Micro-seismic signal detection device and hydraulic fracturing monitoring system and method

Abstract

The invention discloses a micro-seismic signal detection device, a hydraulic fracturing monitoring system and a hydraulic fracturing monitoring method. The device comprises a micro-seismic sensor, a mounting seat and a heating device, the micro-seismic sensor is mounted on the mounting seat; the mounting seat comprises a connecting rod and a shell mounted outside the connecting rod; the shell can deform along with the temperature; the mounting seat can penetrate into a rock mass; the heating device is used for heating the shell; after the mounting base penetrates into the rock mass, the heating device heats the shell, the shell is heated to deform, and the mounting base can be fixed in the rock mass and is convenient to disassemble; according to the system, in the hydraulic fracturing process, micro-seismic signals are monitored, the hydraulic fracturing effect is monitored, hydraulic fracturing parameters are adjusted in time according to the monitoring result of the hydraulic fracturing effect, the hydraulic fracturing effect is guaranteed, and the exploitation efficiency of hot dry rock geothermal resources is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic fracturing monitoring, and in particular to a microseismic signal detection device, a hydraulic fracturing monitoring system and a method. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Hot dry rock is a green, renewable and clean energy source with the advantages of stability, reliability, continuity and high utilization rate. However, there is a risk of induced earthquakes in the hydraulic fracturing transformation of hot dry rock thermal storage and the entire process of later development, which seriously restricts the safe and efficient development of hot dry rock.

[0004] In the development of hot dry rock geothermal resources, hydraulic fracturing technology is an important means to improve the permeability of rock formations to promote the exploitation of geothermal resources. There is a risk of induced earthquakes in the hydraulic fracturing transformation of hot dry rock thermal storage and the entire process of later development, which seriously restricts the safe and efficient development of hot dry rocks. The mechanism and law of induced earthquakes are quite different from those of other rock masses, with larger magnitudes and more prominent risks. Microseismic monitoring technology has been widely used in the hydraulic fracturing process to monitor the expansion of cracks inside the rock mass in real time. Existing hydraulic fracturing monitoring technology mainly uses fixed microseismic sensors installed underground or at the wellhead, but this method has certain difficulties in installation and disassembly, and it is difficult to carry out long-term monitoring. In addition, how to accurately evaluate the effect of hydraulic fracturing and optimize the design is also one of the challenges facing current technology. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a microseismic signal detection device, a hydraulic fracturing monitoring system and a method, which can realize real-time monitoring and optimization of hydraulic fracturing effects.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, a microseismic signal detection device is proposed, comprising a microseismic sensor, a mounting seat and a heating device;

[0008] The microseismic sensor is mounted on the mounting base;

[0009] The mounting seat includes a connecting rod and a shell mounted outside the connecting rod; the shell can deform with temperature; and the mounting seat can penetrate into the rock mass;

[0010] A heating device, used for heating the shell;

[0011] When the mounting seat penetrates into the rock mass, the heating device heats the outer shell, and the outer shell is deformed by the heat, so that the mounting seat can be fixed in the rock mass.

[0012] Furthermore, a connecting head is provided at one end of the shell, and the other end of the shell is a free end; the shell is sleeved on the outside of the connecting rod, and the shell is connected to the connecting rod through the connecting head; when the shell is not heated and is in an initial state, the free end of the shell is in contact with the connecting rod, and the free end is in a closed state; when the shell is deformed by heat, the free end of the shell gradually opens and moves away from the connecting rod.

[0013] Furthermore, a plurality of shells are arranged along the axial direction of the connecting rod, and a set distance is spaced between the plurality of shells.

[0014] Furthermore, after the mounting seat penetrates into the rock mass, the mounting seat is fixedly connected to the rock mass by cement mortar.

[0015] Furthermore, one end of the connecting rod is connected to the mounting block, and the microseismic sensor is connected to the mounting block.

[0016] In the second aspect, a hydraulic fracturing monitoring system is proposed, comprising:

[0017] A microseismic signal detection device proposed in the first aspect is used to obtain microseismic signals;

[0018] A data acquisition device for extracting microseismic signal characteristics;

[0019] The host is used to determine the hydraulic fracturing effect according to the characteristics of the microseismic signal; judge whether the hydraulic fracturing effect meets the requirements; when the hydraulic fracturing effect does not meet the requirements, determine the target hydraulic fracturing parameters according to the target hydraulic fracturing effect; and perform hydraulic fracturing operations according to the target hydraulic fracturing parameters.

