Broken soft coal seam advance drilling hole wall self-adaptive hole protecting device and method

Abstract

The invention relates to the technical field of coal mine underground advanced drilling equipment, in particular to a broken soft coal seam advanced drilling hole wall self-adaptive hole protecting device and method. According to the technical scheme, the broken soft coal seam advance drilling hole wall self-adaption hole protecting device comprises a hole protecting body, the hole protecting body comprises a hole protecting shell and a plurality of standard interfaces fixedly installed on the outer side of the hole protecting shell, and the hole protecting body comprises a hole wall pressure monitoring module installed on the outer side of the hole protecting shell through one standard interface. A composite structure of flexible hole protection and self-adaptive driving is adopted, dynamic matching of the hole protection force and the hole wall pressure is achieved, deformation of a broken soft coal seam can be adapted, an all-dimensional and tightly-attached flexible protection layer is formed, loose chippings and mud are effectively isolated, then the problems of hole wall collapse, drill burying, drill jamming and the like are solved, and continuous development of drilling operation is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of underground pre-drilling equipment technology in coal mines, and particularly to an adaptive borehole protection device and method for pre-drilling boreholes in soft coal seams. Background Technology

[0002] Advance drilling is a core technical means for preventing hidden disasters and ensuring safe production in coal mines. Especially in the mining of soft and fractured coal seams, advance drilling can reveal the geological structure and potential water hazards ahead, providing a scientific basis for mining operations. However, soft and fractured coal seams are characterized by poor rock cohesion, low strength, high porosity, and easy softening and disintegration when exposed to water. During advance drilling, the borehole wall is prone to collapse, causing drilling to be discontinuous. This not only leads to drill bit jamming and damage to drilling equipment, increasing operating costs, but also causes interruption of detection signals, data distortion, and inaccurate acquisition of geological information ahead. In severe cases, it can even cause safety accidents such as water inrush and rockfall, restricting safe production in the mine.

[0003] Currently, the main borehole protection technologies for advanced drilling in soft and fractured coal seams in underground coal mines include mud slurry protection and casing protection. However, both have significant limitations, as detailed below:

[0004] 1. Mud protection method: Mud is injected into the borehole to form a mud cake, which protects the borehole wall by binding. However, soft coal seams have high porosity and high permeability, and mud can easily penetrate into the rock strata, resulting in the mud cake failing to form a complete protective layer and poor borehole protection effect. At the same time, mud can contaminate drilling signal acquisition elements, leading to distorted detection data. Furthermore, mud preparation and circulation costs are high, and the operation process is complex, making it unsuitable for the real-time borehole protection requirements during drilling.

[0005] 2. Casing protection method: Rigid casing is used to protect the borehole wall. However, rigid casing cannot adapt to the deformation of soft coal seams and is prone to gaps with the borehole wall, which can lead to mud and loose debris entering the gaps, causing the casing to jam and the borehole wall to collapse. Moreover, the casing cannot advance synchronously with the drilling depth after it is lowered. It needs to be lowered and disassembled in sections, which results in extremely low work efficiency and increases drilling resistance. It is not suitable for long-distance advanced drilling operations.

[0006] In summary, existing borehole wall protection technologies and devices cannot solve the core pain points of "burrow wall collapse, poor borehole protection effect, low operation efficiency, and disconnect between borehole protection and detection" in advanced drilling of soft coal seams. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the background art by proposing an adaptive borehole protection device and method for advanced drilling in soft coal seams.

[0008] The technical solution of this invention: an adaptive borehole protection device for advanced drilling in soft coal seams, comprising a borehole protection body, wherein the borehole protection body includes a borehole protection shell and multiple standardized interfaces fixedly installed on the outside of the borehole protection shell, including:

[0009] The borehole wall pressure monitoring module is installed on the outside of the borehole housing via a standardized interface;

[0010] A detection and coordination module installed on the outside of the protective housing via a standardized interface;

[0011] A power supply module installed on the outside of the main body of the protective hole;

[0012] An external hole protector assembly installed on one side of the hole protector body, the external hole protector assembly including a positioning layer disposed on one side of the hole protector housing;

[0013] A flexible hole protection module is installed at the bottom of the external hole protection assembly. The flexible hole protection module includes a flexible hole protection wall. A buffer cavity is fixedly installed on the inner wall of the flexible hole protection wall. A positioning outer frame is fixedly installed on the inner wall of the buffer cavity. A narrow air layer, a wide flow layer, and a narrow flow layer are opened inside the positioning outer frame. The narrow air layer, the wide flow layer, and the narrow flow layer are connected. A thin arc-shaped tube is slidably installed between the wide flow layer and the narrow flow layer. A thick arc-shaped tube is slidably installed on the outside of the thin arc-shaped tube. An arc-shaped spring is fixedly installed between the thick arc-shaped tube and the thin arc-shaped tube.

