preferred embodiment, a sixth magnetic block and a fourth spring are provided in the fixing groove, and the new cutting tooth is fixed in the fixing groove through the sixth magnetic block. At this time, the fourth spring is compressed.

[0048] The present invention can utilize the restoring force of the fourth spring to push the new cutting tooth into the fixing groove.

[0049] In a preferred embodiment, the blade is mounted on the outer wall of the drill body by bolts.

[0050] In a preferred embodiment, the outer wall of the drill body is provided with a connecting groove for connecting the mounting cavity and the cavity; the outer wall of the drill body is provided with a wing plate on the outside of the connecting groove, and the blade is connected to the wing plate by a bolt, and the mounting cavity is formed between the wing plate and the blade.

[0051] The method for replacing the PDC drill bit includes the following steps:

[0052] S1. Operate the drive assembly so that the storage unit corresponds to the positioning slot, and use the storage unit to pull out and collect the old cutting teeth in the positioning slot;

[0053] S2. Operate the drive assembly to return the storage unit to its original position, then operate the drive assembly to make the storage unit storing the new cutting teeth correspond to the positioning slot, use the storage unit to push the new cutting teeth into the positioning slot, and use the locking assembly to fix the cutting teeth in the positioning slot.

[0054] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0055] The occurrence of rock spill and the like in the well may cause serious damage to the drill bit, causing heavy damage to the drill bit and causing heavy stones to break off and get out of the well.The longer the life of the PDC drill bit, the higher the risk of rock spill. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0057] Figure 1 Schematic diagram of the structure of the PDC drill bit of the present invention;

[0058] Figure 2 A half-section view of a PDC drill bit according to the present invention;

[0059] Figure 3 This is a schematic diagram of the collecting plate installed in the blade in Example 1 of the present invention;

[0060] Figure 4 This is a schematic diagram of the collecting plate and the storage plate being installed in the blade in Example 1 of the present invention;

[0061] Figure 5 for Figure 4 A partial enlarged view of point A in the middle;

[0062] Figure 6 Schematic diagram of the cutting teeth installed on the side wall of the blade in Example 1 of the present invention Figure 1 ;

[0063] Figure 7 Schematic diagram of the cutting teeth installed on the side wall of the blade in Example 1 of the present invention Figure 2 ;

[0064] Figure 8 Schematic diagram of the storage plate in Example 2 of the present invention Figure 1 ;

[0065] Figure 9 Schematic diagram of the storage plate in Example 2 of the present invention Figure 2 ;

[0066] Figure 10 This is a schematic diagram of the rotating storage plate installed in the blade in Example 3 of the present invention.

[0067] Markings and corresponding parts names in the accompanying drawings:

[0068] 1-drill bit body; 2-connecting column; 3-blade; 4-cutting tooth; 5-collecting plate; 6-storage plate; 7-rotating storage plate; 8-first telescopic member; 9-locking assembly; 10-second telescopic member; 11-cavity; 12-wing plate; 31-positioning slot; 32-positioning slot; 33-first magnetic block; 34-first spring; 41-hollow part; 42-second magnetic block; 43-cover plate; 44-guide slot; 45-fixing column; 51-collecting slot; 52-third magnetic block; 61-storage slot; 62-fourth magnetic block; 63-second spring; 64-sliding plate; 65-fixing plate; 71-fixing slot; 72-connecting plate; 73-rotating shaft; 91-fixing sleeve; 92-third spring; 93-adjusting rod; 94-positioning column; 95-fifth magnetic block; 100-bolt; 121-through hole. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the examples. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. The embodiments described below are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0070] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other examples, well-known structures, materials, or methods are not specifically described to avoid obscuring the present invention. The materials, instruments, and reagents used in the following examples, unless otherwise specified, are commercially available. The techniques used in the examples, unless otherwise specified, are conventional techniques well known to those skilled in the art.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0072] Example 1:

