CN-122014251-A - Hydraulic fracturing real-time control system based on microseism monitoring and application method

CN122014251ACN 122014251 ACN122014251 ACN 122014251ACN-122014251-A

Abstract

The invention belongs to the technical field of underground hydraulic fracturing of coal mines, 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 processing unit, a fracturing pump control system and a feedback regulation system, wherein the microseism detection device can capture microseism events generated in the fracturing process in real time, convert energy, azimuth and the like of the microseism events into electric signal data, transmit the electric signal data to the data analysis processing unit, the data analysis processing unit analyzes the crack expansion trend and the expansion strength in the fracturing process in real time, and automatically regulate the pressure, the flow and the crack direction of a fracturing pump according to data such as a pressure sensor and a flow sensor, so that the hydraulic fracturing parameter regulation module can optimize the hydraulic fracturing effect, form an intelligent closed loop system of perception-analysis-decision-execution, reduce potential damage to a coal seam structure and guarantee operation safety.

Inventors

ZOU QINGHAI
WANG HUIFENG
JIAO JIANJUN
SUN FULONG
LI RUILONG
LI YONGYUAN
WANG GANG
MA HE

Assignees

华能庆阳煤电有限责任公司核桃峪煤矿
华能煤炭技术研究有限公司
山东科技大学

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (10)

