Variable-diameter and variable-wall-thickness drill rod for large-diameter directional drilling of top plate of extra-thick coal seam

Abstract

The invention discloses a variable-diameter and variable-wall-thickness drill rod for large-diameter directional drilling of a top plate of an extra-thick coal seam. The drill rod is divided into four functional sections in the axial direction, namely, a near-bit strengthening section, a deflection / stable deflection flexible section, a main body transmission section and a tail connection strengthening section. Different outer diameters and wall thicknesses are adopted for all the functional sections according to the actual stress state of the functional sections in the directional drilling process, and matching of material distribution and stress requirements is achieved. The near-bit strengthening section adopts the maximum outer diameter and the thickest wall thickness so as to bear high torque and abrasion; the deflection / stable deflection flexible section has certain flexibility on the premise of ensuring the bending fatigue strength; the wall thickness of the main body transmission section is optimized to realize light weight; and the tail connection reinforcing section improves the connection reliability through local thickening. The problems that a traditional equal-diameter equal-wall-thickness drill rod is integrally heavy, locally prone to damage, insufficient in adaptability and the like in large-diameter directional long drilling construction are solved, the overall service life of the drill rod is prolonged, and the drilling efficiency and economic benefits of the drill rod are improved.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment for mine roadways, specifically to a variable diameter and variable wall thickness drill rod for large-diameter directional drilling of the roof of extra-thick coal seams. Background Technology

[0002] In coal mine gas control projects, drilling large-diameter (usually greater than Φ153mm) directional long boreholes in the roof strata of extra-thick coal seams has become a core technical approach for intercepting gas accumulation in mining-induced fracture zones and ensuring safe and efficient mining operations. This technology, with its advantages of precise target area, large extraction radius, and ability to replace high-cost rock tunnels, has been widely applied in high-gas mining areas such as Binchang and Shendong. However, the large-scale promotion of this technology is facing an increasingly prominent engineering bottleneck: the reliability, lifespan, and economy of the drill pipe, a key component in drilling, are difficult to match with stringent construction requirements.

[0003] Currently, drill pipes used in construction are mainly derived from the API standard for oil drilling, adhering to a homogeneous design concept, meaning that each drill pipe is typically a uniform structure with a uniform outer diameter and wall thickness. This simplified design, originating from traditional vertical drilling, has its inherent defects amplified dramatically when faced with the large-diameter, long-distance, and complex trajectory conditions of directional drilling in coal mines. To resist the instantaneous peak torque and complex loads that may occur near the drill bit, designers have to select thick-walled, high-strength steel pipes capable of withstanding these loads for every section of the entire drill string, based on these extreme conditions. This directly results in an astonishing total weight of the drill string, making the manual handling and unloading operations in the well extremely strenuous, posing significant safety hazards, and severely hindering construction efficiency. More importantly, this fixed design completely ignores the non-uniform axial load spectrum that the drill pipe experiences in the actual three-dimensional borehole trajectory, thus causing a sharp contradiction between overall overperformance and insufficient local strength.

[0004] In actual directional drilling operations, the stress state of the drill pipe varies significantly along its axial direction. The proximal section, directly connected to the drill bit, continuously endures high-amplitude rotational torque, axial impact loads, and severe borehole wall wear when breaking hard rock formations or traversing fracture zones. Its main failure modes are torsional overload and surface wear failure. When drilling reaches the build-up or trajectory adjustment section, the drill pipe travels along the curved wellbore shape, and the tubing is subjected to periodically changing bending stresses. This area is prone to the initiation and propagation of fatigue cracks, a common origin of many sudden fracture accidents. Furthermore, in the threaded areas of all drill pipe connections, the abrupt changes in geometry and material stiffness create inherent stress concentration phenomena. Under combined tensile, compressive, torsional, and bending loads, connection failure modes such as disengagement, sticking, or leakage are highly likely to occur. Traditional homogeneous drill pipes use the same specifications throughout their entire length, requiring them to resist wear, fatigue, and overload simultaneously. This results in the material properties not being fully utilized in most low-stress sections, while exhibiting insufficient strength in a few high-stress critical sections. In essence, this approach sacrifices overall structural design, increasing weight and cost while failing to effectively prevent early failures in localized areas. Field practice shows that in large-diameter directional drilling, drill rod failures are mostly caused by early damage in these localized areas, and rarely by overall pipe yielding. Such localized failures easily lead to difficult-to-handle accidents such as broken drill rods and embedded drill bits, severely impacting hole formation rate and project economics.

