Multistage hydraulic variable-diameter while-drilling reamer

Abstract

The application relates to the field of oil drilling and borehole technology, and discloses a multistage ball-throwing type hydraulic variable-diameter while-drilling reamer, which comprises a shell, an upper joint and a lower joint, a mandrel body is slidably connected in the shell, the outer wall of the mandrel body is provided with mandrel guide rails with gradually decreasing outer diameters, the inner side of a rotary connecting blade wing in the shell abuts against the mandrel guide rails, a limiter is arranged on the bottom end of the mandrel body, a positioning block on the shell is slidably connected in a broken line-shaped groove on the outer wall of the limiter, a ball-throwing seat is slidably connected below the limiter, the two are drivingly connected through a shift pin and a groove structure, a plurality of claw bodies are arranged in an array on the inner wall of the ball-throwing seat, a reset base plate is arranged on the bottom end of the ball-throwing seat, a heavy spring is arranged below the reset base plate, and a collector is arranged in the lower joint. The mandrel guide rails are driven to go up and support the blade wing to expand the hole through ball-throwing pressure holding, the positioning block guides the limiter to rotate and shift gears and drives the claw bodies to spread and release pressure, the heavy spring is rebounded, multistage variable-diameter and automatic pressure release in single-trip drilling are realized.

Description

Technical Field

[0001] This invention relates to the field of oil well drilling technology, specifically to a multi-stage ball-dropping type hydraulic variable diameter reamer while drilling. Background Technology

[0002] As global oil and gas exploration and development rapidly advances towards complex conditions such as deep, ultra-deep, extended reach wells, windowed sidetracking, and salt-gypsum formations, conventional wellbore sizes are no longer sufficient to meet the demands for cementing clearance optimization, reservoir protection, subsequent well completion operations, and long-term wellbore stability. As a core supporting technology for drilling engineering, reaming technology can simultaneously enlarge the wellbore diameter during drilling without the need for additional tripping. Reaming technology can increase the clearance between the casing and the wellbore annulus, improve cementing quality, and solve problems such as creep shrinkage in salt-gypsum formations and wellbore instability in complex formations. It plays a key role in shortening the drilling cycle, reducing operating costs, and ensuring construction safety. However, existing drilling reaming tools have significant limitations in functionality and adaptability. Current tools only have two-stage ball dropping and single-stage reaming functions. The reaming range of existing tools is fixed, and it is impossible to flexibly adjust the reaming diameter according to formation changes during downhole operations. The working mode means that the tools do not support multi-stage coordinated operations during a single drilling trip, resulting in uneven reaming effects when encountering complex formations. At the same time, due to the limitations of the basic mechanical structure design, the overall reliability of existing tools is poor during long-term downhole operations. Moreover, after depressurization, the ball of traditional ball dropping tools often falls with the drilling fluid, clogging the water holes of the lower drill string, which is difficult to meet the construction requirements of efficient and continuous drilling under current complex well conditions. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a multi-stage ball-throwing type hydraulic variable diameter reamer while drilling, which solves the problems of fixed reamerization gears, inability to achieve multi-stage diameter changes and pressure relief in a single drilling run of existing reamers while drilling tools.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: a multi-stage ball-throwing type hydraulic variable diameter reamer, comprising a housing, an upper connector and a lower connector, wherein the housing is fixedly connected to the bottom end of the upper connector, the top end of the lower connector is fixedly connected to the bottom end of the housing, a mandrel body is slidably connected inside the housing, and the outer wall of the mandrel body is provided with multiple mandrel guide rails; Both outer walls of the housing are provided with blade wing grooves, and the inner wall of the blade wing groove extends into the interior of the housing. The inner wall of the housing is fixedly connected to a blade wing rotation shaft, and the outer wall of the blade wing rotation shaft is rotatably connected to a blade wing. The inner side wall of the blade wing abuts against the outer wall of the spindle guide rail, and the end of the blade wing away from the spindle guide rail passes through the blade wing groove. A limiter is fitted at the bottom end of the mandrel body, and a positioning block is threadedly connected to the side wall of the housing. One end of the positioning block passes through the side wall of the housing and is slidably connected to the outer wall of the limiter. A ball-throwing seat is provided below the limiter. The outer wall of the ball-throwing seat is slidably connected to the inner wall of the housing. The top end of the ball-throwing seat is connected to the bottom end of the limiter through a pin groove structure.

