Microseismic event signal-to-noise ratio improving method based on threshold-free polarization filtering

Abstract

The invention provides a microseismic event signal-to-noise ratio improving method based on threshold-free polarization filtering, and the method comprises the steps: carrying out the sliding window segmentation of a three-component signal of a microseismic event, so as to obtain a plurality of three-component sample signals in a sliding window with a preset time length; rotating the three-component sample signal around a coordinate axis of the reference coordinate system through an azimuth angle and an inclination angle of the selected three-component sample signal in the reference coordinate system, so that linear polarization energy corresponding to the three-component signal is concentrated on a single component signal, and the other two component signals are eliminated; and rotating the single component signal back to the reference coordinate system to obtain noise-reduced three-component signals in each sliding window, and combining the noise-reduced three-component signals to form continuous noise-reduced data of the micro-seismic event. Therefore, the three-component signal energy is concentrated on a single component by rotating the coordinate system, so that random noise or other nonlinear polarization noise is indirectly attenuated, non-threshold polarization filtering is realized, and the signal-to-noise ratio of a micro-seismic event is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mine microseismic monitoring, and in particular, to a method and device for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering. Background Art

[0002] Microseismic monitoring technology has played an important role in reservoir characterization, fracture development monitoring, etc. because it can observe the formation and expansion process of underground rock fractures in real time. However, microseismic data usually has a low to medium signal-to-noise ratio, and the presence of noise brings great uncertainty and inaccuracy to subsequent data analysis and interpretation.

[0003] In related technologies, noise in microseismic data is removed by time-domain or frequency-domain filtering. However, time-domain filtering requires setting the cut-off frequency based on experience, resulting in signal component leakage of microseismic data and the problem that noise cannot be effectively attenuated. Frequency-domain filtering attenuates noise by performing threshold processing in the time-frequency domain, but it is difficult to determine the threshold parameter, which easily leads to signal distortion of microseismic data. Therefore, there is an urgent need for a more reliable method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related technologies to some extent.

[0005] To this end, the first object of the present invention is to propose a method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering. By rotating the coordinate system, the energy of the three-component signal is concentrated on a single component, thereby indirectly attenuating random noise or other non-linearly polarized noise, so as to achieve thresholdless polarization filtering and improve the signal-to-noise ratio of microseismic events.

[0006] The second object of the present invention is to propose a device for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering.

[0007] The third object of the present invention is to propose an electronic device.

[0008] The fourth object of the present invention is to propose a non-transitory computer-readable storage medium storing computer instructions.

[0009] To achieve the above object, the first aspect embodiment of the present invention proposes a method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering, and the method includes:

[0010] Performing sliding window segmentation on the three-component signal of the microseismic event to obtain three-component sample signals within a plurality of sliding windows of a preset time length, and the three-component sample signals include a vertical component signal, a radial component signal, and a tangential component signal;

[0011] Select the azimuth and dip angle of the three-component sample signals in each sliding window in the reference coordinate system. Here, the dip angle refers to the angle between the vertical component signal and the horizontal plane, and the azimuth angle refers to the angle between the radial component signal and the reference direction in the horizontal plane;

[0012] Based on the azimuth and dip angle, rotate the three-component sample signals around the coordinate axes of the reference coordinate system, so that the linear polarization energy corresponding to the three-component signals is concentrated on the vertical component signal, and the radial component signal and the tangential component signal are eliminated;

[0013] Rotate the vertical component signal back to the reference coordinate system to obtain the noise-reduced three-component signals in each sliding window, and merge the noise-reduced three-component signals of each sliding window to form continuous denoised data of the microseismic event.

