Screw drill

Abstract

The utility model relates to a screw drill, including fixed connection's outer cylinder and righting bend casing, fixedly connected with stator in the outer cylinder, the inside of stator is provided with hollow rotor, the inner wall of hollow rotor is fixedly connected with flexible axle, and flexible axle is limited in the outer cylinder, the lower end fixedly connected with transmission shaft of flexible axle, the lower end fixedly connected with mounting sleeve of transmission shaft, the drill bit is installed in mounting sleeve, and mounting sleeve and drill bit are detachably connected, and the rotation of mounting sleeve can drive the rotation of drill bit. The utility model greatly shortens the overall length of screw drill, makes it can adapt to those complex geological conditions of extremely small radius requirement of well drilling, and further not only improves the flexibility of well drilling operation, but also significantly enhances the applicability of screw drill in narrow space, effectively improves the well drilling efficiency, can quickly complete the replacement of drill bit, and further improves the efficiency of drill bit dismounting and replacement, convenient to use.

Description

Technical Field

[0001] This utility model belongs to the field of drilling tool technology, and specifically relates to a screw drill bit. Background Technology

[0002] Horizontal wells and extended reach wells with complex structures are the best way to efficiently develop oil and gas reservoirs. Downhole curved shell power drills are the main drilling tools used in China for drilling complex structure wells. After years of development, China has basically matured in the technology of manufacturing conventional curved shell power drills, but they are mainly used for drilling medium and long radius horizontal wells. Curved shell power drills for short radius horizontal wells are still a foreign technology in China. Existing curved shell power drills in China mainly consist of a screw motor and a transmission device with a curved shell. The distance from the bending point to the drill bit is 1.7 meters to 2.2 meters, and the bending angle is divided into 0.5 degrees, 1 degree, 1.25 degrees, 1.5 degrees, 1.75 degrees, 2 degrees, and 3 degrees to meet the requirements of different well build-up rates. The drilling process uses two methods: sliding drilling in the build-up section and combined drilling in the stabilization section.

[0003] Existing screw drills still have certain shortcomings. For example, most conventional screw drills have separate motors and deflectors, meaning the deflector is installed on one side of the motor rotor and rotates through the motor rotor. As a result, the length of conventional screw drills is generally around 6 meters, which is too long and inconvenient for drilling short-radius horizontal wells, thus making them inconvenient to use. The drill bit and drive shaft are mostly connected by threaded connections. Threaded connections are prone to breakage and the connection strength is not stable enough. In addition, the drill bit is a consumable and is easily damaged during drilling. It is also not convenient to quickly disassemble and replace the drill bit, making it inconvenient to use.

[0004] Therefore, it is necessary to design a screw drill tool that is shorter in length to facilitate drilling of short-radius horizontal wells and to facilitate the disassembly and replacement of drill bits. Utility Model Content

[0005] In order to solve all or some of the above problems, the purpose of this utility model is to provide a screw drill bit. The screw drill bit of this utility model shortens the length of the screw drill bit and improves the efficiency of drill bit disassembly and replacement.

[0006] According to one aspect of the present invention, a screw drill is provided, comprising an outer cylinder and a straightening bend shell fixedly connected. A stator is fixedly connected inside the outer cylinder, and a hollow rotor is disposed inside the stator. A flexible shaft is fixedly connected to the inner wall of the hollow rotor and is confined within the outer cylinder. A drive shaft is fixedly connected to the lower end of the flexible shaft, and an installation sleeve is fixedly connected to the lower end of the drive shaft. A drill bit is installed inside the installation sleeve, and the installation sleeve is detachably connected to the drill bit. Rotation of the installation sleeve can drive the drill bit to rotate.

[0007] Furthermore, an intermediate cylinder is fixedly connected to the lower end of the outer cylinder, and the intermediate cylinder is fixedly connected to the straightening bend shell. A sealing ring is fixedly connected to both the side of the outer cylinder near the intermediate cylinder and the side of the intermediate cylinder near the straightening bend shell. The outer cylinder and the intermediate cylinder, and the intermediate cylinder and the straightening bend shell are respectively sealed and connected by the sealing ring.

