Modularized horizontal directional drilling system for land wind power line

Abstract

The invention discloses a modularized horizontal directional drilling system for an onshore wind power line, and belongs to the technical field of horizontal directional drilling. The system comprises a composite drill bit assembly, an extensible drill rod system, a steering structure, a guiding system and a central controller. Efficient rock breaking and wall protecting, high-precision track control and intelligent construction under the complex geology are achieved by dynamically adjusting the rotating speed of the drill bit, slurry jetting and the steering amount, the problems of poor adaptability and low precision of a traditional technology are solved, and the method is suitable for long-distance hole forming when a wind power line penetrates through obstacles.

Description

Technical Field

[0001] This invention relates to the field of horizontal directional drilling technology, and in particular to a modular horizontal directional drilling system for onshore wind power lines. Background Technology

[0002] With the rapid development of the onshore wind power industry, transmission lines need to cross complex obstacles such as highways, rivers, farmland, and buildings. Horizontal directional drilling (HDD) technology has become a key method for laying wind power transmission lines due to its low surface disturbance and high construction efficiency. However, existing HDD systems have significant limitations in complex geological conditions (such as soft soil, gravel layers, and weathered rock interbedded layers): Insufficient rock breaking and wall protection capabilities of the drill bit: Traditional single-cone or PDC drill bits have low cutting efficiency and are prone to wear in hard rock formations, and the mud injection is mostly axial and direct, making it difficult for the wall protection slurry to evenly cover the borehole wall, which can easily lead to borehole collapse and diameter reduction; Poor terrain adaptability of the drill rod system: Conventional drill rods use rigid connections, which cannot adapt to undulating terrain, and the torque transmission loss is large during long-distance drilling, which can easily cause the drill to get stuck; Low steering control accuracy: Existing steering mechanisms mostly rely on a single hydraulic oil. The cylinder or mechanical bend has a large deflection angle (usually >5°) and a slow response, making it difficult to achieve small trajectory adjustments. The cumulative error is significant during long-distance drilling. The guidance and correction capabilities are weak: traditional guidance systems mostly use wired measurement or single-point magnetic field positioning, which has low positioning accuracy (error >5cm) and lacks a real-time correction mechanism. It is difficult to recover quickly after the trajectory deviates. There is a lack of intelligent collaborative control: the operating parameters (drill bit speed, mud pressure, steering sensitivity) mostly rely on manual experience to set and cannot be dynamically adjusted according to changes in the formation, resulting in low drilling efficiency and serious equipment wear in complex geological conditions.

[0003] Therefore, there is an urgent need for a modular horizontal directional drilling system that can adapt to complex geology, has high-precision trajectory control, and intelligent collaborative adjustment, in order to meet the requirements of long-distance, high-precision, and high-efficiency drilling for onshore wind power line construction. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a modular horizontal directional drilling system for onshore wind power lines.

[0005] To achieve the above-mentioned technical objectives, the core technical solution of this invention lies in using a composite drill bit assembly to achieve efficient rock breaking and wall protection, an expandable drill rod system to adapt to terrain, a steering structure to precisely control the trajectory, and a guidance system for real-time positioning. Combined with the intelligent collaborative control of the central controller, this solves the problem of drilling wind power lines in complex geological conditions. As a preferred embodiment of the present invention, the present invention includes: a composite drill bit assembly comprising a three-conical rotatable drill bit unit and three sets of symmetrical mud nozzles; the three-conical rotatable drill bit unit comprises three conical drill bits symmetrically arranged 120° circumferentially, each conical drill bit being movably connected to the drill bit body via a micro-rotating shaft to achieve rotation, and the head of the conical drill bit being provided with carbide teeth; the three sets of symmetrical mud nozzles are spaced apart from the conical drill bits along the axial direction of the drill bit body and integrated inside the drill bit body, each set of mud nozzles including a high-pressure nozzle, and a mud pipe penetrating through a standard section of the drill pipe and communicating with the high-pressure nozzle; The expandable drill pipe system includes several drill pipe standard sections with detachable first-to-last connections. Each drill pipe standard section has a universal joint at its end, and adjacent drill pipe standard sections can rotate relative to each other through the universal joints. The steering structure includes three electrically operated telescopic rods symmetrically arranged at 120° along the circumference of the drill pipe. The two ends of each electrically operated telescopic rod are respectively hinged to preset hinge positions on the circumference of the adjacent standard section of the drill pipe, and the drill bit body is deflected at a small angle through coordinated telescopic movement. The guidance system includes a magnetic field emitting probe fixed to the outside of the drill bit body and a magnetic field receiver set on the ground, which is used to receive magnetic field signals and achieve trajectory positioning. The central controller integrates a collaborative control algorithm and communicates with the composite drill bit assembly, expandable drill pipe system, steering structure, and guidance system. It dynamically adjusts the rotation speed of the conical drill bit, the mud nozzle group injection mode, and the extension and retraction of the steering structure according to geological parameters.