[0005] To address the aforementioned technical challenges, the industry has implemented numerous technological improvements, such as using higher-grade steel to comprehensively enhance drill pipe strength, optimizing joint thread types to improve connection performance, and adding wear-resistant bushings near the drill bit. However, these improvements, in general, remain within the design scope of homogeneous drill pipes, representing localized reinforcements within the existing structural framework. They fail to fundamentally resolve the core issue of the mismatch between drill pipe material distribution and dynamic stress distribution throughout the borehole. Therefore, the effectiveness of existing improvements has certain limitations. To substantially overcome the current technical bottleneck and fully realize the technological potential of large-diameter directional drilling, it is essential to develop a new drill pipe structure capable of actively adapting to changes in axial load and precisely matching the drill pipe's mechanical properties with actual downhole conditions. This invention aims to meet this urgent technical need. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a variable diameter and variable wall thickness drill rod for large-diameter directional drilling of the roof of extra-thick coal seams.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This application provides a variable diameter and variable wall thickness drill rod for large-diameter directional drilling of the roof of extra-thick coal seams. The outer diameter and wall thickness of the drill rod tube, from the drill bit connection end to the tail connection end, exhibit non-constant but regular changes along the axial direction, forming a functional partition structure.

[0009] The structure includes at least: a near-bit reinforcement section, a directional drilling / stabilization flexible section, a main transmission section, and a tail connection reinforcement section; wherein, the outer diameter and wall thickness parameters of each functional section are designed differently based on the dominant load spectrum and main failure modes during the drilling process, so as to achieve active matching between material distribution and axial dynamic stress field.

[0010] Furthermore, the near-bit reinforcement section is located at the front end of the drill pipe, with an axial length of 0.5 meters to 1.5 meters; this section has the maximum outer diameter of the entire drill pipe. and the maximum wall thickness along the entire length And satisfy the following relation: ;in The wall thickness of the main transmission section.

[0011] Furthermore, the inner wall of the near-drill bit reinforced section is integrally formed with axially extending reinforcing ribs, which are spiral or straight; and / or,

[0012] The pipe section is made of ultra-high strength alloy steel, and its outer surface is treated with nitriding or chrome plating.

[0013] Furthermore, the flexible section for creating / stabilizing the directional drift is seamlessly connected to the rear end of the near-bit reinforcement section, and its axial length is 1.0 m to 3.0 m;

[0014] outer diameter of this section satisfy: , ;

[0015] The wall thickness of this section satisfy: Furthermore, the material undergoes sub-temperature quenching and low-temperature tempering heat treatment processes to obtain high fracture toughness and high fatigue limit, with Charpy V-notch impact energy Akv≥60J at -20℃.

[0016] Furthermore, the main transmission section constitutes the main length portion of the drill pipe, and its outer diameter... Maintain a constant outer diameter and match the outer diameter of the inclined / stabilizing flexible section. equal;

[0017] Its wall thickness This is a constant value used for lightweight back-calculation optimization based on the tensile safety factor and rated output torque of the drill string at the maximum design hole depth, and it satisfies... .

[0018] Furthermore, the tail connection reinforcement section is located at the end of the drill pipe. A thickened transition zone is formed by locally axially upsetting the tail of the pipe body, and a connecting thread is machined in the thickened transition zone.

[0019] The connecting thread is a non-API standard special thread with variable taper, large circular arc tooth root and negative angle bearing surface, and the tail connecting reinforcement section is entirely subjected to induction hardening treatment.

