An intelligent device and method for recognizing optimal sealing position of a coal mine drilling hole

Abstract

The application discloses a kind of coal mine drilling optimal hole sealing position intelligent identification device and method, it is related to coal mine gas extraction and drilling sealing technical field.This device includes ground / tunnel control unit and downhole drilling execution unit, is connected with gas circuit by cable, ground / tunnel control unit includes gas source input and general control module, intelligent shunt and interlock module, pressure monitoring and intelligent feedback module and central control unit, downhole drilling execution unit is set to hierarchical trigger blocking execution unit.This method is triggered by hierarchical pressure to block multi-depth bag, pressure decay rate dynamic monitoring, pre-accurate positioning optimal hole sealing section and electromagnetic valve interlocking and intelligent digital display pressure gauge closed-loop control, realize from "experience preset, after remedy" to "active detection, data decision-making" change.The application decision-making is objective, test is preposed, process is automatic, performance is direct and device is modular, effectively solve the defects of prior art, meet the precision and low carbon demand of coalbed gas large-scale extraction.

Description

Technical Field

[0001] This invention belongs to the field of coal mine gas extraction and borehole sealing technology, and particularly relates to an intelligent identification device and method for the optimal sealing position of coal mine boreholes. Background Technology

[0002] The efficient extraction and utilization of coalbed methane (gas) in underground coal mines is a key pathway to achieving synergy between clean energy substitution and safe coal mine production. Whether it's directional long-borehole coalbed methane pre-extraction or nitrogen injection to enhance gas recovery, the fundamental prerequisite for the effectiveness of these technologies is reliable borehole sealing. The sealing quality directly determines whether the nitrogen injection pressure can effectively act on the target coal seam and whether the extraction negative pressure can effectively act on the gas-rich area, thus affecting the extraction concentration, recovery rate, and overall economic benefits of the project.

[0003] However, scientifically determining the optimal sealing location (initial depth and length) remains a core problem that has long remained unresolved within the existing technological system. Currently, the industry mainly relies on empirical and semi-empirical methods, lacking quantitative, in-situ testing methods that match the actual, dynamically changing damage state and fracture development degree of coal seams. The existing technological approach has significant limitations.

[0004] 1. "Static length" judgment based on regulations and experience: This method ignores the "dynamic response" and "spatial heterogeneity" of coal and rock masses, mechanically applies a fixed sealing depth, which can easily lead to "undersealing" causing gas leakage or "oversealing" causing resource waste. In essence, it is "using static control" and "generalizing from one case to another", and cannot respond to the specific geomechanical environment of the borehole.

[0005] 2. Judgment based on "surface phenomena" of hole probing method: High-precision detection equipment is expensive, and single-hole operation takes a long time, making it difficult to popularize on a large scale; the detection depth and judgment dimensions are limited, and it can only reflect the "surface" condition of the hole wall. It cannot identify the micro-fracture network inside the coal seam, and it provides "geological appearance parameters" rather than "engineering performance parameters", which cannot directly and quantitatively prove the sealing ability of the coal seam.

[0006] 3. "Post-hoc remediation" based on "dynamic sealing" and repeatable grouting: This method does not address the root cause of "determining the optimal sealing position" and follows a passive response logic of "pre-planned construction → monitoring failure → passive remediation". The grouting effect is uncertain and increases material consumption, labor costs and system complexity, failing to eliminate the risk of sealing failure from the source.

[0007] Existing technologies suffer from four core defects: lack of sealing accuracy, insufficient fracture detection capability, low testing efficiency, and deviation from low-carbon goals. These defects are causally related, making it impossible to accurately determine the "coal seam damage-fracture distribution-sealing location" from the source. Instead, they can only be remedied through "trial and error" or "post-failure repair," failing to meet the precision and low-carbon requirements of large-scale coalbed methane extraction. Therefore, there is an urgent need to develop a device and method capable of intelligently comparing and selecting the optimal sealing starting position in the early stages of final sealing construction. Summary of the Invention

[0008] In view of the problems existing in the prior art, the purpose of this invention is to provide an intelligent identification device and method for the optimal sealing position of coal mine boreholes.

[0009] To solve the above problems, the present invention adopts the following technical solution:

[0010] A smart identification device for the optimal sealing position of a coal mine borehole includes a surface / roadway control unit and an underground drilling execution unit, wherein the surface / roadway control unit and the underground drilling execution unit are connected to a gas circuit via a cable;

[0011] 1. Ground / tunnel control unit, including gas source input and main control module, intelligent diversion and interlock module, pressure monitoring and intelligent feedback module and central control unit;

[0012] (1) Gas source input and main control module, including inlet pipeline, main switch solenoid valve and electronically controlled proportional regulating valve. The main switch solenoid valve and electronically controlled proportional regulating valve are connected in series on the inlet pipeline. The main switch solenoid valve realizes the start and termination of the entire identification process. The electronically controlled proportional regulating valve can receive control signals to realize the linear and slow increase of nitrogen injection pressure, completely avoiding the damage caused by pressure shock to the test system and borehole wall, and ensuring the stability and safety of the test process;

[0013] (2) Intelligent diversion and interlocking module, including a three-way valve, a first control solenoid valve, a second control solenoid valve and a second relay. The three-way valve divides the pipeline after the electronically controlled proportional regulating valve into a plugging test branch and a borehole pressure test branch. The first control solenoid valve is installed on the plugging test branch and the second control solenoid valve is installed on the borehole pressure test branch. The first control solenoid valve and the second control solenoid valve are electrically hard interlocked through the second relay. The logic is: when the first control solenoid valve is open, the second control solenoid valve is forcibly closed; when the second control solenoid valve is open, the first control solenoid valve is forcibly closed. The electrical hard interlock design ensures that at any time, gas can only enter one branch, preventing process confusion and misoperation caused by the simultaneous performance of plugging test and pressure test. It ensures the rigor and reliability of the test process from a structural perspective and avoids test data distortion caused by branch interference.