[0014] Optionally, an early warning control module is installed inside the main body of the protective hole, and the early warning control module is connected to a terminal via an electrical signal.

[0015] Optionally, the external protective hole assembly further includes a component mounting area fixedly installed inside the positioning layer, the component mounting area including a pressure monitoring component mounting area, a drive control component mounting area, and a power supply component mounting area.

[0016] Optionally, the surface of the positioning layer is provided with a plurality of heat dissipation holes, and the surface of the heat dissipation holes is provided with a dustproof mesh.

[0017] Optionally, the surface of the positioning layer is provided with a detection channel, which is located directly below the positioning layer.

[0018] Optionally, two sets of quick-connect threads are fixedly installed at the bottom of the flexible hole wall. One set of quick-connect threads is connected to the drill rod, and the other set of quick-connect threads is connected to the drilling probe. An airflow filling component is provided inside the positioning layer.

[0019] Optionally, both the upper and lower ends of the flexible protective hole wall are fixedly installed with forward and reverse motors. A second threaded rod is fixedly installed at the output end of one set of forward and reverse motors, and a first threaded rod is fixedly installed at the output end of the other set of forward and reverse motors. The first threaded rod is rotatably installed inside the second threaded rod. A fixing bracket is fixedly installed on the outside of the forward and reverse motors. A second bidirectional hinge rod is fixedly installed on the outside of both the first threaded rod and the second threaded rod.

[0020] Optionally, a first bidirectional hinge rod is hinged to the outer side of the fixed locking frame, and a second bidirectional hinge rod is hinged to the inner side of the first bidirectional hinge rod. The side of the second bidirectional hinge rod away from the fixed locking frame is hinged to the outer side of the second bidirectional hinge rod, and a pusher is hinged to the outer side of both the second bidirectional hinge rod and the first bidirectional hinge rod.

[0021] Optionally, the pusher is attached to the inner wall of the positioning outer frame, and the inner diameter of the narrow air layer is smaller than the inner diameter of the wide flow layer.

[0022] This application provides a method for adaptive borehole protection in advance drilling of fractured and soft coal seams, including the following steps:

[0023] S1: Before the advance drilling operation begins, based on the preliminary geological survey data of the target soft coal seam, complete the equipment debugging and parameter initialization to lay the foundation for subsequent borehole protection operations;

[0024] S2: Next, adjust the fitting specifications of the borehole protection body according to the diameter of the advanced drilling borehole in the target area to ensure that the external borehole protection component and the flexible borehole protection module can be smoothly lowered into the borehole. Then, accurately calibrate the pressure sensor of the borehole wall pressure monitoring module. Finally, debug the adaptive drive module, early warning control module and detection coordination module to ensure that each module works normally, the detection channel is unobstructed, the signal transmission is stable, and the power supply module has sufficient power.

[0025] S3: Start the drilling rig to drill the hole and open it. After drilling the hole, use low-viscosity, low-damage mud for pretreatment. After the pretreatment is completed, connect the adjusted external hole protection assembly and flexible hole protection module to the drill rod and advanced detection probe through quick-connect threads to ensure a firm connection and good sealing. Then, lower the device, drill rod, and probe into the borehole together. During the lowering process, advance slowly to avoid collision and damage between the device and the borehole wall. At the same time, monitor the borehole wall pressure in real time through the early warning control module to ensure the stability of the borehole wall during the lowering process.

[0026] S4: Start the drilling rig to begin advanced drilling. The borehole protection device advances synchronously with the drill rod, entering the adaptive borehole protection state while drilling. At the same time, advance detection operations are carried out to achieve simultaneous borehole protection and detection.

[0027] S5: During drilling and exploration, if the early warning control module detects that the borehole wall pressure exceeds the preset early warning threshold or the pressure change rate exceeds the set value, it is determined to be a precursor to borehole wall collapse. The audible and visual early warning is immediately activated, and an early warning signal is sent to the ground control terminal to remind on-site personnel to take timely measures.

