An intelligent monitoring system based on passive seismic ground detection of slurry diffusion range

Abstract

The present application relates to coal slurry monitoring technical field, specifically disclose a kind of intelligent monitoring system based on passive seismic ground detection slurry diffusion range, including passive seismic detection unit, subsequent space grouting effect monitoring unit, void variation monitoring unit and grouting range control unit, passive seismic detection unit is obtained by adaptive rolling circle radius to the phase of background noise filtering, subsequent space grouting effect monitoring unit monitors grouting speed, grouting pressure, grouting volume and mine water flow, void variation monitoring unit monitors the subsequent void three-dimensional change under the premise of considering microseismic influence, grouting range control unit controls the parameter of grouting equipment according to slurry diffusion radius;It solves the deficiency that the data obtained by combining the existing monitoring method with passive seismic ground detection technology, and grouting effect, void variation are not comprehensive evaluation and timely control to slurry diffusion range.

Description

Technical Field

[0001] This invention relates to the field of coal mine slurry monitoring technology, and more specifically, to an intelligent monitoring system based on passive seismic ground detection of slurry diffusion range. Background Technology

[0002] Existing underground coal gangue disposal technologies only utilize the coal seam mining space and do not fully utilize the subsequent space. The subsequent space includes the non-compacted areas such as the collapse zone, fracture zone, and delamination area resulting from the deformation of the overlying strata after coal seam mining. This is addressed in the paper published by Zhang Jixiong et al. (Zhang Jixiong, Zhou Nan, Gao Feng et al. Method for grouting and filling gangue in the subsequent space of coal mine mining [J]. Journal of Coal Science, 2023, 48(01):150-162. DOI:10.13225). The paper ( / j.cnki.jccs.2022.1604.) elaborates on the connotation of subsequent space gangue grouting filling method, the steady-state control mechanism of heterogeneous gangue slurry flowability, the characteristics and spatiotemporal evolution law of subsequent space void structure, the migration and diffusion law of subsequent space gangue slurry, and the control mechanism of subsequent space gangue grouting filling rock strata. It describes how gangue is crushed, mixed with water according to a certain particle size distribution to form a slurry, and then transported to the coal seam after mining using filling pumps and pipelines. In the subsequent space, high-pressure injection of gangue slurry is used to achieve efficient underground disposal of gangue. However, the gangue slurry moves in various flow forms in the subsequent space, and its properties change continuously with the formation. The complex diffusion patterns of the gangue slurry reduce the filling efficiency. When the gangue slurry migrates and diffuses in the subsequent space, the diffusion diameter, accumulation height, and interaction between the gangue slurry and the rock blocks in the subsequent space can be predicted using a similar model of gangue grouting diffusion in the subsequent space. Based on the flow state of the slurry in the rock mass voids, the tortuosity and theoretical diffusion path of the slurry can be calculated. However, in the existing subsequent space gangue grouting filling effect, the grouting effect is intelligently monitored using high-definition video monitoring, remote communication, and intelligent coordination and control technologies. The grouting effect and void changes are comprehensively evaluated, but the data obtained from passive seismic ground detection technology, as well as the grouting effect and void changes, are not combined to comprehensively evaluate and timely adjust the slurry diffusion range. To address the aforementioned problems, a technical solution is provided. Summary of the Invention

[0003] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide an intelligent monitoring system for grout diffusion range based on passive seismic ground detection. By employing an adaptive rolling circle radius method in the passive seismic detection unit, background noise filtering is applied to the acquired seismic phases, improving data accuracy and reliability. This allows for more precise analysis of underground fractures and reservoir conditions. Subsequently, a spatial grouting effect monitoring unit monitors grouting speed, grouting pressure, grouting volume, and mine water flow, enabling real-time monitoring and evaluation of the grouting effect during the grouting process. This ensures that the grouting operation meets design requirements, improving grouting efficiency and quality. A void change monitoring unit monitors subsequent three-dimensional void changes. Combined with the influence of microseismic events, it can monitor void changes during grout diffusion in real time, assessing the grout diffusion radius and providing accurate reference for subsequent grouting range control. The grouting range control unit, based on the grout diffusion analysis radius, adjusts the grouting speed, grouting pressure, and grouting volume of the grouting equipment, considering the influence coefficients of mine water flow and microseismic events, to achieve precise control of the grouting range, ensuring that the grouting effect meets the expected goals, thus solving the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] An intelligent monitoring system for grout diffusion range based on passive seismic ground detection includes a passive seismic detection unit, a subsequent spatial grouting effect monitoring unit, a void change monitoring unit, and a grouting range control unit. The passive seismic detection unit uses an adaptive rolling circle radius to filter background noise from the acquired seismic phases. The subsequent spatial grouting effect monitoring unit monitors grouting speed, grouting pressure, grouting volume, and mine water flow. The void change monitoring unit monitors the three-dimensional changes in the voids of the gangue grout considering the influence of microseismic events, and evaluates the grout diffusion analysis radius. The grouting range control unit adjusts the parameters of the grouting equipment according to the grout diffusion radius, regulating the grouting speed, grouting pressure, and grouting volume under the influence of mine water flow and microseismic events. In the passive seismic detection unit, the adaptive radius formula of the rolling circle is:

[0006]

[0007] In the formula: R zw D is the adaptive radius of the rolling circle. d D represents the amplitude under background noise. u Q is the upper bound of the background noise. s S is the empirical range expansion coefficient, obtained empirically. xh The information entropy of background noise;

[0008] The slurry diffusion analysis radius is the product of the subsequent three-dimensional change evaluation value of the voids and the designed diffusion radius of the slurry. The formula for the slurry diffusion analysis radius is:

[0009] l a =B s *l s

[0010] In the formula: l a B represents the slurry diffusion analysis radius. s For subsequent assessment of three-dimensional changes in porosity, l s The design diffusion radius of the slurry;

[0011] In the grouting control unit, the formulas for mine water flow rate and microseismic influence coefficient are as follows:

[0012] α=-Q j +V w

[0013] In the formula: α represents the mine water flow rate and the microseismic influence coefficient, Q j V represents the mine water flow rate. w The volume of subsequent spatial changes caused by microseismic events.