[0014] (3) Pressure monitoring and intelligent feedback module, including a first intelligent digital display pressure gauge, a second intelligent digital display pressure gauge, a first relay, a third relay and a fourth relay. The first intelligent digital display pressure gauge is installed on the plugging test branch, and the second intelligent digital display pressure gauge is installed on the borehole pressure test branch. The first intelligent digital display pressure gauge is linked with the first control solenoid valve through the fourth relay. The second intelligent digital display pressure gauge is linked with the main switch solenoid valve through the first relay and with the second control solenoid valve through the third relay. The dual intelligent digital display pressure gauges realize real-time and accurate monitoring of the pressure of different branches. Through the linkage control of the relay and the solenoid valve, a fast-response pressure feedback mechanism is realized. The first intelligent digital display pressure gauge can accurately control the pressure threshold of the plugging test. The second intelligent digital display pressure gauge can capture the pressure change in the pressure test in a timely manner, providing accurate and real-time pressure data support for subsequent intelligent decision-making, avoiding the delay and error of manual monitoring.

[0015] (4) Central control unit, including monitoring substation, controller and ground monitoring computer. All solenoid valves, electronically controlled proportional regulating valves and pressure gauges are connected to the monitoring substation through optical fiber. The monitoring substation is connected to the controller. The controller is connected to the ground monitoring computer through the mine communication network. The controller is the core control hub. It is preferably an intrinsically safe PLC programmable logic controller for mining. It realizes centralized scheduling and control of each component. The ground monitoring computer realizes remote parameter setting, process monitoring, data storage and analysis.

[0016] 2. A downhole drilling execution unit, comprising several graded triggering mining casing-type plugging units. These plugging units are spaced apart on a plugging test branch and lowered to a preset test depth within the borehole. Each plugging unit includes a single-interface main pipe section and a unidirectional threshold pressure conduction component. The single-interface main pipe section is a pipe with a through hole on its sidewall, connected in series on the plugging test branch. The end of the plugging test branch is a closed end. The unidirectional threshold pressure conduction component plugs the through hole of the single-interface main pipe section, and a unique opening pressure threshold is preset within it. The opening pressure of the unidirectional threshold pressure conduction components of the several plugging units is... The threshold pressure increases in a stepwise manner along the borehole from shallow to deep. The outlet of the unidirectional threshold pressure conduction component is connected to a mine-use flexible inflatable plugging airbag. The graded triggering plugging unit design realizes the "one-time deployment, sequential activation" scheme, which can complete tests at multiple depths without moving downhole components, greatly improving testing efficiency. The stepwise pressure threshold setting of the unidirectional threshold pressure conduction component ensures accurate triggering of plugging units at different depths and avoids test confusion caused by false triggering. The mine-use flexible inflatable plugging airbag can fit tightly against the borehole wall to achieve temporary sealing and provide a stable sealing environment for pressure buildup tests.

[0017] Furthermore, the mine-use flexible inflatable sealing airbag is made of mine-use flame-retardant and antistatic polyurethane elastomer material, and its surface is designed with an enhanced sealing structure. This material has flame-retardant and antistatic properties, meeting the explosion-proof safety requirements of underground coal mines and avoiding safety accidents caused by material properties. At the same time, polyurethane elastomer has good flexibility and wear resistance, and can adapt to the irregular shape of the borehole wall to ensure the sealing performance. Specifically, the enhanced sealing structure on the surface of the mine-use flexible inflatable sealing airbag is a ring-shaped sawtooth or thread distributed on the surface of the airbag. The teeth or threads are made of elastic material or are integrally molded with the flexible inflatable sealing airbag for mining. For irregular surfaces in the borehole, the annular teeth or threads fit perfectly into the uneven areas, improving the sealing between the airbag and the borehole. For smooth surfaces in the borehole, the annular teeth or threads on the surface of the airbag deform under pressure and fit against the smooth surface, which can also achieve a seal. Moreover, when the airbag expands, the annular teeth or threads grip the borehole wall, increasing the friction between the airbag and the borehole. When the airbag is inflated, it prevents the internal pressure of the borehole from being too high and pushing the airbag out, thus improving the sealing performance.

[0018] Furthermore, the one-way threshold pressure conduction component is a one-way valve. The one-way valve has a simple structure and high reliability. When the pressure reaches the preset opening pressure threshold, it quickly conducts to inflate the airbag. When the pressure does not reach the threshold, it remains closed. At the same time, the one-way valve can effectively prevent the gas in the airbag from flowing back.

[0019] Furthermore, the first intelligent digital display pressure gauge can be set with a pressure upper limit. The pressure upper limit is greater than the opening pressure threshold of the current blocking unit to be triggered and less than the opening pressure threshold of the next blocking unit to be triggered. When the pressure of the blocking test branch reaches the pressure upper limit, the first intelligent digital display pressure gauge closes the first control solenoid valve by outputting a signal through the fourth relay. By dynamically setting the pressure upper limit of the first intelligent digital display pressure gauge, it is ensured that the air bladder of the current target blocking unit is fully inflated to achieve a reliable sealing effect, and the excessive pressure is absolutely avoided from mistakenly triggering the next blocking unit. This realizes the orderly progress of graded blocking and solves the technical problem of controlling the triggering sequence of multiple blocking units.