[0020] Furthermore, the tooth profile of the special thread is an asymmetrical composite shape with a negative angle on the bearing surface and a continuous large arc at the root, which makes the tensile strength and torsional strength of the connecting thread higher than those of the pipe body.

[0021] Furthermore, a tapered transition zone is provided between any two adjacent functional segments; the tapered angle α of the tapered transition zone is 5°~15°, and its axial transition length is... The following relationship must be satisfied: ,in and These represent the wall thicknesses of two adjacent functional sections.

[0022] Furthermore, the surface of the conical transition zone is precision machined to a surface roughness Ra of no more than 3.2 μm, in order to achieve a smooth transition in stress distribution.

[0023] Furthermore, the functional partition structure provides a physical basis for integrating sensing elements on the pipe body for real-time status monitoring and closed-loop control during the drilling process.

[0024] Compared with the prior art, this application has the following beneficial effects:

[0025] This invention achieves precise matching between the material distribution and the actual axial load distribution of the drill pipe through a functional zoning design with variable diameter and wall thickness: the near-bit reinforced section significantly improves torsional resistance and wear resistance, solving the problem of easy damage at the near end of traditional drill pipes; the directional drilling / stabilization flexible section balances flexibility and fatigue resistance, effectively preventing fatigue fracture in the bending section; the lightweight design of the main transmission section greatly reduces the overall weight, improving handling and drilling efficiency; and the tail connection reinforcement section enhances connection reliability, avoiding thread failure. This design fundamentally overcomes the shortcomings of traditional equal-diameter, equal-wall-thickness drill pipes in large-diameter directional drilling, which are characterized by "overall bulkiness, local fragility, and uneven service life," significantly improving the overall service life, construction safety, and economic benefits of the drill pipe. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the axial full section structure of the variable diameter and variable wall thickness drill pipe provided by the present invention.

[0027] Figure 2 The diagram shows the distribution and structure of the ribs in the near-bit reinforcement section, where (a) is an axial sectional view of the ribs and (b) is a detailed dimensional diagram of the ribs.

[0028] Figure 3 This is a detailed drawing of the special thread profile used in the tail connection of this invention and a comparison with the traditional API thread.

[0029] Figure 4 for Figure 3 Schematic diagram of special tooth profile parameters.

[0030] Figure 5 This is a comparison table of tooth shapes.

[0031] Figure 6 A comparison table and illustrations of the tooth profiles of conventional API threads and the special threads of this invention are provided, wherein (a) is a schematic diagram of conventional API threads and (b) is a schematic diagram of the special threads of this invention. Detailed Implementation

[0032] The technical solutions of 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.

[0033] Furthermore, in this invention, an element referred to as fixed to or disposed on another element may be directly disposed on the other element, or there may be an intermediate element. When an element is considered to be connected to another element, it may be directly connected to the other element, or there may be an intermediate element present simultaneously. The terms vertical, horizontal, left, right, and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0034] Example 1

[0035] The purpose of this invention is to overcome the technical defects of existing homogeneous drill pipes in large-diameter directional drilling, such as overall bulkiness, local fragility, and uneven service life. This invention provides a variable-diameter, variable-wall-thickness mining large-diameter directional drilling drill pipe based on a load-matching design concept. This drill pipe achieves a high degree of synergy between material distribution and stress field distribution through refined functional zoning and parametric variable cross-section design of its axial structure. While ensuring overall safety margin, it achieves localized strengthening, overall lightweighting, and balanced service life, thereby significantly improving drilling efficiency and economy.

[0036] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0037] See Figures 1-6 This application provides a large-diameter directional drilling drill pipe for mining with variable diameter and wall thickness. The outer diameter and / or wall thickness of the drill pipe body, from the drill bit connection end to the tail connection end, exhibit a non-constant but regular variation along the axial direction. This variation is determined through a zoning design based on the type, magnitude, and failure mode of the dominant load borne by the drill pipe at different axial positions during a complete drilling cycle. Specifically, the drill pipe is divided into at least four continuous sections with distinct functional characteristics, preferably including: a near-bit reinforcement section for withstanding extreme torque and wear; a flexible section for adapting to bending trajectories and resisting fatigue; and a main transmission section for efficiently transmitting tension, compression, and torque. At the tail of the main transmission section, a tail connection reinforcement section can also be integrated or connected to ensure connection reliability.