[0005] The ball-throwing pressure-driven spindle body is pushed downward by hydraulic pressure to complete the gear shift preparation and automatic pressure relief. After pressure relief, the heavy spring releases and pushes the spindle body to rebound upward. The spindle guide rail squeezes the blade to open and expand the hole. At the same time, the limiter, positioning block and ball-throwing seat form a linkage mechanism. The axial movement and circumferential rotation of the limiter control the blade opening angle and realize fixed-distance pressure relief.

[0006] Furthermore, the limiter includes an in-situ limiting groove, a first limiting groove, a second limiting groove, and a third limiting groove. The in-situ limiting groove, the first limiting groove, the second limiting groove, and the third limiting groove are connected to form a zigzag shape and are arranged at intervals along the outer wall of the limiter. The positioning block is slidably connected in the zigzag-shaped channel formed by the in-situ limiting groove, the first limiting groove, the second limiting groove, and the third limiting groove.

[0007] The positioning block cooperates with the zigzag groove to convert the axial movement of the limiter into follow-up rotation, so that the mandrel body stops in the limit grooves of different depths in turn, thereby changing the radial thrust of the mandrel body on the blade and realizing the step-by-step adjustment of the enlargement diameter.

[0008] Furthermore, the pitching stand includes multiple claw bodies, which are arranged in a circumferential array along the interior of the pitching stand. Each claw body has a positioning pin fixedly connected to its top surface. The bottom surface of the limiter has an annular lower end surface groove, and the tops of the multiple positioning pins are slidably connected to the lower end surface groove.

[0009] The limiter rotates, causing the lower end face groove to rotate. The lower end face groove moves the positioning pin, driving the multi-piece claw body to move radially outward to expand the center diameter of the ball-throwing seat, causing the blocking ball to fall and relieving the pressure inside the pipe.

[0010] Furthermore, a reset base is provided at the bottom of the ball-throwing seat. The outer wall of the reset base is slidably connected to the inner wall of the housing. A radially extending sliding groove is provided on the top surface of the reset base. The bottom ends of the multiple claw bodies are provided with key structures, and the key structures at the bottom ends of the multiple claw bodies are slidably connected to the corresponding sliding grooves.

[0011] The key structure and the sliding groove provide guidance for the multi-piece claw body, restricting the multi-piece claw body to only perform radial linear motion, and preventing the multi-piece claw body from jamming due to circumferential deflection when it disperses or gathers.

[0012] Furthermore, a heavy-duty spring is provided below the reset chassis, and the top end of the lower connector is hollow. The heavy-duty spring is sleeved in the cavity of the lower connector, the top end of the heavy-duty spring abuts against the bottom end surface of the reset chassis, and the bottom end of the heavy-duty spring abuts against the support surface inside the lower connector.

[0013] After the pressure inside the pipe is released, the heavy spring releases its elastic potential energy, pushing the reset chassis and the upper components to reset and move upward. During the upward movement, the positioning block gets stuck in the adjacent limit groove, completing the stage switching.

[0014] Furthermore, a collector is provided on the inner side of the heavy-duty spring. The collector includes a funnel, a funnel connector, a collecting cylinder, and a one-way opener. The top opening of the funnel faces the bottom of the pitching seat. The top of the funnel connector is fixedly connected to the bottom of the funnel. The bottom of the funnel connector is fixedly connected to the top of the collecting cylinder. The one-way opener is provided inside the funnel connector. The bottom of the one-way opener is fixedly connected to the collecting cylinder. A gap is left between the top of the one-way opener and the bottom of the funnel. The bottom of the collecting cylinder is fixedly connected to the inner wall of the lower connector.

[0015] The funnel guides the falling balls into the collection cylinder, preventing them from entering the lower drill string with the drilling fluid and clogging the water holes. At the same time, a one-way opener is used to prevent the balls from accidentally falling out of the collector during operation.

[0016] Furthermore, the multiple mandrel guide rails are arranged sequentially from top to bottom along the outer wall of the mandrel body, and the outer diameter of the multiple mandrel guide rails increases progressively from top to bottom.