[0020] Furthermore, the second intelligent digital display pressure gauge is used to monitor the pressure inside the borehole. It can be set with an upper limit for the target pressure during the pressure build-up test, a lower limit for determining leakage, and a delay time for sending signals. When the pressure inside the borehole reaches the set upper limit, the second intelligent digital display pressure gauge triggers the main switch solenoid valve to close via the first relay. When the pressure reaches the lower limit, the second intelligent digital display pressure gauge triggers the main switch solenoid valve to open via the first relay and disconnects the second control solenoid valve via the third relay. By setting the upper and lower pressure limits and the delay time for sending signals on the second intelligent digital display pressure gauge, pressure monitoring of the borehole within a certain holding time is achieved. The linkage control with the main switch solenoid valve and the second control solenoid valve enables automatic start / stop and process switching of the pressure build-up test without manual intervention.

[0021] The present invention also provides a method for intelligent identification of the optimal sealing position of coal mine boreholes based on the above-mentioned device, comprising the following steps:

[0022] S1: The system prepares for the Nth level of blocking, with N initially set to 1.

[0023] S1-1: In the initial state, the main switch solenoid valve is closed, the first control solenoid valve is open, the second control solenoid valve is closed, and the gas passage is directed to the sealing test branch.

[0024] S1-2: Open the main switch solenoid valve to supply gas, and the electronically controlled proportional regulating valve slowly increases the pipeline pressure.

[0025] S1-3: When the pressure rises to the opening pressure threshold of the Nth sealing unit, its internal one-way threshold pressure conduction component opens, and gas is injected into the corresponding mine flexible inflatable sealing airbag, causing it to expand and seal the borehole.

[0026] S1-4: The pressure continues to rise slowly until it reaches the dynamic upper limit set by the first intelligent digital display pressure gauge for the Nth level test. The dynamic upper limit is greater than the opening pressure threshold of the Nth blockage unit and less than the opening pressure threshold of the N+1th blockage unit. At this time, the first intelligent digital display pressure gauge sends a signal, the controller closes the first control solenoid valve, the second control solenoid valve opens automatically, and the system switches to the pressure hold test mode.

[0027] S2: Pressure resistance test at the Nth level sealing location:

[0028] S2-1: Gas enters the borehole pressure test branch and pressurizes the deep borehole section that has been isolated by the blocked point;

[0029] S2-2: The system monitors the reading of the second intelligent digital pressure gauge and starts timing, employing two parallel evaluation paths:

[0030] Path 1: If the pressure inside the borehole reaches the preset upper limit within the set delay signal transmission time, the second intelligent digital display pressure gauge sends a signal, the controller controls the main switch solenoid valve to close, and the system enters the "pressure holding" stage. Observe the pressure decay. If the pressure can remain stable or drop very slowly, it is determined that the sealing position is good. If the pressure drops quickly to the preset lower limit pressure value, it is determined that there is air leakage and poor sealing.

[0031] Path 2: If the continuous inflation time exceeds the delay time and the pressure inside the borehole still fails to reach the upper limit, the second intelligent digital pressure gauge will send a signal to determine that the sealing at that location is poor.

[0032] S2-3: If the current Nth level sealing position is determined to have "poor sealing", the signal sent by the second intelligent digital display pressure gauge will trigger the process to reset through the third relay, close the second control solenoid valve, reopen the first control solenoid valve, and the system will prepare to perform the N+1 level test.

[0033] S3: Progressive Testing and Optimal Position Determination:

[0034] S3-1: The system pressurizes again through the blocking test branch. Due to the action of the already triggered mine flexible inflatable blocking airbag and its corresponding one-way threshold pressure conduction component, the pressure bypasses the already triggered low threshold component and continues to rise.

[0035] S3-2: When the pressure rises to the opening pressure threshold of the N+1th sealing unit, the corresponding mine flexible inflatable sealing airbag expands and seals at a deeper position, and the sealing starting point moves to this depth;

[0036] S3-3: Adjust the upper pressure limit of the first intelligent digital display pressure gauge to make it greater than the opening pressure threshold of the N+1 level sealing unit and less than the opening pressure threshold of the N+2 level sealing unit, and confirm that the sealing is completed;

[0037] S3-4: Repeat steps S1 and S2 to perform a pressure resistance test on the new sealing location;

[0038] S3-5: Repeat steps S3-1 to S3-4 until, in a certain pressure test, the pressure can remain stable after reaching the upper limit, and the cycle ends.

[0039] S3-6: The system records the depth of the sealing point that successfully passes the pressure test, which is the optimal starting position for sealing. All test data is uploaded to the ground monitoring computer platform to generate a test report.