[0038] Furthermore, the specific design features of each functional segment are as follows:

[0039] a. Near-bit reinforcement section:

[0040] This section is defined as the pipe portion extending 0.5 to 1.5 meters backward from the front face of the drill pipe. Its core function is to directly and efficiently convert drilling rig power into rock-breaking torque and withstand complex loads at the bottom of the hole. Therefore, this section is designed to have the maximum outer diameter of the entire drill pipe length (…). ) and maximum wall thickness . outer diameter The wall thickness can be close to the nominal diameter of the borehole to reduce the annular space clearance and enhance guiding stability; The wall thickness can be increased by 20% to 40% compared to the main body section. More preferably, the inner wall of this section has integrally formed spiral or straight internal ribs extending axially. These internal ribs can greatly improve the torsional section modulus and bending stiffness of the pipe without significantly increasing the outer diameter and weight. The material for this section can be ultra-high strength alloy steel, and it can be nitrided or chrome-plated to simultaneously improve the core strength, surface wear resistance, and corrosion resistance.

[0041] b. Flexible section for tilting / stabilizing:

[0042] This section connects to the near-bit reinforcement section, and its length is determined by the borehole design build-up rate, typically ranging from 1.0 meter to 3.0 meters. Its core function is to provide necessary compliance during borehole trajectory changes (build-up point, azimuth torsion section) while withstanding high-cycle alternating bending stresses without fatigue failure. The outer diameter of this section ( The design is less than or equal to the outer diameter of the near-bit reinforcement section. ), preferably: To moderately reduce bending stiffness. Its wall thickness ( The wall thickness of the main transfer section should not be less than that of the main transfer section, and is usually equal to or slightly thinner than that of the near-drill bit section to ensure sufficient bending strength. The heat treatment process of this section is crucial, and a process aimed at obtaining high fracture toughness and high fatigue limit should be adopted, such as sub-critical quenching followed by low-temperature tempering, so that it still maintains excellent impact toughness (Akv value should be greater than 60J) at high strength, thereby effectively inhibiting the initiation and propagation of fatigue cracks.

[0043] c. Main Transmission Section:

[0044] This section constitutes the majority of the drill pipe's length, and its function is singular and stable: transmitting torque and tensile / compressive loads. This section utilizes a constant, lightweight, optimized outer diameter and wall thickness. Specifically, the outer diameter... Typically related to the outer diameter of the flexible section for tilting / stabilizing. Maintain consistency to ensure smooth flow; wall thickness Then, based on the tensile safety factor of the entire drill string at the maximum drilling depth (usually taken as 1.5), 2.0) and rated torque were back-calculated and optimized, and their values ​​were significantly smaller than By thinning this long section, the overall weight of the drill string can be significantly reduced (expected weight reduction of 10% to 20%), directly reducing rotational resistance and energy consumption.

[0045] d. Tail-end connection reinforcement section:

[0046] This section, located at the end of the drill pipe, is used to achieve a reliable connection between drill pipes. Instead of simply relying on thickened joints, it employs a combined reinforcement scheme of "local upsetting and forging of the pipe body + overall heat treatment + thread optimization." First, a section of the pipe tail (approximately 0.3... After undergoing medium-frequency heating (0.7 meters), the section is axially upset to increase its outer diameter and wall thickness, forming a thickened zone with a smooth transition. Then, connecting threads are machined into this thickened zone. These threads are preferably non-API standard special threads with variable taper, large circular arc root, and negative angle bearing surface; their connection strength (tensile and torsional strength) should be higher than that of the pipe body itself. Finally, this section undergoes surface strengthening treatments such as induction hardening to generate beneficial residual compressive stress at the thread root.