[0014] To achieve the above object, an embodiment of the second aspect of the present invention proposes a device for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering. The device includes:

[0015] A segmentation module for segmenting the three-component signals of the microseismic event by sliding windows to obtain three-component sample signals in multiple sliding windows of a preset time length. The three-component sample signals include a vertical component signal, a radial component signal, and a tangential component signal;

[0016] A selection module for respectively selecting the azimuth and dip angle of the three-component sample signals in each sliding window in the reference coordinate system. Here, the dip angle refers to the angle between the vertical component signal and the horizontal plane, and the azimuth angle refers to the angle between the radial component signal and the reference direction in the horizontal plane;

[0017] A first rotation module for rotating the three-component sample signals around the coordinate axes of the reference coordinate system based on the azimuth and dip angle, so that the linear polarization energy corresponding to the three-component signals is concentrated on the vertical component signal, and the radial component signal and the tangential component signal are eliminated;

[0018] A second rotation module for rotating the vertical component signal back to the reference coordinate system to obtain the noise-reduced three-component signals in each sliding window, and merging the noise-reduced three-component signals of each sliding window to form continuous denoised data of the microseismic event.

[0019] To achieve the above object, an embodiment of the third aspect of the present invention proposes an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in the first aspect.

[0020] To achieve the above object, an embodiment of the fourth aspect of the present invention provides a non-transitory computer-readable storage medium storing computer instructions, and the computer instructions are used to cause the computer to execute the method described in the first aspect.

[0021] The method, device, electronic device and storage medium for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering according to the embodiments of the present invention divide the three-component signals of microseismic events by a sliding window to obtain three-component sample signals within multiple sliding windows of a preset time length; by selecting the azimuth angle and dip angle of the three-component sample signals in the reference coordinate system, rotate the three-component sample signals around the coordinate axes of the reference coordinate system to concentrate the linear polarization energy corresponding to the three-component signals on a single component signal and eliminate the other two component signals; rotate the single component signal back to the reference coordinate system to obtain the noise-reduced three-component signals within each sliding window, and merge them to form continuous denoised data of microseismic events. Thus, by rotating the coordinate system, the energy of the three-component signals is concentrated on a single component, thereby indirectly attenuating random noise or other non-linearly polarized noise, so as to achieve thresholdless polarization filtering and improve the signal-to-noise ratio of microseismic events.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, wherein:

[0024] Figure 1 is a schematic flowchart of a method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering provided by an embodiment of the present invention;

[0025] Figure 2 is a schematic flowchart of another method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of a device for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering provided by an embodiment of the present invention. Detailed Embodiments

[0027] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0028] It should be noted that in the technical solution of the present invention, the acquisition, storage, use, processing, etc. of data all comply with the relevant regulations of relevant laws and regulations.

[0029] The following describes a method and apparatus for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering according to an embodiment of the present invention with reference to the accompanying drawings.

[0030] Figure 1 It is a schematic flow chart of a method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering provided by an embodiment of the present invention.

[0031] As Figure 1 shown, the method includes the following steps:

[0032] Step 101: Perform sliding window segmentation on the three-component signals of the microseismic event to obtain three-component sample signals within multiple sliding windows of a preset time length. The three-component sample signals include a vertical component signal, a radial component signal, and a tangential component signal.

[0033] In some embodiments, the sliding window adopts an overlapping manner, and each time a sampling point of a three-component sample signal is slid. The window moving method slides the three-component signal in an overlapping manner each time.

[0034] Further, the preset time length N of the sliding window a is generally taken to be about 1.5 to 2 times the main period of the expected three-component signal, and can be specifically set according to the center frequency of the microseismic signal corresponding to the micro-earth event.

[0035] Among them, the window function can be a Hann window, but is not limited thereto.

[0036] Step 102: Select the azimuth angle and dip angle of the three-component sample signal in each sliding window in the reference coordinate system respectively. Among them, the dip angle refers to the angle between the vertical component signal and the horizontal plane, and the azimuth angle refers to the angle between the radial component signal and the reference direction in the horizontal plane.