[0006] As a preferred embodiment of the present invention, the carbide teeth of the conical drill head are arranged in a gradient, including high-density small-sized teeth at the front end of the cutting edge and medium-low density large-sized teeth at the rear end, with a cutting edge inclination angle of 15°-30°; the micro-rotating shaft allows the conical drill to adaptively deflect within a range of ±10°; the injection direction of the high-pressure nozzle is at an angle of 30°-45° to the cutting direction of the conical drill and is arranged circumferentially toward the conical drill, for injecting wall-protecting slurry.

[0007] As a preferred embodiment of the present invention, the universal joint of the expandable drill pipe system is a ball cage universal joint, the inner ring of which is fixedly connected to the end of the standard drill pipe section through a bearing seat, and the outer ring is connected to the end spline of the adjacent standard drill pipe section to realize torque transmission and angle compensation; a dust cover is provided on the outside of the universal joint.

[0008] As a preferred embodiment of the present invention, the electric telescopic rod of the steering structure includes a cylinder, a piston rod, and a hinge plate; the end of the cylinder is hinged to a second hinge on the circumference of the drill pipe standard section via a first hinge seat, and the end of the piston rod is hinged to a fourth hinge on the side of the universal joint via a third hinge seat.

[0009] As a preferred embodiment of the present invention, the magnetic field transmitting probe is provided in four shapes, arranged in a rectangular or ring shape on the outside of the drill bit body, with the probe axis and the drill bit body axis forming an angle of 0°-5°; the magnetic field receiver includes at least four magnetic induction elements, which transmit positioning data to the central controller.

[0010] As a preferred embodiment of the present invention, the three electric telescopic rods of the steering structure are controlled by a central controller to achieve a coordinated action of one extension and two retractions: one electric telescopic rod extends while the other two electric telescopic rods retract synchronously, generating a resultant torque around the drill rod axis, driving the drill bit body to deflect by 0.5°-3°; the electric telescopic rods have built-in displacement sensors and force sensors to provide real-time feedback on the extension amount and load status.

[0011] As a preferred embodiment of the present invention, the magnetic field transmitting probe of the guiding system emits a low-frequency alternating magnetic field, and the magnetic field receiver calculates the probe coordinates by triangulation, with a positioning accuracy of ±2cm; when the trajectory deviation exceeds the set threshold, the central controller triggers an alarm and generates a correction command.

[0012] As a preferred embodiment of the present invention, the central controller integrates a geological parameter database, storing drill bit rotation speed range, mud pressure threshold, and steering sensitivity parameters corresponding to different geological types; the system also includes a geological sensor, which is installed on the outer wall of the standard section of the drill pipe, for real-time acquisition of formation resistivity and hardness data and transmission to the central controller.

[0013] On the other hand, the present invention provides a method for horizontal directional drilling construction of onshore wind power lines, comprising the following steps: Step S1: Geological exploration and parameter input. Target stratum parameters are collected through geological sensors, and the central controller calls the geological parameter database to match the initial parameters. Step S2: Dynamically adjust the operating parameters. Based on real-time geological data, the central controller optimizes the rotation speed of the conical drill bit, the high-pressure injection ratio and flow rate of the mud nozzle group through a collaborative control algorithm. Step S3: Track monitoring and correction. The magnetic field receiver provides real-time feedback on the drill bit position. When a track deviation is detected, the central controller controls the electric telescopic rod of the steering structure to perform a one-extension-two-retraction action, driving the drill bit body to deflect slightly to correct the deviation. Step S4: Modular drill pipe extension. According to the drilling depth, connect the standard drill pipe sections in sequence, and use universal joints to adapt to the terrain undulations until the target position is reached. Step S5: Post-drilling treatment: Stop the drill bit rotation, inject solidifying slurry through the mud nozzle assembly, and retrieve the drill rod system after the borehole wall has stabilized.

