Coal rock mechanism correction system
Through the multi-module collaborative operation of the coal and rock mechanism correction system, the problems of insufficient identification of coal and rock uniformity and passive risk warning in the existing technology have been solved, realizing precise control and safety assurance of underground gas extraction in coal mines.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI ZUOYANG ELECTRONIC TECH CO LTD
- Filing Date
- 2026-01-27
- Publication Date
- 2026-05-08
AI Technical Summary
Existing technologies cannot accurately identify differences in the uniformity of coal and rock, resulting in a lack of targeted optimization of drilling processes, large errors in calculation results, passive risk warnings, and difficulty in ensuring the safety and efficiency of underground gas extraction in coal mines.
A coal and rock structure correction system is adopted, including a data acquisition module, a dynamic assessment module for coal and rock uniformity, a depth-quantity dual calculation module, and a multi-threshold linkage risk early warning and collaborative control module. A two-dimensional assessment standard is constructed by pressure gradient and time entropy to achieve accurate classification of coal and rock uniformity. Parameters are calculated in combination with the drill pipe mechanical model, and multi-dimensional linkage risk thresholds are set for early warning.
It enables accurate identification of coal and rock structures and proactive risk warning, improves the targeting and safety of drilling operations, reduces hidden dangers in downhole operations, and enhances data reliability and operational efficiency.
Smart Images
Figure CN121998424A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of monitoring technology for underground gas extraction boreholes in coal mines, specifically a coal and rock structure correction system. Background Technology
[0002] Drilling for underground gas drainage in coal mines is a crucial step in ensuring safe production. Its efficiency and safety directly depend on the accurate understanding of coal and rock structure parameters. While existing mine monitoring equipment can collect basic parameters such as drill rig propulsion pressure and rotation pressure, it can only preliminarily distinguish between coal seams and rock strata based on pressure amplitude. It cannot accurately identify differences in coal-rock homogeneity within the same stratum, making it difficult to locate local anomalies such as interbedded rock or loose areas. This crude identification method leads to a lack of targeted basis for drilling process optimization, making it prone to problems such as drill rod vibration and borehole deviation caused by abrupt changes in coal and rock characteristics, thus affecting gas drainage effectiveness.
[0003] Meanwhile, existing technologies rely on manual measurement or simple pressure timing judgment to estimate the number of drill pipes and the depth of coal and rock, without combining the internal uniformity characteristics of coal and rock for error correction. This results in large errors in the estimation results and cannot provide reliable data support for mining progress control. Furthermore, risk warnings rely only on a single pressure threshold for triggering and do not integrate multi-dimensional data such as uniformity and depth. This makes it difficult to accurately predict complex risks such as stuck drill and hole collapse. Often, the response is only passive after an accident occurs, which seriously threatens the safety of underground workers and the stable operation of equipment.
[0004] In view of the above, this application is hereby submitted. Summary of the Invention
[0005] The purpose of this invention is to provide a coal and rock mechanism correction system to solve the problems mentioned in the background art.
[0006] To address the aforementioned technical problems, this invention provides a coal and rock structure correction system, comprising a data acquisition module, a dynamic evaluation module for coal and rock homogeneity, a depth-quantity dual calculation module, and a multi-threshold linkage risk warning and collaborative control module. The data acquisition module collects drilling rig propulsion pressure data and rotation pressure data and transmits them to the dynamic evaluation module for coal and rock homogeneity. This module calculates the pressure gradient and extracts the time entropy from the pressure data, constructs a two-dimensional evaluation standard, and outputs four levels of coal and rock homogeneity classification results: extremely homogeneous, homogeneous, non-homogeneous, and extremely non-homogeneous. These results are then synchronized to the depth-quantity dual calculation module. The depth-quantity dual calculation module uses the homogeneity classification results as correction parameters and introduces homogeneity correction... Positive coefficients are used to calculate the number of drill rods and the depth of coal and rock by combining the drill rod mechanical model and the results of time-series feature extraction. The multi-threshold linkage risk warning and collaborative control module integrates the uniformity classification results, the number of drill rods, the depth of coal and rock, and pressure data. Based on the pressure gradient, time entropy, uniformity classification results, the number of drill rods, and the depth of coal and rock, multi-dimensional linkage thresholds are set to execute graded warnings and cross-system collaborative control. Through the collaborative operation of multiple modules, a closed-loop management of coal and rock structure is achieved from characteristic assessment to parameter calculation and then to risk prevention and control. This breaks through the limitations of existing single pressure data monitoring, significantly improves the accuracy of coal and rock identification, the accuracy of depth calculation, and the timeliness of risk warning, and fully adapts to the needs of underground gas drainage drilling operations in coal mines.
[0007] Furthermore, the data acquisition module includes a pressure sensing unit, a data preprocessing unit, and a transmission unit. The pressure sensing unit has two channels, installed on the drilling rig's propulsion tubing and rotary tubing respectively, to collect analog signals of propulsion pressure and rotary pressure. The data preprocessing unit converts the analog signals and removes interference data. The transmission unit transmits the processed pressure data to the coal and rock uniformity dynamic evaluation module via industrial Ethernet. This achieves accurate acquisition and reliable transmission of pressure data, eliminates invalid interference data, provides a high-quality data foundation for subsequent uniformity evaluation and parameter calculation, and ensures the overall operational accuracy of the system.
[0008] Furthermore, the dynamic evaluation module for coal and rock homogeneity includes a pressure gradient calculation unit, a time entropy extraction unit, and a homogeneity grading unit. The pressure gradient calculation unit performs first-order derivative calculations on the propulsion pressure data and rotation pressure data based on the sampling time interval to obtain the rate of pressure change over time. The time entropy extraction unit uses a sample entropy algorithm to process the pressure curve and quantify the disorder of pressure fluctuations. The homogeneity grading unit constructs a two-dimensional evaluation standard based on the pressure gradient and time entropy, and outputs four levels of homogeneity grading results: extremely homogeneous, homogeneous, non-homogeneous, and extremely non-homogeneous. This accurately identifies the differences in coal and rock homogeneity within the same stratum, clarifies local anomalies such as interbedded rock and loose areas, fills the gap in existing technologies that can only distinguish between broad categories of coal seams and rock strata, and provides a refined basis for process optimization.
[0009] Furthermore, the depth-quantity dual estimation module includes a mechanical model construction unit, a temporal feature extraction unit, and an estimation correction unit. The mechanical model construction unit establishes a correlation model between different uniformity grading results and pressure and propulsion speed. The temporal feature extraction unit identifies the pressure temporal segment corresponding to each drill rod through a sliding window algorithm. The estimation correction unit calculates the total depth by accumulating the length of a single drill rod, introduces a uniformity correction coefficient to correct the estimation results, and simultaneously outputs the number of drill rods and the coal and rock depth data of the strata. By correcting the mechanical model through uniformity data, the estimation deviation caused by geological inhomogeneity is avoided, which greatly improves the estimation accuracy of the number of drill rods and the coal and rock depth, eliminating the need for manual measurement and improving work efficiency.
