Hydraulic fracturing real-time control system based on microseism monitoring and application method

Abstract

The invention belongs to the technical field of coal mine underground hydraulic fracturing, and particularly relates to a hydraulic fracturing real-time control system based on microseism monitoring and an application method. The system comprises a microseism detection device, a data analysis and processing unit, a fracturing pump control system and a feedback adjustment system, in the hydraulic fracturing process, the microseism detection device can capture microseism events generated in the fracturing process in real time and convert energy, orientation and the like of the microseism events into electric signal data; the data are transmitted to a data analysis processing unit, the data analysis processing unit analyzes the crack extension trend and extension strength in the fracturing process in real time, and a hydraulic fracturing parameter adjusting module automatically adjusts the pressure and flow of a fracturing pump and the crack direction according to the data of a pressure sensor, a flow sensor and the like and the calculated data; the hydraulic fracturing effect is optimized, an intelligent closed-loop system of perception-analysis-decision-execution is formed, potential damage to a coal seam structure is reduced, and operation safety is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic fracturing technology in coal mines, specifically relating to a real-time control system and application method for hydraulic fracturing based on microseismic monitoring. Background Technology

[0002] Hard, thick coal seams are difficult to fracture, leading to reduced mining efficiency and increasing the likelihood of safety accidents such as roof falls, thus severely limiting safe and efficient coal mining. Underground hydraulic fracturing, a technique for enhancing the permeability of underground coal seams, can create a complex network of fractures within the coal seam, effectively disrupting its integrity and improving coal recovery and extraction efficiency. However, existing hydraulic fracturing technologies suffer from unstable effects and are highly susceptible to geological characteristics.

[0003] Due to the influence of coal seam stress distribution characteristics, the direction and size of the main and branch fractures formed during hydraulic fracturing cannot be clearly determined, making it impossible to make reasonable adjustments to fracturing parameters based on fracture development characteristics during hydraulic fracturing. Therefore, monitoring and analyzing the degree and direction of fracture propagation during hydraulic fracturing, and making timely and reasonable adjustments to hydraulic fracturing parameters, is of great significance for increasing the effective influence range of coal seam hydraulic fracturing and improving the top coal venting effect.

[0004] Microseismic monitoring devices can capture microseismic events generated during hydraulic fracturing in real time and convert the energy and orientation of these events into electrical signals. They are the core sensing unit of a real-time hydraulic fracturing control system. Current control methods are mostly based on simple empirical rules and lack a high-precision three-dimensional geomechanical model that is updated in real time with microseismic data. This model should be able to dynamically predict stress field changes and fracture propagation based on injection data and microseismic feedback. Further improvements are needed in the calculation, processing, and application of microseismic event signals, as well as intelligent control, to achieve control over the direction, length, width, and injection volume of fractures during hydraulic fracturing using microseismic monitoring devices. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a real-time control system and application method for hydraulic fracturing based on microseismic monitoring. During the hydraulic fracturing process, the microseismic monitoring device can capture microseismic events generated during the fracturing process in real time and convert the energy and orientation of the microseismic events into electrical signal data, which is transmitted to the data analysis and processing unit. The data analysis and processing unit analyzes and obtains the fracture propagation trend and propagation intensity in real time during the fracturing process. Based on the data from pressure sensors, flow sensors, etc., the hydraulic fracturing parameter adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracture opening according to the calculated data to optimize the hydraulic fracturing effect and reduce potential damage to the coal seam structure.

[0006] The technical solution adopted is as follows: A real-time hydraulic fracturing control system based on microseismic monitoring includes a microseismic detection device, a data analysis and processing unit, a fracturing pump control system, and a feedback regulation system. The microseismic monitoring device includes a microseismic sensor, a data acquisition module, a first transmission line, a first time synchronization device, and a data processing and interpretation module; the data acquisition module transmits data to the data processing and interpretation module through the first transmission line; The fracturing pump control system includes a motor, a main control computer, a water tank, a fracturing pump, a high-pressure hose, a fracturing string, at least one pressure sensor and at least one flow sensor. The inlet end of the high-pressure hose is connected to the outlet end of the fracturing pump, and the outlet end of the high-pressure hose is connected to the fracturing string. The data analysis and processing unit includes a data analysis and processing module, which is connected to or installed on the main control computer. Data transmitted by the speed, pressure, and flow sensors of the hydraulic fracturing motor are sent to the data analysis and processing module. The data analysis and processing module performs comprehensive data processing and analysis, and analyzes in real time to obtain the fracture propagation trend and propagation intensity during the fracturing process, generating images or results. The main control computer includes a feedback adjustment system, a second time synchronization device, and a second transmission line; The feedback adjustment system includes a data adjustment module, a control module, and a communication module; wherein, the data adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracturing string based on the results of the data analysis and processing module, and outputs the results through the control module.