[0073] In order to reduce the frequency of drilling trips, Figure 1-Figure 7 As shown, a PDC drill bit with automatic tooth replacement in downhole includes a drill bit body 1, a connecting column 2 is provided at one end of the drill bit body 1, and is connected to the drill pipe through the connecting column 2; a plurality of blades 3 are provided on the outer wall of the drill bit body 1, one end of the blade 3 is placed on the top of the drill bit body 1, and the other end extends to the outer wall of the drill bit body 1. The overall shape of the drill bit body 1 is cylindrical, and the top of the drill bit body 1 is a circular arc surface. A cavity 11 for installing other components is formed inside the drill bit body 1. A plurality of cutting teeth 4 are provided on the blade 3, such as Figure 1 As shown, a plurality of cutting teeth 4 are arranged in a row; in this embodiment, in order to realize automatic replacement of the cutting teeth 4 underground, the structure of the blade wing 3 is improved in this embodiment. The blade wing 3 of this embodiment is provided with a mounting cavity, which is communicated with the cavity 11 in the drill bit body 1; that is, the interior of the blade wing 3 of this embodiment is a hollow structure, which can be used to realize the recovery of old or to-be-replaced cutting teeth 4, and the storage of new cutting teeth 4.

[0074] In this embodiment, the blade wing 3 is mounted to the outer wall of the drill body 1 via bolts 100. Specifically, the outer wall of the drill body 1 is provided with a connecting groove for connecting the mounting cavity and the cavity 11. The outer wall of the drill body 1 is provided with a wing plate 12 outside the connecting groove. The wing plate 12 is provided with a through hole 121 for passing the bolt 100. The blade wing 3 is connected to the wing plate 12 via the bolt 100, and the mounting cavity is formed between the wing plate 12 and the blade wing 3.

[0075] In order to realize the automatic replacement of the cutting teeth 4 underground, the side wall of the blade 3 of this embodiment is provided with a plurality of positioning grooves 31, and the inner and outer sides of the blade 3 are connected through the positioning grooves 31; the positioning grooves 31 correspond to the cutting teeth 4 one by one, that is, a cutting tooth 4 can be detachably installed in each positioning groove 31, and the inner wall of the positioning groove 31 is provided with a positioning card groove 32. The number of positioning card grooves 32 provided on the inner wall of each positioning groove 31 can be 1, 2 or 3, etc. Figure 6 、 Figure 7 As shown, two positioning slots 32 are symmetrically provided on the inner wall of the positioning slot 31 .

[0076] The cutting tooth 4 is detachably fixed in the positioning slot 31 by the locking assembly 9 in conjunction with an external force. The locking assembly 9 includes a positioning post 94, which can be inserted into or removed from the positioning slot 32. The working principle of this embodiment for locking and removing the cutting tooth 4 is as follows:

[0077] When the cutting tooth 4 needs to be installed, the cutting tooth 4 is inserted into the positioning groove 31 from one side of the installation cavity by external force, and the cutting tooth 4 is pushed forward in the positioning groove 31 by external force. When the positioning column 94 does not reach the position corresponding to the positioning slot 32, the positioning column 94 is restricted by the inner wall of the positioning slot 31. When the positioning column 94 reaches the position corresponding to the positioning slot 32, the restriction of the inner wall of the positioning slot 31 is lost, and the positioning column 94 moves radially into the positioning slot 32 to achieve the installation and fixation of the cutting tooth 4. At this time, one end of the cutting tooth 4 protrudes from the positioning slot 31 and eats into the rock and soil during the drilling process of the PDC drill bit. In an optional method, such as Figure 6-Figure 7 As shown, the outer diameter of the cutting tooth 4 is the same as the inner diameter of the positioning groove 31 .

[0078] When the cutting teeth 4 need to be recovered, an external force is applied in the opposite direction to that used during installation, and the cutting teeth 4 are pulled out and recovered by the external force.

[0079] Therefore, in order to facilitate the movement of the cutting tooth 4 in the positioning groove 31 during the installation and recovery process, the end of the positioning column 94 that contacts the inner wall of the positioning groove 31 can be set to an arc surface, and then the structure of the positioning slot 32 can be designed based on the specific structural adaptability of the positioning column 94. In an optional manner, as shown in FIG. Figure 6-Figure 7 As shown, the positioning post 94 is cylindrical in shape, and one end of the column is an arc surface. The positioning slot 32 is a conical cavity with a triangular cross section.