[0014] This invention also provides a method for monitoring and correcting the trajectory of horizontal directional drilling for onshore wind power lines. The correction process includes: ① The magnetic field receiver calculates the lateral and angular deviations between the current trajectory and the target trajectory; ② When the central controller determines that the lateral deviation is greater than the lateral deviation threshold or the angular deviation is greater than the angular deviation threshold, it activates the steering structure; ③ The electric telescopic rod operates in a one-extension-two-retraction mode, with a single correction angle not exceeding 2°, and multiple iterations are performed until the deviation meets the standard; ④ After the correction is completed, the electric telescopic rod is reset and the preload is maintained.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The three conical rotatable drill bit unit has three conical drill bits arranged symmetrically along the circumference at 120°. It works with a micro-rotating shaft to achieve ±10° adaptive deflection. Combined with gradient-arranged cemented carbide teeth (high-density small teeth at the front end to break hard rock, and medium-low density large teeth at the rear end to improve efficiency), it significantly improves the rock-breaking efficiency and wear resistance of soft soil to moderately weathered rock formations. The three sets of symmetrical mud nozzles spray wall-protecting slurry at an angle of 30°-45° around the circumference to form a uniform mud cake, which effectively prevents hole collapse and diameter reduction. It is especially suitable for loose formations such as sand and gravel. 2. The expandable drill pipe system uses a ball cage universal joint to connect the standard drill pipe sections. The inner ring bearing seat is fixed, and the outer ring spline connection realizes torque transmission and angle compensation to adapt to terrain undulations. With the dust cover to protect the joints, it solves the risk of stuck drill in rigid connection during long-distance drilling and supports flexible expansion of drilling depth. 3. The steering structure generates a resultant torque around the drill rod axis through three electric telescopic rods, one extending and two retracting, which drives the drill bit body to deflect slightly. The single correction is ≤2°. Combined with displacement / force sensors to provide real-time feedback on the load status, it avoids over-adjustment or under-adjustment and achieves accurate trajectory tracking for long-distance drilling. 4. The central controller integrates a geological parameter database and real-time geological sensors, and dynamically adjusts the drill bit speed, mud injection ratio and steering sensitivity through a collaborative control algorithm; the magnetic field guidance system provides real-time feedback on trajectory deviations, and automatically triggers correction commands when the threshold is exceeded, reducing manual intervention and lowering the rate of operational errors.

[0016] In summary, this invention optimizes the entire process of horizontal directional drilling in complex geological conditions, from rock breaking to wall protection to turning, guiding, and control. It provides key technical support for the safe and efficient construction of onshore wind power lines and has significant engineering application value and market promotion prospects. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is the front view of the present invention; Figure 3 This is a cross-sectional structural diagram of the present invention; Figure 4 This is a partially enlarged view of the present invention; Figure 5 This is a partially enlarged view of the composite drill bit assembly in this invention; In the diagram: 1. Composite drill bit assembly; 2. Expandable drill pipe system; 3. Steering structure; 4. Guiding system; 5. Central controller; 11. Three-cone rotatable drill bit unit; 12. Mud nozzle assembly; 21. Standard drill pipe section; 22. Universal joint; 31. Electric telescopic rod; 41. Magnetic field emitting probe; 42. Magnetic field receiver; 51. Geological parameter database; 52. Geological sensor; 111. Conical drill bit; 112. Miniature rotating shaft; 113. Drill bit body; 114. Carbide teeth; 121. High-pressure nozzle; 122. Mud pipe; 221. Bearing housing; 222. Dust cover; 311. Cylinder body; 312. Piston rod; 313. Hinge plate; 314. First hinge seat; 315. Second hinge seat; 316. Third hinge seat; 317. Fourth hinge seat. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] In the attached diagram, all identical reference numerals refer to the same components.