[0017] Different outer diameter mandrel guide sections correspond to different limit groove positions. When the mandrel body is locked in the corresponding position, the corresponding outer diameter mandrel guide section supports the inner wall of the blade wing and maintains the set hole enlargement diameter.

[0018] Furthermore, a mandrel connection port is fixedly connected to the bottom end of the mandrel body, and the top end of the limiter is sleeved on the outer wall of the mandrel connection port. A bearing is provided between the stepped surface of the outer wall of the limiter and the stepped surface of the outer wall of the mandrel connection port.

[0019] The bearing isolates the end face friction between the spindle connection port and the limiter, reducing the resistance of the limiter to circumferential rotation under axial heavy load.

[0020] Furthermore, an upper ring cover is provided at the connection between the mandrel body and the limiter. The upper ring cover is located inside the housing. The top end of the upper ring cover is axially fixedly connected to the protrusion at the bottom end of the mandrel body, and the bottom end of the upper ring cover is fixedly connected to the groove at the top end of the limiter.

[0021] The upper ring cover axially fixes the spindle body and the limiter, so that the spindle body and the limiter can move axially linearly synchronously within the housing.

[0022] Furthermore, a lower ring cover is sleeved on the outside of the connection between the limiter and the reset base. The top end of the inner wall of the lower ring cover is threadedly connected to the groove on the outer wall of the bottom end of the limiter, and the bottom end of the inner wall of the lower ring cover is threadedly connected to the outer wall of the top end of the reset base.

[0023] The lower ring cover connects the limiter and the reset chassis, making the limiter, ball seat and reset chassis an integral module, realizing the continuous transmission of axial force.

[0024] This invention provides a multi-stage ball-drop type hydraulic variable diameter reamer while drilling. It has the following beneficial effects: 1. This invention provides a series of interconnected, zigzag-shaped in-situ limiting grooves (first, second, and third) on the outer wall of the limiter. These grooves, along with a positioning block fixed to the housing, guide the limiter to rotate and shift gears when pressed downwards and when the spring rebounds. Combined with a multi-segment mandrel guide rail with progressively increasing outer diameter on the outer wall of the mandrel body, the invention can stably lock the mandrel body in different axial positions through repeated ball-throwing, pressure-accumulating, and pressure-releasing rebound operations. This supports the corresponding extension of the cutter wings, enabling multi-stage diameter expansion and cutter wing retraction during a single drilling process.

[0025] 2. This invention, by opening an annular lower end face groove on the bottom end face of the limiter to move the positioning pin at the top of the claw body, and by using the radial sliding groove on the top surface of the reset chassis to guide and restrict the key structure at the bottom of the claw body, can convert the rotational motion of the limiter during shifting and rebounding into the radial translation of multiple claw bodies, forcing the multiple claw bodies to spread outwards to make the ball fall and release pressure, or pulling the multiple claw bodies to regroup and restore the reduced diameter during rebound, thereby realizing the automatic establishment and release of pressure difference in the pipe.

[0026] 3. This invention provides a collector in the cavity inside the heavy spring, with the top opening of the funnel facing the bottom of the ball-dropping seat. The bottom collection cylinder is fixedly connected to the inner wall of the lower connector. This allows the small balls that have lost support after completing the interception task to be guided and collected in a concentrated manner, preventing the working small balls from continuing to flow downward with the drilling fluid and causing blockage of the water holes in the lower drilling tools. Attached Figure Description

[0027] Figure 1 This is a perspective view of the overall appearance of the present invention; Figure 2 This is a schematic diagram of the overall half-section structure in the initial state of the present invention; Figure 3 This is a schematic diagram of the overall half-section structure of the present invention under the maximum diameter expansion state; Figure 4 This is a schematic diagram of the limiter of the present invention; Figure 5 This is a schematic diagram of the structure of the pitching stand of the present invention; Figure 6 This is a schematic diagram of the mandrel structure of the present invention; Figure 7 This is a schematic diagram of the collector of the present invention; Figure 8 This is a partial cross-sectional structural schematic diagram of the positioning block of the present invention; Figure 9 This is a partial cross-sectional view of the upper ring cover of the present invention. Figure 10 The diagram shows the structure of the hole-expanding assembly of the present invention under different working conditions: where I is the initial retraction state, II is the first-level hole-expanding state, III is the second-level hole-expanding state, and IV is the third-level hole-expanding state.