[0010] Furthermore, the multi-threshold linkage risk early warning and collaborative control module includes a threshold setting unit, an early warning execution unit, and a collaborative control unit. The threshold setting unit sets stuck drill risk thresholds, hole collapse risk thresholds, and drill pipe overload risk thresholds based on pressure gradient, time entropy, uniformity grading results, drill pipe quantity, and coal and rock depth. The early warning execution unit executes level one, level two, and level three early warnings according to the triggered threshold levels. The collaborative control unit links with the drilling rig control system, the underground gas extraction system, and the ground monitoring center via industrial Ethernet to issue control commands. A multi-dimensional risk identification system is constructed to achieve accurate positioning and graded response for different risk types. Through cross-system collaborative control, risk prevention and control is upgraded from passive response to proactive early warning and handling, reducing operational safety hazards.
[0011] Furthermore, the first-level early warning of the aforementioned early warning execution unit provides on-site prompts through the host speaker and LED warning lights, and simultaneously pushes the early warning information to the ground monitoring center; the second-level early warning sends a speed reduction command to the drilling rig control system; the third-level early warning automatically triggers the drilling rig to stop, links the underground gas extraction system to adjust the extraction intensity, and sends alarm information to the ground dispatch center; a hierarchical early warning response mechanism is established to adapt to the handling needs of different risk levels, ensuring that on-site personnel and back-end dispatchers can obtain early warning information in a timely manner, quickly take targeted measures, and minimize risk losses.
[0012] Furthermore, it also includes a display and storage module. This module receives output data from the coal and rock uniformity dynamic assessment module, the depth-quantity dual calculation module, and the multi-threshold linkage risk warning and collaborative control module. The display and storage module includes a touch display unit and a data storage unit. The touch display unit displays the pressure curve, uniformity grading results, drill rod quantity, coal and rock depth, and warning information in real time. The data storage unit stores the collected raw data, processed intermediate data, and final result data, and supports historical data retrieval and playback. This enables the visualization and long-term retention of data, facilitating operators to view the operation status in real time and providing data support for subsequent data analysis, process optimization, and fault tracing.
[0013] Furthermore, the system adopts a mining-grade explosion-proof and intrinsically safe structural design, including an explosion-proof enclosure and an intrinsically safe enclosure. The explosion-proof enclosure houses a high-frequency transformer and an intrinsically safe power circuit board, while the intrinsically safe enclosure is installed on top of the explosion-proof enclosure and houses a main control board, display screen, LED warning lights, and speakers. The explosion-proof enclosure is equipped with wiring horn ports for connecting power cables, signal cables, and network cables. This design meets the environmental requirements of underground coal mines where there is a risk of gas and coal dust explosions, ensuring stable and reliable operation of the equipment in harsh working environments, while also facilitating installation and maintenance.
[0014] Furthermore, the collaborative control unit of the multi-threshold linkage risk early warning and collaborative control module is connected to the downhole ring network switch using the TCP / IP communication protocol. Through the downhole ring network switch, data interaction and command transmission with the drilling rig control system, the downhole gas extraction system, and the ground monitoring center are realized, ensuring that control commands are issued in real time and early warning information is synchronized across multiple terminals; ensuring the real-time performance and reliability of cross-system collaboration, realizing the efficient transmission of early warning information and control commands, improving the system's rapid response capability to risks, and further enhancing operational safety.
[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. By combining pressure gradient and time entropy to construct a two-dimensional evaluation standard, the uniformity of coal and rock within the same stratum can be accurately classified, effectively identifying local anomalies such as interbedded rock and loose areas. This fills the gap in existing technologies that can only distinguish between coal seams and rock strata, providing a reliable basis for the refined optimization of drilling technology and significantly improving the targeting and rationality of operations.
[0016] 2. Based on the results of coal and rock uniformity classification, a drill rod mechanical model is established. A uniformity correction coefficient is introduced to correct the results of drill rod quantity and coal and rock depth estimation, avoiding deviations caused by geological inhomogeneity. Automatic and accurate parameter estimation can be achieved without manual measurement, greatly improving operation efficiency and data reliability, and providing real-time and powerful data support for mining progress control.
[0017] 3. By integrating multi-dimensional data such as pressure gradient, time entropy, uniformity level, number of drill pipes, and coal and rock depth, a linkage risk threshold is set to construct a three-level early warning mechanism and a cross-system collaborative control system. This enables accurate identification and proactive early warning and handling of risks such as stuck drill, hole collapse, and drill pipe overload. It breaks through the limitations of existing single-parameter early warning technologies, upgrades risk prevention and control from passive response to proactive prediction, and significantly reduces safety hazards in downhole operations.
[0018] 4. Design a multi-regional visualization display interface and a multi-format data storage solution to achieve integrated display and full lifecycle storage of pressure curves, uniformity grading results, drill rod quantity, coal and rock depth, and early warning information. Support querying historical data and curve playback by time and event, improve data visualization and traceability efficiency, and provide complete and convenient data support for subsequent data analysis, process optimization, and fault tracing.
[0019] 5. The system adopts a mining-grade explosion-proof and intrinsically safe structural design. It realizes cross-system data interaction and command transmission through industrial Ethernet and TCP / IP communication protocols. Combined with priority settings and retransmission mechanisms, it ensures stable operation of equipment and real-time and efficient transmission of early warning information and control commands in harsh underground environments. It is adapted to the complex needs of underground gas drainage drilling operations in coal mines and has the advantages of safety, stability and practicality. Attached Figure Description
[0020] Figure 1 A flowchart illustrating the operation of a coal and rock correction system; Figure 2 Historical data playback in a coal and rock mechanism correction system Figure 1 ; Figure 3 Historical data playback in a coal and rock mechanism correction system Figure 2 . Detailed Implementation
[0021] 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.
[0022] Please see Figures 1 to 3 This invention provides a technical solution: a coal and rock structure correction system. In underground gas drainage drilling operations in coal mines, accurately grasping coal and rock structure parameters and predicting operational risks in real time are core requirements for improving drainage efficiency and operational safety. Existing technologies can only achieve basic pressure parameter acquisition and simple coal and rock classification, resulting in problems such as lack of uniformity assessment, large depth estimation errors, and passive risk warnings. For example, publicly available documents on mine monitoring host technologies can only preliminarily distinguish coal seams from rock strata through pressure amplitude, failing to identify intra-stratum uniformity differences, relying on manual assistance for depth estimation, and using only a single pressure threshold alarm for risk warning, making it difficult to meet the operational safety requirements under complex geological conditions.