[0040] Based on the above technical solutions, this invention addresses the pain points of existing technologies where the determination of the sealing position relies on subjective experience and lacks in-situ quantitative testing methods, leading to high sealing failure rates and frequent rework. It provides an intelligent identification device and method for the optimal sealing position in boreholes based on intelligent linkage between stepped pressure triggering and pressure buildup feedback. The core concept of this technical solution is: before implementing the final, irreversible engineering sealing (such as grout injection), a modular, reusable testing system is used to simulate the future real nitrogen injection environment. This system proactively and intelligently performs stepped, cyclical in-situ testing and quantitative evaluation of the sealing performance at a series of preset depths in the borehole. By comparing the pressure buildup performance at each test point, the section with the best sealing performance is objectively and accurately selected as the optimal starting position for engineering sealing. This method achieves a fundamental shift from "experience-based pre-setting and post-event remediation" to "proactive detection and data-driven decision-making." Its application scenarios are flexible. It can be used for benchmark hole testing of pre-drainage of long directional boreholes in a region, benchmark hole testing of boreholes for nitrogen injection displacement, and monitoring hole testing at 100-meter intervals in mining faces. It can also obtain accurate sealing parameters that are adapted to the fracture development conditions in different regions.

[0041] Furthermore, in steps S1-3, the initial triggering depth and position of the blocking unit are set according to the actual situation on site.

[0042] Furthermore, in step S2-2, the delayed signal transmission time is set to 10 minutes.

[0043] Furthermore, the spacing between the blocking units is 3m.

[0044] Furthermore, the unidirectional threshold pressure conduction component is provided with 5 components, and the opening pressure thresholds are 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa and 0.9MPa respectively from shallow to deep.

[0045] The key innovation of the above technical solution lies in:

[0046] ① Depth selection mechanism linking "graded unidirectional threshold pressure conduction component" with dynamic pressure control: It creatively combines mechanical pressure threshold triggering element (graded unidirectional threshold pressure conduction component) with electronic dynamic pressure upper limit control (intelligent digital display pressure gauge), which realizes that by simply adjusting the upper limit pressure of the intelligent digital display pressure gauge, the sealing points at different depths in the borehole can be activated accurately, reliably and sequentially, and can effectively prevent false triggering. It is the core hardware foundation for the realization of the whole method.

[0047] ② Intelligent assessment criteria for pressure buildup performance based on "condition triggering": Two independent and complementary leakage judgment conditions are designed, including "pressure decays too rapidly after reaching the upper limit" and "failure to reach the upper limit even after exceeding the inflation time limit". This criterion can comprehensively capture two typical sealing failure modes, "sudden large leakage" and "continuous slow leakage", ensuring the rigor and reliability of the assessment and avoiding misjudgments or omissions that may be caused by a single criterion.

[0048] ③ Automated process control system based on relay interlock and pressure feedback signals: A complete control system was constructed with a PLC controller as the brain, pressure sensors as the nerves, and relay interlock circuits and solenoid valves as actuators. This system can automatically decide whether to "end the test" or "proceed to the next level" based on test results, achieving full automation of the entire step-by-step testing optimization process and transforming complex geological decision-making problems into reliable engineering control problems.

[0049] ④ Intelligent identification device with "reusable main control system + replaceable plugging module": This design proposes a concept that separates expensive control and monitoring components from disposable plugging execution components. The main control pipeline and instruments can be reused for a long time, and only the airbag part of the plugging unit going down into the well needs to be replaced, which greatly reduces the cost of single-hole testing and makes this technology practical and economical for large-scale application in underground coal mines.

[0050] The beneficial effects of this invention are:

[0051] Compared with the prior art, the advantages of this invention are:

[0052] 1. Objectifying decision-making and eliminating reliance on experience: Through a standardized "test-pressure holding-evaluation" cycle, the objective physical quantity of "whether the pressure is maintained" is used as the sole criterion, completely replacing subjective experience-based judgments that vary from person to person. This ensures the scientific nature of the selection of the sealing position from the source and effectively avoids gas leakage caused by "under-sealing" and resource waste caused by "over-sealing".

[0053] 2. Pre-testing to avoid major waste: Conducting low-cost testing before permanent engineering sealing, which consumes a lot of materials and time, can eliminate unsuitable sealing positions in advance, greatly reducing the risk of rework, material waste and project delays. At the same time, it reduces extra pre-extraction time, reduces carbon emissions, and is in line with the "dual carbon" goal.

[0054] 3. Process automation for intelligent optimization: The system has a complete closed-loop control capability of "perception-judgment-execution-re-perception", which can automatically complete progressive testing and comparison from the first level to the final level without manual intervention in depth selection and process switching. It has a high degree of intelligence, is easy to operate, greatly improves testing efficiency, and reduces labor costs and human error.

[0055] 4. Direct Performance and Perception of Microscopic Damage: The "pressure buildup" test directly simulates the state of the borehole under future working pressure. Its pressure decay rate is highly sensitive to both macroscopic fractures and microscopic leakage channels. The evaluation results directly correspond to the actual performance of the project, and its reliability is far higher than that of indirect geological observation, effectively solving the problem of blind spots in the detection of microscopic fractures.

[0056] 5. Modular design of the device, combining high efficiency and economy: The ingenious design of the graded trigger sealing unit allows for testing of multiple depths with a single deployment. Consumable parts such as airbags are easy to replace, and the main control system is reusable, which greatly reduces the cost of single-hole testing. This makes the technology practical and economical for large-scale application in coal mines, while reducing the need for slurry replenishment and resource consumption, meeting the requirements of low-carbon operation. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the structure of the present invention;

[0058] Figure 2 This is a schematic diagram of the sealing unit of the present invention;

[0059] Figure 3 This is a state diagram showing the initial stage of the blockade process in this invention;

[0060] Figure 4 This is a state diagram of the present invention under the condition of leakage during primary sealing;

[0061] Figure 5 This is a diagram showing the state of the present invention under good sealing conditions during level four sealing;

[0062] Figure 6 This is a schematic diagram of the intelligent recognition process of the present invention.