[0020] Furthermore, the host is used to determine the hydraulic fracturing effect according to the correspondence between the microseismic signal and the set microseismic signal characteristics and the hydraulic fracturing effect; and determine the target hydraulic fracturing parameters according to the correspondence between the target hydraulic fracturing effect and the set hydraulic fracturing effect and the hydraulic fracturing parameters.

[0021] Furthermore, the host is used to establish the correspondence between the microseismic signal characteristics and the hydraulic fracturing effect through the Bayesian inference model; establish the correspondence between the microseismic signal characteristics and the hydraulic fracturing parameters through the integrated tree model; obtain the correspondence between the hydraulic fracturing effect and the hydraulic fracturing parameters through the correspondence between the microseismic signal characteristics and the hydraulic fracturing effect, and the correspondence between the microseismic signal characteristics and the hydraulic fracturing parameters.

[0022] Furthermore, the microseismic signal characteristics extracted by the data acquisition device include energy release characteristics, earthquake inelastic deformation characteristics, stress adjustment characteristics and the number of microseismic events.

[0023] In the third aspect, a hydraulic fracturing monitoring method is proposed, comprising:

[0024] Acquire microseismic signals;

[0025] Extract microseismic signal features;

[0026] Determine the hydraulic fracturing effect based on the characteristics of microseismic signals;

[0027] Determine whether the hydraulic fracturing effect meets the requirements;

[0028] When the hydraulic fracturing effect does not meet the requirements, the target hydraulic fracturing parameters are determined according to the target hydraulic fracturing effect;

[0029] Hydraulic fracturing operations are performed according to target hydraulic fracturing parameters.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention proposes a microseismic signal detection device, a hydraulic fracturing monitoring system and a method. The device is implemented by installing a microseismic sensor on a mounting seat, and providing a shell on the mounting seat that can deform with temperature; when the mounting seat is inserted into a rock mass, the shell is heated by a heating device to deform the shell, and the mounting seat with the microseismic sensor is fixed in the rock mass; when the microseismic sensor needs to be removed from the rock mass, the shell is heated to restore the shell to its initial state and separate from the rock mass, so that the mounting seat can be removed conveniently; by adopting a shell that can deform with temperature, the microseismic sensor can be conveniently installed and disassembled; the system monitors the microseismic signal during the hydraulic fracturing process to monitor the hydraulic fracturing effect, and adjusts the hydraulic fracturing parameters in a timely manner according to the monitoring results of the hydraulic fracturing effect to ensure the hydraulic fracturing effect and effectively improve the mining efficiency of hot dry rock geothermal resources.

[0032] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0034] Figure 1 A schematic diagram of the structure of a microseismic signal detection device disclosed in an embodiment;

[0035] Figure 2 A schematic diagram of a state in which a housing of a microseismic signal detection device disclosed in an embodiment is folded;

[0036] Figure 3 A monitoring flow chart of a hydraulic fracturing monitoring system disclosed in an embodiment.

[0037] Among them: 1. connecting wire, 2. microseismic sensor, 3. mounting block, 4. connecting head, 5. connecting rod, 6. outer shell, 7. cement mortar. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0042] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0043] Example 1

[0044] In this embodiment, a microseismic signal detection device is disclosed, such as Figure 1 , Figure 2 As shown, it includes a microseismic sensor 2, a mounting base and a heating device;

[0045] The microseismic sensor 2 is mounted on the mounting base;

[0046] The mounting seat 2 includes a connecting rod 5 and a housing 6 mounted outside the connecting rod 5; the housing 6 can deform with temperature; and the mounting seat can penetrate into the rock mass;

[0047] A heating device, used for heating the shell;

[0048] When the mounting seat penetrates into the rock mass, the heating device heats the outer shell 6, and the outer shell is deformed by the heat, so that the mounting seat can be fixed in the rock mass.

[0049] In the microseismic signal detection device disclosed in this embodiment, after the mounting base penetrates into the rock mass, the mounting base is fixedly connected to the rock mass by cement mortar 7 .

[0050] One end of the connecting rod 5 is connected to the mounting block 3, and the microseismic sensor 2 is connected to the mounting block 3. A connector 4 is provided at one end of the housing 6, and the other end of the housing 6 is a free end; the housing 6 is sleeved on the outside of the connecting rod, and the housing 6 is connected to the connecting rod 5 through the connector 4; when the housing 6 is not heated and is in the initial state, the free end of the housing 6 contacts the connecting rod 5, and the free end is in a closed state; when the housing 6 is deformed by heat, the free end of the housing 6 gradually opens and moves away from the connecting rod 5.