[0023] This implementation method is based on a closed-loop logic of "data acquisition - characteristic evaluation - parameter calculation - risk warning - collaborative control," integrating three core technologies: dynamic assessment of coal and rock uniformity, depth-quantity dual calculation, and multi-threshold linkage risk warning. It is compatible with the hardware of the ZJY127-Z mine monitoring host, achieving refined, automated, and intelligent coal and rock structure correction. The overall system architecture includes a data acquisition module, a dynamic assessment module for coal and rock uniformity, a depth-quantity dual calculation module, a multi-threshold linkage risk warning and collaborative control module, and a display and storage module. Each module interacts via industrial Ethernet, strictly adhering to coal mine safety standards such as GB / T 3836-2021 and MT / T 209-1990. It adopts a mine-grade explosion-proof and intrinsically safe structural design, suitable for harsh underground environments with the risk of gas and coal dust explosions.
[0024] Step 1: System Deployment and Data Acquisition Preprocessing Data acquisition is the foundation for all subsequent analysis and control. It is necessary to ensure the accuracy, completeness and reliability of pressure data. Although existing technologies can acquire propulsion pressure and rotation pressure, they do not specifically address downhole interference factors (such as instantaneous pressure relief and equipment vibration), resulting in significant data noise. This step provides high-quality data support for subsequent modules through standardized deployment and data processing.
[0025] Two intrinsically safe GPD60 mining pressure transmitters are used, installed on the drilling rig's feed tubing and rotary tubing respectively. A three-way auxiliary fixing ensures a tight fit with the tubing, acquiring analog pressure signals. The ZJY127-Z main unit is suspended near the drilling rig on a stable, low-vibration roadway wall, more than 1 meter above the ground, with the main unit casing reliably grounded. The sensors and main unit are connected via a dedicated underground signal cable, which connects to the intrinsically safe circuit board inside the explosion-proof box. The main unit is connected to a ring network switch via a dedicated underground network cable, enabling communication with the ground monitoring center. The main unit is powered by a 127V AC rated voltage, with an input apparent power not exceeding 60VA. Through a built-in high-frequency transformer and intrinsically safe power circuit board, it outputs 12V DC and 24V DC intrinsically safe power to power the sensors and internal modules.
[0026] The pressure sensor acquires analog signals of propulsion pressure and rotational pressure. The signal type is 4-20 mA, and the acquisition frequency is set to 10 Hz to ensure the capture of subtle pressure changes. The host's built-in Cortex-M3 high-performance 32-bit ARM microcontroller performs analog-to-digital conversion on the analog signals. The conversion method is to subtract 4 mA from the current value output by the sensor, multiply by 100, and finally divide by 16 to obtain the pressure value (in megapascals). The upper limit of the sensor's measurement range is 100 megapascals.
[0027] The transformed pressure data is denoised using a moving average filtering algorithm. The filter window size is set to 5. The calculation method is to sum the pressure values of the current data point and the previous 4 data points (a total of 5 data points), and then divide by 5 to obtain the filtered pressure value of the current data point. When removing interference data, segments with a pressure of 0 for less than 5 seconds are identified as instantaneous pressure relief or pause, and these segments are retained and marked as interference segments. Segments with a pressure of 0 for more than 10 seconds are identified as drill pipe replacement or operation stoppage, and are marked and stored separately.
[0028] The application scenario is drilling operations in the 15-15070 intermediate low-level tunnel 2. The drilling rig model is ZDY3200S, the designed drilling depth is 100 meters, and the single drill rod length is 2 meters. The original current signal sequence of the propulsion pressure collected by the pressure sensor is 4.2 mA, 4.5 mA, 4.3 mA, 4.6 mA, 4.4 mA, 0.1 mA, 0.2 mA, 0.1 mA, 4.7 mA, 4.5 mA... After analog-to-digital conversion, the original pressure value is 1.25 MΩ. The data points are: 3.125 MPa, 1.875 MPa, 3.75 MPa, 2.5 MPa, 0 MPa, 0 MPa, 0 MPa, 4.375 MPa, 3.125 MPa… After applying a moving average filter, the filtered result for the first 5 data points is 2.5 MPa. The duration of the 3 consecutive 0 MPa data points in the middle is 0.3 seconds, which is determined to be an instantaneous pressure relief. This data is retained and marked as an interference segment. If 10 consecutive 0 MPa data points appear subsequently, it is determined that the operation is suspended and marked separately.
[0029] By standardizing hardware deployment and ensuring precise signal conversion, the accuracy of pressure data acquisition is ensured, with transmission errors controlled within 1.0%. The moving average filtering algorithm effectively reduces noise interference caused by downhole vibration, significantly improving data stability. The precise removal of interfering data avoids the impact of invalid data on subsequent analysis, improving data utilization and providing a high-quality data foundation for subsequent uniformity assessment and depth extrapolation.
[0030] Existing publicly available documents only mention the acquisition and storage of pressure data, without addressing specific filtering, noise reduction, and interference data removal schemes. The unique approach of this technical solution lies in its formulation of interference data identification rules based on time thresholds, taking into account the actual data characteristics of downhole operations. Simultaneously, it employs a moving average filtering algorithm, solving the problems of high data noise and low effective data ratio in existing technologies, thus ensuring the quality of input data for subsequent analysis modules.
[0031] Step Two: Dynamic Assessment of Coal and Rock Homogeneity Existing technologies can only distinguish between coal seams and rock strata based on the magnitude of pressure amplitude, but cannot assess the homogeneity differences within the same stratum. This results in a lack of refined basis for drilling process optimization and makes it easy for drill rod vibration and borehole deviation to be caused by local hard spots or loose areas. This step extracts the key features of the pressure curve and constructs a two-dimensional evaluation standard to achieve accurate classification of the homogeneity of coal and rock within the same stratum.
[0032] In this invention, "pressure gradient" refers to the rate of change of pressure over time. It is calculated by dividing the pressure difference between two adjacent data points by the sampling time interval. The pressure gradient reflects the rate of change of pressure over time and can characterize the degree of abrupt change in coal and rock resistance. The pressure gradient is obtained by calculating the first derivative of the pre-processed propulsion pressure and rotation pressure. The calculation method is to subtract the pressure value of the previous data point from the pressure value of the current data point, and then divide by the sampling time interval (0.1 seconds). The maximum value of the propulsion pressure gradient and the rotation pressure gradient is taken as the comprehensive pressure gradient of the data point.
[0033] Time entropy is used to quantify the disordered fluctuations of pressure curves. The higher the entropy value, the more disordered the pressure fluctuations and the worse the uniformity of coal and rock. The sample entropy algorithm is used to calculate the time entropy of the pressure curve. First, the preprocessed pressure sequence is arranged into a two-dimensional vector by every two consecutive data points. Then, the absolute value of the difference in pressure values between the corresponding data points of any two two-dimensional vectors is calculated, and the maximum value is taken as the distance between the two vectors. The threshold is set to 0.2 times the overall standard deviation of the pressure sequence. For each vector, the number of all other vectors whose distance to this vector is less than the threshold is counted, and then divided by the total number of vectors minus 1 to obtain the proportion value corresponding to the vector. The proportion values of all vectors are averaged to obtain the average proportion value corresponding to the two-dimensional vector. Then, the vector dimension is increased to three dimensions, and the above steps are repeated to obtain the average proportion value corresponding to the three-dimensional vector. Finally, the average proportion value of the three-dimensional vector is divided by the average proportion value of the two-dimensional vector, and the natural logarithm is added with a negative sign to obtain the sample entropy. The average sample entropy of the advancing pressure sequence and the rotating pressure sequence is taken as the comprehensive time entropy of this data segment. The basis for choosing 2D and 3D vector dimensions is as follows: verified by 100 sets of downhole drilling pressure data, 2D vectors can effectively capture the short-term fluctuation characteristics of pressure, while 3D vectors can reflect the continuous change trend of pressure. The combination of the two can balance recognition accuracy and computational efficiency, and is the optimal choice to balance performance and complexity.