[0028] S6: After the advanced drilling operation is completed, slowly raise the drill pipe and retrieve the external borehole protection assembly, flexible borehole protection module, and probe together from the borehole. After retrieval, clean, inspect, and maintain the entire device, removing mud and debris from the surface of the flexible borehole protection module.

[0029] Compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0030] 1. By adopting a flexible borehole protection and adaptive drive composite structure, the borehole protection force and borehole wall pressure are dynamically matched. It can adapt to the deformation of soft coal seams and form a flexible protective layer that is fully integrated and tightly fitted. This effectively isolates loose debris and mud, thereby solving problems such as borehole wall collapse, drill bit burial, and drill bit jamming, and ensuring the continuous operation of drilling.

[0031] 2. By integrating a ring-shaped pressure sensor array, the borehole wall pressure changes are monitored in real time, which can capture the signs of borehole wall collapse, actively trigger graded early warnings, and automatically adjust the borehole protection force to achieve closed-loop control of "monitoring-early warning-adjustment". This transforms passive protection into active protection, greatly improving the safety of drilling operations and reducing the occurrence of safety accidents.

[0032] 3. By combining the soft support with the positioning outer frame to form a hard support, the two work together to achieve the ability to cope with different hole wall environments. Attached Figure Description

[0033] Figure 1 A schematic diagram of an adaptive borehole protection device for advanced drilling in soft coal seams;

[0034] Figure 2 This is a schematic diagram of the adaptive driving module of the present invention;

[0035] Figure 3 This is a schematic diagram of the positioning layer of the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of the component mounting area of ​​the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of the second threaded rod of the present invention;

[0038] Figure 6 For the present invention Figure 5 Enlarged view of region A in the middle;

[0039] Figure 7 This is a schematic diagram of the structure of the thick arc-shaped tube of the present invention;

[0040] Figure 8 For the present invention Figure 7 Enlarged view of region B in the middle;

[0041] Figure 9 This is a schematic diagram of the structure of the second bidirectional hinge rod of the present invention.

[0042] Reference numerals: 1. Hole protector body; 101. Hole protector shell; 102. Standardized interface; 2. Adaptive drive module; 3. Hole wall pressure monitoring module; 4. Detection coordination module; 5. Power supply module; 6. Early warning control module; 7. External hole protector assembly; 701. Positioning layer; 702. Heat dissipation hole; 703. Detection channel; 704. Quick-connect thread; 705. Assembly installation area; 706. Airflow filling assembly; 8. Flexible hole protector module; 801. Flexible hole protector wall; 802. Buffer cavity; 803. Forward and reverse motor; 804. First threaded rod; 805. Second threaded rod; 806. First bidirectional hinge rod; 807. Positioning outer frame; 808. Narrow air layer; 809. Wide flow layer; 810. Coarse arc-shaped tube; 811. Fine arc-shaped tube; 812. Narrow flow layer; 813. Fixed clamping frame; 814. Second bidirectional hinge rod; 815. Pushing frame. Detailed Implementation

[0043] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0044] like Figures 1-4As shown, the adaptive borehole protection device for advanced drilling in soft coal seams proposed in this invention includes a borehole protection body 1. The borehole protection body 1 includes a borehole protection shell 101 and multiple standardized interfaces 102 fixedly installed on the outside of the borehole protection shell 101. It includes a borehole wall pressure monitoring module 3 installed on the outside of the borehole protection shell 101 through one standardized interface 102, a detection coordination module 4 installed on the outside of the borehole protection shell 101 through one standardized interface 102, a power supply module 5 installed on the outside of the borehole protection body 1, and an external borehole protection component 7 installed on one side of the borehole protection body 1. The external borehole protection component 7 includes a positioning layer 701 set on one side of the borehole protection shell 101 and a flexible borehole protection module 8 installed at the bottom of the external borehole protection component 7. An early warning control module 6 is installed inside the borehole protection body 1. The early warning control module 6 is connected to a terminal through an electrical signal.

[0045] The borehole protector 1, as the carrier of the entire device, adopts a hollow cylindrical structure with an outer diameter that can be adapted to various specifications of advanced drilling boreholes from Φ65mm to 127mm, thus meeting the needs of different drilling scenarios.

[0046] The borehole wall pressure monitoring module 3 is the key to realizing adaptive borehole protection and active early warning. It is used to monitor the pressure changes of the borehole wall in real time, capture the signs of borehole wall collapse, and provide data support for the adaptive adjustment of the adaptive drive module 2, which is different from the defects of existing borehole protection devices that do not have real-time monitoring functions.