[0051] Preferably, the connecting rod 5 is made of threaded steel; the shell 6 is made of memory alloy, and the shell 6 is deformed when heated. When the shell 6 stops being heated and the temperature drops to a normal value, the shape of the shell 6 returns to its initial state.

[0052] The microseismic sensor 2 and the connecting rod 5 are both threadedly connected to the mounting block 3; the connector 4 and the connecting rod 5 are threadedly connected.

[0053] A plurality of housings 6 are arranged along the axial direction of the connecting rod 5 , and a set distance is spaced between the plurality of housings 6 .

[0054] The microseismic sensor 2 is connected with a connecting line 1 , and the connecting line 1 is used to transmit the microseismic signal acquired by the microseismic sensor 2 .

[0055] The present embodiment discloses a microseismic signal detection device. When in use, the microseismic sensor 2 connected with the connecting line 1 is connected to the mounting block 3, the connecting rod 5 is threadedly connected to the mounting block 3, and the connecting rod with the shape memory alloy shell is driven into the rock mass. After the connecting rod is installed in place, a small amount of cement mortar is injected into the gap between the rock mass and the mounting rod to ensure that the mounting rod and the rock mass are fully coupled. After the cement mortar solidifies, the shell 6 is heated by utilizing the temperature control characteristics of the shape memory alloy shell, and the shell 6 is deformed. The free end of the shell 6 opens and the mounting seat is firmly fixed in the rock mass. When the sensor needs to be removed, the shell 6 is cooled to restore the outer shape of the shell 6, and the free end of the shell 6 is gradually closed to separate the shell 6 from the rock mass, and the mounting seat is removed. The microseismic sensor is conveniently installed and disassembled, and the complexity and cost of the operation are reduced.

[0056] Example 2

[0057] In this embodiment, a hydraulic fracturing monitoring system is disclosed, comprising:

[0058] A microseismic signal detection device disclosed in embodiment 1 is used to obtain microseismic signals;

[0059] A data acquisition device for extracting microseismic signal characteristics;

[0060] The host is used to determine the hydraulic fracturing effect according to the characteristics of the microseismic signal; and determine the hydraulic fracturing parameters according to the target hydraulic fracturing effect.

[0061] Hydraulic fracturing effect; judging whether the hydraulic fracturing effect meets the requirements; when the hydraulic fracturing effect does not meet the requirements, determining the target hydraulic fracturing parameters according to the target hydraulic fracturing effect; and performing hydraulic fracturing operations according to the target hydraulic fracturing parameters.

[0062] Among them, the microseismic signal characteristics extracted by the data acquisition device include energy release characteristics, earthquake inelastic deformation characteristics, stress adjustment characteristics and the number N of microseismic events.

[0063] Energy release characteristics include microseismic energy E and energy index EI; earthquake inelastic deformation characteristics include seismic moment M 0 and the apparent volume V A ; Stress adjustment characteristics include apparent stress σ app and stress drop Δσ.

[0064] The seismic moment is

[0065] M 0 =μDS (1)

[0066] or

[0067]

[0068] Moment M 0 Also known as "seismic source moment", it is the point source moment (N·m) equivalent to the fault dislocation that causes the earthquake. In formula (1) and (2), μ is the rigidity coefficient of the fault material, DS is the volume of the rock mass with inelastic deformation at the source, and Ω 0 is the low frequency amplitude, v S is the velocity of the S wave, ρ is the medium density, R is the distance from the sensor to the source, R s Radiation directivity factor, R e Free surface reflection coefficient, S c Site correction factor.

[0069] The microseismic energy is

[0070]

[0071] The microseismic energy E is the elastic strain energy (J) released by rock mass rupture. In formula (3), ρ is the rock density, v is the microseismic wave velocity, R is the distance from the monitoring point to the earthquake source, and t s is the time span of the seismic wave signal, U corr is the displacement function of the seismic wave at the receiving end, i.e., the velocity pulse time function.

[0072] Apparent stress is

[0073] σ a =μE / M 0 (4)

[0074] Apparent stress σ a represents the stress release level (MPa). In formula (4), μ is the shear modulus, E is the microseismic energy, and M 0 is the earthquake moment.