[0047] To ensure a smooth transition in mechanical properties between functional sections and avoid stress concentration caused by abrupt changes in cross-section, a tapered transition zone is provided between adjacent sections. The taper angle α of the tapered transition zone is preferably between 5° and 15°, and its axial length... It should meet the following requirements: ,in and This represents the wall thickness between two adjacent sections. The surface of the transition zone must be smoothly processed, free of scratches or pits.

[0048] Example 2

[0049] See Figure 1 This embodiment provides a large-diameter directional drilling drill pipe for mining with variable diameter and wall thickness. The outer diameter and wall thickness of the drill pipe body change systematically according to functional zones from the drill bit connection end (left end) to the tail connection end (right end). Specifically, it is divided into four continuous sections: a near-drill bit reinforcement section, a directional drilling / stabilization flexible section, a main body transmission section, and a tail connection reinforcement section.

[0050] Near-bit reinforcement section: Its axial length is 1.0 meter. The outer diameter of this section... The diameter is Φ178mm (similar to the nominal diameter of a Φ180mm borehole), and the wall thickness is... It is 16mm. The inner wall of this section is integrally formed with 6 spiral internal ribs extending axially (see...). Figure 2 The helix angle is 45°. The material is 42CrMo ultra-high strength alloy steel. After forging, it undergoes quenching and tempering heat treatment, and finally, the outer surface is subjected to gas nitriding treatment. The nitriding layer depth is ≥0.3mm and the surface hardness is ≥750HV.

[0051] Flexible section for inclination building / stabilization: Its axial length is 2.0 meters. The outer diameter of this section... It is Φ174mm (i.e.) ), wall thickness The diameter is 14mm. The material is also 42CrMo, but the heat treatment process uses "sub-temperature quenching (840℃) + low-temperature tempering (200℃)" to achieve an excellent balance of strength and toughness. Testing showed that this section of material achieved a Charpy V-notch impact energy (Akv) of 75J at -20℃, significantly improving its fatigue limit.

[0052] Main transmission section 103: Outer diameter of this section The outer diameter is kept consistent with the flexible section, at Φ174mm. Based on the maximum design hole depth of 800 meters, a drill string safety factor of 1.8, and the rated output torque of the drilling rig, back-calculation optimization was performed to determine the optimal wall thickness. The wall thickness is 10mm. By using this optimized wall thickness, the weight of a single drill pipe (based on a 12-meter length) is reduced by approximately 18% compared to a homogeneous drill pipe with a full length wall thickness of 16mm.

[0053] Tail-end Reinforcement Section: After medium-frequency induction heating of the 0.5-meter length of the pipe tail, axial upsetting forging is performed to form a thickened transition zone with an outer diameter increased to Φ190mm and a wall thickness increased to 18mm. The machining of this thickened zone is shown in the attached figure. Figure 3 , 4 The special thread shown in Figure 5 is a non-API standard thread with a variable taper (1:16 to 1:12 transition), a large radius root (R=0.8mm), and a bearing surface angle of -5°. After machining, the section is subjected to overall induction hardening to achieve a surface hardness of HRC50-55 in the thread area and to form a residual compressive stress layer at the root of the thread.

[0054] The functional sections are connected by tapered transition zones. For example, the transition zone between the near-bit reinforcement section and the build-up / stabilization flexibility section has a taper angle α of 10° and an axial length of... Calculated according to the formula: The actual design is 60mm to ensure a smooth transition. All transition zone surfaces are precision ground, with the surface roughness Ra controlled below 1.6μm.

[0055] Example 3:

[0056] Based on Example 1, the parameters of each section can be adjusted according to different borehole designs and rock formation conditions. For example, for boreholes with higher build-up rates, the length of the build-up / stabilization flexible section can be shortened to 1.5 meters to provide more concentrated flexibility. For extremely abrasive formations, the surface treatment of the near-bit reinforcement section can be changed to hard chrome plating with a chrome layer thickness of 0.05-0.10 mm.