[0028] The components include: 1. Housing; 2. Blade; 3. Upper connector; 4. Lower connector; 5. Positioning block; 6. Heavy-duty spring. 7. Collector; 701. Funnel; 702. Funnel connector; 703. Collection cylinder; 704. One-way opener / closer; 8. Bearings; 9. Pitching seat; 901. Lower end face groove; 902. Claw body; 903. Positioning pin; 904. Sliding groove; 10. Mandrel body; 11. Limiter; 1100. In-situ limit groove; 1101. First limit groove; 1102. Second limit groove; 1103. Third limit groove; 12. Mandrel connection port; 13. Upper ring cover; 14. Mandrel guide rail; 15. Lower ring cover; 16. Blade groove; 17. Blade rotation shaft; 18. Reset base. Detailed Implementation

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

[0030] Please see the appendix Figure 1 - Appendix Figure 3 and attached Figure 10 This invention provides a multi-stage ball-throwing type hydraulic variable diameter reamer, including a housing 1, an upper connector 3, and a lower connector 4. The housing 1 is fixedly connected to the bottom end of the upper connector 3, and the top end of the lower connector 4 is fixedly connected to the bottom end of the housing 1. A mandrel body 10 is slidably connected inside the housing 1. The outer wall of the mandrel body 10 is provided with multiple mandrel guide rails 14. Both outer walls of the housing 1 are provided with cutter wing grooves 16, and the inner wall of the cutter wing grooves 16 extends into the interior of the housing 1. A cutter wing rotation shaft 17 is fixedly connected to the inner wall of the housing 1. The outer wall of the cutter wing rotation shaft 17 is... A blade 2 is rotatably connected. The inner wall of the blade 2 abuts against the outer wall of the spindle guide rail 14. One end of the blade 2 away from the spindle guide rail 14 passes through the blade groove 16. A limiter 11 is sleeved on the bottom end of the spindle body 10. A positioning block 5 is threadedly connected to the side wall of the housing 1. One end of the positioning block 5 passes through the side wall of the housing 1 and is slidably connected to the outer wall of the limiter 11. A ball-throwing seat 9 is provided below the limiter 11. The outer wall of the ball-throwing seat 9 is slidably connected to the inner wall of the housing 1. The top end of the ball-throwing seat 9 and the bottom end of the limiter 11 are connected by a pin groove structure. Specifically, in the initial non-operational stage, the upper connector 3 is fixed to the upper drill string, and the lower connector 4 is connected to the lower drill string. When reaming is performed, a small ball is dropped into the drill string. The ball falls with the drilling fluid into the ball-dropping seat 9, forming a flow trap. Under the pressure differential thrust, the ball-dropping seat 9 moves downward, causing the mandrel body 10 and the limiter 11 to combine into a whole and slide downward along the housing 1. Figure 10 The four working states are shown. In working state I, the blade 2 is completely retracted into the blade groove 16. The mandrel guide rail 14 moves upward with the mandrel body 10. The outer wall of the mandrel guide rail 14 presses against the inner wall of the blade 2, driving the blade 2 to rotate outward around the blade rotation axis 17 fixed in the housing 1 and extend out of the blade groove 16. With the outer diameter of the mandrel guide rail 14 increasing step by step from top to bottom, the first-level hole enlargement state as shown in working state II, the second-level hole enlargement state as shown in working state III, and the third-level hole enlargement state with the largest cutting extension as shown in working state IV are realized in sequence, thus achieving hole enlargement by cutting the formation.