[0020] Example 1: Construction of soft soil and gravel strata like Figure 1-4 As shown, this embodiment is applied to the laying of onshore wind power lines through a layer of sand and gravel, with a target trajectory of 800 meters horizontally and 6 meters deep.

[0021] System Assembly and Connection: The composite drill bit assembly 1 is installed at the foremost end of the drill rod. Three sets of symmetrical mud nozzle assemblies 12 are fixed to the outside of its drill bit body 113. Each set contains a high-pressure nozzle 121. The mud pipe 122 runs through the inside of the standard section 21 of the drill rod to the ground slurry supply system. The three conical rotatable drill bit unit 11 has three conical drill bits 111 arranged circumferentially at 120°. They are movably connected to the drill bit body 113 through a miniature rotating shaft 112. The carbide teeth 114 at the head are arranged in a gradient (high-density small teeth at the front end and medium-low density large teeth at the rear end), with a cutting edge inclination angle of 25°.

[0022] The expandable drill pipe system 2 consists of 10 drill pipe standard sections 21 connected end to end. Each section is equipped with a ball cage universal joint 22 at the end. The inner ring is fixed to the drill pipe standard section 21 through a bearing seat 221, and the outer ring is connected to the adjacent section by a spline. The outer side is covered with a dust cover 222 to prevent mud and sand from entering.

[0023] The three electric telescopic rods 31 of the steering structure 3 are arranged 120° around the drill pipe. The cylinder body 311 is hinged to the second hinge seat 315 on the circumference of the drill pipe standard section 21 through the first hinge seat 314. The piston rod 312 is hinged to the fourth hinge seat 317 on the side of the universal joint 22 through the third hinge seat 316.

[0024] The guidance system 4 has four magnetic field emitting probes 41, which are arranged in a rectangle on the outside of the drill bit body 113, with the axis of the probes making an angle of 3° with the axis of the drill bit body 113; a magnetic field receiver 42 is set on the ground, which contains four magnetic induction elements.

[0025] The central controller 5 integrates a geological parameter database 51, and the geological sensor 52 is attached to the outer wall of the standard section 21 of the drill pipe to collect formation resistivity and hardness data in real time.

[0026] Operation Process: After startup, the conical drill bit 111 rotates under the drive of the micro-rotating shaft 112, and the carbide teeth 114 break up sand and gravel. Three sets of mud nozzles 12 spray wall-protecting slurry circumferentially at a 40° angle, and the mud pipe 122 delivers high-pressure slurry to form a mud skin for wall protection. The geological sensor 52 collects formation hardness data, and the central controller 5 calls the database 51 to match parameters, setting the rotation speed of the conical drill bit 111 to 80 rpm and the mud flow rate to 150 L / min. During drilling, the magnetic field receiver 42 provides real-time feedback on the drill bit position (accuracy ±2 cm) through triangulation. When the lateral deviation reaches 3 cm, the central controller 5 controls one electric telescopic rod 31 of the steering structure 3 to extend and the other two to retract, generating a resultant torque to drive the drill bit body 113 to deflect by 1.5°. After a single correction, it resets and maintains the preload. After drilling to 800 meters, the drill bit rotation stops, and solidified slurry is injected through the mud nozzles 12. After the borehole wall stabilizes, the drill rod system is retrieved.

[0027] Example 2: Long-distance crossing construction of weathered rock strata This embodiment is applied to onshore wind power lines crossing weathered rock layers, with a target trajectory horizontal distance of 1200 meters and a burial depth of 8 meters.

[0028] System adjustment and function implementation: The tapered drill bit 111 of the composite drill bit assembly 1 has a micro rotating shaft 112 that allows for ±10° adaptive deflection, and the cutting edge inclination angle of the carbide teeth 114 is adjusted to 20° to enhance the hard rock cutting capability; the high-pressure nozzle 121 of the mud nozzle assembly 12 is adjusted to a 35° angle to increase the coverage of the wall protection slurry.

[0029] The expandable drill pipe system 2 increases to 15 standard drill pipe sections 21, the universal joint 22 compensates for changes in drill pipe angle caused by terrain undulations, and the dust cover 222 ensures joint cleanliness.