[0063] In the diagram: 1. Main switch solenoid valve; 2. Electrically controlled proportional regulating valve; 3. Three-way valve; 4-1. First control solenoid valve; 4-2. Second control solenoid valve; 5-1. First intelligent digital display pressure gauge; 5-2. Second intelligent digital display pressure gauge; 6-1. First relay; 6-2. Second relay; 6-3. Third relay; 6-4. Fourth relay; 7-1. Inlet pipeline; 7-2. Sealing test branch; 7-3. Borehole pressure test branch; 8. Sealing unit; 8-1. Single-interface main pipe section; 8-2. One-way threshold pressure conduction component; 9. Mine-use flexible inflatable sealing airbag; 10. Monitoring substation; 11. Controller; 12. Mine communication network; 13. Ground monitoring computer. Detailed Implementation

[0064] 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.

[0065] like Figure 1-5 As shown, the present invention provides an intelligent identification device and method for the optimal sealing position of coal mine boreholes. The intelligent identification device includes a surface / roadway control unit and an underground drilling execution unit, which are connected to the gas circuit via cables.

[0066] 1. Ground / tunnel control unit, including gas source input and main control module, intelligent diversion and interlock module, pressure monitoring and intelligent feedback module and central control unit.

[0067] (1) Gas source input and main control module: The inlet pipe 7-1 of the device is connected to the downhole nitrogen input source. The main switch solenoid valve 1 and the electronically controlled proportional regulating valve 2 are connected in series on the inlet pipe 7-1. The main switch solenoid valve 1 is controlled by the core logic of the system to realize the start and termination of the entire identification process; the electronically controlled proportional regulating valve 2 is used to receive control signals to realize the linear and slow increase of nitrogen injection pressure and completely avoid pressure shock.

[0068] (2) Intelligent diversion and interlocking module: The inlet pipeline 7-1, after pressure regulation by the electrically controlled proportional regulating valve 2, is connected to a three-way valve 3, which divides the pipeline into two completely independent branches: the plugging test branch 7-2 and the borehole pressure test branch 7-3. The two branches are respectively equipped with the first control solenoid valve 4-1 and the second control solenoid valve 4-2. The two solenoid valves are electrically hard interlocked through the second relay 6-2. The logic is: when 4-1 is open, 4-2 is forcibly closed; when 4-2 is open, 4-1 is forcibly closed. This design fundamentally ensures that at any time, gas can only choose to enter the borehole to perform the plugging action or to perform the pressure test, eliminating process confusion and misoperation, and ensuring system safety.

[0069] (3) Pressure monitoring and intelligent feedback module:

[0070] ① The first intelligent digital display pressure gauge 5-1 is installed on the sealing test branch 7-2 to monitor and control the pressure during the sealing process. The first intelligent digital display pressure gauge 5-1 is linked to the first control solenoid valve 4-1 through the fourth relay 6-4. Its core function is to set a pressure upper limit. This pressure upper limit is greater than the opening pressure threshold of the sealing unit 8 to be triggered, and less than the opening pressure threshold of the next sealing unit 8 to be triggered. When the pressure in the borehole pressure test branch 7-3 reaches the pressure upper limit, it indicates that the target airbag has been fully inflated and the triggering of the next airbag should be avoided. The first intelligent digital display pressure gauge 5-1 outputs a signal through the fourth relay 6-4 to close the first control solenoid valve 4-1.

[0071] ② The second intelligent digital display pressure gauge 5-2, installed on the borehole pressure test branch 7-3, is used to monitor the pressure inside the borehole and is a key sensor for evaluating sealing performance. The second intelligent digital display pressure gauge 5-2 is linked to the main switch solenoid valve 1 via the first relay 6-1 and to the second control solenoid valve 4-2 via the third relay 6-3. It can be set with an upper limit for the target pressure during the pressure test, a lower limit for determining leakage, and a delay time for sending signals. When the pressure inside the borehole reaches the set upper limit, the second intelligent digital display pressure gauge 5-2 triggers the main switch solenoid valve 1 to close via the first relay 6-1, stopping the gas supply. When the pressure reaches the lower limit, the second intelligent digital display pressure gauge 5-2 triggers the main switch solenoid valve 1 to open via the first relay 6-1, restarting the gas supply. When the second intelligent digital display pressure gauge 5-2 reaches the lower limit, it also disconnects the second control solenoid valve 4-2 via the third relay 6-3.

[0072] (4) Central control unit: All solenoid valves, electrically controlled proportional regulating valves 2, and pressure gauges are connected to the monitoring substation 10 via optical fiber. The monitoring substation 10 is then connected to the intrinsically safe mine-use PLC programmable logic controller 11. The controller 11 is responsible for executing preset test programs, processing sensor feedback signals, and directing each actuator to operate according to a precise timing sequence. The controller 11 is connected to the ground monitoring computer 13 through the mine communication network 12 to realize remote parameter setting, process monitoring, data storage, and analysis.

[0073] 2. The downhole drilling execution unit has a closed end at the end of the plugging test branch 7-2, on which 5 graded triggering mining casing-type plugging units 8 are connected in series. These plugging units 8 are arranged at intervals (one every 3m) on the plugging test branch 7-2 and are lowered into the borehole to a preset test depth sequence. The initial triggering depth and position of the plugging unit 8 are set according to the actual site conditions (e.g., at a depth of 3m).