[0037] In some embodiments, before respectively selecting the azimuth angle and dip angle of the three-component sample signal in each sliding window in the reference coordinate system, a window function based on linearity is further multiplied to each three-component sample signal in each sliding window to further enhance the effect of component signals and suppress noise. Thus, when calculating the rotation angles (azimuth angle and dip angle), in order to avoid instability caused by insufficient sampling points at the endpoints, a window function (such as a Hann window) is multiplied to the three-component sample signal in the sliding window to improve the stability and smoothness of the azimuth angle and dip angle estimation values.

[0038] Further, in the case where the reference coordinate system is a Cartesian coordinate system (X, Y, Z), one implementation of respectively selecting the azimuth and dip angles of the three-component sample signals in each sliding window in the reference coordinate system can be as follows: In each sliding window, rotate the three-component sample signal around the Z-axis in the Cartesian coordinate system (X, Y, Z) to minimize the linear polarization energy of the X-axis component signal. When a preset proportion of the linear polarization energy only exists in the Y-Z plane, the first optimal rotation angle is obtained, and this first optimal rotation angle is used as the azimuth angle of the three-component sample signal in the Cartesian coordinate system. Here, minimizing the linear polarization energy refers to the process of reducing the linear polarization energy of the component signal to the minimum. After obtaining the azimuth angle, based on the azimuth angle, rotate the component signal after rotating around the Z-axis around the Z-axis to a new coordinate system (X', Y', Z'), and then rotate the three-component sample signal around the X'-axis in (X', Y', Z') to minimize the linear polarization energy of the Y'-axis component signal. When a preset proportion of the linear polarization energy only exists in the Z'-axis component signal, the second optimal rotation angle is obtained, and this second optimal rotation angle is used as the dip angle of the three-component sample signal in the Cartesian coordinate system.

[0039] Specifically, let there be N w sampling points in the sliding window, and x i , y i , z i be the three component signals of the i-th sampling point in the reference coordinate system (Cartesian coordinate system), respectively.

[0040] The calculation method of the azimuth angle α is as shown in formula (1):

[0041]

[0042] Rotate the three-component sample signal (x i , y i , z i ) around the Z-axis in the Cartesian coordinate system (X, Y, Z). The rotation matrix around the Z-axis is as shown in formula (2):

[0043]

[0044] The component signals x', y', z' after rotating around the Z-axis can be expressed as formula (3):

[0045]

[0046] To obtain the optimal azimuth angle, it can be obtained by minimizing the linear polarization energy of the X-axis component signal y'. If E(y') represents the energy of y' of all sampling points in each sliding window, and E(y') is as shown in formula (4), then:

[0047]

[0048] By making formula (5) hold, the optimal azimuth angle α can be obtained. Formula (5) is expressed as:

[0049]

[0050] In addition, after obtaining the optimal azimuth angle α, the three-component sample signal is rotated around the Z axis to a new coordinate system (X', Y', Z'), and then the three-component sample signal is rotated around the X' axis in (X', Y', Z') to minimize the linear polarization energy of the Y' axis component signal y” or maximize the linear polarization energy of the Z' axis component signal z”. The calculation method of the inclination angle β is as shown in formula (6):

[0051]

[0052] When the three-component sample signal is rotated around the X' axis in (X', Y', Z'), the rotation matrix around the X' axis is as shown in formula (7):

[0053]

[0054] Among them, in the target component signals x”, y”, z” after rotation around the X' axis, maximizing the linear polarization energy of z” or minimizing the linear polarization energy of y”, as shown in formula (5), the optimal inclination angle β can be obtained.

[0055] Step 103: Based on the azimuth angle and the inclination angle, rotate the three-component sample signal around the coordinate axes of the reference coordinate system to concentrate the linear polarization energy corresponding to the three-component signal on the vertical component signal and eliminate the radial component signal and the tangential component signal.