[0030] The electric telescopic rod 31 of the steering structure 3 has built-in displacement and force sensors to provide real-time feedback on the telescopic amount and load; the central controller 5 uses a collaborative control algorithm to control the electric telescopic rod 31 to make fine adjustments in 0.5° steps when it detects an increase in rock hardness, with a single correction not exceeding 2° to avoid over-adjustment.

[0031] The magnetic field emitting probe 41 of the guidance system 4 emits a low-frequency alternating magnetic field, and the magnetic field receiver 42 calculates the coordinate deviation. When the angle deviation exceeds 1°, an alarm is triggered, and the central controller 5 generates a correction command.

[0032] The central controller 5 calls the corresponding parameters of weathered rock in the geological parameter database 51, increases the rotation speed of the cone drill bit 111 to 100 rpm, and sets the mud pressure threshold to 5 MPa. This threshold is consistent with the parameters of weathered rock in the geological parameter database (51). The geological sensor 52 uploads the formation resistivity data in real time and dynamically optimizes the injection ratio.

[0033] Key process: Upon reaching a depth of 600 meters and encountering moderately weathered rock, the geological sensor 52 detected a sudden increase in resistivity. The central controller 5 immediately increased the mud flow rate to 180 L / min to enhance wall protection. Simultaneously, the steering structure 3 performed three extension and two retraction maneuvers, cumulatively correcting the trajectory by 3°, bringing it back to the target. The entire process was monitored by the magnetic field guidance system 4, and the final lateral deviation of the borehole was controlled within 2 cm, meeting the accuracy requirements for wind power line pipeline laying.

[0034] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A modular horizontal directional drilling system for onshore wind power lines, characterized in that, include: The composite drill bit assembly (1) includes a three-cone rotatable drill bit unit (11) and three sets of symmetrical mud nozzles (12); the three-cone rotatable drill bit unit (11) includes three conical drill bits (111) arranged symmetrically along the circumference at 120°, each conical drill bit (111) is movably connected to the drill bit body (113) through a micro rotating shaft (112) to achieve self-rotation, and the head of the conical drill bit (111) is provided with carbide teeth (114); the three sets of symmetrical mud nozzles (12) are spaced apart from the conical drill bits (111) along the axial direction of the drill bit body (113) and integrated inside the drill bit body (113), each mud nozzle (12) includes a high-pressure nozzle (121), and a mud pipe (122) passes through the drill rod standard section (21) and is connected to the high-pressure nozzle (121); The expandable drill pipe system (2) includes several drill pipe standard sections (21) that are detachably connected at the front and rear. Each drill pipe standard section (21) has a universal joint (22) at its end. Adjacent drill pipe standard sections (21) can rotate relative to each other through the universal joint (22). The steering structure (3) includes three electric telescopic rods (31) arranged symmetrically along the circumference of the drill pipe at 120°. The two ends of each electric telescopic rod (31) are respectively hinged to the preset hinge position on the circumference of the adjacent standard section (21) of the drill pipe, and the drill bit body (113) is deflected at a small angle through coordinated telescopic movement. The guidance system (4) includes a magnetic field transmitting probe (41) fixed to the outside of the drill bit body (113) and a magnetic field receiver (42) set on the ground, which is used to receive magnetic field signals and realize trajectory positioning; The central controller (5) integrates a collaborative control algorithm and communicates with the composite drill bit assembly (1), the expandable drill pipe system (2), the steering structure (3), the guidance system (4), and the geological sensor (52). It dynamically adjusts the rotation speed of the tapered drill bit (111), the injection mode of the mud nozzle group (12), and the extension and retraction of the steering structure (3) according to geological parameters. The geological sensor (52) is set on the outer wall of the standard section of the drill pipe (21) and is used to collect formation resistivity and hardness data in real time and transmit them to the central controller (5).

2. The modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The carbide teeth (114) on the head of the tapered drill bit (111) are arranged in a gradient, including high-density small teeth at the front end of the cutting edge and medium-low density large teeth at the rear end, with a cutting edge inclination angle of 15°-30°; the micro-rotating shaft (112) allows the tapered drill bit (111) to self-adaptively deflect within a range of ±10°; the injection direction of the high-pressure nozzle (121) is at an angle of 30°-45° to the cutting direction of the tapered drill bit (111) and is arranged circumferentially along the drill bit body (113) for injecting wall-protecting slurry into the hole wall.