[0080] The external force used in this embodiment can be any structure that can realize bidirectional movement of the cutting teeth 4, for example: it can be realized by magnetic adsorption forces in different directions, telescopic structures, etc., wherein the magnetic adsorption force is realized by the on-off point method between the two magnetic blocks. When power is turned on, there is mutual attraction between the two magnetic blocks. When one of the magnetic blocks is fixed, the other magnetic block is pulled closer by attraction, so that the other magnetic block drives the movement of the component fixed to it. Turning on power to make the two magnetic blocks attract each other is an existing technology, and the magnetic field generated by the magnet when power is turned on is used to adsorb metal, that is, in specific implementation, the fixed magnetic block can be set as a magnet, and the movable magnetic block can be set as a metal block that can be adsorbed and moved; when the power is turned off, the attraction between the two magnetic blocks is lost, and the other magnetic block can use the restoring force of other elastic components to return to its position; the telescopic structure can be specifically a hydraulic cylinder.

[0081] In this embodiment, a specific structure for realizing the movement of the cutting tooth 4 is as follows: one end of the cutting tooth 4 is a solid part, and the other end is provided with a hollow part 41; when the cutting tooth 4 is installed in the positioning groove 31, the solid part of the cutting tooth 4 protrudes entirely or partially from the positioning groove 31.

[0082] The locking assembly 9 is mounted within the hollow portion 41 and includes two adjustment rods 93 . One end of the adjustment rod 93 is hinged within the hollow portion 41 , and the other end is connected to a positioning post 94 . Preferably, the end of the positioning post 94 away from the adjustment rod 93 is an arc surface. The two adjustment rods 93 are connected by a third spring 92 . When the positioning posts 94 are restrained by the inner wall of the positioning slot 31 , the two positioning posts 94 are relatively close together. At this time, the third spring 92 is in a compressed state. When the positioning posts 94 move to a position corresponding to the positioning slot 32 , the return action of the third spring 92 pushes the positioning posts 94 into the positioning slot 32 , thereby securing the cutting teeth 4 . The sidewalls of the hollow portion 41 are provided with guide slots 44 for the positioning posts 94 to pass through. To facilitate the articulation of the adjustment rod 93, a fixed column 45 is provided within the hollow portion 41. The locking assembly 9 also includes a fixed sleeve 91, which is fixed to the outer wall of the fixed column 45. A hinged portion is provided on the fixed sleeve 91 for achieving an articulated connection with one end of the adjustment rod 93. The hinged portion can specifically be a shaft, on which one end of the adjustment rod 93 is rotatably mounted. The rotation of one end of the adjustment rod 93 enables the opening and closing of the two adjustment rods 93. Preferably, to facilitate the installation of the locking assembly 9, one end of the hollow portion 41 is set as an open end, and a detachable cover plate 43 is provided at the open end.

[0083] In a preferred embodiment, to facilitate quick and smooth removal of the cutting tooth 4 from the positioning slot 31 when retrieving the cutting tooth 4, a fifth magnetic block 95 is provided at the other end of the adjustment rod 93. When energized, the two fifth magnetic blocks 95 exert an attractive force between them. When the cutting tooth 4 needs to be retrieved, the fifth magnetic block 95 is energized, attracting the two fifth magnetic blocks 95 together, causing the positioning post 94 to move out of the positioning slot 32, allowing an external force to be applied to remove the cutting tooth 4 from the positioning slot 31.

[0084] In a preferred case, in order to achieve better stability of the cutting tooth 4 after it is installed in the positioning slot 31, the cutting tooth 4 is provided with a second magnetic block 42 on the outer wall of a hollow portion 41; the inner wall of the blade 3 is provided with a first magnetic block 33 that cooperates with the second magnetic block 42 on the outside of the positioning slot 31. When power is turned on, there is an attractive force between the first magnetic block 33 and the second magnetic block 42. When the positioning column 94 is embedded in the positioning slot 32, the first magnetic block 33 and the second magnetic block 42 are adsorbed and connected together. Specifically, the first magnetic block 33 is a fixed structure and can be made of a magnet, while the second magnetic block 42 that moves with the cutting tooth 4 can be made of a metal that can be attracted and moved by a magnet, such as iron. This embodiment can improve the stability of the fixing of the cutting tooth 4 by utilizing the adsorption effect of the first magnetic block 33 and the second magnetic block 42 during drilling.