[0008] Furthermore, the flexible shaft is connected to the transmission shaft via an intermediate connecting shaft, which is positioned between the intermediate cylinder and the straightening bend shell, so that the flexible shaft is positioned within the outer cylinder.

[0009] Furthermore, a locking block is fixedly connected to the upper end of the drill bit, and a sliding groove extending upward from the lower end is provided inside the mounting sleeve. The locking block enters the mounting sleeve through the sliding groove. A rotating groove is connected to the upper end of the sliding groove, and a locking groove is connected to the lower end of the rotating groove. The locking block can enter the locking groove through the rotating groove. After the locking block is located in the locking groove, the rotation of the mounting sleeve drives the drill bit to rotate. After the locking block enters the locking groove, the drill bit and the mounting sleeve are sealed together.

[0010] Furthermore, a sealing block is provided in the groove below the slot, and the sealing block is detachably connected to the mounting sleeve. A second sealing ring is fixedly connected to the outer wall of the drill bit. After the block enters the slot, the sealing block contacts the second sealing ring, and the drill bit and the mounting sleeve are sealed together through the sealing block and the second sealing ring.

[0011] Furthermore, both the sealing block and the mounting sleeve are provided with threaded holes, and the sealing block and the mounting sleeve are connected by screws passing through the threaded holes.

[0012] Furthermore, a thrust spring is provided inside the mounting sleeve, and one end of the mounting sleeve is connected to the thrust spring, while the other end of the thrust spring is fixedly connected to an abutment block.

[0013] Furthermore, an anti-drop plate is fixedly connected to the upper end of the flexible shaft, and an anti-drop ring is fixedly connected to the outer cylinder above the stator. The anti-drop plate is located above the anti-drop ring, and the anti-drop plate cannot pass through the anti-drop ring. Furthermore, keyways are provided at the upper end of the flexure shaft and on the anti-drop plate, and the flexure shaft and the anti-drop plate are connected by an anti-drop key passing through the two keyways.

[0014] Furthermore, the outer diameter of the anti-drop plate is larger than the inner diameter of the anti-drop ring.

[0015] As can be seen from the above technical solution, the screw drill provided by this utility model has the following beneficial effects: This utility model embodiment combines a hollow rotor with a flexible shaft to form an integrated design, thereby shortening the length of the screw drill bit. The length of the screw drill bit in this embodiment is one-third of the length of the traditional screw drill bit, which greatly shortens the overall length of the screw drill bit, making it able to adapt to complex geological conditions with extremely small drilling radius requirements. This not only improves the flexibility of drilling operations, but also significantly enhances the applicability of the screw drill bit in narrow spaces, effectively improving drilling efficiency. The design incorporates a thrust spring, locking block, locking groove, sliding groove, and drill bit, enabling rapid drill bit replacement and improving the efficiency of drill bit disassembly and replacement. It is also convenient to use. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of the overall structure of a high-angle drilling tool for short-radius drilling according to this utility model; Figure 2 and Figure 3 This is a schematic diagram of the installation sleeve portion of this utility model; Figure 4 for Figure 1 Enlarged structural diagram at point A in the middle; Figure 5 for Figure 1 Enlarged structural diagram at point B; Figure 6 for Figure 1 Enlarged structural diagram at point C. Detailed Implementation

[0017] To better understand the purpose, structure, and function of this utility model, a screw drill tool of this utility model will be described in further detail below with reference to the accompanying drawings.

[0018] like Figure 1As shown, this invention illustrates a screw drill according to an embodiment of the present invention, comprising an outer cylinder 1 and a straightening bend housing 2 fixedly connected. A stator 3 is fixedly connected inside the outer cylinder 1, and a hollow rotor 4 is disposed inside the stator 3. A flexible shaft 5 is fixedly connected to the inner wall of the hollow rotor 4, and the flexible shaft 5 is confined within the outer cylinder 1. A drive shaft 6 is fixedly connected to the lower end of the flexible shaft 5, and an installation sleeve 7 is fixedly connected to the lower end of the drive shaft 6. A drill bit 8 is installed inside the installation sleeve 7. The installation sleeve 7 and the drill bit 8 are detachably connected, and the rotation of the installation sleeve 7 can drive the drill bit 8 to rotate.