[0056] In some embodiments, an implementation manner of rotating the three-component sample signal around the coordinate axes of the reference coordinate system based on the azimuth angle and the inclination angle to concentrate the linear polarization energy corresponding to the three-component signal on the vertical component signal and eliminate the radial component signal and the tangential component signal can be as follows: Based on the azimuth angle, rotate the three-component sample signal around the Z axis in the Cartesian coordinate system (X, Y, Z) to obtain the rotated component signals x', y', z'; and according to the inclination angle, rotate the component signals x', y', z' around the X' axis in (X', Y', Z') to obtain the target component signals x”, y”, z”; Take x” as the vertical component signal on which the linear polarization energy corresponding to the three-component signal is concentrated, and take y” and z” as the radial component signal and the tangential component signal respectively, and y” and z” are noise amounts and are eliminated. Thus, the linear polarization energy of the three-component signal is concentrated on one component, and the other two components are eliminated to achieve noise reduction.

[0057] Further, after completing the above two rounds of rotation, considering x” and y” in the new coordinate system (X', Y', Z') as noise amounts and directly setting them to zero is equivalent to attenuation (elimination).

[0058] Step 104: Rotate the vertical component signal back to the reference coordinate system to obtain the noise-reduced three-component signals within each sliding window, and merge the noise-reduced three-component signals of each sliding window to form continuous denoised data of the microseismic event.

[0059] In some embodiments, an implementation manner of rotating the vertical component signal back to the reference coordinate system to obtain the noise-reduced three-component signals within each sliding window and merging the noise-reduced three-component signals of each sliding window to form continuous denoised data of the microseismic event can be as follows: Before rotating the vertical component signal back to the reference coordinate system, multiply the three-component sample signals within each sliding window by a window function based on linearity to obtain optimized sliding windows; rotate the vertical component signal back to the reference coordinate system to obtain the initial noise-reduced three-component signals of the optimized sliding windows, and apply the noise-reduced three-component signals to a polarization filter to multiply with a time function based on the linearity of the three-component signals to obtain the noise-reduced three-component signals within the optimized sliding windows; and merge the noise-reduced three-component signals of the optimized sliding windows to form continuous denoised data of the microseismic event, and a simplified linearity calculation method is proposed, which does not require complex eigenvalue and eigenvector calculations.

[0060] Optionally, the time function based on the linearity of the three-component signals is as shown in formula (8):

[0061]

[0062] where r(t) is the linearity, and the value range is from 0 to 1, e x 、e y 、e u are the linear polarization energies of the rotated x, y, and u (main direction z) component signals. When the component signals are linearly polarized, e x 、e y are close to 0, and r(t) is close to 1; when the component signals are random noises, e x 、e y 、e u are similar and close to 0.

[0063] Thus, by multiplying the initial noise-reduced three-component signals with r(t), the linearly polarized component signal part remains basically unchanged, and the noise part is significantly weakened. Through this method, further suppression of noise can be achieved without threshold setting. And this operation is independently performed within each sliding window, and then the noise-reduced three-component signals after processing all sliding windows are spliced together to obtain the final global filtering result (denoised data).

[0064] The method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering according to the embodiments of the present invention performs sliding window segmentation on the three-component signals of microseismic events to obtain three-component sample signals within multiple sliding windows of a preset time length; by the azimuth angle and dip angle of the selected three-component sample signals in the reference coordinate system, the three-component sample signals are rotated around the coordinate axes of the reference coordinate system, so that the linear polarization energy corresponding to the three-component signals is concentrated on a single component signal, and the other two component signals are eliminated; the single component signal is rotated back to the reference coordinate system to obtain the noise-reduced three-component signals within each sliding window, and they are combined to form continuous denoised data of the microseismic event. Thus, by rotating the coordinate system, the energy of the three-component signals is concentrated on a single component, thereby indirectly attenuating random noise or other non-linearly polarized noise, so as to achieve thresholdless polarization filtering and improve the signal-to-noise ratio of microseismic events.