[0014] As a further embodiment of the present invention, the passive seismic detection unit includes a fiber optic microseismic sensor, a microseismic acquisition substation, a downhole switch, a surface switch, a monitoring host, a time server, and a data analysis host. The data analysis host includes a monitoring data acquisition unit, a microseismic fracture interpretation unit, and a slurry diffusion and development analysis unit. The microseismic fracture interpretation unit uses passive seismic detection technology to obtain the energy distribution maps of three-component and single-component nodal seismic waves, seismic signal waveforms, and spectrum maps after adaptive rolling filtering. It uses numerical inversion of the hydraulic fracturing source mechanism caused by gangue slurry injection, and fuses the numerical inversion information and the seismic signal information from microseismic monitoring to obtain a three-dimensional distribution map of hydraulic fracturing fractures caused by gangue slurry injection.

[0015] As a further aspect of this invention, the grout diffusion development analysis unit, combined with the microseismic fracture interpretation unit, obtains a three-dimensional distribution map of hydraulic fracturing fractures caused by gangue grouting. The hydraulic fracturing fractures caused by microseismic events induced by grouting are isolated and labeled, and displayed in three dimensions within the distribution map. Simultaneously, numerical simulation is used to calculate and statistically analyze the voxels of the hydraulic fracturing fractures caused by microseismic events induced by grouting. The number of voxels is multiplied by the volume of each voxel to obtain the total volume of the hydraulically developed fractures and the number of fracture branches. The ratio of the total fracture volume to the number of fracture branches is used as the hydraulic fracturing analysis value. The formula for the hydraulic fracturing analysis value is:

[0016]

[0017] In the formula: F yl V is the value from hydraulic fracturing analysis. lx Let n be the total volume of the crack. lx This represents the number of crack branches.

[0018] As a further aspect of the present invention, the hydraulic fracturing monitoring data acquisition unit uses a downhill comparison method based on time domain analysis to pick up arrival times for waveform characteristics with insignificant arrival time differences and low signal-to-noise ratios.

[0019] As a further aspect of this invention, in the passive seismic detection unit, the subsequent three-dimensional change assessment value of the void is determined by correlation analysis based on the factors affecting the subsequent void. These factors include lateral void change values, vertical void change values, and longitudinal void change values. The subsequent void change caused by grouting and microseismic activity is assessed based on the Wilson correlation coefficients between the lateral, vertical, and longitudinal void change values ​​and the subsequent spatial volume change. The formula for the subsequent three-dimensional void change assessment value is as follows:

[0020]

[0021] In the formula: X b Y represents the variation in lateral porosity. b Z represents the longitudinal porosity variation. b σ1 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume, σ2 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume, and σ3 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume.

[0022] As a further aspect of this invention, in the passive seismic detection unit, the diffusion of slurry in the subsequent space is treated as planar flow of slurry in the delamination space. Based on Darcy's law and mechanical theory, a Bingham plastic fluid diffusion model for planar high-density fracture dynamic water grouting is established to calculate the design diffusion radius of the slurry. The equation satisfied by the design diffusion radius of the slurry is:

[0023]

[0024] In the formula: l s Let r0 be the design diffusion radius of the slurry, T be the effective grouting time of the gangue slurry (starting from monitoring and detection until the slurry reaches the subsequent space and begins filling), r0 be the radius of the grouting well, η be the plastic viscosity of the gangue slurry, p0 be the grouting pressure, and p be the design diffusion radius of the slurry. w The dynamic water pressure generated by the flow rate of mine water.

[0025] As a further embodiment of the present invention, the microseismic sensor is connected to the microseismic acquisition substation, the microseismic acquisition substation is connected to the downhole switch, the downhole switch is connected to the ground switch via optical cable, the ground switch is connected to the monitoring host, and the monitoring host is also connected to the time server and the data analysis host.

[0026] As a further aspect of the present invention, in the grouting range control unit, the arithmetic square root of the product of the grout diffusion analysis radius, the mine water flow rate, and the micro-vibration influence coefficient is multiplied by the initial grouting speed, and this is used as the grouting speed control value to regulate the grouting speed. The formula for the grouting speed control value is as follows:

[0027]

[0028] In the formula: v t v0 is the initial grouting speed, where v0 is the grouting speed control value.

[0029] The grouting pressure control value is positively correlated with the hydraulic fracturing analysis value and the grout diffusion analysis radius, and the initial grouting pressure. The formula for the grouting pressure control value is:

[0030] p z = (log5F) yl +0.3l a )*p0

[0031] In the formula: p z p0 is the initial grouting pressure, where p0 is the grouting pressure control value.

[0032] The grouting volume adjustment value is the product of the cross-sectional area of ​​the grouting well, the grouting rate, and the grouting duration. The formula for the grouting volume adjustment value is:

[0033] V z =v t *s j *T

[0034] In the formula: V z s is the grouting volume adjustment value. j This represents the cross-sectional area of ​​the grouting well.

[0035] As a further aspect of the present invention, the process of obtaining and analyzing the three-dimensional distribution map of hydraulic fracturing using the microseismic fracture interpretation unit includes:

[0036] Step S1, Passive seismic detection: Using passive seismic detection technology, a pre-specified number of seismic nodes (fiber optic microseismic sensors) are deployed in the region of interest. These nodes record the three components of the seismic wave, namely the horizontal P-wave and S-wave, and the vertical wave. These data are used as the raw data.