[0007] Preferably, the motor is mounted on the fracturing pump, a reflux valve and a flow sensor are installed on the outlet pipe of the fracturing pump, and the main control computer is mounted on the fracturing pump; wherein, the flow sensor is arranged outside the reflux valve, on the side away from the fracturing pump.

[0008] Preferably, the fracturing string includes, in sequence, a safety release device, a packer, a throttle device, a one-way valve, and a guide valve. The fracturing string forms a sealed space in the borehole and releases high-pressure water. A pressure sensor is installed inside the fracturing string.

[0009] Preferably, the micro-vibration sensor is any one of an optical fiber sensor, a piezoelectric ceramic sensor, or a moving coil velocity detector, with 8 to 12 sensors arranged along the main fracturing roadway and 4 to 6 sensors arranged in adjacent roadways.

[0010] Preferably, the microseismic sensor is a fiber optic sensor (DAS / DTS); in the main fracturing roadway, the spacing between each fiber optic sensor is 10-20m, forming a linear array; in adjacent roadways, the spacing between each fiber optic sensor is 20-30m, forming preliminary three-dimensional coverage, which can transmit data to the data acquisition module in real time via wireless transmission.

[0011] Preferably, the data acquisition module is connected to the first time synchronization device via the first transmission line, and then connected to the data processing and interpretation module.

[0012] Preferably, the first and second time synchronization devices can provide a unified timestamp for the hydraulic fracturing real-time control system to ensure that the time of each module is consistent.

[0013] This invention also provides an application method for a real-time hydraulic fracturing control system based on microseismic monitoring, comprising the following steps: (1) Start the fracturing pump. The fracturing pump injects pressurized water into the borehole. The fracturing string is sealed to form a closed space. The high-pressure water fills the closed space and fracturing begins. (2) The data acquisition module of the microseismic monitoring device collects microseismic events caused by fracture opening during the hydraulic fracturing process in real time, and transmits the location, intensity and frequency data signals of the microseismic events to the data processing and interpretation module in real time. The data processing and interpretation module transmits the data to the data analysis and processing unit. The data of the speed, pressure sensor and flow sensor of the hydraulic fracturing motor are also transmitted to the data analysis and processing unit in real time. (3) The data analysis and processing unit performs comprehensive analysis on the microseismic event signal data and fracturing parameters, calculates the direction, length and width of the cracks and generates a three-dimensional image; the data adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracturing string according to the results of the data analysis and processing module, and outputs the results through the control module. Among them, the first and second time synchronization devices coordinate with each module to unify the timestamp; the control module transmits and controls data through the communication module; (4) The microseismic monitoring device, pressure sensor and flow sensor monitor the hydraulic fracturing adjustment process in real time, and repeat steps (2) and (3) until the hydraulic fracturing requirements are met; (5) After the fracturing process is completed, the main control computer automatically shuts down the hydraulic fracturing motor in real time, adjusts the reflux valve to the maximum, and completes and safely stops the hydraulic fracturing process.

[0014] Preferably, the direction, length, and width of the crack are calculated and a three-dimensional image is generated. The calculation formula is as follows: (1) The data acquired by the microseismic monitoring device are as follows: Event location (x) i , y i , z i ); Event occurred at time t i ; Event magnitude M i ; Focal mechanism parameters: crack orientation φ, dip angle δ; Where xᵢ is the x-coordinate of the i-th event; yᵢ is the y-coordinate of the i-th event; zᵢ is the z-coordinate of the i-th event; tᵢ is the time of occurrence of the i-th event; and Mᵢ is the magnitude of the i-th event. i represents the i-th eigenvalue, i = 1, 2, 3...n; (2) The fracturing parameter data includes: injection flow rate Q, injection pressure P, fracturing fluid viscosity μ, and injection time t.