[0031] Please see the appendix Figure 1 - Appendix Figure 4 Appendix Figure 6 Appendix Figure 8 and attached Figure 9In a preferred embodiment of the present invention, an upper ring cover 13 is provided at the connection between the mandrel body 10 and the limiter 11. The upper ring cover 13 is located inside the housing 1. The top end of the upper ring cover 13 is axially fixedly connected to a protrusion at the bottom end of the mandrel body 10, and the bottom end of the upper ring cover 13 is fixedly connected to a groove at the top end of the limiter 11. A mandrel connection port 12 is fixedly connected inside the bottom end of the mandrel body 10. The top end of the limiter 11 is sleeved on the outer wall of the mandrel connection port 12. The stepped surface of the outer wall of the limiter 11 and the stepped surface of the outer wall of the mandrel connection port 12 are aligned. A bearing 8 is provided between the surfaces. The limiter 11 includes an in-situ limiting groove 1100, a first limiting groove 1101, a second limiting groove 1102 and a third limiting groove 1103. The in-situ limiting groove 1100, the first limiting groove 1101, the second limiting groove 1102 and the third limiting groove 1103 are connected to form a zigzag shape and are arranged at intervals along the outer wall of the limiter 11. The positioning block 5 is slidably connected in the zigzag groove. The multi-segment spindle guide rail 14 is arranged axially from top to bottom along the outer wall of the spindle body 10, and the outer diameter increases step by step from top to bottom. Specifically, the upper ring cover 13 axially fixes the spindle body 10 and the limiter 11 without restricting their rotational movement. The lower end surfaces of the steps of the upper ring cover 13 and the lower ring cover 15 are both knurled and lubricated during operation to reduce friction caused by relative rotation. When the limiter 11 moves downward, the positioning block 5 slides relative to each other in the zigzag groove, guiding the limiter 11 to rotate and change gears. The bearing 8 reduces contact friction during pressure rotation. After depressurization, the stationary positioning block 5 slides along the zigzag groove and gets stuck inside the first limit groove 1101, locking the spindle body 10 in the first gear. The spindle guide rails 14 with different outer diameters support the blade wing 2 to maintain the corresponding enlarged hole diameter. If the ball is thrown again in the future, the positioning block 5 slides into the second limit groove 1102 and the third limit groove 1103 in sequence to achieve multi-stage diameter change.

[0032] Please see the appendix Figure 2 - Appendix Figure 5In a preferred embodiment of the present invention, the pitching stand 9 includes multiple claw bodies 902, which are arranged in a circumferential array along the interior of the pitching stand 9. Each claw body 902 has a positioning pin 903 fixedly connected to its top surface. The bottom surface of the limiter 11 has an annular lower end face groove 901, and the tops of the multiple positioning pins 903 are slidably connected to the lower end face groove 901. A reset base 18 is provided at the bottom of the pitching stand 9, and the outer wall of the reset base 18 slides... The upper surface of the reset base 18 is provided with a radially extending sliding groove 904, which is dynamically connected to the inner wall of the housing 1. The bottom end of the multiple claw bodies 902 is provided with a key structure, which is slidably connected in the sliding groove 904. The connection between the limiter 11 and the reset base 18 is externally fitted with a lower ring cover 15. The top end of the inner wall of the lower ring cover 15 is threadedly connected to the groove of the outer wall of the bottom end of the limiter 11, and the bottom end of the inner wall of the lower ring cover 15 is threadedly connected to the outer wall of the top end of the reset base 18. Specifically, when the limiter 11 is passively rotated under the guidance of the positioning block 5, the lower end face groove 901 of the bottom end face of the limiter 11 rotates synchronously, actuating the positioning pin 903 connected to the claw body 902. Since the key structure at the bottom of the multi-claw body 902 is restricted by the sliding groove 904 on the reset base 18, the rotational force is converted into radial thrust, pushing the multi-claw body 902 to move radially outward along the sliding groove 904, making the center diameter of the ball seat 9 larger, and the intercepting ball loses support and falls. At the same time, the limiter 11 continues to rotate in the positive direction when it rebounds and enters the groove with the component, always in the clockwise direction when viewed from above. The lower end face groove 901 and the positioning pin 903 cooperate in the forward direction, pulling the multi-claw body 902 to regroup, so that the ball seat 9 returns to the reduced diameter state. The lower ring cover 15 ensures that the axial position of the limiter 11 and the reset base 18 is relatively fixed through the threaded connection, maintaining the stable transmission of the pin groove structure.