3. A modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The universal joint (22) is a ball cage universal joint. Its inner ring is fixedly connected to the end of the drill rod standard section (21) through the bearing seat (221), and its outer ring is fixedly connected to the end of the adjacent drill rod standard section (21). Torque transmission and angle compensation are achieved through the steel balls inside the ball cage. A dust cover (222) is provided on the outside of the universal joint (22).

4. A modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The electric telescopic rod (31) of the steering structure (3) includes a cylinder (311), a piston rod (312), and a hinge plate (313); the end of the cylinder (311) is hinged to the second hinge seat (315) on the circumference of the drill pipe standard section (21) through the first hinge seat (314), and the end of the piston rod (312) is hinged to the fourth hinge seat (317) on the side of the universal joint (22) through the third hinge seat (316).

5. A modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The magnetic field transmitting probe (41) is provided in four, arranged in a rectangular or ring shape on the outside of the drill bit body (113), with the probe axis and the drill bit body (113) axis forming an angle of 0°-5°; the magnetic field receiver (42) contains at least four magnetic induction elements and transmits positioning data to the central controller (5).

6. A modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The three electric telescopic rods (31) of the steering structure (3) are controlled by the central controller (5) to achieve a coordinated action of one extension and two retractions: one electric telescopic rod (31) extends while the other two electric telescopic rods (31) retract synchronously, generating a resultant torque around the drill rod axis, driving the drill bit body (113) to deflect by 0.5°-3°, with a single correction angle of 0.5°-2°; the electric telescopic rod (31) has built-in displacement sensors and force sensors to provide real-time feedback on the extension amount and load status.

7. A modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The magnetic field transmitting probe (41) of the guidance system (4) emits a low-frequency alternating magnetic field, and the magnetic field receiver (42) calculates the probe coordinates by the triangulation method, with a positioning accuracy of ±2cm; when the trajectory deviation exceeds the set threshold, the central controller (5) triggers an alarm and generates a correction command.

8. A modular horizontal directional drilling system for onshore wind power lines according to claim 1, characterized in that, The central controller (5) integrates a geological parameter database (51) to store the drill bit rotation speed range, mud pressure threshold and steering sensitivity parameters corresponding to different geological types; the geological sensor (52) is set on the outer wall of the standard section (21) of the drill pipe to collect formation resistivity and hardness data in real time and transmit them to the central controller (5).

9. A method for horizontal directional drilling construction of onshore wind power lines based on the system described in any one of claims 1-8, characterized in that, Includes the following steps: Step S1: Geological exploration and parameter input. Target stratum parameters are collected by geological sensors (52), and the central controller (5) calls the geological parameter database (51) to match the initial parameters. Step S2: Dynamically adjust the operating parameters. Based on real-time geological data, the central controller (5) optimizes the rotation speed of the conical drill bit (111), the high-pressure injection ratio and flow rate of the mud nozzle group (12) through a collaborative control algorithm. Step S3: Track monitoring and correction. The magnetic field receiver (42) provides real-time feedback on the drill bit position. When a track deviation is detected, the central controller (5) controls the electric telescopic rod (31) of the steering structure (3) to perform a one-extension-two-retraction action, driving the drill bit body (113) to deflect slightly to correct the deviation. Step S4: Modular drill pipe extension. According to the drilling depth, connect the standard drill pipe sections (21) in sequence, and use the universal joint (22) to adapt to the terrain undulations until the target position is reached; Step S5: Post-hole treatment: Stop the drill bit rotation, inject solidified slurry through the mud nozzle assembly (12), and recover the drill rod system after the hole wall stabilizes.

10. The method according to claim 9, characterized in that, In step S3, the correction process includes: ① The magnetic field receiver (42) calculates the lateral deviation and angular deviation between the current trajectory and the target trajectory; ② When the central controller (5) determines that the lateral deviation is greater than the lateral deviation threshold or the angular deviation is greater than the angular deviation threshold, the steering structure (3) is activated. ③ The electric telescopic pole (31) operates in a one-extend-two-retract mode, with a single correction angle not exceeding 2°, and iterates multiple times until the deviation meets the standard; ④ After the correction is completed, the electric telescopic rod (31) is reset and the preload is maintained.

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