[0085] In a preferred case, in order to facilitate the extraction of the cutting tooth 4 during recovery, a first spring 34 is provided on the outside of the positioning slot 31 on the inner wall of the blade 3; when the first magnetic block 33 and the second magnetic block 42 are adsorbed together, the first spring 34 is squeezed and compressed by the second magnetic block 42; when the cutting tooth 4 needs to be extracted, the first magnetic block 33 and the second magnetic block 42 are powered off and lose their adsorption force, and the cutting tooth 4 is pushed out of the positioning slot 31 under the action of the restoring force of the first spring 34.

[0086] A replacement assembly is disposed within the installation cavity, comprising a storage unit for collecting old cutting teeth 4, a storage unit for storing new cutting teeth 4, and a drive assembly for driving the old cutting teeth 4 into the storage unit and securing the new cutting teeth 4 within the positioning slots 32. This embodiment utilizes the replacement assembly to automatically replace the aforementioned detachable cutting teeth 4.

[0087] Specifically, the replacement assembly includes a collecting plate 5 and a storage plate 6 ; the collecting plate 5 and the storage plate 6 are arranged parallel to the side wall of the blade 3 provided with the positioning groove 31 , and the collecting plate 5 is placed between the side wall and the storage plate 6 .

[0088] Among them, a plurality of collecting slots 51 are provided on the collecting plate 5, and a third magnetic block 52 is provided at the bottom of the collecting slot 51, and the collecting slot 51 corresponds one to one with the positioning slot 31; at this time, a second magnetic block 42 is provided on the outer wall of the hollow portion 41 of the cutting tooth 4, or a magnetic block is provided on the cover plate 43 of the cutting tooth 4. When power is turned on, there is a magnetic attraction force between the third magnetic block 52 and the end of the cutting tooth 4, and the cutting tooth 4 is adsorbed into the collecting slot 51 for fixation by utilizing the magnetic attraction force. Specifically, the third magnetic block 52 can be a magnet, and the cover plate 43 or the second magnetic block 42 is a metal such as iron that can be adsorbed and moved by a magnet.

[0089] Among them, a plurality of storage slots 61 are provided on the storage plate 6, and a fourth magnetic block 62 and a second spring 63 are provided in the storage slot 61. The new cutting tooth 4 is fixed in the storage slot 61 by the fourth magnetic block 62, at which time the second spring 63 is compressed; the storage slot 61 corresponds one-to-one with the positioning slot 31. Specifically, the fourth magnetic block 62 is provided on the inner wall of the storage slot 61, and the fourth magnetic block 62 is an annular magnetic block, wherein the middle part has a central through hole that can pass through the second spring 63. One end of the second spring 63 is fixed to the bottom of the storage slot 61, and the other end passes through the central through hole. The outer wall of the hollow portion 41 of the cutting tooth 4 is provided with a second magnetic block 42. The cutting tooth 4 is fixed in the storage slot 61 by the magnetic attraction of the second magnetic block 42 and the fourth magnetic block 62. Specifically, the fourth magnetic block 62 is a magnet that can generate magnetic attraction when energized, and the second magnetic block 42 is a metal that can be attracted and moved by a magnet, such as iron. When the cutting tooth 4 needs to be replaced, after the old cutting tooth 4 has been pulled out of the positioning slot 31, the fourth magnetic block 62 is powered off, the magnetic attraction force between the fourth magnetic block 62 and the second magnetic block 42 is lost, and the cutting tooth 4 stored in the storage slot 61 is pushed into the corresponding positioning slot 31 under the action of the restoring force of the second spring 63.