1. The hydraulic fracturing real-time control system based on microseism monitoring is characterized by comprising a microseism detection device, a data analysis processing unit, a fracturing pump control system and a feedback regulation system; The microseism monitoring device comprises a microseism sensor, a data acquisition module, a first transmission line, a first time synchronization device and a data processing interpretation module, wherein the data acquisition module transmits data to the data processing interpretation module through the first transmission line; The fracturing pump control system comprises a motor, a main control computer, a water tank, a fracturing pump, a high-pressure rubber tube, a fracturing string, at least one pressure sensor and at least one flow sensor, wherein the water inlet end of the high-pressure rubber tube is connected with the water outlet end of the fracturing pump, and the water outlet end of the high-pressure rubber tube is connected with the fracturing string; The data analysis processing unit comprises a data analysis processing module, a data analysis processing module and a data processing module, wherein the data analysis processing module is connected or installed on a main control computer, the data transmitted by the rotating speed, the pressure sensor and the flow sensor of the motor for hydraulic fracturing are transmitted to the data analysis processing module, the data analysis processing module performs data comprehensive processing and analysis, and the data analysis processing module analyzes the crack expansion trend and the crack expansion strength in the fracturing process in real time to generate an image or result; the main control computer comprises a feedback regulation system, a second time synchronization device and a second transmission line; The feedback regulation system comprises a data regulation module, a control module and a communication module, wherein the data regulation module automatically regulates the pressure and the flow of the fracturing pump and the direction of the fracturing string according to the result of the data analysis and processing module, and outputs the pressure and the flow and the direction of the fracturing string through the control module.
2. The hydraulic fracturing real-time control system based on microseism monitoring, according to claim 1, is characterized in that the motor is arranged on the fracturing pump, a return valve and a flow sensor are arranged on a water outlet end pipeline of the fracturing pump, the main control computer is arranged on the fracturing pump, and the flow sensor is arranged on the outer side of the return valve and far away from one side of the fracturing pump.
3. The hydraulic fracturing real-time control system based on microseism monitoring, which is disclosed by claim 1, is characterized in that the fracturing string sequentially comprises a safety release, a packer, a restrictor, a packer, a one-way valve and a diversion, the fracturing string forms a closed space in a drill hole and releases high-pressure water, and a pressure sensor is arranged in the fracturing string.
4. The hydraulic fracturing real-time control system based on microseism monitoring of claim 1, wherein the microseism sensor is any one of an optical fiber sensor, a piezoelectric ceramic sensor and a moving coil type speed detector, 8-12 sensors are arranged along a fracturing main roadway, and 4-6 sensors are arranged in adjacent roadways.
5. The hydraulic fracturing real-time control system based on microseism monitoring, which is disclosed by claim 4, is characterized in that the microseism sensors are optical fiber sensors, the distance between the optical fiber sensors in a fracturing main roadway is 10-20 m to form a linear array, the distance between the optical fiber sensors in adjacent roadways is 20-30 m to form primary three-dimensional coverage, and data can be transmitted to a data acquisition module in real time in a wireless transmission mode.
6. The hydraulic fracturing real-time control system based on microseism monitoring of claim 1, wherein the data acquisition module is connected with the first time synchronization device through a first transmission line and then connected with the data processing interpretation module.
7. The microseismic monitoring-based hydraulic fracturing real-time control system of claim 1 wherein the first and second time synchronizing devices are capable of unifying time stamps for the hydraulic fracturing real-time control system to ensure consistent module times.
8. A method of using a microseismic monitoring-based hydraulic fracturing real-time control system according to any of claims 1-7, comprising the steps of: (1) Starting a fracturing pump, injecting pressurized water into a borehole by the fracturing pump, sealing the fracturing string to form a closed space, and filling the closed space with high-pressure water to start fracturing; (2) The data acquisition module of the microseism monitoring device acquires microseism events caused by fracture cracking in the fracturing process in real time, and transmits data signals of positions, intensities and frequencies of the microseism events to the data processing and interpretation module in real time, wherein the data processing and interpretation module transmits data to the data analysis and processing unit; (3) The data analysis processing unit comprehensively analyzes the microseismic event signal data and the fracturing parameters, calculates the direction, length and width of the cracking crack and generates a three-dimensional stereoscopic image; the control module transmits and controls the first time synchronization device and the second time synchronization device through the communication module; (4) The microseism monitoring device, the pressure sensor and the flow sensor monitor the hydraulic fracturing adjustment process in real time, and repeat the step (2) and the step (3) until the index of the hydraulic fracturing requirement is reached; (5) After the fracturing process is finished, the main control computer automatically closes the motor for hydraulic fracturing in real time, adjusts the reflux valve to the maximum, and finishes and safely stops the hydraulic fracturing process.
9. The method for applying the hydraulic fracturing real-time control system based on microseism monitoring according to claim 8, wherein the direction, the length and the width of a cracking crack are calculated and a three-dimensional stereo image is generated, and the calculation formula is as follows: (1) The acquired data of the microseismic monitoring device are as follows: event location (x i , y i , z i ); event occurrence time t i ; Event magnitude M i ; The seismic source mechanism parameters are crack trend phi and dip angle delta; Wherein xi is the x coordinate of the ith event, yi is the y coordinate of the ith event, zi is the z coordinate of the ith event, ti is the occurrence time of the ith event, mi is the magnitude of the ith event; i represents the i-th eigenvalue, i=1, 2,3. N; (2) The fracturing parameter data comprise injection flow Q, injection pressure P, fracturing fluid viscosity mu and injection time t; (3) Crack direction calculation: Through principal component analysis, the microseismic event lattice matrix is: ; The covariance matrix C is expressed as: ; Characteristic value decomposition: ; Wherein λ is a eigenvalue of a covariance matrix C, C has three eigenvalues, λ 1 、λ 2 、λ 3 is respectively, λ 1 is greater than λ 2 and λ 3 ;X T is a transpose matrix of X, and v i is a transpose matrix representing an i-th direction; the crack direction is calculated by the following formula, v 1、 v 2、 v 3 represents the normal vector of the plane in the length direction, width direction and height direction respectively, and n, d1 and d2 refer to three directions: n= v 3 ; d 1 = v 1 ; d 2 = v 2 ; Crack strike phi and dip delta: ; Wherein n x represents the component of the normal vector of the fracture surface in the x direction, and the rest is the y direction and the z direction; (4) And (3) calculating the crack size: ① Calculation of crack length L: Microseismic event envelope method: ; Wherein x max is the maximum coordinate value of the microseismic event in the x direction, x min , the minimum coordinate value of the microseismic event in the x direction, and the rest are corresponding; ② Calculation of crack width W: the mass balance based on the injection volume V frac is: ; ; Wherein V leak is the fluid loss volume, A is the fracture area, and phi is the porosity; ③ Calculation of crack height H: The microseismic events are vertically distributed, and the formula is: ; Wherein σ z is the standard deviation in the vertical direction.
10. The application method of the hydraulic fracturing real-time control system based on microseism monitoring according to claim 8, wherein the control module adjusts fracturing parameters in real time, adjusts the direction of a drilling crack, changes the rotating speed of a motor, changes the pressure and the flow output by a fracturing pump and adjusts the output pressure and the flow in the hydraulic fracturing process according to the processing result of the data analysis processing unit.