[0037] Step S2, Adaptive Rolling Filter: Apply an adaptive rolling filtering algorithm to the acquired seismic wave data. This algorithm calculates the rolling circle radius of each node according to the adaptive radius formula of the rolling circle, and filters the seismic wave data according to the adaptive radius to remove background noise.

[0038] Step S3, obtain energy distribution map, seismic signal waveform map, and spectrum map: Based on the filtered data, calculate the energy of the seismic wave signal of each node, obtain the seismic wave energy distribution map of each node, and draw the filtered seismic wave signal waveform map and spectrum map for each node;

[0039] Step S4, numerical inversion: The fracture source mechanism information obtained by inverting gangue slurry is fused with the seismic signal information from microseismic monitoring. The numerical inversion results are compared and matched with the measured data to obtain a three-dimensional distribution map of the hydraulic fracturing fractures caused by gangue slurry injection.

[0040] Step S5, Results Display and Analysis: In the grout development analysis unit, the three-dimensional distribution map of cracks is analyzed in conjunction with other data to obtain the hydraulic fracturing development data caused by gangue grout injection.

[0041] The technical effects and advantages of the intelligent monitoring system for slurry diffusion range based on passive seismic ground detection of the present invention are as follows:

[0042] This invention utilizes an adaptive rolling circle radius method within a passive seismic detection unit to filter background noise from acquired seismic phases, improving data accuracy and reliability. This allows for more precise analysis of underground fractures and reservoir conditions. Subsequently, a spatial grouting effect monitoring unit monitors grouting speed, pressure, volume, and mine water flow, enabling real-time monitoring and evaluation of the grouting process. This ensures the grouting operation meets design requirements, improving efficiency and quality. A void change monitoring unit monitors subsequent three-dimensional void changes. Combined with microseismic influence, it monitors void changes during grout diffusion in real time, assessing the grout diffusion radius and providing accurate reference for subsequent grouting range control. The grouting range control unit, based on the grout diffusion analysis radius, adjusts the grouting speed, pressure, and volume of the grouting equipment, considering mine water flow and the influence coefficient of microseismic factors, to achieve precise control of the grouting range and ensure the grouting effect meets the expected goals. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of an intelligent monitoring system for the diffusion range of slurry based on passive seismic ground detection, according to the present invention.

[0044] Figure 2 This is a flowchart illustrating the process of acquiring and analyzing a three-dimensional distribution map of hydraulic fracturing in a microseismic crack interpretation unit within an intelligent monitoring system based on passive seismic ground detection of slurry diffusion range, as described in this invention. Detailed Implementation

[0045] 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.

[0046] Example 1

[0047] This invention discloses an intelligent monitoring system for grout diffusion range based on passive seismic ground detection. By employing an adaptive rolling circle radius method within the passive seismic detection unit, background noise filtering is applied to the acquired seismic phases, improving data accuracy and reliability. This allows for more precise analysis of underground fractures and reservoir conditions. Subsequently, a spatial grouting effect monitoring unit monitors grouting speed, pressure, volume, and mine water flow, enabling real-time monitoring and evaluation of the grouting effect. This ensures the grouting operation meets design requirements, improving grouting efficiency and quality. A void change monitoring unit monitors subsequent three-dimensional void changes. Combining this with microseismic influence, it can monitor void changes during grout diffusion in real time, assessing the grout diffusion radius and providing accurate reference for subsequent grouting range control. The grouting range control unit, based on the grout diffusion analysis radius, adjusts the grouting speed, pressure, and volume of the grouting equipment, considering the influence coefficients of mine water flow and microseismic activity, to achieve precise control of the grouting range and ensure the grouting effect meets the expected goals.

[0048] Figure 1 The present invention provides a structural block diagram of an intelligent monitoring system for grout diffusion range based on passive seismic ground detection. The system includes a passive seismic detection unit, a subsequent spatial grouting effect monitoring unit, a void change monitoring unit, and a grouting range control unit. The passive seismic detection unit uses an adaptive rolling circle radius to filter background noise from the acquired seismic phases. The subsequent spatial grouting effect monitoring unit monitors grouting speed, grouting pressure, grouting volume, and mine water flow. The void change monitoring unit monitors the three-dimensional changes in the voids of the gangue grout, considering the influence of microseismic events, and evaluates the grout diffusion analysis radius. The grouting range control unit adjusts the parameters of the grouting equipment according to the grout diffusion radius, controlling the grouting speed, grouting pressure, and grouting volume under the influence of mine water flow and microseismic events. In the passive seismic detection unit, the adaptive radius formula of the rolling circle is:

[0049]

[0050] In the formula: R zw D is the adaptive radius of the rolling circle. d D represents the amplitude under background noise. u Q is the upper bound of the background noise. sS is the empirical range expansion coefficient, obtained empirically. xh The information entropy is the background noise.

[0051] The adaptive radius formula of the rolling circle allows for automatic adjustment based on actual background noise conditions. By calculating the radius based on the lower amplitude, upper bound, and entropy of the background noise, it can adapt to changes in different noise environments. This adaptability improves the extraction effect of seismic signals and reduces background noise interference. The radius calculated by the adaptive radius formula of the rolling circle is used for background noise filtering. By removing background noise, the clarity and reliability of seismic signals are improved, making subsequent analysis and interpretation more accurate. Background noise is one of the common problems in seismic signal analysis. By using an appropriate radius calculated by the adaptive rolling circle radius formula, the influence of background noise is effectively reduced, and the signal-to-noise ratio between signal and noise is improved. This helps to better extract seismic signals and effectively analyze underground structures and geological features. By adaptively determining the radius of the rolling circle based on the characteristics of background noise, data quality control can be performed. Filtering out background noise improves the accuracy and reliability of data, thus providing a more reliable foundation for subsequent data analysis and interpretation.