[0019] Specifically, the screw drill bit of this embodiment includes a stator 3 and a hollow rotor 4. The stator 3 is fixedly connected to the outer cylinder 1, the hollow rotor 4 is disposed inside the stator 3, and the flexible shaft 5 is disposed inside the hollow rotor 4 and fixedly connected to the hollow rotor 4. This embodiment of the invention combines the hollow rotor 4 and the flexible shaft 5 into an integrated design, thereby shortening the length of the screw drill bit. The length of the screw drill bit in this embodiment is one-third of the length of the traditional screw drill bit, thus significantly shortening the overall length of the screw drill bit. This allows it to adapt to complex geological conditions with extremely small drilling radius requirements, thereby not only improving the flexibility of drilling operations but also significantly enhancing the applicability of the screw drill bit in confined spaces, effectively improving drilling efficiency.

[0020] During drilling, the mud pumped out by the mud pump enters the motor, creating a pressure difference between the inlet and outlet of the motor. This pressure difference drives the hollow rotor 4 to rotate around the axis of the stator 3. When the hollow rotor 4 rotates, it drives the inner wall of the flexible shaft 5 to rotate. The rotation of the flexible shaft 5 drives the transmission shaft 6 to rotate, thereby transmitting the speed and torque to the drill bit 8 through the flexible shaft 5 and the transmission shaft 6, thus realizing the drilling operation.

[0021] Among them, such as Figure 6 As shown, the lower end of the outer cylinder 1 is fixedly connected to the intermediate cylinder, and the intermediate cylinder and the straightening shell 2 are fixedly connected. A sealing ring 15 is fixedly connected to both the side of the outer cylinder 1 near the intermediate cylinder and the side of the intermediate cylinder near the straightening shell 2. The outer cylinder 1 and the intermediate cylinder, and the intermediate cylinder and the straightening shell 2 are respectively sealed and connected by the sealing ring 15.

[0022] The sealing ring 15 in this embodiment facilitates the improvement of the tightness and sealing of the connection between the outer cylinder 1 and the straightening bend shell 2. In specific implementations, for example, the outer cylinder 1 and the intermediate cylinder, as well as the intermediate cylinder and the straightening bend shell 2, are all threaded connections.

[0023] The flexible shaft 5 is connected to the transmission shaft 6 via an intermediate connecting shaft. The intermediate connecting shaft is positioned between the intermediate cylinder and the straightening bend shell 2, so that the flexible shaft 5 is positioned within the outer cylinder 1.

[0024] The configuration in this embodiment achieves the purpose of confining the flexible shaft 5 within the outer cylinder 1.

[0025] Among them, such as Figure 2 , Figure 3 and Figure 4 As shown, a locking block 9 is fixedly connected to the upper end of the drill bit 8. A sliding groove 10 extending upward from the lower end is provided inside the mounting sleeve 7. The locking block 9 enters the mounting sleeve 7 through the sliding groove 10. A rotating groove 11 is connected to the upper end of the sliding groove 10, and a locking groove 12 is connected to the lower end of the rotating groove 11. The locking block 9 can enter the locking groove 12 through the rotating groove 11. After the locking block 9 is located in the locking groove 12, the rotation of the mounting sleeve 7 will drive the drill bit 8 to rotate. After the locking block 9 enters the locking groove 12, the drill bit 8 and the mounting sleeve 7 are sealed together.

[0026] This embodiment facilitates the disassembly and installation of the drill bit 8, thereby effectively improving the efficiency of drill bit 8 replacement. Specifically, during disassembly: push the drill bit 8 upwards, and the drill bit 8 will cause the locking block 9 to disengage from the locking groove 12 and enter the interior of the rotating groove 11. Then rotate the drill bit 8 to cause the locking block 9 to rotate on the inner wall of the rotating groove 11. Finally, the locking block 9 rotates into the sliding groove 10. Then pull the drill bit 8, and the drill bit 8 will move the locking block 9 downwards in the sliding groove 10. Finally, the locking block 9 moves away from the sliding groove 10 and the installation sleeve 7, and the drill bit 8 is removed. During installation, the operation is carried out in the reverse order and in the opposite direction.