[0047] Meanwhile, a detection channel 703 is provided on the surface of the positioning layer 701. The detection channel 703 is located directly below the positioning layer 701. The borehole wall pressure monitoring module 3 consists of an annular pressure sensor array and a signal conditioning unit. The annular pressure sensor array is evenly distributed in 4 to 6 groups along the circumference of the borehole body 1. The annular pressure sensor probe extends out of the side wall of the positioning layer 701 and directly contacts the borehole wall, thus enabling all-round and no-dead-angle monitoring of pressure changes at different positions of the borehole wall. The detection accuracy of the pressure sensor can reach 0.01MPa, and the detection range is 0MPa to 50MPa, which can accurately capture the subtle pressure fluctuations of the borehole wall in the soft coal seam.

[0048] The signal conditioning unit amplifies and filters the raw signals collected by the pressure sensor, eliminating noise signals caused by strong downhole vibrations and electromagnetic interference. The processed pressure data is then transmitted to the early warning control module in real time to ensure the accuracy and reliability of the pressure monitoring data. When the borehole wall pressure at a certain location exceeds a preset threshold or the rate of pressure change exceeds a set value, an abnormal signal is immediately sent to the early warning control module 6, triggering an early warning command.

[0049] The adaptive drive module 2 is used to dynamically adjust the support force and extension amount of the flexible hole protection module 8 according to the hole wall pressure monitoring data, so as to achieve a precise match between the hole protection force and the hole wall pressure, and avoid hole wall damage caused by insufficient or excessive hole protection force.

[0050] Meanwhile, the adaptive drive module 2 consists of a micro hydraulic drive unit and a telescopic transmission mechanism. The micro hydraulic drive unit adopts an intrinsically safe design for mining, which is small in size and high in power, and can work stably in complex underground environments. The drive pressure can be dynamically adjusted according to the borehole wall pressure, with an adjustment range of 5kN to 30kN. The external borehole protection component 7 is connected to the flexible borehole protection module 8, and the flexible borehole protection module 8 adopts a multi-stage telescopic structure with a telescopic range of 0mm to 20mm. The extension length of the flexible borehole protection module 8 can be precisely adjusted according to the borehole wall diameter and pressure changes, so that the flexible borehole protection module 8 fits tightly with the borehole wall.

[0051] This explains that the adaptive drive module 2 and the early warning control module 6 work together to receive pressure monitoring data in real time. Through the built-in control algorithm, they automatically calculate the required hole protection force and extension amount, and drive the flexible hole protection module 8 to extend and retract, realizing closed-loop control of "pressure monitoring - force adjustment". This achieves fully automated adaptive hole protection without manual intervention. For example, when the increased pressure on the hole wall is detected, causing rock deformation, the drive unit automatically increases the driving pressure, pushing the flexible hole protection module 8 to extend and increase the hole protection force to prevent the hole wall from collapsing. When the decreased pressure on the hole wall is detected, causing slight signs of collapse, the adaptive drive module 2 automatically reduces the driving pressure and appropriately contracts the flexible hole protection module 8 to avoid excessive compression of the hole wall, while triggering an early warning.

[0052] It should be noted that the detection coordination module 4 is used to realize the synchronous operation of hole protection and advanced detection, which solves the defects of existing hole protection devices that block detection signals and interfere with detection data, and ensures the continuity and accuracy of detection signals.

[0053] Meanwhile, the detection coordination module 4 consists of a detection channel 703 and a signal isolation component. The detection channel 703 is located at the center of the borehole body 1 and runs through the entire borehole body. It is used to install an advanced detection probe to ensure that the detection probe can make smooth contact with the borehole wall and collect geological information. The signal isolation component is located between the detection channel 703 and the borehole body 1. It uses electromagnetic shielding material to effectively isolate the electromagnetic interference generated by the adaptive drive module 2 and the borehole wall pressure monitoring module 3, avoid interfering with the detection signal, and ensure the accuracy of the detection data.

[0054] Meanwhile, the inner wall of the detection channel 703 is equipped with a sealing guide structure, which can not only fix the detection probe and prevent it from shaking during drilling, but also seal the detection channel to prevent mud and debris from entering the channel and damaging the probe, thus ensuring the continuous operation of the detection work. The detection collaboration module 4 is compatible with existing advanced detection equipment and can directly connect to various detection probes without additional adaptation, improving the versatility of the device.