[0074] like Figure 2As shown, each sealing unit 8 includes a single-interface main pipe section 8-1 and a one-way threshold pressure conduction component 8-2. The single-interface main pipe section 8-1 is a pipe with through holes on the side wall, connected in series with the sealing test branch 7-2. The one-way threshold pressure conduction component 8-2 is a one-way valve, which is used to seal the through hole of the single-interface main pipe section 8-1. It has a preset unique opening pressure threshold. The opening pressure thresholds of the one-way threshold pressure conduction components 8-2 of the five sealing units 8 increase in a stepwise manner from shallow to deep along the borehole, namely 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, and 0.9MPa. The outlet of the one-way threshold pressure conduction component 8-2 is connected to a mine-use flexible inflatable sealing airbag 9. The airbag is made of high-molecular materials such as mine-use flame-retardant and antistatic polyurethane elastomer, and its surface is designed with an enhanced sealing structure (such as annular serrations or threads). Once the component is turned on, high-pressure gas instantly fills the airbag, causing it to expand rapidly and achieve a tight mechanical temporary seal against the borehole wall. The annular serrations or threads on the surface of the airbag fill the uneven areas of the borehole wall to achieve a seal, while also increasing the friction between the airbag and the borehole wall.

[0075] like Figure 6 As shown, the method for intelligently identifying the optimal sealing position of coal mine boreholes using the above-mentioned device includes the following specific steps:

[0076] S1: As Figure 3 As shown, the system is preparing for the Nth level of blocking, with N initially set to 1:

[0077] S1-1: In the initial state, the main switch solenoid valve 1 is closed, the first control solenoid valve 4-1 is open, the second control solenoid valve 4-2 is closed, and the gas passage is directed to the sealing test branch 7-2.

[0078] S1-2: Start-up and staged sealing: Open the main switch solenoid valve 1, supply gas from the gas source, and slowly increase the pipeline pressure using the electronically controlled proportional regulating valve 2;

[0079] S1-3: Triggering Blocking: When the pressure rises to the opening pressure threshold of the first blocking unit 8 (0.5MPa), the one-way threshold pressure conduction component 8-2 opens, and gas fills the corresponding airbag 9, causing it to expand and block the borehole.

[0080] S1-4: Confirmation of sealing completion: The pressure continues to rise slowly until it reaches the dynamic upper limit of 0.55MPa (greater than 0.5MPa and less than 0.6MPa) set by the first intelligent digital display pressure gauge 5-1. The first intelligent digital display pressure gauge 5-1 sends a signal, the controller 11 closes the first control solenoid valve 4-1, the second control solenoid valve 4-2 opens automatically, and the system switches to the pressure stagnation test mode.

[0081] S2: Pressure resistance test at the first-level sealing location:

[0082] S2-1: Drilling pressurization: Gas enters the borehole pressurization test branch 7-3 and pressurizes the deep borehole section (3m or deeper) that has been isolated by the blocked point;

[0083] S2-2: Pressure Hold-up Test and Criteria: The system monitors the reading of the second intelligent digital display pressure gauge 5-2 and starts timing, with the signal delay time set to 10 minutes.

[0084] Path 1 (Pressure Reach Type): If the borehole pressure reaches the preset upper limit (e.g., 0.55 MPa) within the delay time (e.g., 10 minutes), controller 11 closes the main switch solenoid valve 1, the system enters the "pressure holding" stage, and timing begins. The system calculates and monitors the pressure decay rate (V) in real time, defined as V = ΔP / Δt, where ΔP is the pressure drop value and Δt is the monitoring time interval. If the pressure decay rate V is always ≤ [set threshold A, e.g., 0.005 MPa / min] within the preset pressure holding monitoring period (e.g., 30 minutes), the sealing performance of the plugging location is determined to be "good". If, within the monitoring period, the pressure decay rate V is ≥ [set threshold B, e.g., 0.05 MPa / min] in any continuous time period (e.g., 5 minutes), or the pressure value drops directly to the preset lower limit pressure value (e.g., 0.4 MPa), it is determined to be "leaking" and the sealing performance is poor. Figure 4 As shown;

[0085] Path 2 (Pressure Not Reached): If the pressure still does not reach the upper limit (0.55MPa) after 10 minutes, the sealing performance is directly judged as poor.

[0086] S2-3: If the sealing performance is determined to be poor, the second intelligent digital display pressure gauge 5-2 sends a signal to trigger a process reset, closes the second control solenoid valve 4-2, reopens the first control solenoid valve 4-1, and prepares for the second stage test.

[0087] S3: Progressive Testing and Optimal Position Determination:

[0088] S3-1: The system pressurizes again through the blocked test branch 7-2, and the pressure continues to rise, bypassing the already triggered low threshold component;

[0089] S3-2: When the pressure rises to the opening pressure threshold of the second sealing unit 8, which is 0.6MPa, the corresponding airbag 9 expands and seals at a deeper location (6m depth);

[0090] S3-3: Adjust the upper pressure limit of the first intelligent digital display pressure gauge 5-1 to 0.65MPa (greater than 0.6MPa and less than 0.7MPa) to confirm that the sealing is complete;

[0091] S3-4: Repeat steps S1 and S2 to perform a pressure resistance test on the new sealing location;

[0092] S3-5: Repeat steps S3-1 to S3-4 until the pressure reaches the upper limit and remains stable during a pressure test, at which point the cycle ends.