[0075] The number of microseismic events N represents the number of times the rock mass micro-fractures and elastic waves are generated.

[0076] Apparent volume

[0077]

[0078] Apparent volume V A represents the volume of the rock mass in the inelastic deformation zone of the microseismic source (m 3 ). In formula (5), μ is the shear modulus, E is the microseismic energy, M 0 is the seismic moment, σ a For apparent stress.

[0079] The energy index is

[0080]

[0081] The energy index EI is the ratio of instantaneous energy to average energy. In formula (6), E is the microseismic energy, M is 0 is the seismic moment, c and d are obtained by lgM 0 The slope and intercept of the straight line fitted by lgE.

[0082] The hydraulic fracturing effects obtained by the host include water flow pressure, rate and diffusion range.

[0083] The host of this embodiment is used to determine the hydraulic fracturing effect according to the correspondence between the microseismic signal and the set microseismic signal characteristics and the hydraulic fracturing effect; and determine the target hydraulic fracturing parameters according to the target hydraulic fracturing effect and the correspondence between the set hydraulic fracturing effect and the hydraulic fracturing parameters.

[0084] Specifically, the host is used to establish the correspondence between microseismic signal characteristics and hydraulic fracturing effects through a Bayesian inference model; establish the correspondence between microseismic signal characteristics and hydraulic fracturing parameters through an integrated tree model; obtain the correspondence between hydraulic fracturing effects and hydraulic fracturing parameters through the correspondence between microseismic signal characteristics and hydraulic fracturing effects, and the correspondence between microseismic signal characteristics and hydraulic fracturing parameters.

[0085] The host is used to determine the target microseismic signal characteristics according to the target hydraulic fracturing effect and the Bayesian inference model; and to determine the target hydraulic fracturing parameters according to the target microseismic signal characteristics and the integrated tree model.

[0086] Among them, hydraulic fracturing parameters include injection pressure, flow rate, type of injected liquid and fracturing depth.

[0087] In the process of hydraulic fracturing using corresponding hydraulic fracturing parameters, this embodiment obtains microseismic signals, and uses hydraulic fracturing sensors to obtain hydraulic fracturing effects including water flow pressure, velocity and diffusion range; the microseismic signals here are training microseismic signals, and the hydraulic fracturing parameters and hydraulic fracturing effects here are the hydraulic fracturing parameters and hydraulic fracturing effects corresponding to the training microseismic signals.

[0088] Extract the characteristics of the training microseismic signals; analyze the characteristics of the training microseismic signals and their corresponding hydraulic fracturing parameters and hydraulic fracturing effects, determine the correspondence between the microseismic signal characteristics and the hydraulic fracturing parameters and the correspondence between the microseismic signal characteristics and the hydraulic fracturing effects; further, based on the correspondence between the microseismic signal characteristics and the hydraulic fracturing parameters and the correspondence between the microseismic signal characteristics and the hydraulic fracturing effects, obtain the correspondence between the hydraulic fracturing effects and the hydraulic fracturing parameters, and provide data support for subsequent optimization of the hydraulic fracturing effects.

[0089] This embodiment also uses the intensity, frequency, waveform and other characteristics of the microseismic signal as evaluation indicators, scores and optimizes the sensor layout according to the evaluation indicators, and selects the optimal sensor layout solution.

[0090] like Figure 3 As shown, this embodiment optimizes the training microseismic signal features and their corresponding hydraulic fracturing effects through a Bayesian inference model, and establishes a corresponding relationship between the microseismic signal features and the hydraulic fracturing effects.

[0091] Among them, the Bayesian inference model is:

[0092]

[0093] The Bayesian inference model is used to optimize the training microseismic signal features and their corresponding hydraulic fracturing effects. Since there is a dependency between the hydraulic fracturing effect and the microseismic signal features, a conditional probability table is used to describe the relationship between the hydraulic fracturing effect and the microseismic signal features; among them, P(A|B) is the probability of A occurring under the condition of given B, P(B|A) is the probability of B occurring under the condition of given A, P(A) is the prior probability of A occurring, and P(B) is the probability of B occurring.

[0094] The ensemble tree model is used to optimize and analyze the characteristics of the training microseismic signals and their corresponding hydraulic fracturing parameters, and the corresponding relationship between the microseismic signal characteristics and the hydraulic fracturing parameters is established.