[0065] In addition, for better understanding of the present invention, the present invention also provides a schematic flow chart of another method for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering. Specifically, by inputting the three-component signals of microseismic events and performing sliding window segmentation, multiple sliding windows with a preset time length of N a , and there are N w sampling points in the window. Taking the three-component sample signal i within the sliding window as the center and windowing (multiplying by a window function based on linearity), calculating the azimuth angle α i of the three-component sample signal i within the sliding window in the reference coordinate system (Cartesian coordinate system), rotating the three-component sample signal around the Z axis in the Cartesian coordinate system (X, Y, Z) to obtain the rotated component signals x', y', z', performing windowing processing on the sliding window (adding a Hann window), after selecting the azimuth angle, based on the azimuth angle, rotating the three-component sample signal around the Z axis to a new coordinate system (X', Y', Z'), calculating the dip angle β i , and based on the dip angle β i , then rotating x', y', z' around the X' axis in (X', Y', Z') to obtain the target component signals x”, y”, z”, eliminating y” and z”, and then performing X' axis reverse rotation and Z axis reverse rotation on the obtained z” to rotate back to the reference coordinate system to obtain the initial noise-reduced three-component signals within each sliding window, and applying the noise-reduced three-component signals to a polarization filter to multiply by a time function based on the linearity of the three-component signals, obtaining the noise-reduced three-component signals within each sliding window and combining them to output continuous denoised data of the microseismic event.

[0066] Thus, the method proposed by the present invention can minimize the waveform (signal) distortion of microseismic events and denoise the component signals without threshold processing. The algorithm improves the signal-to-noise ratio by rotating the three-component signals until most of their linearly polarized energy is forced to concentrate on a preselected component signal. Then, the linearly polarized energy in the remaining two component signals is removed, and the component signals are rotated back to the original direction. The principal direction of particle motion is estimated by rotating the three-component signals until the linearly polarized energy of two of the component signals is minimized (energy minimization, EM, referring to the process of reducing the linearly polarized energy of the component signals to the minimum).

[0067] To implement the above embodiments, the present invention also proposes a device for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering.

[0068] Figure 3 FIG. is a schematic structural diagram of a device for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering provided by an embodiment of the present invention.

[0069] As Figure 3 shown, the device 30 for improving the signal-to-noise ratio of microseismic events based on thresholdless polarization filtering includes: a segmentation module 31, a selection module 32, a first rotation module 33, and a second rotation module 34.

[0070] The segmentation module 31 is configured to perform sliding window segmentation on the three-component signals of the microseismic events to obtain three-component sample signals within a plurality of sliding windows of a preset time length. The three-component sample signals include a vertical component signal, a radial component signal, and a tangential component signal.

[0071] The selection module 32 is configured to respectively select the azimuth angle and the inclination angle of the three-component sample signals in each sliding window in the reference coordinate system. The inclination angle refers to the angle between the vertical component signal and the horizontal plane, and the azimuth angle refers to the angle between the radial component signal and the reference direction in the horizontal plane.

[0072] The first rotation module 33 is configured to rotate the three-component sample signals around the coordinate axes of the reference coordinate system based on the azimuth angle and the inclination angle, so that the linearly polarized energy corresponding to the three-component signals is concentrated on the vertical component signal, and the radial component signal and the tangential component signal are eliminated.

[0073] The second rotation module 34 is configured to rotate the vertical component signal back to the reference coordinate system to obtain the three-component denoised signals within each sliding window, and merge the three-component denoised signals of each sliding window to form continuous denoised data of the microseismic event.

[0074] Further, in a possible implementation manner of the embodiment of the present invention, the sliding window adopts an overlapping manner, and each time it slides by a sampling point of a three-component sample signal. Before respectively selecting the azimuth angle and inclination angle of the three-component sample signal in the reference coordinate system in each sliding window, a windowing function based on linearity is also multiplied to the three-component sample signal in each sliding window.