[0052] The slurry diffusion analysis radius is the product of the subsequent three-dimensional change evaluation value of the voids and the designed diffusion radius of the slurry. The formula for the slurry diffusion analysis radius is:

[0053] l a =B s *l s

[0054] In the formula: l a B represents the slurry diffusion analysis radius. s For subsequent assessment of three-dimensional changes in porosity, l s The design diffusion radius of the slurry.

[0055] By multiplying the subsequent three-dimensional change assessment value of the voids by the designed diffusion radius of the slurry, the slurry diffusion analysis radius is obtained. This allows for an objective assessment of whether the actual slurry diffusion range matches the design. Comparing the assessment value with the design value reveals deviations in the diffusion range, enabling timely adjustments and improvements. The slurry diffusion analysis radius formula, based on the product of the subsequent three-dimensional change assessment value of the voids and the designed diffusion radius, provides a more accurate prediction of the slurry diffusion range. This is of great significance for the planning, design, and execution of engineering projects, helping to rationally arrange the layout of grouting equipment and adjust operating parameters, thereby ensuring the slurry's... Effective diffusion and injection range: By accurately predicting the grout diffusion range, over-grouting or under-grouting is avoided, saving construction materials and energy costs. At the same time, reasonable control of the grout diffusion range can improve construction efficiency, reduce unnecessary workload and time, and thus improve the overall efficiency and quality of the project. In engineering practice, there is a certain gap between the designed grout diffusion radius and the actual situation. By using the grout diffusion analysis radius formula, the difference between the actual diffusion range and the design can be identified and evaluated in a timely manner, providing a basis for subsequent project improvement and adjustment, making the design closer to reality, and improving the controllability and reliability of the project.

[0056] In the grouting control unit, the formulas for mine water flow rate and microseismic influence coefficient are as follows:

[0057] α=-Q j +V w

[0058] In the formula: α represents the mine water flow rate and the microseismic influence coefficient, Q j V represents the mine water flow rate. w The volume of subsequent spatial changes caused by microseismic events.

[0059] Water flow rate in mines is a crucial factor in the grouting process. Considering the mine water flow rate allows for a more accurate assessment of water flow velocity and direction, facilitating the control of grouting speed, pressure, and volume to adapt to varying water flow conditions and improve grouting stability and effectiveness. Micro-seismic events are seismic events caused by changes in fissures or rock mass during grouting. These micro-seismic events lead to subsequent spatial volume changes. By considering the subsequent spatial volume changes caused by micro-seismic events, we can better understand and predict the changes in fissures and rock mass during grouting. Based on the micro-seismic influence coefficient, we can control the grouting speed, pressure, and volume to adapt to the subsequent spatial changes caused by micro-seismic events. This allows for more precise grouting control. By considering mine water flow and the microseismic influence coefficient, the grouting control unit adjusts parameters according to actual conditions to better adapt to changes caused by mine water flow and microseismic activity, improving the stability and effectiveness of grouting. Reasonable control of grouting speed, pressure, and volume reduces unnecessary grout loss and energy consumption, improving grouting quality and construction efficiency. Considering mine water flow and the microseismic influence coefficient helps identify potential geological hazards in advance. Adjusting grouting speed, pressure, and volume through the grouting control unit allows for better control of the construction process, reducing the probability of geological hazards and improving the safety and controllability of the project.

[0060] It should be noted that the passive seismic detection unit includes fiber optic microseismic sensors, microseismic acquisition substations, downhole switches, surface switches, monitoring hosts, time servers, and data analysis hosts. The data analysis hosts include monitoring data acquisition units, microseismic fracture interpretation units, and slurry diffusion and development analysis units. The microseismic fracture interpretation unit uses passive seismic detection technology to obtain three-component and single-component nodal seismic wave energy distribution maps, seismic signal waveform maps, and spectrum maps after adaptive rolling filtering. It uses numerical inversion of the hydraulic fracturing source mechanism caused by gangue slurry injection, and integrates the numerical inversion information and the seismic signal information from microseismic monitoring to obtain a three-dimensional distribution map of hydraulic fracturing fractures caused by gangue slurry injection.

[0061] Specifically, the microseismic sensor is connected to the microseismic acquisition substation, the microseismic acquisition substation is connected to the downhole switch, the downhole switch is connected to the ground switch via optical cable, the ground switch is connected to the monitoring host, and the monitoring host is also connected to the time server and the data analysis host.

[0062] Through equipment such as fiber optic microseismic sensors, microseismic acquisition substations, and data analysis hosts, multidimensional data acquisition of seismic waves can be achieved, including energy distribution maps of three-component and single-component nodal seismic waves, seismic signal waveforms, and spectrum diagrams. This data provides detailed seismic wave characteristics and energy distribution, which is helpful for crack detection and analysis. The adaptive rolling filter method in the microseismic crack interpretation unit can effectively filter out background noise, extract crack signals, enhance the clarity and accuracy of seismic signals, and improve the precision of crack detection. By using numerical inversion of the hydraulic fracturing source mechanism caused by gangue grout injection, the mechanism information of the crack source can be inferred. Through numerical inversion, a deeper understanding of the crack formation mechanism can be obtained, providing valuable reference for engineering practice. By fusing the numerical inversion information with the seismic signal information from microseismic monitoring, a three-dimensional distribution map of hydraulic fracturing cracks caused by gangue grout injection can be obtained. Such a distribution map can provide key information on the location, shape, and propagation direction of cracks, providing basic data for engineering construction and risk assessment, thereby increasing the safety and reliability of the project.