[0015] (3) Crack direction calculation: Principal component analysis yielded the following microseismic event lattice matrix: ; The covariance matrix C is expressed by the formula: ; Eigenvalue decomposition: ; Where λ is the eigenvalue of the covariance matrix C, which has three eigenvalues: λ1, λ2, and λ3, with λ1 greater than λ2 and λ3; X T Let v be the transpose of X. i Let i represent the i-th direction.

[0016] The crack direction is calculated using the following formula, v 1、 v 2、 v3 represents the plane normal vectors in the length, width, and height directions, respectively; n, d1, and d2 represent the three directions, then: n = v3; d1 = v1; d2 = v2; Crack orientation φ and dip angle δ: ; Where, n x This represents the component of the crack surface normal vector in the x-direction, with the remainder in the y-direction and z-direction.

[0017] (4) Crack size calculation: ① Calculation of crack length L: Microseismic event envelope method: ; Where, x max Let x be the maximum coordinate value of the microseismic event in the x-direction. min , where is the minimum coordinate value of the microseismic event in the x-direction, and the rest correspond to it.

[0018] ② Calculation of crack width W: Based on injection volume V fracThe mass balance equation is: ; ; Among them, V leak φ represents the filtration volume; A represents the crack area; and φ represents the porosity.

[0019] ③ Calculation of crack height H: The vertical distribution of microseismic events is expressed by the following formula: ; Where, σ z This represents the standard deviation in the vertical direction.

[0020] Preferably, the control module adjusts the fracturing parameters in real time based on the data analysis and processing unit's processing results, adjusts the borehole fracture direction, changes the motor speed, and changes the output pressure and flow rate of the fracturing pump, thereby regulating the output pressure and flow rate during the hydraulic fracturing process.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention relates to a real-time hydraulic fracturing control system based on microseismic monitoring. During the hydraulic fracturing process, the microseismic monitoring device can capture microseismic events generated during fracturing in real time and convert the energy and orientation of the microseismic events into electrical signal data. The data obtained from the microseismic event monitoring is transmitted to a data analysis and processing unit. The data analysis and processing unit integrates all data and analyzes them in real time to determine the fracture propagation trend and propagation intensity during the fracturing process. The feedback adjustment module can automatically adjust the pressure and flow rate of the fracturing pump according to the data from the data analysis and processing unit to optimize the hydraulic fracturing effect, improve the targeting and effectiveness of coal seam fracturing, reduce unnecessary energy consumption and costs, and reduce potential damage to the coal seam structure.

[0022] When the system of the present invention is applied, a microseismic monitoring device is introduced for real-time monitoring, and a data analysis and processing unit performs data fusion and rapid processing and analysis. Based on the analysis results, adaptive intelligent control is realized, forming a closed-loop system of "perception-analysis-decision-execution".

[0023] The application method of this invention enables dynamic optimization and adaptive control of fracturing parameters, significantly improving construction safety and wellbore integrity. It can provide early warning of fractures approaching faults or adjacent wells, and the control module can immediately take measures such as "reducing discharge rate" to prevent the accident from escalating, ensure operational safety, and protect the geological environment and existing well network.

[0024] The application method of this invention enhances real-time decision-making capabilities, achieves precise control, and reduces ineffective operations. Through the first and second time synchronization devices, the timestamps of microseismic events and fracturing construction parameters are highly consistent, which is the foundation for accurate data analysis and closed-loop control. The communication module enables seamless connection between various subsystems, forming a truly integrated intelligent fracturing system. By viewing three-dimensional images of fracture growth in real time through the main control computer, the fracturing effect can be grasped instantly and globally. For example, if a certain formation responds poorly, construction on that section can be terminated early, and resources can be transferred to a more promising section. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the system of the present invention.

[0026] Figure 2 This is a flowchart of the application method of the present invention.

[0027] In the diagram, 1-micro-vibration sensor, 2-data acquisition module, 3-first transmission line, 4-first time synchronization device, 5-data processing and interpretation module, 6-data analysis and processing module, 7-water tank, 8-fracturing pump, 9-high pressure hose, 10-fracturing string, 11-motor, 12-return valve, 13-main control computer, 14-pressure sensor, 15-flow sensor, 16-second transmission line, 17-second time synchronization device, 18-control module. Detailed Implementation

[0028] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Certain embodiments of the invention will be described more fully below with reference to the accompanying drawings, and some, but not all, of these embodiments will be shown. In fact, various embodiments of the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the invention to meet applicable legal requirements.