[0027] A sealing block 16 is provided in the slide groove 10 below the slot 12. The sealing block 16 is detachably connected to the mounting sleeve 7. A second sealing ring 19 is fixedly connected to the outer wall of the drill bit 8. After the chuck 9 enters the slot 12, the sealing block 16 contacts the second sealing ring 19. The drill bit 8 and the mounting sleeve 7 are sealed together by the sealing block 16 and the second sealing ring 19.

[0028] In this embodiment, the sealing block 16 and the sealing ring 19 are designed to facilitate sealing, thereby enhancing the tightness and sealing between the drill bit 8 and the inner wall of the mounting sleeve 7.

[0029] Both the sealing block 16 and the mounting sleeve 7 are provided with threaded holes 17, and the sealing block 16 and the mounting sleeve 7 are connected by screws 18 passing through the threaded holes 17.

[0030] The screw 18 and threaded hole 17 in this embodiment facilitate the installation and removal of the sealing block 16.

[0031] In this embodiment, during disassembly: first, the sealing block 16 needs to be removed, then the drill bit 8 is pushed upward so that the drill bit 8 drives the chuck 9 out of the chuck groove 12 and into the interior of the rotating groove 11. Then, the drill bit 8 is rotated to drive the chuck 9 to rotate on the inner wall of the rotating groove 11. Finally, the chuck 9 rotates into the slide groove 10. Then, the drill bit 8 is pulled so that the drill bit 8 drives the chuck 9 to move downward in the slide groove 10. Finally, the chuck 9 moves away from the slide groove 10 and the mounting sleeve 7, and the drill bit 8 is removed.

[0032] The mounting sleeve 7 is equipped with a thrust spring 13. One end of the mounting sleeve 7 is connected to the thrust spring 13, and the other end of the thrust spring 13 is fixedly connected to an abutment block 14.

[0033] In this embodiment, the thrust spring 13 and the abutment block 14 serve to buffer the collision between the drill bit 8 and the mounting sleeve 7.

[0034] Among them, such as Figure 5 As shown, an anti-fall plate 21 is fixedly connected to the upper end of the flexural shaft 5, and an anti-fall ring 20 is fixedly connected inside the outer cylinder 1 above the stator 3. The anti-fall plate 21 is located above the anti-fall ring 20, and the anti-fall plate 21 cannot pass through the anti-fall ring 20. Both the upper end of the flexure shaft 5 and the anti-drop plate 21 are provided with keyways 22, and the flexure shaft 5 and the anti-drop plate 21 are connected by an anti-drop key 23 passing through the two keyways 22.

[0035] The outer diameter of the anti-drop plate 21 is larger than the inner diameter of the anti-drop ring 20.

[0036] In this embodiment, the cooperation between the anti-drop plate 21 and the release ring prevents the flexural shaft 5 from falling off, thus ensuring the rotational stability of the flexural shaft 5.

[0037] The working principle of the screw drill bit according to the present invention is explained again as follows: The mud pumped out by the mud pump enters the motor, creating a pressure difference between the inlet and outlet of the motor. This pressure difference drives the hollow rotor 4 to rotate around the axis of the stator 3. When the hollow rotor 4 rotates, it drives the inner wall of the flexible shaft 5 to rotate. The rotation of the flexible shaft 5 drives the transmission shaft 6 to rotate, thereby transmitting the speed and torque to the drill bit 8 through the flexible shaft 5 and the transmission shaft 6, thus realizing the drilling operation. By combining the hollow rotor 4 and the flexible shaft 5 into one unit, the length of the screw drill bit is significantly shortened, making it suitable for complex geological conditions with extremely small drilling radius requirements. This not only improves the flexibility of drilling operations but also enhances the applicability of the screw drill bit.