[0034] A two-dimensional evaluation standard was constructed based on the comprehensive pressure gradient and comprehensive time entropy, classifying coal and rock homogeneity into four levels: extremely homogeneous (comprehensive pressure gradient not exceeding 0.5 MPa / s and comprehensive time entropy not exceeding 0.3), homogeneous (comprehensive pressure gradient greater than 0.5 MPa / s but not exceeding 1.0 MPa / s and comprehensive time entropy greater than 0.3 but not exceeding 0.6), non-homogeneous (comprehensive pressure gradient greater than 1.0 MPa / s but not exceeding 2.0 MPa / s and comprehensive time entropy greater than 0.6 but not exceeding 0.9), and extremely non-homogeneous (comprehensive pressure gradient greater than 2.0 MPa / s and comprehensive time entropy greater than 0.9). A sliding window method was used to segment the pressure sequence, with a window length of 100 data points (corresponding to 10 seconds). The window slid every 50 data points, calculating the comprehensive pressure gradient and comprehensive time entropy for each window to determine the corresponding homogeneity level, thus obtaining the homogeneity distribution curve for the entire drilling process.
[0035] Continuing with the application scenario from step one, during the drilling operation at 30-31 seconds (corresponding to a depth of 3-3.2 meters), the pre-processed thrust pressure sequence is 8.2 MPa, 8.3 MPa, 8.1 MPa, 8.4 MPa, 8.2 MPa, 8.5 MPa, 8.3 MPa, 8.6 MPa, 8.4 MPa, 8.7 MPa… and the rotational pressure sequence is 9.1 MPa, 9.2 MPa, 9.0 MPa, 9.3 MPa, 9.1 MPa, 9.4 MPa, 9.2 MPa, 9.5 MPa, 9.3 MPa, 9.6 MPa…; the thrust pressure gradient at the second data point is 1.0 MPa / s, and the rotational pressure gradient is… The pressure gradient was 1.0 MPa / s, and the calculated pressure gradients for subsequent data points were all between 0.8 and 1.2 MPa / s. The average comprehensive pressure gradient for this window was 1.0 MPa / s. The standard deviation of the advancing pressure sequence was calculated to be 0.2 MPa, and the threshold was 0.04 MPa. After constructing a two-dimensional vector, the sample entropy of the advancing pressure sequence was calculated to be 0.4, the sample entropy of the rotating pressure sequence was 0.45, and the comprehensive time entropy was 0.425. The average comprehensive pressure gradient for this window was 1.0 MPa / s, and the comprehensive time entropy was 0.425. Therefore, the coal and rock homogeneity level corresponding to this period was determined to be homogeneous.
[0036] When drilling reached the 45-46 second mark (corresponding to a depth of 4.5-4.7 meters), the propulsion pressure sequence was 12.5 MPa, 10.3 MPa, 13.1 MPa, 9.8 MPa, 14.2 MPa, 8.5 MPa, 15.1 MPa, 7.9 MPa, 16.3 MPa, 7.2 MPa… The rotational pressure sequence was 13.2 MPa, 11.1 MPa, 14.3 MPa, 10.5 MPa, 15.6 MPa, 9.2 MPa, 16.8 MPa, 8.7 MPa, 18.2 MPa, 8.1 MPa… …; The absolute value of the advancing pressure gradient at the second data point is 22.0 MPa / s, the absolute value of the rotating pressure gradient is 21.0 MPa / s, and the combined pressure gradient is 22.0 MPa / s. The average combined pressure gradient for this window is 2.5 MPa / s. The standard deviation of the advancing pressure sequence is 3.5 MPa, the threshold is 0.7 MPa, and the sample entropy of the advancing pressure sequence is 1.2, the sample entropy of the rotating pressure sequence is 1.15, and the combined time entropy is 1.175. The coal and rock homogeneity level corresponding to this period is determined to be extremely heterogeneous.
[0037] By extracting dual features of pressure gradient and time entropy, the accurate classification of coal and rock homogeneity within the same stratum is achieved. This can effectively identify local anomalies such as interbedded rock and loose areas, filling the gap in existing technologies that can only distinguish between coal seams and rock strata. The homogeneity distribution curve provides a clear basis for the subsequent fine optimization of drilling technology. The advance speed and rotation pressure can be adjusted for different homogeneity levels to reduce drill rod vibration and borehole deviation.
[0038] Existing publicly available coal and rock identification technologies distinguish coal seams from rock strata solely based on pressure amplitude, neglecting the homogeneity differences within the same stratum. The unique approach of this technical solution lies in combining pressure gradient and time entropy to construct a two-dimensional homogeneity assessment model. This model quantifies the rate of pressure change and the disorder of fluctuations to achieve homogeneity grading, rather than relying on traditional qualitative observation. Simultaneously, it employs a sliding window method to achieve dynamic, real-time homogeneity assessment, overcoming the limitation of existing technologies that only focus on pressure amplitude. This is not obvious to those skilled in the art, and it solves the problem of insufficient perception of the internal characteristics of coal and rock in existing technologies, providing a completely new technical path for the refined management of drilling operations.
[0039] Step 3: Calculation of both drill rod quantity and coal / rock depth: Existing technologies cannot accurately estimate the number of drill rods and the depth of coal and rock through pressure data. They rely on manual measurement, which is inefficient and prone to errors, and cannot provide real-time data support for mining progress control. This step combines the results of coal and rock uniformity classification to establish a mechanical model of drill rods, so as to realize the automatic calculation of the number of drill rods and the depth of coal and rock.
[0040] Based on the physical properties (hardness, strength) of coal and rock under different homogeneity levels, a correlation model between homogeneity level and pressure and drilling speed was established. Through statistical analysis of a large amount of historical data, the drilling pressure range and drilling time range corresponding to different homogeneity levels were determined. The drilling pressure range corresponding to extremely homogeneous homogeneity is 6-10 MPa and the drilling time of a single drill rod is 15-20 seconds; the drilling pressure range corresponding to homogeneity is 10-15 MPa and the drilling time of a single drill rod is 20-25 seconds; the drilling pressure range corresponding to non-homogeneity is 15-25 MPa and the drilling time of a single drill rod is 25-30 seconds; and the drilling pressure range corresponding to extremely non-homogeneity is 25-40 MPa and the drilling time of a single drill rod is 30-40 seconds. The drilling speed is calculated by dividing the length of a single drill rod (2 meters) by the drilling time.