[0029] Example 1 like Figure 1 As shown, a real-time hydraulic fracturing control system based on microseismic monitoring includes a microseismic detection device, a data analysis and processing unit, a fracturing pump control system, and a feedback regulation system. The microseismic monitoring device includes a microseismic sensor, a data acquisition module, a first transmission line, a first time synchronization device, and a data processing and interpretation module; the data acquisition module transmits data to the data processing and interpretation module through the first transmission line; The fracturing pump control system includes a motor, a main control computer, a water tank, a fracturing pump, a high-pressure hose, a fracturing string, at least one pressure sensor and at least one flow sensor. The inlet end of the high-pressure hose is connected to the outlet end of the fracturing pump, and the outlet end of the high-pressure hose is connected to the fracturing string. The data analysis and processing unit includes a data analysis and processing module, which is connected to or installed on the main control computer. Data transmitted by the speed, pressure, and flow sensors of the hydraulic fracturing motor are sent to the data analysis and processing module. The data analysis and processing module performs comprehensive data processing and analysis, and analyzes in real time to obtain the fracture propagation trend and propagation intensity during the fracturing process, generating images or results. The main control computer includes a feedback adjustment system, a second time synchronization device, and a second transmission line; The feedback adjustment system includes a data adjustment module, a control module, and a communication module; wherein, the data adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracturing string based on the results of the data analysis and processing module, and outputs the results through the control module.

[0030] The motor is mounted on the fracturing pump, and a reflux valve and a flow sensor are installed on the outlet pipe of the fracturing pump. The main control computer is mounted on the fracturing pump. The flow sensor is located outside the reflux valve, on the side away from the fracturing pump.

[0031] The fracturing string sequentially includes a safety release device, a packer, a throttle device, a one-way valve, and a guide valve. The fracturing string forms a sealed space in the borehole and releases high-pressure water. A pressure sensor is installed inside the fracturing string.

[0032] The microseismic sensor is a fiber optic sensor (DAS / DTS). Eight sensors are arranged along the main fracturing roadway, and four sensors are arranged in adjacent roadways. In the main fracturing roadway, the fiber optic sensors are spaced 20m apart to form a linear array; in adjacent roadways, the fiber optic sensors are spaced 30m apart to form preliminary three-dimensional coverage, which can transmit data to the data acquisition module in real time via wireless transmission.

[0033] The data acquisition module is connected to the first time synchronization device via the first transmission line, and then connected to the data processing and interpretation module.

[0034] The first and second time synchronization devices can provide a unified timestamp for the hydraulic fracturing real-time control system to ensure that the time of each module is consistent.

[0035] like Figure 2 As shown, the present invention also provides an application method for a real-time hydraulic fracturing control system based on microseismic monitoring, comprising the following steps: (1) Start the fracturing pump. The fracturing pump injects pressurized water into the borehole. The fracturing series creates a sealed space. The high-pressure water fills the sealed space and fracturing begins. The sealing is achieved by expanding two packers to form a sealed space in the borehole. The pressure inside can be measured by a pressure sensor.

[0036] (2) The data acquisition module of the microseismic monitoring device collects microseismic events caused by fracture opening during the hydraulic fracturing process in real time, and transmits the location, intensity and frequency data signals of the microseismic events to the data processing and interpretation module in real time. The data processing and interpretation module transmits the data to the data analysis and processing unit. The data of the speed, pressure sensor and flow sensor of the hydraulic fracturing motor are also transmitted to the data analysis and processing unit in real time. (3) The data analysis and processing unit performs comprehensive analysis on the microseismic event signal data and fracturing parameters, calculates the direction, length and width of the cracks and generates a three-dimensional image; the data adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracturing string according to the results of the data analysis and processing module, and outputs the results through the control module. Among them, the first and second time synchronization devices coordinate with each module to unify the timestamp; the control module transmits and controls data through the communication module; (4) The microseismic monitoring device, pressure sensor and flow sensor monitor the hydraulic fracturing adjustment process in real time, and repeat steps (2) and (3) until the hydraulic fracturing requirements are met; (5) After the fracturing process is completed, the main control computer automatically shuts down the hydraulic fracturing motor in real time, adjusts the reflux valve to the maximum, and completes and safely stops the hydraulic fracturing process.