[0038] When it is necessary to disassemble and replace drill bit 8, unscrew screw 18 from threaded hole 17, remove sealing block 16 so that it is no longer set in slide groove 10, then push drill bit 8 inward to drive chuck 9 to squeeze thrust spring 13, chuck 9 disengages from chuck groove 12 and moves into rotating groove 11, rotate drill bit 8 to drive chuck 9 to rotate in rotating groove 11 and rotate chuck 9 into slide groove 10, finally pull drill bit 8 to move chuck 9 outward in slide groove 10, and finally remove drill bit 8 for replacement. This embodiment facilitates the disassembly and replacement of drill bit 8, effectively improving the replacement efficiency of drill bit 8.

[0039] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0040] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This utility model is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A screw drill bit, characterized in that, The device includes a fixedly connected outer cylinder and a straightening bend shell. A stator is fixedly connected inside the outer cylinder, and a hollow rotor is disposed inside the stator. A flexible shaft is fixedly connected to the inner wall of the hollow rotor and is confined within the outer cylinder. A drive shaft is fixedly connected to the lower end of the flexible shaft, and a mounting sleeve is fixedly connected to the lower end of the drive shaft. A drill bit is installed inside the mounting sleeve, and the mounting sleeve and the drill bit are detachably connected. Rotation of the mounting sleeve can drive the drill bit to rotate.

2. The screw drill bit according to claim 1, characterized in that, The lower end of the outer cylinder is fixedly connected to the intermediate cylinder, and the intermediate cylinder and the straightening bend shell are fixedly connected. A sealing ring is fixedly connected to both the side of the outer cylinder near the intermediate cylinder and the side of the intermediate cylinder near the straightening bend shell. The outer cylinder and the intermediate cylinder, and the intermediate cylinder and the straightening bend shell are respectively sealed and connected by the sealing ring.

3. The screw drill bit according to claim 2, characterized in that, The flexible shaft is connected to the transmission shaft via an intermediate connecting shaft, which is positioned between the intermediate cylinder and the straightening bend shell, so that the flexible shaft is positioned within the outer cylinder.

4. The screw drill bit according to claim 1, characterized in that, A locking block is fixedly connected to the upper end of the drill bit. A sliding groove extending upward from the lower end is provided inside the mounting sleeve. The locking block enters the mounting sleeve through the sliding groove. A rotating groove is connected to the upper end of the sliding groove, and a locking slot is connected to the lower end of the rotating groove. The locking block can enter the locking slot through the rotating groove. After the locking block is located in the locking slot, the rotation of the mounting sleeve drives the drill bit to rotate. After the locking block enters the locking slot, the drill bit and the mounting sleeve are sealed together.

5. The screw drill bit according to claim 4, characterized in that, A sealing block is provided in the groove below the slot. The sealing block is detachably connected to the mounting sleeve. A second sealing ring is fixedly connected to the outer wall of the drill bit. After the block enters the slot, the sealing block contacts the second sealing ring. The drill bit and the mounting sleeve are sealed together by the sealing block and the second sealing ring.

6. The screw drill bit according to claim 5, characterized in that, Both the sealing block and the mounting sleeve have threaded holes, and the sealing block and the mounting sleeve are connected by screws passing through the threaded holes.

7. The screw drill bit according to claim 1, characterized in that, A thrust spring is provided inside the mounting sleeve. The mounting sleeve is connected to one end of the thrust spring, and an abutment block is fixedly connected to the other end of the thrust spring.

8. The screw drill bit according to claim 1, characterized in that, An anti-drop plate is fixedly connected to the upper end of the flexible shaft, and an anti-drop ring is fixedly connected to the outer cylinder above the stator. The anti-drop plate is located above the anti-drop ring, and the anti-drop plate cannot pass through the anti-drop ring.

9. The screw drill bit according to claim 8, characterized in that, Both the upper end of the flexure shaft and the anti-drop plate are provided with keyways, and the flexure shaft and the anti-drop plate are connected by an anti-drop key passing through the two keyways.

10. The screw drill bit according to claim 8, characterized in that, The outer diameter of the anti-drop plate is larger than the inner diameter of the anti-drop ring.

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