[0057] The working process of the drill pipe of this invention is as follows: During drilling, the near-bit reinforced section, with its maximum torsional stiffness and wear resistance, efficiently transmits rock-breaking torque and resists bottom hole wear. When the drilling trajectory needs to be adjusted, the directional / stabilizing flexible section provides the necessary bending compliance, while its excellent fatigue resistance ensures that no cracks are generated under alternating bending stress. The main transmission section, with its lightweight structure, stably transmits the axial force and torque from the drilling rig, significantly reducing overall rotational inertia and energy consumption. The drill pipes are connected by special threads in the tail-end connecting reinforced section, whose high strength and high reliability effectively prevent connection failures such as derailment and leakage. The gentle conical transition zone between each section avoids stress concentration and ensures the overall mechanical continuity of the drill pipe.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A variable-diameter, variable-wall-thickness drill rod for large-diameter directional drilling of the roof of extra-thick coal seams, characterized in that, The outer diameter and wall thickness of the drill pipe, from the drill bit connection end to the tail connection end, exhibit non-constant but regular variations along the axial direction, forming a functional partition structure. The structure includes at least: a near-bit reinforcement section, a directional drilling / stabilization flexible section, a main transmission section, and a tail connection reinforcement section; wherein, the outer diameter and wall thickness parameters of each functional section are designed differently based on the dominant load spectrum and main failure modes during the drilling process, so as to achieve active matching between material distribution and axial dynamic stress field.

2. The drill pipe according to claim 1, characterized in that, The near-bit reinforcement section is located at the front end of the drill pipe, with an axial length of 0.5 meters to 1.5 meters; this section has the maximum outer diameter of the entire drill pipe. and the maximum wall thickness along the entire length And satisfy the following relation: ;in The wall thickness of the main transmission section.

3. The drill pipe according to claim 2, characterized in that, The inner wall of the near-drill bit reinforced section is integrally formed with axially extending reinforcing ribs, which are spiral or straight; and / or, The pipe section is made of ultra-high strength alloy steel, and its outer surface is treated with nitriding or chrome plating.

4. The drill pipe according to claim 1, characterized in that, The flexible section for creating / stabilizing the directional drift is seamlessly connected to the rear end of the near-bit reinforcement section, and its axial length is 1.0 m to 3.0 m. outer diameter of this section satisfy: , ; The wall thickness of this section satisfy: Furthermore, the material undergoes sub-temperature quenching and low-temperature tempering heat treatment processes to obtain high fracture toughness and high fatigue limit, with Charpy V-notch impact energy Akv≥60J at -20℃.

5. The drill pipe according to claim 1, characterized in that, The main transmission section constitutes the main length portion of the drill pipe, and its outer diameter... Maintain a constant outer diameter and match the outer diameter of the inclined / stabilizing flexible section. equal; Its wall thickness This is a constant value used for lightweight back-calculation optimization based on the tensile safety factor and rated output torque of the drill string at the maximum design hole depth, and it satisfies... .

6. The drill pipe according to claim 1, characterized in that, The tail connection reinforcement section is located at the end of the drill pipe. A thickened transition zone is formed by local axial upsetting forging of the tail of the pipe body, and a connecting thread is machined in the thickened transition zone. The connecting thread is a non-API standard special thread with variable taper, large circular arc tooth root and negative angle bearing surface, and the tail connecting reinforcement section is entirely subjected to induction hardening treatment.

7. The drill pipe according to claim 6, characterized in that, The special thread has an asymmetrical composite shape with a negative angle on its bearing surface and a continuous large arc at the root, which makes the tensile strength and torsional strength of the connecting thread higher than those of the pipe body.

8. The drill pipe according to any one of claims 1 to 7, characterized in that, A tapered transition zone is provided between any two adjacent functional sections; the tapered angle α of the tapered transition zone is 5°~15°, and its axial transition length is... The following relationship must be satisfied: ,in and These represent the wall thicknesses of two adjacent functional sections.

9. The drill pipe according to claim 8, characterized in that, The surface of the conical transition zone is precision machined to a surface roughness Ra of no more than 3.2 μm, so as to achieve a smooth transition of stress distribution.

10. The drill pipe according to claim 1, characterized in that, The functional partition structure provides a physical basis for integrating sensing elements on the pipe body for real-time status monitoring and closed-loop control during the drilling process.

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