[0033] Please see the appendix Figure 2 - Appendix Figure 3 and attached Figure 7In a preferred embodiment of the present invention, a heavy-duty spring 6 is provided below the reset base 18. The top end of the lower connector 4 is hollow, and the heavy-duty spring 6 is sleeved in the cavity of the lower connector 4. The top end of the heavy-duty spring 6 abuts against the bottom end face of the reset base 18, and the bottom end of the heavy-duty spring 6 abuts against the support surface inside the lower connector 4. A collector 7 is provided inside the heavy-duty spring 6. The collector 7 includes a funnel 701, a funnel connector 702, a collection cylinder 703, and a one-way opener 704. The top opening of the hopper 701 faces the bottom of the pitching stand 9. The top of the funnel connector 702 is fixedly connected to the bottom of the funnel 701. The bottom of the funnel connector 702 is fixedly connected to the top of the collecting cylinder 703. A one-way opener 704 is provided inside the funnel connector 702. The bottom of the one-way opener 704 is fixedly connected to the collecting cylinder 703. A gap is left between the top of the one-way opener 704 and the bottom of the funnel 701. The bottom of the collecting cylinder 703 is fixedly connected to the inner wall of the lower connector 4. Specifically, when the ball-throwing seat 9 is pressed, it pushes the reset base 18 downward and compresses the heavy spring 6. After the multi-piece claw body 902 disperses and the ball falls, the flow obstruction inside the pipe is released, the pressure difference disappears, and the compressed heavy spring 6 rebounds, pushing the reset base 18 and the entire internal assembly upward. During the rebound process, it cooperates with the positioning block 5 to complete the gear switching of the limit groove. If the operation is over and the blade 2 needs to be retracted, simply put the ball in again and repeat the process of pressing down, dropping the ball to release pressure, and spring rebound. The positioning block 5 eventually slides back to its original position. The positioning groove 1100 returns the spindle body 10 to its initial second-lowest position, and the cutter wing 2 retracts accordingly. At the same time, the ball falling from the ball-dropping seat 9 enters the collector 7 inside the heavy spring 6, and passes through the funnel 701 with its opening facing upward, the funnel connector 702, and the one-way opener 704 in sequence. The one-way opener 704 opens when subjected to downward pressure, acting as a one-way channel, and falls into the collection cylinder 703 fixed on the inner wall of the lower connector 4, preventing the ball from blocking the water hole of the lower drill string as it descends with the drilling fluid.