Description

Hydraulic fracturing real-time control system based on microseism monitoring and application method Technical Field The invention belongs to the technical field of underground hydraulic fracturing of coal mines, and particularly relates to a hydraulic fracturing real-time control system based on microseism monitoring and an application method. Background The coal mining efficiency is reduced due to the fact that the hard thick-roof coal seam is difficult to fracture, the occurrence probability of safety accidents such as roof collapse and the like is increased, and the safe and efficient mining of the coal mine is greatly limited. The hydraulic fracturing of the underground coal mine drilling is used as a technical measure of permeability improvement of an underground coal seam, a complex crack network can be formed in the coal body, the integrity of the coal body is effectively damaged, and the coal recovery rate and the recovery efficiency are improved. However, the existing hydraulic fracturing technology has the phenomena of unstable effect, great influence of geological characteristics and the like. Under the influence of the stress distribution characteristics of the coal body, the directions and the sizes of main cracks and branch cracks formed in the hydraulic fracturing process cannot be determined, and the fracturing parameters cannot be reasonably adjusted according to the development characteristics of the cracks in the hydraulic fracturing process. Therefore, how to monitor and analyze the extent and direction of crack expansion in the hydraulic fracturing process and make reasonable adjustment on hydraulic fracturing parameters in time has great significance for increasing the effective influence range of hydraulic fracturing of a coal bed and improving the caving effect of top coal. The microseism monitoring device can capture microseism events generated in the fracturing process in real time, and convert energy, azimuth and the like of the microseism events into electric signal data, so that the microseism monitoring device is a core sensing unit of a hydraulic fracturing real-time control system. The current control is mostly based on simple empirical rules, and lacks a high-precision three-dimensional geomechanical model updated synchronously with microseismic data in real time. The model should be able to dynamically predict stress field changes and fracture propagation based on injection data and microseismic feedback. In the hydraulic fracturing process, the direction, length, width and water injection quantity of a cracking crack are controlled through a microseism monitoring device, and calculation, processing and application of microseism event signals and intelligent control are still to be further improved. Disclosure of Invention The invention aims to provide a hydraulic fracturing real-time control system and an application method based on microseism monitoring, wherein in the hydraulic fracturing process, a microseism monitoring device can capture microseism events generated in the fracturing process in real time, convert energy, azimuth and the like of the microseism events into electric signal data, transmit the electric signal data to a data analysis processing unit, the data analysis processing unit analyzes and obtains crack expansion trend and expansion strength in the fracturing process in real time, and according to data such as a pressure sensor, a flow sensor and the like, a hydraulic fracturing parameter adjusting module automatically adjusts pressure, flow and crack direction of a fracturing pump according to calculated data so as to optimize hydraulic fracturing effect, and meanwhile reduce potential damage to a coal seam structure. The technical scheme adopted is as follows: A hydraulic fracturing real-time control system based on microseism monitoring comprises a microseism detection device, a data analysis processing unit, a fracturing pump control system and a feedback regulation system; The microseism monitoring device comprises a microseism sensor, a data acquisition module, a first transmission line, a first time synchronization device and a data processing interpretation module, wherein the data acquisition module transmits data to the data processing interpretation module through the first transmission line; The fracturing pump control system comprises a motor, a main control computer, a water tank, a fracturing pump, a high-pressure rubber tube, a fracturing string, at least one pressure sensor and at least one flow sensor, wherein the water inlet end of the high-pressure rubber tube is connected with the water outlet end of the fracturing pump, and the water outlet end of the high-pressure rubber tube is connected with the fracturing string; The data analysis processing unit comprises a data analysis processing module, a data analysis processing module and a data processing module, wherein the data analysis processing module is connected or installed on a