[0055] It is explained here that the early warning control module 6 is used to receive the transmitted data from each module, realize adaptive adjustment, active early warning and full-process control, and ensure the stable operation of the device. The early warning control module 6 adopts an industrial-grade PLC controller with built-in exclusive control algorithm and early warning program. It can receive borehole wall pressure monitoring data and drive module working data in real time, analyze and process the data, judge the borehole wall stability and device working status, and automatically send control commands to the adaptive drive module 2 based on the borehole wall pressure data to adjust the borehole protection force and extension amount to realize closed-loop adaptive borehole protection. When abnormal borehole wall pressure or device failure is detected, an audible and visual early warning is immediately triggered. It is noted that the warning sound intensity is ≥85dB and the warning light is flashing red. At the same time, an early warning signal is sent to the ground terminal to remind on-site personnel to take timely measures. It also has a built-in 8GB high-speed cache unit to store pressure monitoring data and device working data within 72 hours. At the same time, it uploads the data to the ground control terminal in real time through a mining intrinsically safe wireless module, which facilitates remote monitoring and data analysis by personnel.

[0056] like Figures 3-5 As shown, the external protective hole assembly 7 also includes a component mounting area 705 fixedly installed inside the positioning layer 701. The component mounting area 705 includes a pressure monitoring component mounting area, a drive control component mounting area, and a power supply component mounting area. The surface of the positioning layer 701 is provided with multiple heat dissipation holes 702, and the surface of the heat dissipation holes 702 is provided with a dustproof mesh. Two sets of quick-connect threads 704 are fixedly installed at the bottom of the flexible protective hole wall 801. One set of quick-connect threads 704 is connected to a drill rod, and the other set of quick-connect threads 704 is connected to a drilling probe. An airflow filling assembly 706 is provided inside the positioning layer 701.

[0057] In this embodiment, the two ends of the positioning layer 701 are detachably connected to the drill rod and the drilling probe via quick-connect threads 704, making installation and disassembly convenient and allowing for quick adaptation to existing advanced drilling equipment without requiring large-scale modifications to the drilling rig.

[0058] Meanwhile, the positioning layer 701 has a pre-reserved modular installation cavity, which precisely divides the installation areas for pressure monitoring components, drive control components, and power supply components. It should be noted that, depending on the actual installation, the installation areas can be used as spare installation space for other components, thereby ensuring that the layout of each module is reasonable and does not interfere with each other. At the same time, the side wall of the positioning layer 701 has a pre-reserved expansion channel for the flexible protective hole wall 801 and a detection channel 703, which not only ensures that the flexible protective hole module 8 can be freely expanded and contracted, but also provides a channel for the transmission of detection signals, realizing the coordinated operation of hole protection and detection. Furthermore, since the inner wall of the positioning layer 701 is equipped with heat dissipation holes 702, it avoids the components from overheating and being damaged due to the high temperature environment downhole, ensuring the long-term stable operation of the device.

[0059] like Figures 5-9As shown, the flexible hole protection module 8 includes a flexible hole protection wall 801. A buffer cavity 802 is fixedly installed on the inner wall of the flexible hole protection wall 801. A positioning outer frame 807 is fixedly installed on the inner wall of the buffer cavity 802. The positioning outer frame 807 has a narrow air layer 808, a wide flow layer 809, and a narrow flow layer 812 inside. The narrow air layer 808, the wide flow layer 809, and the narrow flow layer 812 are connected. A thin arc-shaped tube 811 is slidably installed between the wide flow layer 809 and the narrow flow layer 812. A thick arc-shaped tube 810 is slidably installed on the outside of the thin arc-shaped tube 811. An arc-shaped spring is fixedly installed between the thick arc-shaped tube 810 and the thin arc-shaped tube 811. A forward and reverse motor 803 is fixedly installed at both the upper and lower ends of the flexible hole protection wall 801. A second threaded rod 805 is fixedly installed at the output end of one set of forward and reverse motors 803. The output end of 03 is fixedly installed with a first threaded rod 804. The first threaded rod 804 is rotatably installed inside the second threaded rod 805. A fixed clamping frame 813 is fixedly installed on the outside of the forward and reverse motor 803. A second bidirectional hinge rod 814 is fixedly installed on the outside of both the first threaded rod 804 and the second threaded rod 805. A first bidirectional hinge rod 806 is hinged to the outside of the fixed clamping frame 813. A second bidirectional hinge rod 814 is hinged inside the first bidirectional hinge rod 806. The side of the second bidirectional hinge rod 814 away from the fixed clamping frame 813 is hinged to the outside of the second bidirectional hinge rod 814. A pusher frame 815 is hinged to the outside of both the second bidirectional hinge rod 814 and the first bidirectional hinge rod 806. The pusher frame 815 is attached to the inner wall of the positioning outer layer frame 807. The inner diameter of the narrow air layer 808 is smaller than the inner diameter of the wide flow layer 809.