[0034] Working principle: When not in operation, the upper connector 3 is fixed to the upper drill string, and the lower connector 4 is connected to the lower drill tool. The upper connector 3 and the lower connector 4 are protected by the housing 1. At this time, the heavy spring 6, which is sleeved in the cavity at the top of the lower connector 4, is compressed but not to the limit. The bottom end of the heavy spring 6 abuts against the internal support surface of the lower connector 4, and the top end pushes against the reset base 18, so that all internal moving components are in the second lowest position. The positioning block 5, which is fixed on the side wall of the housing 1, is inserted into the original position limiting groove 1100 on the surface of the limiter 11, and the cutter wing 2 is in a retracted state and hidden in the cutter wing groove 16 opened on both sides of the housing 1. When reaming is required, a small ball is dropped from the ground into the drill string. The ball falls into the ball-dropping seat 9 with the drilling fluid. At this time, the multiple claws 902 distributed in a circumferential array inside the ball-dropping seat 9 are in a contracted state, which jams the ball and forms a flow cutoff, establishing a drilling hydraulic differential. Under the thrust of this pressure differential, the ball-dropping seat 9 pushes the reset base 18 downward, overcoming and compressing the heavy spring 6. Since the top of the mandrel body 10 is fitted with the inner wall of the upper connector 3 through the upper ring cover 13, and the outer wall of the mandrel connection port 12 at the bottom of the mandrel body 10 is fitted with a limiter 11, the bottom of the limiter 11 is fixedly connected to the reset base 18 through the lower ring cover 15, the mandrel body 10, the limiter 11, the ball-dropping seat 9 and the reset base 18 are combined into a whole and slide downward along the inside of the housing 1. As the entire device moves downward, the positioning block 5 remains stationary on the housing 1, and the downward-moving limiter 11 is compressed. The positioning block 5 slides relative to the limiter 11 in the connecting zigzag groove on the surface of the limiter 11. The trajectory of the zigzag groove guides the limiter 11 to rotate once. The bearing 8, which is set between the limiter 11 and the stepped surface of the spindle connection port 12, reduces friction and ensures the rotation of the limiter 11. As the limiter 11 rotates passively, the annular lower end face groove 901 opened on the bottom end face of the limiter 11 also rotates synchronously. The rotational force moves the positioning pin 903 that is slidably connected in the lower end face groove 901. Since multiple positioning pins 903 are respectively fixedly connected to the top end face of the corresponding claw body 902, and the key structure at the bottom end of each claw body 902 is restricted in the sliding groove 904 that extends radially on the top surface of the reset base 18, the rotational force is converted into a radial thrust, which pushes multiple claw bodies 902 to spread outward along the sliding groove 904. At this time, the central aperture of the ball-throwing seat 9 becomes larger, the ball loses support and falls, and the falling ball enters the collector 7 set inside the heavy spring 6. It passes through the funnel 701 with the opening facing upward and the funnel connector 702 in sequence, and finally falls into the collection cylinder 703 that is fixed on the inner wall of the lower connector 4 at the bottom. After the ball falls, the flow obstruction inside the pipe is released, the pressure difference is eliminated, and the compressed heavy spring 6 rebounds, pushing the reset base 18 and the entire internal components upward. During the upward movement, the stationary positioning block 5 slides into and locks inside the first limiting groove 1101 along the guide of the zigzag groove. Since the axial position of the bottom of the first limiting groove 1101 is lower than the original limiting groove 1100, the spindle body 10 is locked in the first position, causing it to move upward to a position higher than the initial state. At this time, the spindle guide rail 14 provides support during the upward movement, keeping the blade wing 2 at the diameter of the first-stage expansion hole. At the same time, the limiter 11 rotates forward when it rebounds into the groove, and the lower end face groove 901 and the positioning pin 903 continue to cooperate in the forward direction, pulling the multi-piece claw body 902 to regroup, and the ball-throwing seat 9 returns to the reduced diameter state. If the blade wing 2 needs to be retracted after the operation is completed, it can be retracted by simply moving it back into the groove. The ball is inserted, and the process of pressing down, releasing pressure, and spring rebound is repeated. At this time, the positioning block 5 will slide from the first limiting groove 1101 back to the original limiting groove 1100, so that the spindle body 10 returns to the initial second-lowest position, and the blade 2 retracts to its original position. Since the first limiting groove 1101, the second limiting groove 1102 and the third limiting groove 1103 are alternately connected to the original limiting groove 1100, each change of the diameter expansion gear must pass through the original limiting groove 1100 as the initial transition. Therefore, if the subsequent strata require a larger hole diameter, the ball needs to be inserted again in the restored state. The positioning block 5 will slide from the original limiting groove 1100 into the second limiting groove 1102 to achieve a two-stage diameter expansion. If the ball is inserted again, it will be restored again. This process is repeated multiple times to achieve multi-stage alternating diameter expansion and blade 2 restoration.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended description and its equivalents.

Claims

1. A multi-stage ball-throwing type hydraulic variable diameter reamer, comprising a housing (1), an upper connector (3), and a lower connector (4), characterized in that: The housing (1) is fixedly connected to the bottom end of the upper connector (3), and the top end of the lower connector (4) is fixedly connected to the bottom end of the housing (1). The housing (1) is slidably connected to the spindle body (10), and the outer wall of the spindle body (10) is provided with multiple spindle guide rails (14). Both outer walls of the housing (1) are provided with blade wing grooves (16), and the inner wall of the blade wing groove (16) extends into the interior of the housing (1). The inner wall of the housing (1) is fixedly connected to a blade wing rotation shaft (17), and the outer wall of the blade wing rotation shaft (17) is rotatably connected to a blade wing (2). The inner side wall of the blade wing (2) abuts against the outer wall of the spindle guide rail (14), and one end of the blade wing (2) away from the spindle guide rail (14) passes through the blade wing groove (16). The bottom end of the spindle body (10) is fitted with a limiter (11), and the side wall of the housing (1) is threaded with a positioning block (5). One end of the positioning block (5) passes through the side wall of the housing (1) and is slidably connected to the outer wall of the limiter (11). A ball-throwing seat (9) is provided below the limiter (11). The outer wall of the ball-throwing seat (9) is slidably connected to the inner wall of the housing (1). The top end of the ball-throwing seat (9) and the bottom end of the limiter (11) are connected by a pin groove structure.

2. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 1, characterized in that, The limiter (11) includes an in-situ limiting groove (1100), a first limiting groove (1101), a second limiting groove (1102), and a third limiting groove (1103). The in-situ limiting groove (1100), the first limiting groove (1101), the second limiting groove (1102), and the third limiting groove (1103) are connected to form a zigzag shape and are arranged at intervals along the outer wall of the limiter (11). The positioning block (5) is slidably connected in the zigzag-shaped channel formed by the in-situ limiting groove (1100), the first limiting groove (1101), the second limiting groove (1102), and the third limiting groove (1103).

3. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 1, characterized in that, The pitching stand (9) includes multiple claw bodies (902), which are arranged in a circumferential array along the interior of the pitching stand (9). Each claw body (902) has a positioning pin (903) fixedly connected to its top surface. The bottom surface of the limiter (11) has an annular lower end face groove (901), and the tops of the multiple positioning pins (903) are slidably connected to the lower end face groove (901).

4. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 3, characterized in that, The bottom end of the ball-throwing seat (9) is provided with a reset base (18). The outer wall of the reset base (18) is slidably connected to the inner wall of the housing (1). The top surface of the reset base (18) is provided with a radially extending sliding groove (904). The bottom ends of the multiple claw bodies (902) are all provided with key structures. The key structures at the bottom ends of the multiple claw bodies (902) are slidably connected to the corresponding sliding grooves (904).

5. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 4, characterized in that, A heavy spring (6) is provided below the reset base (18). The top of the lower connector (4) is hollow. The heavy spring (6) is sleeved in the cavity of the lower connector (4). The top of the heavy spring (6) abuts against the bottom surface of the reset base (18). The bottom of the heavy spring (6) abuts against the support surface inside the lower connector (4).

6. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 5, characterized in that, The heavy spring (6) has a collector (7) inside. The collector (7) includes a funnel (701), a funnel connector (702), a collection cylinder (703), and a one-way opener (704). The top opening of the funnel (701) faces the bottom of the ball-throwing seat (9). The top of the funnel connector (702) is fixedly connected to the bottom of the funnel (701). The bottom of the funnel connector (702) is fixedly connected to the top of the collection cylinder (703). The one-way opener (704) is provided inside the funnel connector (702). The bottom of the one-way opener (704) is fixedly connected to the collection cylinder (703). There is a gap between the top of the one-way opener (704) and the bottom of the funnel (701). The bottom of the collection cylinder (703) is fixedly connected to the inner wall of the lower connector (4).

7. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 1, characterized in that, The multiple mandrel guide rails (14) are arranged sequentially from top to bottom along the outer wall of the mandrel body (10), and the outer diameter of the multiple mandrel guide rails (14) increases from top to bottom.

8. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 1, characterized in that, The bottom end of the spindle body (10) is fixedly connected to a spindle connection port (12), and the top end of the limiter (11) is sleeved on the outer wall of the spindle connection port (12). A bearing (8) is provided between the stepped surface of the outer wall of the limiter (11) and the stepped surface of the outer wall of the spindle connection port (12).

9. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 1, characterized in that, An upper ring cover (13) is provided at the connection between the spindle body (10) and the limiter (11). The upper ring cover (13) is located inside the housing (1). The top end of the upper ring cover (13) is axially fixedly connected to the protrusion at the bottom end of the spindle body (10), and the bottom end of the upper ring cover (13) is fixedly connected to the groove at the top end of the limiter (11).

10. The multi-stage ball-throwing type hydraulic variable diameter reamer as described in claim 4, characterized in that, A lower ring cover (15) is sleeved on the outside of the connection between the limiter (11) and the reset base (18). The top of the inner wall of the lower ring cover (15) is threaded to the groove of the outer wall of the bottom end of the limiter (11), and the bottom of the inner wall of the lower ring cover (15) is threaded to the outer wall of the top end of the reset base (18).

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