[0090] The driving assembly includes a second telescopic member 10, and the collecting plate 5 and the storage plate 6 are each connected to a second telescopic member 10. One end of the second telescopic member 10 is connected to the collecting plate 5 or the storage plate 6, and the other end is fixed in the cavity 11. The collecting plate 5 or the storage plate 6 is moved by the telescopic movement of the second telescopic member 10, and then the collecting slot 51 or the storage slot 61 is moved to a position corresponding to the positioning slot 31. Specifically, in this embodiment, all the positioning slots 31 on the blade 3 are located on the same circumference, or at least a plurality of positioning slots 31 are located on the same circumference. In a specific case, such as Figure 3 As shown, each blade 3 is provided with nine positioning slots 31 from top to bottom. The first seven positioning slots 31 are located on a quarter arc of the same circumference, while the remaining two positioning slots 31 are located on a tangent to the circumference and are arranged vertically. In this embodiment, the cutting teeth 4 within the seven positioning slots 31 located on a quarter arc of the same circumference can be replaced. Since replacing the cutting teeth 4 within seven positioning slots 31 already replaces most of the cutting teeth 4, the remaining two remain unchanged, which has little impact on the use of the PDC drill bit and can be manually replaced after drilling out of the well. In actual use, all positioning slots 31 can be arranged on the same circumference to achieve complete replacement of the cutting teeth 4. The circumference of the collecting groove 51 on the collecting plate 5 and the storage groove 61 on the storage plate 6 is always concentric with the circumference of the positioning groove 31, and the telescopic direction of the second telescopic member 10 is the radial direction of the circumference of the collecting groove 51 or the storage groove 61, and is located in the middle of the 1 / 4 arc of the positioning groove 31. The moving path of the second telescopic member 10 is as follows: Figure 3The second telescopic member 10 can be a hydraulic cylinder.

[0091] The method for replacing the PDC drill bit includes the following steps:

[0092] S1. Operate the driving assembly to align the receiving unit with the positioning slot 31, and use the receiving unit to pull out and collect the old cutting teeth 4 in the positioning slot 31;

[0093] S2. Operate the driving assembly to return the storage unit to its original position, then operate the driving assembly to make the storage unit storing the new cutting teeth 4 correspond to the positioning slot 31, use the storage unit to push the new cutting teeth 4 into the positioning slot 31, and use the locking assembly 9 to fix the cutting teeth 4 in the positioning slot 31.

[0094] Specifically, the working principle of this embodiment is as follows:

[0095] A. When the old cutting teeth 4 need to be replaced, the second telescopic member 10 is operated to extend the collecting groove 51 on the collecting plate 5 along the Figure 3 The dotted line shown moves to the position corresponding to the positioning slot 31, that is, the same height. The height here is relative to Figure 3 As shown by the dotted line, the first magnetic block 33 is powered off, so that the magnetic attraction force between the first magnetic block 33 and the second magnetic block 42 is lost, and the cutting tooth 4 is pushed out of the positioning groove 31 under the action of the restoring force of the first spring 34. Then the third magnetic block 52 is powered on, so that the third magnetic block 52 adsorbs the second magnetic block 42 and / or the cover plate 43, and adsorbs the old cutting tooth 4 into the collection groove 51 for fixation.

[0096] B. Then operate the second telescopic member 10 to retract the collecting plate 5 along Figure 3 The dotted line shown moves to a position lower than the positioning slot 31 , so that the collecting plate 5 does not block the new cutting teeth 4 in the storage plate 6 from being pushed into the positioning slot 31 .

[0097] C. Operate the second telescopic member 10 to extend the storage slot 61 in the storage plate 6 along Figure 3 The dotted line shown moves to a position corresponding to the positioning slot 31, that is, the same height; then the fourth magnetic block 62 is powered off, the magnetic attraction force between the fourth magnetic block 62 and the second magnetic block 42 is lost, and the cutting tooth 4 stored in the storage slot 61 is pushed into the corresponding positioning slot 31 under the action of the restoring force of the second spring 63.