[0037] The direction, length, and width of the crack are calculated, and a three-dimensional image is generated. The calculation formula is shown below.

[0038] (1) The data acquired by the microseismic monitoring device are as follows: Event location (x) i , y i , z i ); Event occurred at time t i ; Event magnitude M i ; Focal mechanism parameters: crack orientation φ, dip angle δ; Where xᵢ is the x-coordinate of the i-th event; yᵢ is the y-coordinate of the i-th event; zᵢ is the z-coordinate of the i-th event; tᵢ is the time of occurrence of the i-th event; and Mᵢ is the magnitude of the i-th event. i represents the i-th eigenvalue, i = 1, 2, 3, ..., n.

[0039] (2) The fracturing parameter data includes: injection flow rate Q, injection pressure P, fracturing fluid viscosity μ, and injection time t.

[0040] (3) Crack direction calculation: Principal component analysis yielded the following microseismic event lattice matrix: ; The covariance matrix C is expressed by the formula: ; Eigenvalue decomposition: ; Where λ is the eigenvalue of the covariance matrix C, which has three eigenvalues: λ1, λ2, and λ3, with λ1 greater than λ2 and λ3; X T Let v be the transpose of X. i Let i represent the i-th direction.

[0041] The crack direction is calculated using the following formula, v 1、 v 2、 v3 represents the plane normal vectors in the length, width, and height directions, respectively; n, d1, and d2 represent the three directions, then: n = v3; d1 = v1; d2 = v2; Crack orientation φ and dip angle δ: ; Where, n x This represents the component of the crack surface normal vector in the x-direction, with the remainder in the y-direction and z-direction.

[0042] (4) Crack size calculation: ① Calculation of crack length L: Microseismic event envelope method: ; Where, x max Let x be the maximum coordinate value of the microseismic event in the x-direction. min , where is the minimum coordinate value of the microseismic event in the x-direction, and the rest correspond to it.

[0043] ② Calculation of crack width W: Based on injection volume V frac The mass balance equation is: ; ; Among them, V leak φ represents the filtration volume; A represents the crack area; and φ represents the porosity.

[0044] ③ Calculation of crack height H: The vertical distribution of microseismic events is expressed by the following formula: ; Where, σ z This represents the standard deviation in the vertical direction.

[0045] The data analysis and processing unit automatically calculates and generates data. Based on the processing results from the data analysis and processing unit, the control module adjusts fracturing parameters in real time, adjusts the direction of borehole fractures, changes the motor speed, and alters the output pressure and flow rate of the fracturing pump, thereby regulating the output pressure and flow rate during the hydraulic fracturing process.

[0046] The output pressure and flow rate during the hydraulic fracturing process are adjusted until the required technical indicators for hydraulic fracturing are met. Real-time monitoring and control during the fracturing process avoid the adverse effects of human operation errors and changes in formation characteristics on the hydraulic fracturing effect, significantly improving the hydraulic fracturing effect. No manual intervention is required, the process flow is simplified, energy and water consumption are reduced, and construction costs are saved.

[0047] Example 2 A real-time control system for hydraulic fracturing based on microseismic monitoring includes a microseismic detection device, a data analysis and processing unit, a fracturing pump control system, and a feedback adjustment system. The microseismic sensors are fiber optic sensors, with 12 arranged along the main fracturing roadway and 6 arranged in adjacent roadways. Within the main fracturing roadway, the fiber optic sensors are spaced 10m apart, forming a linear array; within adjacent roadways, the sensors are spaced 20m apart, forming preliminary three-dimensional coverage. This system enables real-time wireless transmission of data to the data acquisition module.

[0048] Other areas not mentioned are the same as in Example 1.

[0049] Application Example 1 The implementation area is the 1803 working face of a certain mine, and the target stratum is the No. 8 coal seam. This coal seam has an average thickness of 14.1 m, a high Protodyakonov strength coefficient, is hard, and has well-developed but poorly connected internal fractures. The immediate roof is silty mudstone. When using top-coal caving mining technology, the natural caving of the top coal is difficult, and the caving performance is poor, requiring artificial weakening. The design adopts a hydraulic fracturing real-time control system and application method based on microseismic monitoring to form a uniform and extensive fracture network within the top coal, improving its fracturing characteristics.