[0095] Specifically, this embodiment uses the training microseismic signal features and their corresponding hydraulic fracturing parameters and hydraulic fracturing effects as training data to train the constructed Bayesian inference model and integrated tree model, and obtains the trained Bayesian inference model and the trained integrated tree model after the training is completed.

[0096] Before the hydraulic fracturing operation, appropriate hydraulic fracturing parameters are selected according to the geological characteristics of the target resource area, and the hydraulic fracturing operation is started using the selected hydraulic fracturing parameters; during the hydraulic fracturing operation, microseismic signals are monitored in real time, and the microseismic signals are analyzed through the trained Bayesian inference model to determine the hydraulic fracturing effect, thereby achieving rapid determination of the hydraulic fracturing effect.

[0097] Determine whether the hydraulic fracturing effect meets the requirements; when the hydraulic fracturing effect does not meet the requirements, determine the target hydraulic fracturing parameters according to the target hydraulic fracturing effect; use the target hydraulic fracturing parameters to perform hydraulic fracturing operations to achieve the expected fracturing effect and maximize the extraction efficiency of hot dry rock geothermal resources.

[0098] This embodiment adjusts the hydraulic fracturing operation plan through a continuous feedback mechanism, continuously optimizes the fracturing effect, and ultimately achieves efficient geothermal resource exploitation.

[0099] This embodiment divides the injection pressure, flow rate, liquid type and fracturing depth that affect the hydraulic fracturing effect into three types:

[0100] Injection pressure: low, medium, high

[0101] Flow rate: low, medium, high

[0102] Liquid type: water-based liquid, foam liquid, acid liquid

[0103] Fracturing depth: shallow, medium, deep

[0104] Based on the factors and levels of the study, the commonly used orthogonal table L9 (3×4) is selected. The L9 orthogonal table is suitable for the case of 3 levels and 4 factors. Each hydraulic fracturing test will include a combination of injection pressure, flow rate, liquid type, and fracturing depth. Fill the selected orthogonal table into the experimental design, and the experimental plan is shown in the following table:

[0105]

[0106]

[0107] In this embodiment, the acquired training microseismic signals and their corresponding hydraulic fracturing effects and hydraulic fracturing parameters are stored in a database; the data in the database is preprocessed to remove abnormal data, erroneous data, and duplicate data, and the features of the preprocessed microseismic signals are extracted; the preprocessed microseismic signal features and the corresponding preprocessed hydraulic fracturing effects and hydraulic fracturing parameters are converted into the same file type to obtain training data.

[0108] 80% of the training data is used to construct a training set for training, and 20% of the data is used to construct a test set for testing. During the training process of the Bayesian inference model, the random forest algorithm (RF) and the extreme random tree algorithm (ET) are used to parallel optimize the Bayesian inference model. The results obtained from the training of the two are voted on, and the majority of the votes of the two are taken as the final prediction result. By combining the outputs of the two into an integrated model, the accuracy of the model can be further improved.

[0109] The Bayesian inference model and the ensemble tree model are optimized using the training set. During the optimization process of the ensemble tree model, each decision tree predicts the parameter input data of the hydraulic fracturing test, such as injection pressure, flow rate, injection fluid type, and fracturing depth, and combines these prediction results by weighting to obtain the final microseismic signal feature prediction output.

[0110] Import the test set into the trained Bayesian inference model and ensemble tree model to evaluate the performance of the model; if it meets expectations, proceed to the next step; if not, re-optimize and increase the number of iterations until it meets expectations.

[0111] This embodiment also performs a global sensitivity analysis on the input and output data of the Bayesian reasoning model and the ensemble tree model, and determines which input variables are most critical to the model or decision-making process by evaluating the impact of changes in input variables on output results.

[0112] After obtaining the trained Bayesian inference model and the integrated tree model, this embodiment analyzes the microseismic signals collected in real time, can quickly determine the hydraulic fracturing effect, and adjust the hydraulic fracturing parameters according to the optimization target.

[0113] A hydraulic fracturing monitoring system disclosed in this embodiment can dynamically adjust hydraulic fracturing parameters and optimize hydraulic fracturing effects through real-time monitoring and data analysis of microseismic signals, thereby avoiding blind operations in traditional fracturing methods. It also improves the scientificity and accuracy of fracturing operations, reduces resource waste, and improves the efficiency of exploitation of hot dry rock geothermal resources through the combination of deep learning and data analysis.