[0041] A sliding window algorithm is used to extract stable operating segments from the pressure curve, excluding interfering segments such as brief pressure relief and pauses, as well as pressureless segments during drill pipe replacement. The upper limit of the pressure range in the "stable operating segment" refers to the upper limit of the propulsion pressure range corresponding to the uniformity level. The determination criteria are that the pressure value is continuously greater than 0 MPa, the pressure fluctuation amplitude is less than 20% of the upper limit of the pressure range corresponding to the uniformity level, and the duration is not less than the lower limit of the single drill pipe propulsion time corresponding to the uniformity level. For each stable operating segment, its corresponding pressure time sequence segment is identified, which is the pressure response of the single drill pipe propulsion process.
[0042] The number of stable operating sections identified is the number of drill pipes. At the same time, the duration of each stable operating section is verified. If the duration of a stable operating section exceeds ±30% of the corresponding uniformity level advance time range, it is determined that multiple drill pipes are advancing continuously or that the drill pipe advance is abnormal. Correction is made in conjunction with the drill pipe replacement mark.
[0043] The total coal and rock depth is calculated by multiplying the number of drill pipes by the length of a single drill pipe, and then introducing a uniformity correction factor to correct for depth estimation errors. The derivation logic of the uniformity correction factor is as follows: Based on the comparative analysis of 100 sets of measured depth data and estimated data, in extremely uniform regions, due to the uniform coal and rock texture and stable drill pipe propulsion resistance, the estimation error is small, and the correction factor is set to 0.98 to offset the slight deviation caused by the elastic deformation of the drill pipe; in uniform regions, the coal and rock characteristics are stable, and the correction factor is set to 1.0; in non-uniform regions, due to local hard spots or loose areas causing fluctuations in propulsion resistance, the estimation error is slightly larger, and the correction factor is set to 1.02; in extremely non-uniform regions, the estimation error is slightly larger due to fluctuations in propulsion resistance caused by local hard spots or loose areas. The presence of interbedded rock or fractures in uniform regions leads to drastic changes in propulsion resistance and the largest estimation error. The correction factor is set to 1.05. Specifically, the correction factor is 0.98 for extremely uniform regions, 1.0 for uniform regions, 1.02 for non-uniform regions, and 1.05 for extremely non-uniform regions. The corrected total depth is calculated by multiplying the total coal and rock depth by the average of the uniformity correction factors corresponding to all stable operating sections. At the same time, based on the uniformity classification results and coal and rock identification rules (rock pressure is greater than coal seam pressure), different depth intervals are divided, generating a three-dimensional profile map of "depth-layer-uniformity".
[0044] Continuing the application scenario from the previous two steps, after 150 seconds of drilling, three stable operating segments have been collected. Stable operating segment 1 lasted 22 seconds, with an average thrust pressure of 12 MPa and a uniformity level of 1.0, indicating that one drill pipe was advancing. Stable operating segment 2 lasted 28 seconds, with an average thrust pressure of 18 MPa and a non-uniformity level of 1.02, indicating that one drill pipe was advancing. Stable operating segment 3 lasted... At 35 seconds, the average pushing pressure was 30 MPa, and the uniformity level was extremely non-uniform, with a corresponding correction factor of 1.05, indicating that one drill pipe was advancing. Drill pipe replacement markers appeared at 60-70 seconds and 120-130 seconds, matching the number of stable operating sections. The estimated number of drill pipes was 3, with a total depth of 6 meters. The average correction factor was 1.023, and the corrected total depth was 6.138 meters. The strata were divided into coal seams (0-2 meters), rock strata (2-4 meters), and rock strata (4-6.138 meters).
[0045] When drilling reaches 300 seconds, two new stable operating sections, 4 and 5, are added. Stable operating section 4 lasts for 20 seconds, with an average thrust pressure of 9 MPa, a uniformity level of extremely uniform, and a correction factor of 0.98. Stable operating section 5 lasts for 24 seconds, with an average thrust pressure of 13 MPa, a uniformity level of uniform, and a correction factor of 1.0. Drill rod replacement markers appear at 180-190 seconds and 240-250 seconds, and two new drill rods are added. The estimated number of drill rods is 5, with a total depth of 10 meters. The average correction factor is 1.01, and the corrected total depth is 10.1 meters. The newly added depth range is 6.138-8 meters in the coal seam and 8-10.1 meters in the coal seam.
[0046] By constructing a drill pipe mechanical model based on uniformity levels, the number of drill pipes and the depth of coal and rock can be automatically calculated without manual measurement, which greatly improves the efficiency of operation. The introduction of uniformity correction coefficient effectively offsets the calculation deviation caused by geological inhomogeneity, and the accuracy of depth calculation is significantly improved. The generated "depth-stratum-uniformity" three-dimensional profile provides intuitive and accurate data support for the geological structure analysis of the working face, reducing the workload of geological exploration.
[0047] Existing publicly available technologies only verify the feasibility of determining the number of drill pipes and the depth of coal and rock through pressure data, but do not provide specific calculation methods and do not consider the impact of geological heterogeneity. The unique approach of this technical solution lies in incorporating the coal and rock homogeneity level into the drill pipe mechanical model, establishing the correlation between homogeneity and pressure, and advancement time. Simultaneously, a homogeneity correction coefficient based on measured data is designed to compensate for calculation errors. By extracting the temporal characteristics of stable operating sections through a sliding window algorithm, accurate identification of the number of drill pipes is achieved. This overcomes the limitations of existing technologies that do not incorporate the internal characteristics of coal and rock, and solves the problems of large calculation errors and reliance on manual verification in existing technologies, providing a reliable technical means for real-time control of mining progress.
[0048] Step 4: Multi-threshold linked risk early warning and collaborative control: Existing technologies only passively record pressure data, making it impossible to predict potential risks such as stuck drill bit, hole collapse, and drill pipe overload. Furthermore, they are isolated from other downhole systems, making it impossible to respond quickly when risks occur. This step integrates multi-source data, sets multi-dimensional linkage risk thresholds, and constructs a three-level early warning mechanism to achieve proactive risk warning and cross-system collaborative control.
[0049] Based on the uniformity grade of coal and rock, the number of drill pipes, the depth of coal and rock, and pressure parameters, three types of core risk linkage thresholds are set. These thresholds are multi-dimensional, including pressure gradient, time entropy, uniformity classification results, number of drill pipes, and depth of coal and rock. The method for determining the stuck drill risk threshold is as follows: Based on the statistics of 500 sets of borehole operation data, when the stuck drill risk occurs, the comprehensive pressure gradient is greater than 2.5 MPa / s, and it is mostly concentrated in the 20-50 meter depth range of the extremely non-uniform region. Therefore, the stuck drill risk threshold is set as follows: comprehensive pressure gradient greater than 2.5 MPa / s, uniformity grade of extremely non-uniform, and coal and rock depth between 20 and 50 meters. The borehole collapse risk threshold is set as follows: sudden drop in rotational pressure (the rotational pressure value of the previous data point minus the rotational pressure value of the current data point, then divided by the rotational pressure value of the previous data point) greater than 50%, uniformity grade of non-uniform, and coal and rock depth between 30 and 60 meters. The drill pipe overload risk threshold is set as follows: single drill pipe advance time greater than 40 seconds, average advance pressure greater than 45 MPa, and uniformity grade of extremely non-uniform.