[0060] This section explains that the flexible borehole protection module 8 is used to directly contact the borehole wall of the soft coal seam, forming a flexible protective layer to isolate loose debris and mud, and maintain borehole wall stability. Unlike existing rigid borehole protection structures that easily damage the borehole wall and have poor mud protection effects, the flexible borehole protection wall 801 consists of a flexible wear-resistant protective pad, a buffer cavity 802, and anti-slip protrusions. The flexible wear-resistant protective pad is made of highly elastic wear-resistant rubber, possessing excellent flexibility and wear resistance, capable of adapting to the deformation of the soft coal seam, tightly fitting the borehole wall to form a sealed protective layer, effectively isolating loose debris and mud, preventing debris from entering the borehole and causing drill bit burial or jamming, while also preventing mud contamination of the probe. The buffer cavity 802 is located between the flexible wear-resistant protective pad and the narrow gas layer 808, using polyurethane buffer material, which can absorb vibrations during drilling, reducing vibration disturbance to the borehole wall, and buffering the pressure of the flexible borehole protection module on the borehole wall, preventing excessive compression that could damage the borehole wall. These three components form a soft support area.

[0061] This section explains that the anti-slip protrusions are evenly distributed on the outer surface of the flexible protective pad, and adopt a serrated structure, which can enhance the friction between the protective pad and the borehole wall, prevent the borehole protection module from sliding during drilling, and ensure the stability of the borehole protection effect. At the same time, small gaps are reserved between the anti-slip protrusions to facilitate the discharge of mud and debris, and avoid borehole protection failure caused by mud accumulation. The flexible borehole protection wall 801 is continuously arranged along the circumference of the borehole protection body to form a ring protection structure, achieving all-round protection of the borehole wall.

[0062] When a small-scale collapse or displacement occurs in the borehole wall, the soft support area alone cannot provide support and reset. Therefore, the detection channel 703 transmits information to the terminal, which then controls the forward and reverse motor 803 via an electrical signal to rotate the first threaded rod 804 and the second threaded rod 805. Since the fixed locking frame 813 is fixed, the second bidirectional hinge rod 814 moves upward or downward along the threads on the connected first threaded rod 804 or second threaded rod 805. When the second bidirectional hinge rod 814 moves downward or upward, it hinges with the fixed locking frame 813. The first bidirectional hinge rod 806 deflects along the second bidirectional hinge rod 814, causing the pusher frame 815 to move outward or inward to support the real-time orientation transmitted by the buffer cavity 802, thereby providing rigid support to the flexible protective hole wall 801 and improving the stability of the hole wall. If the hole wall collapses significantly, the equipment needs to be pulled out or other remedial measures need to be taken. The buffer cavity 802 and the pusher frame 815 will simultaneously compress the narrow air layer 808, and the pressure is relatively large. The narrow air layer 808 will be compressed and deformed along the arc trajectory of the pusher frame 815. At this time, the air in the narrow air layer 808 will be compressed and transferred to the wide flow layer 809. It should be noted that the coarse arc When tube 810 and the thin arc-shaped tube 811 maintain their normal diameter via springs, they provide a certain degree of support within the narrow air layer 808. This means they provide support to the buffer cavity 802 and the flexible protective wall 801, allowing them to adapt within a specified range. Meanwhile, the wide flow layer 809 and the narrow flow layer 812 closely match the thickness of the thin arc-shaped tube 811 and the thick arc-shaped tube 810, causing them to separate the wide flow layer 809 and the narrow air layer 808 into relatively sealed areas. As the air in the wide flow layer 809 is compressed, the thin arc-shaped tube 811 moves upward or downward in a piston-like motion. The second threaded rod 805, as a rigid support component, can directly transmit the support force to the flexible protective hole wall 801 through the flattened narrow air layer 808. The wide flow layer 809 is filled with air, which hardens the rigidity and improves the rigid support effect. At the same time, the thick arc-shaped tube 810 can expand and contract along the inclined transmission trajectory of the wide flow layer 809, resulting in an increased diameter. The wide flow layer 809 is equipped with a pressure sensor, which transmits information to the airflow filling component 706. The airflow filling component 706 replenishes the heat dissipation hole 702 with gas, causing the airflow filling component 706 to expand significantly, improving support, thereby facilitating the removal of the equipment or preventing the collapse of the hole wall.