[0098] D. After the cutting tooth 4 enters the positioning slot, the first magnetic block 33 is energized, and the magnetic attraction force between the first magnetic block 33 and the second magnetic block 42 is used to ensure that the cutting tooth 4 moves forward to the positioning column 94 and is embedded in the positioning slot 32.

[0099] That is, in this embodiment, the magnetic attraction force is used to provide the external force for the cutting teeth 4 to move.

[0100] Example 2:

[0101] like Figures 1-9 As shown, in order to shorten the distance that the new cutting teeth 4 are pushed into the positioning slots 31, the storage plate 6 is configured to include a sliding plate 64 and a fixed plate 65.

[0102] The bottom of the sliding plate 64 is slidably connected to the top of the fixed plate 65, and can be any solid sliding connection in the prior art, which can be a slider matched with a slide rail. The storage slot 61 is provided on the sliding plate 64;

[0103] A first telescopic member 8 for pushing the sliding plate 64 to move is provided in the installation cavity.

[0104] This example works as follows:

[0105] When the storage slot 61 is moved to a position corresponding to the positioning slot 31 by the second telescopic member 10, the first telescopic member 8 is extended, and the sliding plate 64 moves close to the positioning slot 31 until the sliding plate 64 moves above the collecting plate 5, so that the distance between the storage slot 61 and the positioning slot 31 is closer, and then the cutting teeth 4 are pushed into the positioning slot 31.

[0106] Example 3:

[0107] like Figure 1 、 Figure 2 、 Figure 6 、 Figure 7 and 10 As shown: The difference between this embodiment and embodiment 1 is that the structure of the replacement component is different.

[0108] In this embodiment, the replacement component includes a rotating storage plate 7; a number of fixed grooves 71 are provided on the rotating storage plate 7, and new cutting teeth 4 are fixed at intervals in the fixed grooves 71, and the fixed grooves 71 without fixed cutting teeth 4 are used to recover old cutting teeth 4; for example: when 7 positioning grooves 31 are provided on the blade 3, 14 fixed grooves 71 are provided on the rotating storage plate 7, which are numbered 1#-14# respectively, among which the odd-numbered fixed grooves 71 are empty, and the even-numbered ones are fixed with new cutting teeth 4.

[0109] In this embodiment, in order to achieve the correspondence between odd-numbered or even-numbered fixed grooves 71 and positioning grooves 31 by rotation, all positioning grooves 31 on the blade 3 of this example are located on the same circumference, or at least multiple positioning grooves 31 are located on the same circumference; when all positioning grooves 31 are located on the same circumference, all cutting teeth 4 can be replaced, and if some cutting teeth 4 are located on the same circumference, multiple cutting teeth 4 located on the same circumference can be replaced. In actual use, the arrangement of the cutting teeth 4 can be set according to the degree of wear of the cutting teeth 4 at different positions during the drilling process, whether they are all located on the same circumference or only part of it.

[0110] The driving assembly of this embodiment includes a rotating shaft 73 and a power assembly, and the power assembly is used to drive the rotating shaft 73 to rotate; the rotating storage plate 7 is connected to the rotating shaft 73 through the connecting plate 72, and the rotating shaft 73 is located in the cavity 11 and is located at the center of the circle corresponding to the circumference of the plurality of positioning slots 31. That is, the rotation path of the rotating storage plate 7 of this embodiment is as follows Figure 10 Specifically, the power assembly includes a motor and a gear transmission mechanism, which includes a driving wheel and a driven wheel that mesh with each other. The driving wheel is connected to the power output shaft of the motor, and the driven wheel is connected to the rotating shaft 73. When the motor rotates forward, the gear transmission mechanism drives the rotating storage plate 7 to rotate counterclockwise by a certain angle. When the motor rotates reversely, the rotating storage plate 7 returns to its original position.

[0111] In this embodiment, the fixing slot 71 is provided with a sixth magnetic block and a fourth spring. The new cutting tooth 4 is fixed to the fixing slot 71 via the sixth magnetic block, while the fourth spring is compressed. The structure and operating principle of the fixing slot 71 in this embodiment are similar to those of the storage slot 61 in Example 1.