[0050] The host monitors multi-source data in real time and performs risk threshold matching for each data point. If only some conditions of a single risk threshold are met, no warning is triggered. If all conditions of a certain risk threshold are met, the warning level is determined according to the severity of the risk. If the risk threshold is met for the first time and the risk parameter does not continue to deteriorate, it is a Level 1 warning (minor risk). If the risk parameter continues to deteriorate, it is a Level 2 warning (moderate risk). If the risk parameter reaches the critical value, it is a Level 3 warning (severe risk).
[0051] The Level 1 warning activates the built-in 12V DC speaker and LED warning light in the main unit. The speaker's sound level is no less than 85 dB (A-weighted), and the LED warning light flashes at a frequency of 1 Hz. At the same time, the warning information is pushed to the ground monitoring center via industrial Ethernet, and a warning prompt box pops up in the monitoring software interface. The Level 2 warning, based on the Level 1 warning, sends a speed reduction command to the drilling rig control system, reducing the advance speed to 0.2 m / min. The ground monitoring center sends an SMS reminder to the operator. The Level 3 warning, based on the Level 2 warning, automatically triggers the drilling rig shutdown command, cuts off the drilling rig's power supply, and links the downhole gas extraction system to increase the extraction intensity (to address the risk of borehole collapse). An emergency alarm message is sent to the ground dispatch center.
[0052] The system uses the TCP / IP communication protocol to connect with the downhole ring network switch. The application scenario of this protocol is as follows: In the complex electromagnetic environment downhole, the TCP / IP protocol establishes a reliable connection through a three-way handshake to ensure the integrity of data transmission. At the same time, it sets the data transmission priority, with early warning information and control commands having higher priority than ordinary monitoring data. A retransmission mechanism is used to deal with signal attenuation and ensure the real-time performance of cross-system collaboration. Data interaction and command transmission with the drilling rig control system, the downhole gas extraction system and the ground monitoring center are realized through the downhole ring network switch. The transmission delay of early warning information and control commands does not exceed 1 second. All early warning events and control commands are stored in the host's built-in 32GB storage module to support subsequent traceability and analysis.
[0053] Continuing with the previous application scenario, at 2500 seconds into the drilling operation, the coal and rock depth is 50 meters, the uniformity level of the current stable operating section is extremely non-uniform, and the comprehensive pressure gradient is 2.8 MPa / s, meeting all the conditions for the stuck drill risk threshold. In the first second, a Level 1 warning is issued, the main unit speaker activates, the LED warning light flashes, and a warning prompt box pops up at the ground monitoring center. In the second second, the comprehensive pressure gradient rises to 3.0 MPa / s, triggering a Level 2 warning. The main unit sends a speed reduction command to the drilling rig control system, and the ground monitoring center sends a text message to the operator. In the third second, the comprehensive pressure gradient rises to 3.2 MPa / s and remains there for 3 seconds, triggering a Level 3 warning. The main unit automatically triggers a drilling rig shutdown command, activates the gas extraction system to increase extraction intensity, and the ground dispatch center receives an emergency alarm message. After troubleshooting, the operator clicks the "Cancel Warning" button, and the system returns to normal operation.
[0054] In another example, when drilling reached 3800 seconds, the coal and rock depth was 76 meters. The uniformity level of the current stable working section was non-uniform. The rotational pressure suddenly dropped from 28 MPa to 13 MPa, with a drop of approximately 53.6%, meeting all the conditions for the borehole collapse risk threshold. The first time the threshold was met, it was judged as a level one warning. One second later, the rotational pressure continued to drop to 10 MPa, with the drop widening to 64.3%, which was judged as a level two warning. The operator analyzed the cause through the historical data playback function, adjusted the drilling path, and resumed the operation, thus lifting the warning.
[0055] The multi-dimensional linkage risk threshold setting enables accurate identification of risks such as stuck drill, hole collapse, and drill pipe overload. Compared with the single pressure threshold warning of existing technologies, the identification accuracy is greatly improved. The three-level early warning mechanism and cross-system collaborative control upgrade risk prevention and control from passive response to proactive early warning and handling, predicting risks 5-8 seconds in advance and significantly reducing the accident rate. The multi-terminal synchronization of early warning information and control commands ensures rapid response of on-site personnel and back-end dispatch, minimizing risk losses.
[0056] Existing publicly available mining monitoring systems only possess simple alarm functions, lacking a multi-dimensional risk early warning system and unable to coordinate with other systems for control. The unique technical approach of this solution lies in integrating multi-source data such as uniformity level, depth, and pressure to construct a linked risk threshold, overcoming the limitations of existing technologies' "single-parameter early warning"; designing a hierarchical three-level early warning execution mechanism to achieve tiered risk management; and establishing a cross-system collaborative communication link through the TCP / IP protocol, combined with priority settings and retransmission mechanisms, to ensure real-time transmission of early warning information and control commands. This solves the problems of delayed risk early warning and slow emergency response in existing technologies, providing comprehensive safety assurance for underground drilling operations in coal mines.
[0057] Step 5: Data Display, Storage, and Traceability: Visualizing and storing data long-term is the foundation for subsequent data analysis, process optimization, and fault tracing. While existing technologies can display pressure curves and store historical data, they lack integrated display of multi-dimensional data and have low data tracing efficiency. This step uses a touch screen and a large-capacity storage module to achieve data visualization, full lifecycle storage, and convenient tracing.
[0058] The main unit uses a 7-inch Kunlun Tongtai touchscreen, supporting both graphic and Chinese character display. The interface is divided into four areas: the pressure curve display area displays the real-time trends of propulsion pressure (red curve) and rotation pressure (green curve), with the horizontal axis representing time (hour:minute:second) and the vertical axis representing pressure value (MPa), with a range of 0-100 MPa; the key parameter display area displays key parameters such as the current uniformity level, number of drill pipes, coal and rock depth, propulsion speed, and rotation speed in real time, with a value update frequency of 1 Hz; the early warning information display area displays the early warning level, risk type, occurrence time, and corresponding depth when an early warning is triggered, and automatically records the early warning handling results after the early warning is cleared; the operation button area has operation buttons for sensor calibration, historical data playback, early warning clearance, and system settings, supporting interactive operation.
[0059] The main unit has a built-in 32GB storage space, expandable, storing raw pressure data, processed data, early warning and control data, and system logs. Raw pressure data is stored in CSV format, with each record containing a timestamp, propulsion pressure value, and rotation pressure value. Processed data is stored in JSON format, containing filtered pressure data, pressure gradient, and time entropy. Early warning and control data is stored in XML format, containing early warning event records and control command records. System logs are stored in TXT format, containing system operation information such as power-on time and power-off time. Data storage uses a circular overwrite mechanism; when storage space is insufficient, the oldest historical data is automatically deleted. Data can also be exported via USB flash drive for offline analysis.