[0093] S3-6: The system records the depth of this sealing point (12m depth) as the optimal starting position for sealing, such as... Figure 5 As shown, all test data is uploaded to the ground monitoring computer 13 to generate a test report.

[0094] The specific values ​​set in the above-described specific embodiments of the present invention, such as "the sealing units 8 are arranged at intervals (one every 3m)," "the opening pressure threshold of the unidirectional threshold pressure conduction component 8-2 of the 5 sealing units 8 increases in a stepwise manner along the borehole from shallow to deep, namely 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, and 0.9MPa," "the upper pressure limit of the first intelligent digital display pressure gauge 5-1," and "the delay signal transmission time of the second intelligent digital display pressure gauge 5-2 is set to 10 minutes," are only one example and are not limited to this scheme. The actual initial depth, position, and interval distance of the sealing units 8, the opening pressure threshold of the unidirectional threshold pressure conduction component 8-2, the upper and lower pressure limits of the intelligent digital display pressure gauge, and the delay signal transmission time can be set according to the actual situation on site.

[0095] Although specific embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An intelligent identification device for the optimal sealing position of a coal mine borehole, characterized in that, It includes a surface / tunnel control unit and a downhole drilling execution unit, wherein the surface / tunnel control unit and the downhole drilling execution unit are connected to the gas circuit via cables; The ground / tunnel control unit includes a gas source input and main control module, an intelligent diversion and interlock module, a pressure monitoring and intelligent feedback module, and a central control unit; The gas source input and main control module includes an inlet pipeline (7-1), a main switch solenoid valve (1), and an electronically controlled proportional regulating valve (2), wherein the main switch solenoid valve (1) and the electronically controlled proportional regulating valve (2) are connected in series on the inlet pipeline (7-1); The intelligent diversion and interlocking module includes a three-way valve (3), a first control solenoid valve (4-1), a second control solenoid valve (4-2), and a second relay (6-2). The three-way valve (3) divides the pipeline after the electrically controlled proportional regulating valve (2) into a plugging test branch (7-2) and a borehole pressure test branch (7-3). The first control solenoid valve (4-1) is installed on the plugging test branch (7-2), and the second control solenoid valve (4-2) is installed on the borehole pressure test branch (7-3). The first control solenoid valve (4-1) and the second control solenoid valve (4-2) are electrically interlocked through the second relay (6-2). The pressure monitoring and intelligent feedback module includes a first intelligent digital display pressure gauge (5-1), a second intelligent digital display pressure gauge (5-2), a first relay (6-1), a third relay (6-3), and a fourth relay (6-4). The first intelligent digital display pressure gauge (5-1) is installed on the plugging test branch (7-2), and the second intelligent digital display pressure gauge (5-2) is installed on the borehole pressure test branch (7-3). The first intelligent digital display pressure gauge (5-1) is linked to the first control solenoid valve (4-1) through the fourth relay (6-4), and the second intelligent digital display pressure gauge (5-2) is linked to the main switch solenoid valve (1) through the first relay (6-1) and to the second control solenoid valve (4-2) through the third relay (6-3). The central control unit includes a monitoring substation (10), a controller (11), and a ground monitoring computer (13). All solenoid valves, electronically controlled proportional regulating valves (2), and pressure gauges are connected to the monitoring substation (10) via optical fiber. The monitoring substation (10) is connected to the controller (11), and the controller (11) is connected to the ground monitoring computer (13) via the mine communication network (12). The downhole drilling execution unit includes several graded triggering mining casing-type plugging units (8). The plugging units (8) are arranged at intervals on the plugging test branch (7-2) and lowered to a preset test depth in the borehole. Each plugging unit (8) includes a single-interface main pipe section (8-1) and a one-way threshold pressure conduction component (8-2). The single-interface main pipe section (8-1) is a pipe with a through hole on the side wall, connected in series on the plugging test branch (7-2). The end of the plugging test branch (7-2) is a closed end. The one-way threshold pressure conduction component (8-2) is plugged at the through hole of the single-interface main pipe section (8-1). It has a preset unique opening pressure threshold. The opening pressure threshold of the one-way threshold pressure conduction components (8-2) of several plugging units (8) increases stepwise from shallow to deep along the borehole. The outlet of the one-way threshold pressure conduction component (8-2) is connected to a mining flexible inflatable plugging airbag (9).

2. The intelligent identification device for the optimal sealing position of coal mine boreholes according to claim 1, characterized in that, The mine-use flexible inflatable sealing airbag (9) is made of mine-use flame-retardant and antistatic polyurethane elastomer material, and its surface is designed with an enhanced sealing structure.

3. The intelligent identification device for the optimal sealing position of coal mine boreholes according to claim 1, characterized in that, The one-way threshold pressure conduction component (8-2) is a one-way valve.

4. The intelligent identification device for the optimal sealing position of coal mine boreholes according to claim 1, characterized in that, The first intelligent digital display pressure gauge (5-1) can be set with a pressure upper limit. The pressure upper limit is greater than the opening pressure threshold of the current blocking unit (8) to be triggered, and less than the opening pressure threshold of the next blocking unit (8) to be triggered. When the pressure of the borehole pressure test branch (7-3) reaches the pressure upper limit, the first intelligent digital display pressure gauge (5-1) outputs a signal through the fourth relay (6-4) to close the first control solenoid valve (4-1).