[0075] Further, in a possible implementation manner of the embodiment of the present invention, when the reference coordinate system is a Cartesian coordinate system (X, Y, Z), the selection module 32 is specifically configured to:

[0076] Select, in each sliding window, the first optimal rotation angle when the three-component sample signal is rotated around the Z axis in the Cartesian coordinate system (X, Y, Z) to minimize the linear polarization energy of the X-axis component signal, and a preset proportion of the linear polarization energy only exists in the Y-Z plane, and use the first optimal rotation angle as the azimuth angle of the three-component sample signal in the Cartesian coordinate system, where minimizing the linear polarization energy refers to the process of reducing the linear polarization energy of the component signal to the minimum;

[0077] After selecting the azimuth angle, based on the azimuth angle, rotate the three-component sample signal around the Z axis to a new coordinate system (X', Y', Z'), and then rotate the component signal after the Z-axis rotation around the X' axis in (X', Y', Z') to minimize the linear polarization energy of the Y'-axis component signal, and the second optimal rotation angle when a preset proportion of the linear polarization energy only exists in the Z'-axis component signal, and use the second optimal rotation angle as the inclination angle of the three-component sample signal in the Cartesian coordinate system.

[0078] Further, in a possible implementation manner of the embodiment of the present invention, the first rotation module 33 is specifically configured to:

[0079] Based on the azimuth angle, rotate the three-component sample signal around the Z axis in the Cartesian coordinate system (X, Y, Z) to obtain the rotated component signals x', y', z';

[0080] And according to the inclination angle, rotate the component signals x', y', z' around the X' axis in (X', Y', Z') to obtain the target component signals x”, y”, z”;

[0081] Use x” as the vertical component signal where the linear polarization energy of the three-component signal is concentrated, and use y”, z” as the radial component signal and the tangential component signal respectively, and the y”, z” are noise amounts and are eliminated.

[0082] Further, in a possible implementation manner of the embodiment of the present invention, the second rotation module 34 is specifically configured to:

[0083] Before rotating the vertical component signal back to the reference coordinate system, a windowing function based on linearity is also multiplied by the three-component sample signals within each sliding window to obtain optimized sliding windows.

[0084] Rotate the vertical component signal back to the reference coordinate system to obtain the initial noise-reduced three-component signals for each optimized sliding window, and apply the noise-reduced three-component signals to a polarization filter to multiply with a time function based on the linearity of the three-component signals, obtaining the noise-reduced three-component signals within each optimized sliding window.

[0085] And merge the noise-reduced three-component signals of each optimized sliding window to form continuous denoised data of the microseismic event.

[0086] The microseismic event signal-to-noise ratio improvement device based on thresholdless polarization filtering according to the embodiments of the present invention divides the three-component signals of the microseismic event into sliding windows to obtain three-component sample signals within multiple sliding windows of a preset time length; by the azimuth angle and inclination angle of the selected three-component sample signals in the reference coordinate system, rotate the three-component sample signals around the coordinate axes of the reference coordinate system to concentrate the linearly polarized energy corresponding to the three-component signals on a single component signal and eliminate the other two component signals; rotate the single component signal back to the reference coordinate system to obtain the noise-reduced three-component signals within each sliding window, and merge them to form continuous denoised data of the microseismic event. Thus, by rotating the coordinate system to concentrate the energy of the three-component signals on a single component, random noise or other non-linearly polarized noise is indirectly attenuated, thereby realizing thresholdless polarization filtering and improving the signal-to-noise ratio of the microseismic event.

[0087] To implement the above embodiments, the present invention also proposes an electronic device, including:

[0088] At least one processor; and

[0089] A memory communicatively connected to the at least one processor; wherein,

[0090] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the foregoing method.

[0091] To implement the above embodiments, the present invention also proposes a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the foregoing method.

[0092] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0093] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0094] Any process or method description shown in the flowchart or described in other ways herein can be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions may be executed in a manner that is not in the order shown or discussed, including in a substantially simultaneous manner according to the involved functions or in a reverse order, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0095] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in conjunction with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection part having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then storing it in a computer memory.