[0063] The system comprises several subsystems: a microseismic acquisition station, connected to multiple fiber optic microseismic sensors, and a ground-based switch. The ground-based switch receives data from the microseismic acquisition station and forwards it to the surface switch. The surface switch receives data from the ground-based switch and distributes it to the monitoring host for processing and storage. The monitoring host is the core device managing and controlling the entire passive seismic detection system. It receives data from the surface switch, processes, stores, and analyzes it. The monitoring host can also communicate with other devices and provides a user interface for configuring system parameters and monitoring real-time data. The time server provides precise time information, synchronizing and calibrating the entire system. It ensures all devices operate according to the same time standard, guaranteeing data consistency and accuracy.

[0064] It should be noted that the 3D distribution map of hydraulic fracturing fractures caused by grout injection, obtained by the slurry diffusion development analysis unit in conjunction with the microseismic fracture interpretation unit, isolates and marks the hydraulic fracturing fractures caused by microseismic events induced by grout injection, and displays them in 3D on the distribution map. Simultaneously, numerical simulation is used to obtain the voxels of the hydraulic fracturing fractures caused by microseismic events induced by grout injection, and the number of voxels is multiplied by the unit voxel volume to obtain the total volume of the hydraulically developed fractures and the number of fracture branches. The ratio of the total fracture volume to the number of fracture branches is used as the hydraulic fracturing analysis value. The formula for the hydraulic fracturing analysis value is:

[0065]

[0066] In the formula: F yl V is the value from hydraulic fracturing analysis. lx Let n be the total volume of the crack. lx This represents the number of crack branches.

[0067] Hydraulic fracturing (HFL) is a fracture system in rocks and soils induced by grouting. By counting fracture voxels and calculating the total fracture volume, the development degree of HFL can be quantified. Simultaneously, counting the number of fracture branches provides information on the fracture network. HFL analysis values ​​are expressed as the ratio of total fracture volume to the number of fracture branches, assessing the branching development of HFL and providing a basis for engineering safety assessment and risk control. The three-dimensional distribution map of HFL fractures, combined with the calculated results of fracture branch number and total fracture volume, can visually display the spatial distribution and development characteristics of fractures, helping engineers understand and analyze the morphology, connectivity, and propagation direction of fractures, thus providing a basis for engineering construction. Hydraulic fracturing analysis values ​​provide a visual reference for risk control and can serve as an indicator for assessing the development of hydraulic fracturing. Combined with other engineering parameters and design requirements, they can assist in engineering decision-making. Based on the magnitude of the hydraulic fracturing analysis values, engineers can adjust grouting parameters, take remedial measures, or strengthen monitoring to ensure the safety and stability of the project. Through the calculation of hydraulic fracturing analysis values, the development of hydraulic fracturing can be quickly assessed. When the hydraulic fracturing analysis values ​​exceed the predetermined safety threshold, it indicates that the development of hydraulic fracturing is out of control and there is a potential risk. Timely detection and assessment of these risks enable the implementation of corresponding measures for adjustment and control to ensure the safety and reliability of the project.

[0068] It should be noted that the hydraulic fracturing monitoring data acquisition unit uses a downhill comparison method based on time domain analysis to pick up waveforms with insignificant arrival time differences and low signal-to-noise ratios.

[0069] In hydraulic fracturing monitoring, due to the complexity of underground media and the diversity of signal propagation paths, waveform signals often exhibit unclear arrival time differences. Traditional arrival time acquisition methods, such as cross-correlation, cannot accurately capture these differences. However, the downhill comparison method based on time-domain analysis is more adaptable to waveforms with unclear arrival time differences. By comparing the amplitude decrease rate of the signal to determine the arrival time pickup point, it can more accurately pinpoint the waveform's arrival location. Hydraulic fracturing monitoring data often exhibits high background noise and low signal-to-noise ratio. The downhill comparison method based on time-domain analysis, which determines the arrival time pickup point by comparing the amplitude decrease rate, can reduce background noise more effectively compared to energy-based or cross-correlation-based methods. The acoustic interference with arrival time pickup improves the signal extraction effect and accuracy. Compared with the complex frequency domain analysis method, the downhill comparison method based on time domain analysis is simpler and easier to implement. This method only needs to compare the rate of decrease of signal amplitude, without performing spectrum calculations or complex mathematical operations. Therefore, it has lower computational complexity and implementation cost. The downhill comparison method based on time domain analysis can pick up arrival time in real time without a lot of computation and processing time. This is of great significance for the real-time analysis and decision-making of hydraulic fracturing monitoring data. It can quickly obtain arrival time information, perform subsequent data processing and analysis in a timely manner, and improve the real-time performance and work efficiency of the monitoring system.

[0070] It should be noted that in the passive seismic detection unit, the subsequent three-dimensional change assessment value of the void is based on a correlation analysis of the factors affecting the subsequent void. These factors include lateral void change, vertical void change, and longitudinal void change. The subsequent void change caused by grouting and microseismic activity is assessed based on the Wilson correlation coefficients between the lateral, vertical, and longitudinal void change values ​​and the subsequent spatial volume change. The formula for the subsequent three-dimensional void change assessment value is as follows:

[0071]

[0072] In the formula: X b Y represents the variation in lateral porosity. b Z represents the longitudinal porosity variation. b σ1 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume, σ2 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume, and σ3 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume.