[0060] The ground monitoring center is equipped with host computer monitoring software that supports three historical data tracing methods: query by time, query by event, and data playback. Querying by time allows users to input start and end times to query all stored data within that time period, and supports exporting and printing. Querying by event allows users to select the type of warning event and query all relevant data at the time the event occurred. Data playback supports the playback of historical pressure curves, with four playback speed levels controllable via play, pause, stop, and fast forward buttons. The playback interface synchronously displays parameters such as the uniformity level, number of drill pipes, and depth for the corresponding time period.
[0061] Continuing with the previous application scenario, during drilling operations, operators observe the changing trends of propulsion pressure and rotation pressure through the pressure curve display area on the main unit's touchscreen. The key parameter display area shows "Uniformity level: Uniform, Number of drill rods: 5, Coal and rock depth: 10.1 meters, Propulsion speed: 0.3 meters / minute". When a stuck drill risk warning is triggered, the warning information display area shows "Level 3 warning: Stuck drill risk, Occurrence time: 2500 seconds, Depth: 50 meters, Handling status: Stopped".
[0062] After the operation was completed, technicians used the host computer software at the ground monitoring center to trace historical data. They entered the start time 2025-12-14 18:30:00 and end time 2025-12-14 19:30:00 to query all data within that time period and export it as a CSV file. They then selected "Stuck Pipe Risk" in the event query to view the pressure curve and uniformity level changes corresponding to the stuck pipe warning event that occurred at 2500 seconds. By replaying the pressure data before and after 2500 seconds, they observed that the propulsion pressure curve rose sharply after 2500 seconds, while the rotation pressure curve tended to stabilize, and the uniformity level changed from non-uniform to extremely non-uniform, verifying the occurrence process of the stuck pipe risk.
[0063] The visualization of multi-dimensional data enables operators to intuitively grasp the operational status and quickly determine the coal and rock structure and equipment operation without analyzing complex data; the large-capacity storage module realizes the full life cycle storage of data, ensuring data traceability; the multi-mode query and playback function of historical data provides complete data support for subsequent process optimization, fault analysis, and responsibility identification, thereby enhancing the utilization value of the data.
[0064] Existing publicly available host computer software only supports the display of pressure curves and simple historical data playback, without integrating multi-dimensional data such as uniformity level, drill pipe quantity, and early warning information. The unique technical approach lies in the design of a multi-area visualization interface, achieving integrated display of pressure data, key parameters, and early warning information; employing a multi-format storage scheme to categorize and store various types of data, ensuring orderly data management; providing multi-method query functions by time and event; and combining multi-speed level playback functionality to improve the efficiency of historical data tracing, solving the problems of limited data display and inconvenient tracing in existing technologies.
[0065] Overall system testing and verification: The test site was the drilling operation site of the 15-15070 intermediate low-level roadway 2. The underground ambient temperature was 25℃, the relative humidity was 85%, and the atmospheric pressure was 95 kPa, posing a risk of gas and coal dust explosion. The test equipment included the ZJY127-Z mine-use cross-layer borehole coal and rock structure parameter correction and monitoring host, GPD60 mine-use intrinsically safe pressure transmitter, drilling rig control system, underground gas extraction system, and surface monitoring center host computer software. The designed borehole depth was 100 meters, the single drill rod length was 2 meters, and the designed borehole path traversed an alternating coal seam-rock strata-coal seam-rock strata structure.
[0066] The data acquisition accuracy test used a standard pressure source to calibrate the pressure sensor. Different standard pressure values were input, and the pressure data collected by the host was recorded. The acquisition error was calculated. The test results showed that the acquisition errors of propulsion pressure and rotation pressure were both less than 0.5%, which met the design requirement of transmission error ≤1.0%. The data acquisition accuracy was significantly higher than that of existing technologies.
[0067] The uniformity assessment accuracy test combined the geological drilling results after the drilling operation and compared the uniformity level assessed by the system with the actual coal and rock structure. The test results showed that the uniformity level identification accuracy rate reached more than 92%, which can accurately identify the interbedded rock in the coal seam and the loose area in the rock strata. The assessment accuracy meets the requirements of refined management and control.
[0068] After the operation was completed, the actual drilling depth and the number of drill rods used were manually measured and compared with the system's calculation results. The test results showed that the error in the calculation of the number of drill rods was 0, and the error in the calculation of the coal and rock depth was less than 5%. The calculation accuracy was significantly higher than the manual measurement error of the existing technology.
[0069] The risk warning effectiveness test simulated risk scenarios such as stuck drill, hole collapse, and drill pipe overload, testing the system's warning response time and accuracy. The test results showed that the risk warning response time was less than 3 seconds and the warning accuracy reached over 95%. It can effectively trigger the three-level warning mechanism and cross-system collaborative control, successfully preventing the expansion of simulated risks.
[0070] The system stability test involved continuous operation for 72 hours, monitoring the system's operating status, data transmission stability, and equipment reliability. The test results showed that the system operated stably without any crashes or data loss. The data transmission success rate reached 99.9%, and the average fault-free operating time of the equipment exceeded 8,000 hours, meeting the requirements for long-term stable operation underground.
[0071] This coal and rock structure correction system achieves precise correction of coal and rock structure parameters, real-time monitoring of operational status, and proactive risk warning through the coordinated operation of five steps. All performance indicators of the system meet the design requirements. The data acquisition accuracy, uniformity assessment accuracy, depth estimation accuracy, risk warning effectiveness, and system stability are significantly better than existing technologies. It can effectively improve the efficiency and safety of underground gas drainage drilling operations in coal mines and has good practical application value.
[0072] As can be seen from the above, this coal and rock structure correction system addresses the shortcomings of existing technologies by integrating multiple innovative technologies, forming a closed-loop system of "data acquisition - characteristic evaluation - parameter calculation - risk warning - collaborative control," with the following advantages: By combining pressure gradient and time entropy, a two-dimensional coal-rock homogeneity assessment model is constructed, enabling precise classification of coal-rock homogeneity within the same stratum. This fills the gap in existing technologies that can only distinguish between broad categories of coal seams and rock strata, providing a basis for refined process optimization. Existing technologies only focus on pressure amplitude; this system, for the first time, explores the synergistic effect of pressure change rate and fluctuation disorder, achieving dynamic assessment through the sliding window method—a process that is not obvious to those skilled in the art.
[0073] A drill pipe mechanical model based on uniformity levels was established. By extracting the temporal characteristics of stable operating sections, the automatic calculation of the number of drill pipes and the depth of coal and rock was realized. A uniformity correction coefficient based on measured data was introduced to improve the calculation accuracy, solving the problem of large errors caused by reliance on manual measurement in existing technologies. Existing technologies do not consider the influence of the internal properties of coal and rock on the calculation results. This system combines uniformity levels with the mechanical model, significantly improving the calculation accuracy.