5. The intelligent identification device for the optimal sealing position of coal mine boreholes according to claim 1, characterized in that, The second intelligent digital display pressure gauge (5-2) is used to monitor the pressure inside the borehole. It can set the upper limit of the target pressure for the pressure test and the lower limit of the pressure for determining leakage, as well as the time for delaying the signal transmission. When the pressure inside the borehole reaches the set upper limit, the second intelligent digital display pressure gauge (5-2) triggers the main switch solenoid valve (1) to close through the first relay (6-1). When the pressure reaches the lower limit, the second intelligent digital display pressure gauge (5-2) triggers the main switch solenoid valve (1) to open through the first relay (6-1) and disconnects the second control solenoid valve (4-2) through the third relay (6-3).

6. A method for intelligently identifying the optimal sealing position of a coal mine borehole based on the device described in any one of claims 1-5, characterized in that, Includes the following steps: S1: The system prepares for the Nth level of blocking, with N initially set to 1. S1-1: In the initial state, the main switch solenoid valve (1) is closed, the first control solenoid valve (4-1) is open, the second control solenoid valve (4-2) is closed, and the gas passage is directed to the sealing test branch (7-2). S1-2: Open the main switch solenoid valve (1), supply gas from the gas source, and slowly increase the pipeline pressure using the electronically controlled proportional regulating valve (2); S1-3: When the pressure rises to the opening pressure threshold of the Nth sealing unit (8), the one-way threshold pressure conduction component (8-2) inside it opens, and gas is filled into the corresponding mine flexible inflatable sealing airbag (9) to expand and seal the borehole. S1-4: The pressure continues to rise slowly until it reaches the dynamic upper limit set by the first intelligent digital display pressure gauge (5-1) for the Nth level test. The dynamic upper limit is greater than the opening pressure threshold of the Nth segment blocking unit (8) and less than the opening pressure threshold of the N+1th segment blocking unit (8). At this time, the first intelligent digital display pressure gauge (5-1) sends a signal, the controller (11) closes the first control solenoid valve (4-1), the second control solenoid valve (4-2) opens automatically, and the system switches to the pressure holding test mode. S2: Pressure resistance test at the Nth level sealing location: S2-1: Gas enters the borehole pressure test branch (7-3) to pressurize the deep borehole section that has been isolated by the blocked point; S2-2: The system monitors the reading of the second intelligent digital pressure gauge (5-2) and starts timing, employing two parallel evaluation paths: Path 1: If the pressure inside the borehole reaches the preset upper limit within the set delay signal transmission time, the second intelligent digital display pressure gauge (5-2) sends a signal, and the controller (11) controls the main switch solenoid valve (1) to close. The system enters the "pressure holding" stage and observes the pressure decay. If the pressure can remain stable or drop very slowly, it is determined that the sealing position is good. If the pressure drops quickly to the preset lower limit pressure value, it is determined that there is air leakage and poor sealing. Path 2: If the continuous inflation time exceeds the delay time and the pressure inside the borehole still fails to reach the upper limit, the second intelligent digital display pressure gauge (5-2) will send a signal to determine that the sealing at this location is poor. S2-3: If the current Nth level sealing position is determined to have "poor sealing", the signal sent by the second intelligent digital display pressure gauge (5-2) triggers the process reset through the third relay (6-3), closes the second control solenoid valve (4-2), reopens the first control solenoid valve (4-1), and the system is ready to perform the N+1 level test; S3: Progressive Testing and Optimal Position Determination: S3-1: The system pressurizes again through the blocking test branch (7-2). Due to the action of the already triggered mine flexible inflatable blocking airbag (9) and its corresponding one-way threshold pressure conduction component (8-2), the pressure bypasses the already triggered low threshold component and continues to rise. S3-2: When the pressure rises to the opening pressure threshold of the N+1th sealing unit (8), the corresponding mine flexible inflatable sealing airbag (9) expands and seals at a deeper position, and the sealing starting point moves to that depth; S3-3: Adjust the upper limit of the pressure of the first intelligent digital display pressure gauge (5-1) to be greater than the opening pressure threshold of the N+1 level sealing unit (8) and less than the opening pressure threshold of the N+2 level sealing unit (8), and confirm that the sealing is completed; S3-4: Repeat steps S1 and S2 to perform a pressure resistance test on the new sealing location; S3-5: Repeat steps S3-1 to S3-4 until, in a certain pressure test, the pressure can remain stable after reaching the upper limit, and the cycle ends. S3-6: The system records the depth of the sealing point that successfully passes the pressure test, which is the optimal starting position for sealing. All test data is uploaded to the ground monitoring computer (13) platform to generate a test report.

7. The intelligent identification method for the optimal sealing position of coal mine boreholes according to claim 6, characterized in that, In steps S1-3, the initial triggering depth and position of the blocking unit (8) are set according to the actual situation on site.

8. The intelligent identification method for the optimal sealing position of coal mine boreholes according to claim 6, characterized in that, In step S2-2, the delayed signal transmission time is set to 10 minutes.

9. The intelligent identification method for the optimal sealing position of coal mine boreholes according to claim 6, characterized in that, The spacing between the blocking units (8) is 3m.

10. The intelligent identification method for the optimal sealing position of coal mine boreholes according to claim 6, characterized in that, The unidirectional threshold pressure conducting component (8-2) has 5 components, and its opening pressure thresholds from shallow to deep are 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa and 0.9MPa respectively.

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