[0073] By considering the relationship between lateral, longitudinal, and vertical void changes and subsequent spatial volume changes, the subsequent three-dimensional void change assessment value can comprehensively evaluate void changes. This comprehensive assessment provides a more complete understanding of the void evolution process and offers a quantitative assessment of subsequent spatial void changes caused by grouting and microseismic activity. The calculation formula for the subsequent three-dimensional void change assessment value is based on the Wilson correlation coefficient, a commonly used correlation index. By using such an objective index, the degree of correlation between lateral, longitudinal, and vertical void changes and subsequent spatial volume changes can be quantified, providing a comparable and quantifiable assessment index. Through the subsequent three-dimensional void change assessment value, void changes can be analyzed and compared. For subsequent spatial void changes caused by different grouting and microseismic activities, the assessment value can be used to determine their differences and degree of impact, providing a reference for engineering management and control. The subsequent three-dimensional void change assessment value can provide a reference for engineering design and construction. By understanding the void change assessment value, the subsequent spatial volume caused by grouting and microseismic activity can be controlled and optimized, which helps to improve engineering design, adjust construction plans, and ensure the stability and safety of the project.

[0074] It should be noted that in the passive seismic detection unit, the diffusion of slurry in the subsequent space is regarded as the planar flow of slurry in the delamination space. Based on Darcy's law and mechanical theory, a Bingham plastic fluid diffusion model in planar high-density fracture dynamic water grouting is established to calculate the design diffusion radius of the slurry. The equation satisfied by the design diffusion radius of the slurry is:

[0075]

[0076] In the formula: l s Let r0 be the design diffusion radius of the slurry, T be the effective grouting time of the gangue slurry (starting from monitoring and detection until the slurry reaches the subsequent space and begins filling), r0 be the radius of the grouting well, η be the plastic viscosity of the gangue slurry, p0 be the grouting pressure, and p be the design diffusion radius of the slurry. w The dynamic water pressure generated by the flow rate of mine water.

[0077] By establishing a Bingham plastic fluid diffusion model for planar high-density fracture grouting based on Darcy's law and mechanical theory, the design diffusion radius of the grout can be calculated more accurately. This calculation considers factors such as the grouting time of the gangue grout, the radius of the grouting well, the plastic viscosity of the gangue grout, and the dynamic water pressure generated by the grouting pressure and mine water flow, making the calculation results more consistent with reality and improving the accuracy of engineering design. The design diffusion radius of the grout is the distance the grout diffuses in the subsequent space during the grouting process. The calculated diffusion radius can serve as a reference for the grouting range. A reasonable grouting range can ensure that the gangue grout fully fills the target area and achieves the expected engineering effect. Using the design diffusion radius as a reference can help the project... Engineers develop reasonable grouting strategies and parameters to improve the accuracy and effectiveness of grouting. By calculating the design diffusion radius of the grout, a reference basis can be provided for engineering design and construction. A reasonable grouting range and diffusion radius help control the distribution and penetration of gangue grout, avoiding excessive or insufficient grouting, thereby improving the stability and safety of the project. Optimizing engineering design and construction can reduce the waste of materials and resources, and improve the efficiency and sustainability of the project. The design diffusion radius of the grout is calculated based on grouting parameters and material characteristics, and can be used to predict the grouting effect. By comparing the design diffusion radius with the actual engineering situation, the coverage and quality of grouting are evaluated, and grouting strategies and parameters are adjusted in a timely manner to ensure the safety and stability of the project.

[0078] It should be noted that in the grouting range control unit, the arithmetic square root of the product of the grout diffusion analysis radius, the mine water flow rate, and the micro-seismic influence coefficient is multiplied by the initial grouting speed to control the grouting speed. The formula for the grouting speed control value is as follows:

[0079]

[0080] In the formula: v t v0 is the initial grouting speed, where v0 is the grouting speed control value.

[0081] The grouting pressure control value is positively correlated with the hydraulic fracturing analysis value and the grout diffusion analysis radius, and the initial grouting pressure. The formula for the grouting pressure control value is:

[0082] p z = (log5F) yl +0.3l a )*p0

[0083] In the formula: p z p0 is the initial grouting pressure, where p0 is the grouting pressure control value.

[0084] The grouting volume adjustment value is the product of the cross-sectional area of ​​the grouting well, the grouting rate, and the grouting duration. The formula for the grouting volume adjustment value is:

[0085] V z =v t *s j *T

[0086] In the formula: V z s is the grouting volume adjustment value. j This represents the cross-sectional area of ​​the grouting well.

[0087] By leveraging the correlation between slurry diffusion analysis radius, mine water flow rate, microseismic influence coefficient, and initial grouting speed, grouting pressure, and grouting volume, grouting parameters can be dynamically adjusted according to actual conditions. This adjustment method can flexibly respond to different working conditions and geological conditions, making the grouting process more controllable and efficient. Adjusting the grouting speed and pressure based on the slurry diffusion analysis radius and hydraulic fracturing analysis values ​​can control the slurry diffusion range and pressure distribution, thereby improving the quality and effect of grouting. The calculation formulas for the grouting speed and pressure adjustment values ​​are based on the analysis and evaluation of hydraulic fracturing fractures, which can reduce the deviation and non-uniformity of the grouting range and enhance the coverage and uniformity of the grouting. Through dynamic adjustment of the grouting speed and pressure, the grouting parameters can be effectively controlled. Grouting pressure and grouting volume can be optimized according to actual needs to avoid over-grouting or under-grouting, thus saving grouting materials and resources and reducing project costs. At the same time, the calculation formula for the grouting volume adjustment value is based on the cross-sectional area of ​​the grouting well, which can adjust the grouting volume according to the actual situation to avoid excessive waste or insufficient filling. Through precise control of grouting parameters, the development of hydraulic fracturing cracks and the grouting effect can be better controlled. Appropriate grouting speed, grouting pressure and grouting volume can reduce instability and unevenness in the project, improve the safety and stability of the project. The control of grouting parameters can also be dynamically adjusted according to the actual situation of the project to cope with changes and risks and ensure the safe operation of the project.