[0112] The working principle of this embodiment is as follows:

[0113] A. In the initial state, the empty fixing slot 71 on the rotating storage plate 7 is at the same height as the positioning slot 31 and corresponds one to one. When the old cutting tooth 4 needs to be replaced, the old positioning slot 31 in the positioning slot 31 is pushed into the empty fixing slot 71, and the old cutting tooth 4 is fixed by utilizing the adsorption effect of the sixth magnetic block and the second magnetic block 42.

[0114] B. The driving motor drives the rotating storage plate 7 to a certain angle, so that the fixed groove 71 on the rotating storage plate 7 with the new cutting tooth 4 is at the same height and corresponds one to one with the positioning groove 31. Then, the sixth magnetic block in the fixed groove 71 is powered off, and the restoring force of the fourth spring is used to push the new cutting tooth 4 into the corresponding positioning groove 31.

[0115] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0116] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

Claims

1. A PDC drill bit with automatic tooth replacement downhole, comprising a drill bit body (1), a plurality of blades (3) provided on the outer wall of the drill bit body (1), and cutting teeth (4) provided on the blades (3); characterized in that: A mounting cavity is provided in the blade (3); The side wall of the blade (3) is provided with a plurality of positioning slots (31), the positioning slots (31) correspond one-to-one with the cutting teeth (4), and the inner wall of the positioning slot (31) is provided with a positioning slot (32); The cutting teeth (4) are detachably fixed in the positioning slot (31) by means of a locking assembly (9) in cooperation with an external force; the locking assembly (9) comprises a positioning column (94), and the locking assembly (9) is capable of enabling the positioning column (94) to be embedded in or removed from the positioning slot (32); A replacement assembly is provided in the installation cavity, the replacement assembly comprising a storage unit for collecting old cutting teeth (4), a storage unit for storing new cutting teeth (4), and a drive assembly for driving the old cutting teeth (4) into the storage unit and fixing the new cutting teeth (4) in the positioning slot (32); One end of the cutting tooth (4) is a solid portion, and the other end is provided with a hollow portion (41); The locking assembly (9) is installed in the hollow portion (41), and the locking assembly (9) includes two adjusting rods (93), one end of the adjusting rod (93) is hinged in the hollow portion (41), and the other end is connected to the positioning column (94), and the two adjusting rods (93) are connected via a third spring (92); The side wall of the hollow portion (41) is provided with a guide slot (44) for passing the positioning column (94).

2. The downhole automatic tooth replacement PDC drill bit according to claim 1, characterized in that: The other end of the regulating rod (93) is provided with a fifth magnetic block (95), and when power is turned on, there is an attractive force between the two fifth magnetic blocks (95).

3. The downhole automatic tooth replacement PDC drill bit according to claim 1, characterized in that: The cutting tooth (4) is provided with a second magnetic block (42) on the outer wall of the hollow portion (41); the inner wall of the blade (3) is provided with a first magnetic block (33) that matches the second magnetic block (42) on the outer side of the positioning slot (31); when the positioning column (94) is embedded in the positioning slot (32), the first magnetic block (33) is energized to ensure that the first magnetic block (33) and the second magnetic block (42) are adsorbed and connected together.

4. The downhole automatic tooth replacement PDC drill bit according to claim 3, characterized in that: A first spring (34) is provided on the inner wall of the blade wing (3) outside the positioning slot (31); the cutting tooth (4) can be disassembled by utilizing the restoring force of the first spring (34).

5. The downhole automatic tooth replacement PDC drill bit according to claim 1, characterized in that: One end of the positioning column (94) away from the adjusting rod (93) is an arc surface.