[0096] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0097] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the methods of the above embodiments can be completed by a program instructing relevant hardware, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0098] In addition, each functional unit in various embodiments of the present invention may be integrated into a processing module, may exist separately as individual physical units, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0099] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for improving the signal-to-noise ratio of microseismic events based on threshold-free polarization filtering, characterized in that: The method comprises: Sliding window segmentation is performed on the three-component signal of the microseismic event to obtain three-component sample signals within a plurality of sliding windows of preset time lengths, wherein the three-component sample signals include a vertical component signal, a radial component signal, and a tangential component signal; The azimuth and inclination of the three-component sample signals in each sliding window in the reference coordinate system are respectively selected, wherein the inclination refers to the angle between the vertical component signal and the horizontal plane, and the azimuth refers to the angle between the radial component signal in the horizontal plane and the reference direction; Based on the azimuth and inclination, the three-component sample signal is rotated around the coordinate axis of the reference coordinate system so that the linear polarization energy corresponding to the three-component signal is concentrated on the vertical component signal, and the radial component signal and the tangential component signal are eliminated; The vertical component signal is rotated back to the reference coordinate system to obtain the denoised three-component signal in each sliding window, and the denoised three-component signal in each sliding window is merged to form continuous denoised data of microseismic events.

2. The method according to claim 1, characterized in that: The sliding window adopts an overlapping manner, sliding a sampling point of the three-component sample signal each time, and before selecting the azimuth and inclination of the three-component sample signal in each sliding window in the reference coordinate system, the three-component sample signal in each sliding window is multiplied by a linearity-based windowing function.

3. The method according to claim 2, characterized in that When the reference coordinate system is a Cartesian coordinate system (X, Y, Z), the azimuth and inclination of the three-component sample signals in each sliding window in the reference coordinate system are respectively selected, including: Selecting a first optimal rotation angle in each sliding window, rotating the three-component sample signal around the Z axis in the Cartesian coordinate system (X, Y, Z) so that the linear polarization energy of the X-axis component signal is minimized, and a preset proportion of the linear polarization energy exists only in the YZ plane, and using the first optimal rotation angle as the azimuth of the three-component sample signal in the Cartesian coordinate system, wherein minimizing the linear polarization energy refers to the process of reducing the linear polarization energy of the component signal to a minimum; After the azimuth angle is selected, the three-component sample signal is rotated around the Z axis to a new coordinate system (X', Y', Z') based on the azimuth angle, and then the component signal after the Z-axis rotation is rotated around the X' axis in (X', Y', Z') to minimize the linear polarization energy of the Y'-axis component signal, and a second optimal rotation angle is obtained when a preset proportion of linear polarization energy exists only in the Z'-axis component signal, and the second optimal rotation angle is used as the inclination angle of the three-component sample signal in the Cartesian coordinate system.

4. The method according to claim 3, characterized in that The method of rotating the three-component sample signal around the coordinate axis of the reference coordinate system based on the azimuth and the inclination, so that the linear polarization energy corresponding to the three-component signal is concentrated on the vertical component signal, and eliminating the radial component signal and the tangential component signal, includes: Based on the azimuth angle, the three-component sample signal is rotated around the Z axis in the Cartesian coordinate system (X, Y, Z) to obtain rotated component signals x', y', z'; And according to the inclination angle, the X' axis in the component signal x', y', z' (X', Y', Z') is rotated to obtain the target component signal x", y", z"; x" is regarded as the vertical component signal of the linear polarization energy concentration corresponding to the three-component signal, y", and z" are respectively regarded as the radial component signal and the tangential component signal, and the y", and z" are the noise amount and are eliminated.

5. The method according to claim 2, characterized in that: The vertical component signal is rotated back to the reference coordinate system to obtain the denoised three-component signal in each sliding window, and the denoised three-component signal of each sliding window is merged to form continuous denoised data of microseismic events, including: Before rotating the vertical component signal back to the reference coordinate system, the three-component sample signal in each sliding window is multiplied by a linearity-based windowing function to obtain optimized sliding windows; Rotating the vertical component signal back to the reference coordinate system to obtain optimized initial denoised three-component signals in each sliding window, and applying the denoised three-component signals to a polarization filter to multiply them with a time function based on the linearity of the three-component signals to obtain optimized denoised three-component signals in each sliding window; The denoised three-component signals of each optimized sliding window are merged to form continuous denoised data of microseismic events.