[0074] By integrating multi-source data such as uniformity level, depth, and pressure, and setting multi-dimensional linked risk thresholds, this system constructs a three-level early warning mechanism and a cross-system collaborative control system. This enables proactive early warning and rapid response to risks, overcoming the limitations of existing technologies that rely on single-parameter early warning and passive response. By constructing thresholds through multi-dimensional data fusion and combining them with a priority transmission mechanism, this system ensures real-time early warning and control, solving the problems of inaccurate risk identification and delayed response in existing technologies.
[0075] This system features a multi-regional visualization interface and a multi-format data storage solution, supporting historical data queries by time and event, as well as multi-speed playback. This enhances data visualization and traceability efficiency, addressing the limitations of existing technologies such as simplistic data display and inconvenient management. The system also achieves integrated display and categorized storage of multi-dimensional data, providing convenient support for subsequent data analysis.
[0076] This system strictly adheres to coal mine safety standards, adopts a mine-grade explosion-proof and intrinsically safe structural design, is suitable for harsh underground environments, and all technical indicators have reached industry-leading levels. It provides a brand-new technical solution for the intelligent, precise, and safe operation of underground gas drainage drilling in coal mines, and has broad application prospects and promotional value.
Claims
1. A coal and rock mechanism correction system, characterized in that: The system includes a data acquisition module, a dynamic assessment module for coal and rock homogeneity, a depth-quantity dual estimation module, and a multi-threshold linkage risk warning and collaborative control module. The data acquisition module collects drilling rig propulsion pressure data and rotation pressure data and transmits them to the dynamic assessment module for coal and rock homogeneity. The dynamic assessment module for coal and rock homogeneity calculates pressure gradients and extracts time entropy from the pressure data, constructs a two-dimensional assessment standard, and outputs four levels of coal and rock homogeneity classification results (extremely homogeneous, homogeneous, non-homogeneous, and extremely non-homogeneous) which are synchronized to the depth-quantity dual estimation module. The depth-quantity dual estimation module uses the homogeneity classification results as correction parameters, introduces a homogeneity correction coefficient, and combines the drill pipe mechanical model and time-series feature extraction results to estimate the number of drill pipes and the depth of coal and rock. The multi-threshold linkage risk warning and collaborative control module integrates the homogeneity classification results, the number of drill pipes, the depth of coal and rock, and pressure data. Based on the pressure gradient, time entropy, homogeneity classification results, the number of drill pipes, and the depth of coal and rock, it sets multi-dimensional linkage thresholds and executes graded warnings and cross-system collaborative control.
2. The coal and rock mechanism correction system as described in claim 1, characterized in that: The data acquisition module includes a pressure sensing unit, a data preprocessing unit, and a transmission unit. The pressure sensing unit has two channels, which are installed on the drilling rig's propulsion tubing and rotary tubing, respectively, to collect analog signals of propulsion pressure and rotary pressure. The data preprocessing unit converts the analog signals and removes interference data. The transmission unit transmits the processed pressure data to the coal and rock uniformity dynamic evaluation module via an industrial Ethernet.
3. The coal and rock mechanism correction system as described in claim 1, characterized in that: The dynamic evaluation module for coal and rock uniformity includes a pressure gradient calculation unit, a time entropy extraction unit, and a uniformity classification unit. The pressure gradient calculation unit performs first-order derivative calculations on the propulsion pressure data and rotation pressure data based on the sampling time interval to obtain the rate of pressure change over time. The time entropy extraction unit uses a sample entropy algorithm to process the pressure curve and quantify the disorder of pressure fluctuations. The uniformity classification unit constructs a two-dimensional evaluation standard based on the pressure gradient and time entropy, and outputs four levels of uniformity classification results: extremely uniform, uniform, non-uniform, and extremely non-uniform.
4. The coal and rock mechanism correction system as described in claim 1, characterized in that: The depth-quantity dual estimation module includes a mechanical model construction unit, a temporal feature extraction unit, and an estimation correction unit. The mechanical model construction unit establishes a correlation model between different uniformity grading results and pressure and propulsion speed. The temporal feature extraction unit identifies the pressure time sequence segment corresponding to each drill pipe through a sliding window algorithm. The estimation correction unit calculates the total depth by accumulating the length of a single drill pipe, introduces a uniformity correction coefficient to correct the estimation results, and simultaneously outputs the number of drill pipes and the coal and rock depth data of the stratified positions.
5. The coal and rock mechanism correction system as described in claim 1, characterized in that: The multi-threshold linkage risk early warning and collaborative control module includes a threshold setting unit, an early warning execution unit, and a collaborative control unit. The threshold setting unit sets the stuck drill risk threshold, hole collapse risk threshold, and drill pipe overload risk threshold based on pressure gradient, time entropy, uniformity grading results, drill pipe quantity, and coal and rock depth. The early warning execution unit executes level one, level two, and level three early warnings according to the triggered threshold levels. The collaborative control unit links with the drilling rig control system, the underground gas extraction system, and the ground monitoring center via industrial Ethernet to issue control commands.
6. The coal and rock mechanism correction system as described in claim 5, characterized in that: The first-level early warning of the early warning execution unit provides on-site prompts through the host speaker and LED warning lights, and simultaneously pushes the early warning information to the ground monitoring center; The Level 2 warning sends a speed reduction command to the drilling rig control system; the Level 3 warning automatically triggers the drilling rig to stop, coordinates with the downhole gas extraction system to adjust the extraction intensity, and sends an alarm message to the ground dispatch center.
7. The coal and rock mechanism correction system as described in claim 1, characterized in that: It also includes a display and storage module, which receives output data from the coal and rock uniformity dynamic assessment module, the depth-quantity dual calculation module, and the multi-threshold linkage risk warning and collaborative control module. The display and storage module includes a touch display unit and a data storage unit. The touch display unit displays the pressure curve, uniformity classification results, number of drill rods, coal and rock depth, and warning information in real time. The data storage unit stores the collected raw data, processed intermediate data, and final result data, and supports historical data retrieval and playback.
8. The coal and rock mechanism correction system as described in claim 1, characterized in that: The system adopts a mining-grade explosion-proof and intrinsically safe structural design, including an explosion-proof box and an intrinsically safe box. The explosion-proof box contains a high-frequency transformer and an intrinsically safe power circuit board. The intrinsically safe box is installed on the upper part of the explosion-proof box and contains a main control board, display screen, LED warning lights and speakers. The explosion-proof box is equipped with wiring horn ports for connecting power cables, signal cables and network cables.
9. The coal and rock mechanism correction system as described in claim 1, characterized in that: The collaborative control unit of the multi-threshold linkage risk warning and collaborative control module is connected to the downhole ring network switch using the TCP / IP communication protocol. Through the downhole ring network switch, data interaction and command transmission are realized with the drilling rig control system, the downhole gas extraction system and the ground monitoring center, ensuring that control commands are issued in real time and warning information is synchronized across multiple terminals.