6. The downhole automatic tooth replacement PDC drill bit according to claim 1, characterized in that: The replacement assembly comprises a collecting plate (5) and a storage plate (6); the collecting plate (5) and the storage plate (6) are arranged parallel to the side wall of the blade (3) provided with the positioning slot (31), and the collecting plate (5) is placed between the side wall and the storage plate (6); A plurality of collecting slots (51) are provided on the collecting plate (5), a third magnetic block (52) is provided at the bottom of the collecting slots (51), and the collecting slots (51) correspond one to one with the positioning slots (31); The storage plate (6) is provided with a plurality of storage slots (61), and a fourth magnetic block (62) and a second spring (63) are provided in the storage slot (61). The new cutting tooth (4) is fixed in the storage slot (61) through the fourth magnetic block (62), and at this time, the second spring (63) is in a compressed state; the storage slots (61) correspond one to one with the positioning slots (31); The driving assembly comprises a second telescopic member (10), and the collecting plate (5) and the storage plate (6) are each connected to a second telescopic member (10), and the collecting slot (51) or the storage slot (61) is moved to a position corresponding to the positioning slot (31) via the second telescopic member (10).

7. The downhole automatic tooth replacement PDC drill bit according to claim 6, characterized in that: The outer wall of the cutting tooth (4) is provided with a second magnetic block (42); when power is turned on, an attractive force is generated between the second magnetic block (42) and the third magnetic block (52); and an attractive force is generated between the second magnetic block (42) and the fourth magnetic block (62).

8. The downhole automatic tooth replacement PDC drill bit according to claim 6, characterized in that: The storage plate (6) includes a sliding plate (64) and a fixed plate (65); The bottom of the sliding plate (64) is slidably connected to the top of the fixed plate (65), and the storage slot (61) is provided on the sliding plate (64); A first telescopic member (8) for pushing the sliding plate (64) to move is provided in the installation cavity.

9. The downhole automatic tooth replacement PDC drill bit according to claim 6, characterized in that: One end of the second telescopic member (10) is connected to the collecting plate (5) or the storage plate (6), and the other end is fixed in the cavity (11) in the drill body (1).

10. The downhole automatic tooth replacement PDC drill bit according to claim 1, characterized in that: The replacement assembly comprises a rotating storage plate (7); a plurality of fixing grooves (71) are provided on the rotating storage plate (7); new cutting teeth (4) are fixed at intervals in the plurality of fixing grooves (71); and the fixing grooves (71) to which the cutting teeth (4) are not fixed are used to recycle old cutting teeth (4); All of the positioning slots (31) on the blade (3) are located on the same circumference, or at least a plurality of the positioning slots (31) are located on the same circumference; The driving assembly comprises a rotating shaft (73) and a power assembly, wherein the power assembly is used to drive the rotating shaft (73) to rotate; the rotating receiving plate (7) is connected to the rotating shaft (73) via a connecting plate (72), and the rotating shaft (73) is located in the cavity (11) in the drill bit body (1) and is located at the center of a circle corresponding to the circumference of the plurality of positioning slots (31).

11. The downhole automatic tooth replacement PDC drill bit according to claim 10, characterized in that: A sixth magnetic block and a fourth spring are provided in the fixing groove (71), and the new cutting tooth (4) is fixed in the fixing groove (71) via the sixth magnetic block, at which time the fourth spring is compressed.

12. A downhole PDC drill bit with automatic tooth replacement according to any one of claims 1 to 11, characterized in that: The blade (3) is mounted on the outer wall of the drill body (1) via bolts (100).

13. The downhole automatic tooth replacement PDC drill bit according to claim 12, characterized in that: The outer wall of the drill body (1) is provided with a connecting groove for connecting the mounting cavity and the cavity (11) in the drill body (1); the outer wall of the drill body (1) is provided with a wing plate (12) outside the connecting groove, the blade (3) is connected to the wing plate (12) via a bolt (100), and the mounting cavity is formed between the wing plate (12) and the blade (3).

14. The method for replacing a PDC drill bit according to any one of claims 1 to 13, characterized in that: The steps include: S1, operating the driving assembly so that the storage unit corresponds to the positioning slot (31), and using the storage unit to pull out and collect the old cutting teeth (4) in the positioning slot (31); S2. Operate the driving assembly to return the storage unit to its original position, then operate the driving assembly to make the storage unit storing the new cutting tooth (4) correspond to the positioning slot (31), use the storage unit to push the new cutting tooth (4) into the positioning slot (31), and use the locking assembly (9) to fix the cutting tooth (4) in the positioning slot (31).

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