6. A device for improving the signal-to-noise ratio of microseismic events based on threshold-free polarization filtering, characterized in that: The device comprises: A segmentation module is used to perform sliding window segmentation on the three-component signal of the microseismic event to obtain three-component sample signals within a plurality of sliding windows of preset time lengths, wherein the three-component sample signals include a vertical component signal, a radial component signal and a tangential component signal; A selection module is used to select the azimuth and inclination of the three-component sample signal in each sliding window in the reference coordinate system, wherein the inclination refers to the angle between the vertical component signal and the horizontal plane, and the azimuth refers to the angle between the radial component signal in the horizontal plane and the reference direction; A first rotation module is used to rotate the three-component sample signal around the coordinate axis of the reference coordinate system based on the azimuth and inclination, so that the linear polarization energy corresponding to the three-component signal is concentrated on the vertical component signal, and the radial component signal and the tangential component signal are eliminated; The second rotation module is used to rotate the vertical component signal back to the reference coordinate system to obtain the denoised three-component signal in each sliding window, and merge the denoised three-component signal in each sliding window to form continuous denoised data of microseismic events.

7. The device according to claim 6, characterized in that The sliding window adopts an overlapping manner, sliding a sampling point of the three-component sample signal each time, and before selecting the azimuth and inclination of the three-component sample signal in each sliding window in the reference coordinate system, the three-component sample signal in each sliding window is multiplied by a linearity-based windowing function.

8. The device according to claim 7, characterized in that When the reference coordinate system is a Cartesian coordinate system (X, Y, Z), the selection module is specifically used for: Selecting a first optimal rotation angle in each sliding window, rotating the three-component sample signal around the Z axis in the Cartesian coordinate system (X, Y, Z) so that the linear polarization energy of the X-axis component signal is minimized, and a preset proportion of the linear polarization energy exists only in the YZ plane, and using the first optimal rotation angle as the azimuth of the three-component sample signal in the Cartesian coordinate system, wherein minimizing the linear polarization energy refers to the process of reducing the linear polarization energy of the component signal to a minimum; After the azimuth angle is selected, the three-component sample signal is rotated around the Z axis to a new coordinate system (X', Y', Z') based on the azimuth angle, and then the component signal after the Z-axis rotation is rotated around the X' axis in (X', Y', Z') to minimize the linear polarization energy of the Y'-axis component signal, and a second optimal rotation angle is obtained when a preset proportion of linear polarization energy exists only in the Z'-axis component signal, and the second optimal rotation angle is used as the inclination angle of the three-component sample signal in the Cartesian coordinate system.

9. The device according to claim 8, characterized in that The first rotation module is specifically used for: Based on the azimuth angle, the three-component sample signal is rotated around the Z axis in the Cartesian coordinate system (X, Y, Z) to obtain rotated component signals x', y', z'; And according to the inclination angle, the component signal x', y', z' is rotated around the X' axis in (X', Y', Z') to obtain the target component signal x", y", z"; x" is regarded as the vertical component signal of the linear polarization energy concentration corresponding to the three-component signal, y", and z" are respectively regarded as the radial component signal and the tangential component signal, and the y", and z" are the noise amount and are eliminated.

10. The device according to claim 7, characterized in that The second rotation module is specifically used for: Before rotating the vertical component signal back to the reference coordinate system, the three-component sample signal in each sliding window is multiplied by a linearity-based windowing function to obtain optimized sliding windows; Rotating the vertical component signal back to the reference coordinate system to obtain optimized initial denoised three-component signals in each sliding window, and applying the denoised three-component signals to a polarization filter to multiply them with a time function based on the linearity of the three-component signals to obtain optimized denoised three-component signals in each sliding window; The denoised three-component signals of each optimized sliding window are merged to form continuous denoised data of microseismic events.

11. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 5.

12. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer to execute the method according to any one of claims 1-5.

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