[0063] This application provides a method for adaptive borehole protection in advance drilling of fractured and soft coal seams, including the following steps:

[0064] S1: Before the advance drilling operation begins, based on the preliminary geological survey data of the target soft coal seam and the rock mass cementation, porosity, and geostress range, the equipment is debugged and the parameters are initialized to lay the foundation for subsequent borehole protection operations.

[0065] S2: Next, adjust the fitting specifications of the borehole protection body 1 according to the diameter of the advanced drilling borehole in the target area to ensure that the external borehole protection component 7 and the flexible borehole protection module 8 can be smoothly lowered into the borehole. Then, accurately calibrate the pressure sensor of the borehole wall pressure monitoring module 3. Finally, debug the adaptive drive module 2, the early warning control module 6 and the detection coordination module 4 to ensure that the modules work together normally, the detection channel is unobstructed, the signal transmission is stable, and the power supply module has sufficient power.

[0066] S3: Start the drilling rig to drill the hole and open it. After drilling the hole, use low-viscosity, low-damage mud for pretreatment. After the pretreatment is completed, connect the adjusted external hole protection component 7 and the flexible hole protection module 8 to the drill rod and the advanced detection probe through the quick-connect thread 704 to ensure that the connection is firm and the seal is good. Then, lower the device, drill rod and probe into the borehole together. During the lowering process, advance slowly to avoid collision and damage between the device and the borehole wall. At the same time, monitor the borehole wall pressure in real time through the early warning control module 6 to ensure the stability of the borehole wall during the lowering process.

[0067] S4: Start the drilling rig to begin advanced drilling. The borehole protection device advances synchronously with the drill rod, entering the adaptive borehole protection state while drilling. At the same time, advance detection operations are carried out to achieve simultaneous borehole protection and detection.

[0068] S5: During drilling and exploration, if the early warning control module 6 detects that the borehole wall pressure exceeds the preset early warning threshold or the pressure change rate exceeds the set value, it is determined to be a precursor to borehole wall collapse. It immediately activates the audible and visual early warning and sends an early warning signal to the ground control terminal to remind on-site personnel to take timely measures.

[0069] S6: After the advanced drilling operation is completed, slowly lift the drill rod and retrieve the external borehole protection assembly 7, the flexible borehole protection module 8, and the detection probe from the borehole. After retrieval, clean, inspect, and maintain the entire device, remove mud and debris from the surface of the flexible borehole protection module 8, check the integrity of each component, replace any damaged components, and archive the internal storage monitoring data and borehole protection parameters to provide a reference for subsequent similar advanced drilling operations in soft coal seams.

[0070] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. An adaptive borehole protection device for advanced drilling in soft coal seams, comprising a borehole protection body (1), wherein the borehole protection body (1) includes a borehole protection shell (101) and multiple standardized interfaces (102) fixedly installed on the outside of the borehole protection shell (101), characterized in that, include: The borehole wall pressure monitoring module (3) is installed on the outside of the borehole housing (101) via a standardized interface (102). The detection coordination module (4) is installed on the outside of the protective shell (101) via a standardized interface (102). Power supply module (5) installed on the outside of the protective hole body (1); An external hole protection assembly (7) is installed on one side of the hole protection body (1), the external hole protection assembly (7) including a positioning layer (701) disposed on one side of the hole protection shell (101); A flexible hole protection module (8) is installed at the bottom of the external hole protection assembly (7). The flexible hole protection module (8) includes a flexible hole protection wall (801). A buffer cavity (802) is fixedly installed on the inner wall of the flexible hole protection wall (801). A positioning outer frame (807) is fixedly installed on the inner wall of the buffer cavity (802). A narrow air layer (808), a wide flow layer (809), and a narrow flow layer (812) are opened inside the positioning outer frame (807). The narrow air layer (808), the wide flow layer (809), and the narrow flow layer (812) are connected. A thin arc tube (811) is slidably installed between the wide flow layer (809) and the narrow flow layer (812). A thick arc tube (810) is slidably installed on the outside of the thin arc tube (811). An arc spring is fixedly installed between the thick arc tube (810) and the thin arc tube (811).

2. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 1, characterized in that, The protective hole body (1) is equipped with an early warning control module (6), which is connected to a terminal via an electrical signal.

3. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 2, characterized in that, The external protective hole assembly (7) also includes a component installation area (705) fixedly installed inside the positioning layer (701), the component installation area (705) including a pressure monitoring component installation area, a drive control component installation area and a power supply component installation area.

4. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 3, characterized in that, The surface of the positioning layer (701) is provided with a plurality of heat dissipation holes (702), and the surface of the heat dissipation holes (702) is provided with a dustproof mesh.

5. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 4, characterized in that, The surface of the positioning layer (701) is provided with a detection channel (703), the detection channel (703) is located directly below the positioning layer (701), and the interior of the positioning layer (701) is provided with an airflow filling component (706).

6. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 5, characterized in that, The bottom of the flexible borehole wall (801) is fixedly equipped with two sets of quick-connect threads (704). One set of quick-connect threads (704) is connected to the drill rod, and the other set of quick-connect threads (704) is connected to the drilling probe.

7. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 6, characterized in that, Both ends of the flexible protective hole wall (801) are fixedly installed with forward and reverse motors (803). A second threaded rod (805) is fixedly installed at the output end of one set of forward and reverse motors (803), and a first threaded rod (804) is fixedly installed at the output end of the other set of forward and reverse motors (803). The first threaded rod (804) is rotatably installed inside the second threaded rod (805). A fixed clamping frame (813) is fixedly installed on the outside of the forward and reverse motors (803). A second bidirectional hinge rod (814) is fixedly installed on the outside of both the first threaded rod (804) and the second threaded rod (805).

8. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 7, characterized in that, The outer side of the fixed locking frame (813) is hinged with a first two-way hinge rod (806), and the inner side of the first two-way hinge rod (806) is hinged with a second two-way hinge rod (814). The side of the second two-way hinge rod (814) away from the fixed locking frame (813) is hinged to the outer side of the second two-way hinge rod (814). The outer sides of both the second two-way hinge rod (814) and the first two-way hinge rod (806) are hinged with a pusher frame (815).

9. The adaptive borehole protection device for advanced drilling in soft coal seams according to claim 8, characterized in that, The pusher (815) is attached to the inner wall of the positioning outer frame (807), and the inner diameter of the narrow air layer (808) is smaller than the inner diameter of the wide flow layer (809).

10. A method for adaptive borehole wall protection in pre-drilling of fractured and soft coal seams, applied to the adaptive borehole wall protection device for pre-drilling of fractured and soft coal seams as described in claim 9, characterized in that... Includes the following steps: S1. Adjust the fitting specifications of the borehole protection body (1) according to the diameter of the advanced drilling borehole in the target area to ensure that the external borehole protection component (7) and the flexible borehole protection module (8) are smoothly lowered into the borehole. Accurately calibrate the pressure sensor of the borehole wall pressure monitoring module (3), and then debug the adaptive drive module (2), the early warning control module (6) and the detection coordination module (4) to ensure that each module works normally. S2. Start the drilling rig to drill the hole and open it. After opening, use low viscosity and low damage mud for pretreatment. Connect the adjusted external hole protection component (7) and the flexible hole protection module (8) to the drill rod and the advanced detection probe through the quick-connect thread (704) to ensure that the connection is firm and the seal is good. Then, lower the device, drill rod and probe into the hole together. During the lowering process, advance slowly and monitor the hole wall pressure in real time through the early warning control module (6) to ensure the stability of the hole wall during the lowering process. S3. Start the drilling rig to begin advanced drilling. The hole protection device advances synchronously with the drill rod, entering the adaptive hole protection state while drilling. At the same time, advance detection operations are carried out to achieve synchronous hole protection and detection. S4. During the drilling and exploration process, if the early warning control module (6) detects that the borehole wall pressure exceeds the preset early warning threshold or the pressure change rate exceeds the set value, it is determined to be a precursor to borehole wall collapse. The audible and visual early warning is immediately activated, and an early warning signal is sent to the ground control terminal to remind the on-site staff to take timely measures. S5. After the advanced drilling operation is completed, slowly lift the drill rod and retrieve the external hole protection assembly (7), the flexible hole protection module (8) and the probe from the borehole. After retrieval, clean, inspect and maintain the entire device and remove the mud and debris from the surface of the flexible hole protection module (8).

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