[0114] Example 3

[0115] In this embodiment, a hydraulic fracturing monitoring method is disclosed, comprising:

[0116] Acquire microseismic signals;

[0117] Extract microseismic signal features;

[0118] Determine the hydraulic fracturing effect based on the characteristics of microseismic signals;

[0119] Determine whether the hydraulic fracturing effect meets the requirements;

[0120] When the hydraulic fracturing effect does not meet the requirements, the target hydraulic fracturing parameters are determined according to the target hydraulic fracturing effect;

[0121] Hydraulic fracturing operations are performed according to target hydraulic fracturing parameters.

[0122] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with this embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0123] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A microseismic signal detection device, characterized in that: It includes a microseismic sensor, a mounting base and a heating device; The microseismic sensor is mounted on the mounting base; The mounting base includes a connecting rod and a shell mounted outside the connecting rod; the shell can deform with temperature; The mounting base can penetrate into the rock mass; A heating device, used for heating the shell; When the mounting seat penetrates into the rock mass, the heating device heats the outer shell, and the outer shell is deformed by the heat, so that the mounting seat can be fixed in the rock mass.

2. A microseismic signal detection device according to claim 1, characterized in that: A connecting head is provided at one end of the shell, and the other end of the shell is a free end; the shell is sleeved on the outside of the connecting rod, and the shell is connected to the connecting rod through the connecting head; when the shell is not heated and is in an initial state, the free end of the shell is in contact with the connecting rod, and the free end is in a closed state; when the shell is deformed by heat, the free end of the shell gradually opens and moves away from the connecting rod.

3. A microseismic signal detection device according to claim 1, characterized in that: A plurality of shells are arranged along the axial direction of the connecting rod, and a set distance is spaced between the plurality of shells.

4. A microseismic signal detection device according to claim 1, characterized in that: After the mounting seat penetrates into the rock mass, the mounting seat is fixedly connected to the rock mass by cement mortar.

5. A microseismic signal detection device according to claim 1, characterized in that: One end of the connecting rod is connected to the mounting block, and the microseismic sensor is connected to the mounting block.

6. A hydraulic fracturing monitoring system, characterized in that: include: A microseismic signal detection device according to any one of claims 1 to 5, used to obtain microseismic signals; A data acquisition device for extracting microseismic signal characteristics; The host is used to determine the hydraulic fracturing effect according to the characteristics of the microseismic signal; judge whether the hydraulic fracturing effect meets the requirements; when the hydraulic fracturing effect does not meet the requirements, determine the target hydraulic fracturing parameters according to the target hydraulic fracturing effect; and perform hydraulic fracturing operations according to the target hydraulic fracturing parameters.

7. A hydraulic fracturing monitoring system according to claim 6, characterized in that: The host is used to determine the hydraulic fracturing effect according to the correspondence between the microseismic signal and the set microseismic signal characteristics and the hydraulic fracturing effect; and determine the target hydraulic fracturing parameters according to the correspondence between the target hydraulic fracturing effect and the set hydraulic fracturing effect and the hydraulic fracturing parameters.

8. A hydraulic fracturing monitoring system according to claim 7, characterized in that: The host is used to establish the corresponding relationship between the microseismic signal characteristics and the hydraulic fracturing effect through the Bayesian inference model; establish the corresponding relationship between the microseismic signal characteristics and the hydraulic fracturing parameters through the integrated tree model; obtain the corresponding relationship between the hydraulic fracturing effect and the hydraulic fracturing parameters through the corresponding relationship between the microseismic signal characteristics and the hydraulic fracturing effect, and the corresponding relationship between the microseismic signal characteristics and the hydraulic fracturing parameters.

9. A hydraulic fracturing monitoring system according to claim 6, characterized in that: The microseismic signal characteristics extracted by the data acquisition device include energy release characteristics, earthquake inelastic deformation characteristics, stress adjustment characteristics and the number of microseismic events.

10. A hydraulic fracturing monitoring method, characterized in that: include: Acquire microseismic signals; Extract microseismic signal features; Determine the hydraulic fracturing effect based on the characteristics of microseismic signals; Determine whether the hydraulic fracturing effect meets the requirements; When the hydraulic fracturing effect does not meet the requirements, the target hydraulic fracturing parameters are determined according to the target hydraulic fracturing effect; Hydraulic fracturing operations are performed according to target hydraulic fracturing parameters.

Images