[0050] 2. Downhole system layout and tool assembly Based on the geological exploration and engineering design requirements of the working face, the following system configuration and operating parameters are adopted: (1) Construction of the main borehole: A main horizontal borehole was constructed along the dip of the coal seam from the side of the transport roadway. The borehole diameter was 120 mm and the actual drilling length was 230 meters.

[0051] (2) Fracturing construction: The fracturing string is extended into the bottom of the hole using a drilling rig to carry out backward segmented hydraulic fracturing.

[0052] (3) Monitoring system deployment: Install point pressure sensors and flow meters at the upper and lower ends of packers at all levels and at the inlet of branch holes, and arrange microseismic sensors at the orifice to transmit the location, intensity and frequency data signals of microseismic events to the data processing and interpretation module in real time.

[0053] (5) Feedback adjustment: The control module adjusts the fracturing parameters in real time according to the data analysis and processing unit, adjusts the direction of the borehole fracture, changes the motor speed, and changes the output pressure and flow rate of the fracturing pump, so as to adjust the output pressure and flow rate in the hydraulic fracturing process until the fracturing requirements are met.

[0054] In the description of this invention, it should be noted that the terms "inner", "outer", "upper", "lower", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0055] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A real-time control system for hydraulic fracturing based on microseismic monitoring, characterized in that, It includes a microseismic detection device, a data analysis and processing unit, a fracturing pump control system, and a feedback regulation system; The microseismic monitoring device includes a microseismic sensor, a data acquisition module, a first transmission line, a first time synchronization device, and a data processing and interpretation module; the data acquisition module transmits data to the data processing and interpretation module through the first transmission line; The fracturing pump control system includes a motor, a main control computer, a water tank, a fracturing pump, a high-pressure hose, a fracturing string, at least one pressure sensor and at least one flow sensor. The inlet end of the high-pressure hose is connected to the outlet end of the fracturing pump, and the outlet end of the high-pressure hose is connected to the fracturing string. The data analysis and processing unit includes a data analysis and processing module, which is connected to or installed on the main control computer. Data transmitted by the speed, pressure, and flow sensors of the hydraulic fracturing motor are sent to the data analysis and processing module. The data analysis and processing module performs comprehensive data processing and analysis, and analyzes in real time to obtain the fracture propagation trend and propagation intensity during the fracturing process, generating images or results. The main control computer includes a feedback adjustment system, a second time synchronization device, and a second transmission line; The feedback adjustment system includes a data adjustment module, a control module, and a communication module; wherein, the data adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracturing string based on the results of the data analysis and processing module, and outputs the results through the control module.

2. The real-time hydraulic fracturing control system based on microseismic monitoring according to claim 1, characterized in that, The motor is mounted on the fracturing pump, and a reflux valve and a flow sensor are installed on the outlet pipe of the fracturing pump. The main control computer is mounted on the fracturing pump. The flow sensor is located outside the reflux valve, on the side away from the fracturing pump.

3. The real-time hydraulic fracturing control system based on microseismic monitoring according to claim 1, characterized in that, The fracturing string includes, in sequence, a safety release device, a packer, a throttle device, a check valve, and a guide valve. The fracturing string forms a sealed space in the borehole and releases high-pressure water. A pressure sensor is installed inside the fracturing string.

4. The real-time hydraulic fracturing control system based on microseismic monitoring according to claim 1, characterized in that, The micro-vibration sensor is any one of fiber optic sensor, piezoelectric ceramic sensor, or moving coil velocity detector. 8 to 12 sensors are arranged along the main fracturing roadway, and 4 to 6 sensors are arranged in adjacent roadways.

5. A real-time hydraulic fracturing control system based on microseismic monitoring according to claim 4, characterized in that, The micro-vibration sensor is a fiber optic sensor; in the main fracturing roadway, the spacing between each fiber optic sensor is 10-20m, forming a linear array; in adjacent roadways, the spacing between each fiber optic sensor is 20-30m, forming preliminary three-dimensional coverage, which can transmit data to the data acquisition module in real time via wireless transmission.

6. The real-time hydraulic fracturing control system based on microseismic monitoring according to claim 1, characterized in that, The data acquisition module is connected to the first time synchronization device via the first transmission line, and then connected to the data processing and interpretation module.