[0088] Example 2

[0089] The difference between Embodiment 2 and Embodiment 1 is that this embodiment introduces the process of obtaining and analyzing the three-dimensional distribution map of hydraulic fracturing by the microseismic fracture interpretation unit in an intelligent monitoring system based on passive seismic ground detection of slurry diffusion range.

[0090] Figure 2 A flowchart is provided showing the process by which the microseismic fracture interpretation unit in the intelligent monitoring system based on passive seismic ground detection of slurry diffusion range of this invention acquires and analyzes the three-dimensional distribution map of hydraulic fracturing, which includes:

[0091] Step S1, Passive seismic detection: Using passive seismic detection technology, a pre-specified number of seismic nodes (fiber optic microseismic sensors) are deployed in the region of interest. These nodes record the three components of the seismic wave, namely the horizontal P-wave and S-wave, and the vertical wave. These data are used as the raw data.

[0092] Step S2, Adaptive Rolling Filter: Apply an adaptive rolling filtering algorithm to the acquired seismic wave data. This algorithm calculates the rolling circle radius of each node according to the adaptive radius formula of the rolling circle, and filters the seismic wave data according to the adaptive radius to remove background noise.

[0093] Step S3, obtain energy distribution map, seismic signal waveform map, and spectrum map: Based on the filtered data, calculate the energy of the seismic wave signal of each node, obtain the seismic wave energy distribution map of each node, and draw the filtered seismic wave signal waveform map and spectrum map for each node;

[0094] Step S4, numerical inversion: The fracture source mechanism information obtained by inverting gangue slurry is fused with the seismic signal information from microseismic monitoring. The numerical inversion results are compared and matched with the measured data to obtain a three-dimensional distribution map of the hydraulic fracturing fractures caused by gangue slurry injection.

[0095] Step S5, Results Display and Analysis: In the grout development analysis unit, the three-dimensional distribution map of cracks is analyzed in conjunction with other data to obtain the hydraulic fracturing development data caused by gangue grout injection.

[0096] This process organically connects multiple steps, enabling the microseismic fracture interpretation unit to comprehensively analyze data from each stage, from passive seismic detection and filtering to the acquisition of energy distribution maps, seismic signal waveforms, and spectrograms, as well as numerical inversion and result display and analysis. This process combines different types of data to provide comprehensive seismic monitoring and fracture analysis results. The application of adaptive rolling filtering helps remove background noise from seismic data and extract effective seismic signals. This makes the subsequent energy distribution maps, waveforms, and spectrograms clearer and more accurate, providing a high-quality data foundation for subsequent analysis. By integrating the fracture source mechanism information obtained from numerical inversion with the seismic signal information from microseismic monitoring and comparing and matching it with measured data, the accuracy and reliability of numerical inversion can be verified. This enhances the understanding of hydraulic fracturing fractures caused by gangue grouting and provides more reliable data for the three-dimensional distribution of fractures. By comprehensively analyzing the three-dimensional fracture distribution map with other data, the hydraulic fracturing development process can be further studied and understood. Such result display and analysis help evaluate the effect and impact of gangue grouting and guide subsequent engineering design and construction decisions.

[0097] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0098] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An intelligent monitoring system for grout diffusion range based on passive seismic ground detection, comprising a passive seismic detection unit, a subsequent spatial grouting effect monitoring unit, a void change monitoring unit, and a grouting range control unit, characterized in that, The passive seismic detection unit uses an adaptive rolling circle radius to filter background noise from the acquired seismic phases. Subsequently, the spatial grouting effect monitoring unit monitors grouting speed, grouting pressure, grouting volume, and mine water flow. The porosity change monitoring unit monitors the three-dimensional porosity changes of the gangue slurry after considering the influence of microseismic events, assessing the slurry diffusion analysis radius. The grouting range control unit adjusts the parameters of the grouting equipment based on the slurry diffusion radius, regulating the grouting speed, grouting pressure, and grouting volume under the influence of mine water flow and microseismic events. In the passive seismic detection unit, the adaptive radius formula for the rolling circle is: In the formula: R zw D is the adaptive radius of the rolling circle. d D represents the amplitude under background noise. u Q is the upper bound of the background noise. s S is the empirical range expansion coefficient, obtained empirically. xh The information entropy of background noise; The slurry diffusion analysis radius is the product of the subsequent three-dimensional change evaluation value of the voids and the designed diffusion radius of the slurry. The formula for the slurry diffusion analysis radius is: l a ＝B s *l s In the formula: l a B represents the slurry diffusion analysis radius. s For subsequent assessment of three-dimensional changes in porosity, l s The design diffusion radius of the slurry; In the grouting control unit, the formulas for mine water flow rate and microseismic influence coefficient are as follows: α=-Q j +V w In the formula: α represents the mine water flow rate and the microseismic influence coefficient, Q j V represents the mine water flow rate. w The volume of subsequent spatial changes caused by microseismic events.

2. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 1, characterized in that, The passive seismic detection unit includes fiber optic microseismic sensors, microseismic acquisition substations, downhole switches, surface switches, monitoring hosts, time servers, and data analysis hosts. The data analysis hosts include monitoring data acquisition units, microseismic fracture interpretation units, and slurry diffusion and development analysis units. The microseismic fracture interpretation unit uses passive seismic detection technology to acquire three-component and single-component nodal seismic wave energy distribution maps, seismic signal waveform maps, and spectrum maps after adaptive rolling filtering. It uses numerical inversion of the hydraulic fracturing source mechanism caused by gangue slurry injection, and integrates the numerical inversion information and the seismic signal information from microseismic monitoring to obtain a three-dimensional distribution map of hydraulic fracturing fractures caused by gangue slurry injection.

3. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 2, characterized in that, The 3D distribution map of hydraulic fracturing fractures caused by gangue grouting, obtained by the grout diffusion development analysis unit and the microseismic fracture interpretation unit, isolates and marks the hydraulic fracturing fractures caused by microseismic events induced by grouting, and displays them in 3D on the distribution map. Simultaneously, numerical simulation is used to obtain the voxels of the hydraulic fracturing fractures caused by microseismic events induced by grouting, and the number of voxels is multiplied by the unit voxel volume to obtain the total volume of the hydraulically developed fractures and the number of fracture branches. The ratio of the total fracture volume to the number of fracture branches is used as the hydraulic fracturing analysis value. The formula for the hydraulic fracturing analysis value is: In the formula: F yl V is the value from hydraulic fracturing analysis. lx Let n be the total volume of the crack. lx This represents the number of crack branches.

4. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 1, characterized in that, For waveforms with insignificant arrival time differences and low signal-to-noise ratios, the hydraulic fracturing monitoring data acquisition unit uses a downhill comparison method based on time-domain analysis to pick up arrival times.

5. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 1, characterized in that, In the passive seismic detection unit, the subsequent three-dimensional change assessment value of the void is determined by correlation analysis based on the factors affecting the subsequent void. These factors include lateral void change, vertical void change, and longitudinal void change. The subsequent void change caused by grouting and microseismic activity is assessed using the Wilson correlation coefficients between the lateral, vertical, and longitudinal void change values ​​and the subsequent spatial volume change. The formula for the subsequent three-dimensional void change assessment value is as follows: In the formula: X b Y represents the variation in lateral porosity. b Z represents the longitudinal porosity variation. b σ1 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume, σ2 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume, and σ3 is the Wilson correlation coefficient between the change in vertical clearance and the subsequent change in spatial volume.

6. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 1, characterized in that, In the passive seismic detection unit, the diffusion of slurry in the subsequent space is regarded as the planar flow of slurry in the delamination space. Based on Darcy's law and mechanical theory, a Bingham plastic fluid diffusion model for planar high-density fracture dynamic water grouting is established to calculate the design diffusion radius of the slurry. The equation satisfied by the design diffusion radius of the slurry is: In the formula: l s Let r0 be the design diffusion radius of the slurry, T be the effective grouting time of the gangue slurry (starting from monitoring and detection until the slurry reaches the subsequent space and begins filling), r0 be the radius of the grouting well, η be the plastic viscosity of the gangue slurry, p0 be the grouting pressure, and p be the design diffusion radius of the slurry. w The dynamic water pressure generated by the flow rate of mine water.

7. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 1, characterized in that, The microseismic sensor is connected to the microseismic acquisition substation, which is connected to the downhole switch. The downhole switch is connected to the ground switch via optical cable. The ground switch is connected to the monitoring host, which is also connected to the time server and the data analysis host.

8. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 3, characterized in that, In the grouting range control unit, the arithmetic square root of the product of the grout diffusion analysis radius, the mine water flow rate, and the micro-seismic influence coefficient is multiplied by the initial grouting speed to control the grouting speed. The formula for the grouting speed control value is as follows: In the formula: v t v0 is the initial grouting speed, where v0 is the grouting speed control value. The grouting pressure control value is positively correlated with the hydraulic fracturing analysis value and the grout diffusion analysis radius, and the initial grouting pressure. The formula for the grouting pressure control value is: p z (log5F) yl +0.3l a )*p0 In the formula: p z p0 is the initial grouting pressure, where p0 is the grouting pressure control value. The grouting volume adjustment value is the product of the cross-sectional area of ​​the grouting well, the grouting rate, and the grouting duration. The formula for the grouting volume adjustment value is: V z =v t *s j *T In the formula: V z s is the grouting volume adjustment value. j This represents the cross-sectional area of ​​the grouting well.

9. The intelligent monitoring system for slurry diffusion range based on passive seismic ground detection according to claim 2, characterized in that, The process of obtaining and analyzing the three-dimensional distribution map of hydraulic fracturing using the microseismic fracture interpretation element includes: Step S1, Passive seismic detection: Using passive seismic detection technology, a pre-specified number of seismic nodes (fiber optic microseismic sensors) are deployed in the region of interest. These nodes record the three components of the seismic wave, namely the horizontal P-wave and S-wave, and the vertical wave. These data are used as the raw data. Step S2, Adaptive Rolling Filter: Apply an adaptive rolling filtering algorithm to the acquired seismic wave data. This algorithm calculates the rolling circle radius of each node according to the adaptive radius formula of the rolling circle, and filters the seismic wave data according to the adaptive radius to remove background noise. Step S3, obtain energy distribution map, seismic signal waveform map, and spectrum map: Based on the filtered data, calculate the energy of the seismic wave signal of each node, obtain the seismic wave energy distribution map of each node, and draw the filtered seismic wave signal waveform map and spectrum map for each node; Step S4, numerical inversion: The fracture source mechanism information obtained by inverting gangue slurry is fused with the seismic signal information from microseismic monitoring. The numerical inversion results are compared and matched with the measured data to obtain a three-dimensional distribution map of the hydraulic fracturing fractures caused by gangue slurry injection. Step S5, Results Display and Analysis: In the grout development analysis unit, the three-dimensional distribution map of cracks is analyzed in conjunction with other data to obtain the hydraulic fracturing development data caused by gangue grout injection.

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