7. A real-time hydraulic fracturing control system based on microseismic monitoring according to claim 1, characterized in that, The first and second time synchronization devices can provide a unified timestamp for the hydraulic fracturing real-time control system to ensure that the time of each module is consistent.

8. The application method of a real-time hydraulic fracturing control system based on microseismic monitoring as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Start the fracturing pump. The fracturing pump injects pressurized water into the borehole. The fracturing string is sealed to form a closed space. The high-pressure water fills the closed space and fracturing begins. (2) The data acquisition module of the microseismic monitoring device collects microseismic events caused by fracture opening during the hydraulic fracturing process in real time, and transmits the location, intensity and frequency data signals of the microseismic events to the data processing and interpretation module in real time. The data processing and interpretation module transmits the data to the data analysis and processing unit. The data of the speed, pressure sensor and flow sensor of the hydraulic fracturing motor are also transmitted to the data analysis and processing unit in real time. (3) The data analysis and processing unit performs comprehensive analysis on the microseismic event signal data and fracturing parameters, calculates the direction, length and width of the cracks and generates a three-dimensional image; the data adjustment module automatically adjusts the pressure and flow rate of the fracturing pump and the direction of the fracturing string according to the results of the data analysis and processing module, and outputs the results through the control module. Among them, the first and second time synchronization devices coordinate with each module to unify the timestamp; the control module transmits and controls data through the communication module; (4) The microseismic monitoring device, pressure sensor and flow sensor monitor the hydraulic fracturing adjustment process in real time, and repeat steps (2) and (3) until the hydraulic fracturing requirements are met; (5) After the fracturing process is completed, the main control computer automatically shuts down the hydraulic fracturing motor in real time, adjusts the reflux valve to the maximum, and completes and safely stops the hydraulic fracturing process.

9. The application method of a real-time hydraulic fracturing control system based on microseismic monitoring according to claim 8, characterized in that, The direction, length, and width of the crack are calculated, and a three-dimensional image is generated. The calculation formula is as follows: (1) The data acquired by the microseismic monitoring device are as follows: Event location (x) i , y i , z i ); Event occurred at time t i ; Event magnitude M i ; Focal mechanism parameters: crack orientation φ, dip angle δ; Where xᵢ is the x-coordinate of the i-th event; yᵢ is the y-coordinate of the i-th event; zᵢ is the z-coordinate of the i-th event; tᵢ is the time of occurrence of the i-th event; and Mᵢ is the magnitude of the i-th event. i represents the i-th eigenvalue, i = 1, 2, 3...n; (2) The fracturing parameter data includes: injection flow rate Q, injection pressure P, fracturing fluid viscosity μ, and injection time t; (3) Crack direction calculation: Principal component analysis yielded the following microseismic event lattice matrix: ； The covariance matrix C is expressed by the formula: ； Eigenvalue decomposition: ； Where λ is the eigenvalue of the covariance matrix C, which has three eigenvalues: λ1, λ2, and λ3, with λ1 greater than λ2 and λ3; X T Let v be the transpose of X. i To represent the i-th direction; The crack direction is calculated using the following formula, v 1、 v 2、 v3 represents the plane normal vectors in the length, width, and height directions, respectively; n, d1, and d2 represent the three directions, then: n = v3; d1 = v1; d2 = v2; Crack orientation φ and dip angle δ: ； Where, n x This represents the component of the crack surface normal vector in the x-direction, with the remainder in the y-direction and z-direction; (4) Crack size calculation: ① Calculation of crack length L: Microseismic event envelope method: ； Where, x max Let x be the maximum coordinate value of the microseismic event in the x-direction. min The minimum coordinate value of the microseismic event in the x-direction, and the rest correspond to it; ② Calculation of crack width W: Based on injection volume V frac The mass balance equation is: ； ； Among them, V leak φ represents the filtration volume; A represents the crack area; φ represents the porosity. ③ Calculation of crack height H: The vertical distribution of microseismic events is expressed by the following formula: ； Where, σ z This represents the standard deviation in the vertical direction.

10. The application method of a real-time hydraulic fracturing control system based on microseismic monitoring according to claim 8, characterized in that, Based on the data analysis and processing results, the control module adjusts the fracturing parameters in real time, adjusts the direction of the borehole fracture, changes the motor speed, and changes the output pressure and flow rate of the fracturing pump, thereby regulating the output pressure and flow rate during the hydraulic fracturing process.

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