Geophysical prospecting system and method for seismic survey

Abstract

The invention discloses a geophysical prospecting system and method for seismic survey. The system comprises a seismic source and receiving point laying module, a data acquisition module, a data processing module, a three-dimensional imaging module, a data interpretation module, a comprehensive analysis module, auxiliary equipment and an early warning module. The data processing module comprises a preprocessing module, a speed analysis superposition processing module and an offset processing module. According to the invention, data with high quality, signal-to-noise ratio and accuracy can be obtained by adding the density of the receiving points and combining the speed analysis superposition processing module to carry out superposition correction processing on the data, and meanwhile, by combining the reverse time migration technology, an underground structure can be accurately recovered, the imaging quality is improved, the subsequent interpretation and analysis work of personnel is facilitated, and the working efficiency is improved. The exploration accuracy is improved, and personnel can more accurately reveal the underground geologic structure conveniently.

Description

Technical Field

[0001] The present invention relates to the technical field of seismic surveying, and in particular to a geophysical prospecting system and method for seismic surveying. Background Art

[0002] Seismic survey is a method of investigating underground structures mainly related to the exploration of coal, oil, gas or mineral deposits. It is based on the time interval between the arrival of sound waves and the arrival of reflected waves or refracted pulses at one or several seismic detectors, using seismic sources with instruments such as detectors to conduct seismic surveys using refracted or reflected waves;

[0003] The geophysical exploration system for seismic survey in the prior art has the following deficiencies during use: 1. The method for processing survey data is relatively simple. Since seismic data is easily interfered by various noises, the data quality, signal-to-noise ratio and accuracy are low; 2. With the increase of depth, seismic waves attenuate and the signal weakens, resulting in low resolution and accuracy of deep strata, which affects the quality of imaging and the accuracy of subsequent interpretation and analysis; Based on the above, we propose a geophysical exploration system and method for seismic survey. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a geophysical exploration system and method for seismic survey.

[0005] The present invention proposes a geophysical exploration system for seismic survey, comprising a source and receiving point layout module, a data acquisition module, a data processing module, a three-dimensional imaging module, a data interpretation module, a comprehensive analysis module, auxiliary equipment and an early warning module;

[0006] The data processing module includes a pre-processing module, a rapid analysis and overlay processing module, and an offset processing module;

[0007] The three-dimensional imaging module includes a three-dimensional superposition imaging module and a reverse time migration module;

[0008] The data interpretation module includes a three-dimensional visualization module and a geological interpretation module.

[0009] Preferably, the seismic source and receiving point arrangement module is used to arrange mechanical vibrators in a grid on the surface of the coal mine, with the mechanical vibrators serving as seismic source points, and to arrange seismic detector receiving points around the seismic source points, wherein the seismic detectors are arranged in a three-dimensional receiving array, and the seismic detectors convert the mechanical vibrations of the mechanical vibrators into electrical signals, and the distance between two adjacent mechanical vibrators is 100m-120m;

[0010] The auxiliary equipment is a GPS locator, which is installed on each earthquake source point and seismic detector. The GPS locator is used to accurately locate the position of the earthquake source point and the seismic detector.

[0011] Preferably, the data acquisition module is used to receive the seismic wave signal of the seismic detection wave receiving point and the GPS position of the seismic detection wave;

[0012] The preprocessing module in the data processing module is used to remove the interference of direct waves and surface waves from the received data by using filtering technology, and to remove periodic noise by using the frequency domain analysis method of Fourier transform, and to perform static correction according to the arrival time of the first arrival wave to eliminate the influence of the uneven surface and the difference in the position of the receiver, and to remove multiple waves by using the multiple wave removal algorithm;

[0013] The velocity analysis stacking processing module uses the velocity spectrum analysis method to construct a velocity model and stacks the seismic data of multiple excitations to improve the signal-to-noise ratio. The specific logical steps are as follows:

[0014] A: Select several representative common center point gathers and assume a series of different velocity models in the selected CMP gathers, where the common center point gather refers to the collection of all seismic records with the same center point, which is the midpoint between the source point and the receiving point, for example, the source point S1, the receiving point R1, and the center point M1 = (S1 + R1) / 2;

[0015] B: Perform conventional NMO correction on each assumed velocity, calculate the corrected common center point gathers, and stack the corrected common center point gathers to calculate the stacking energy at different velocities;

[0016] When performing conventional NMO correction, the formula used is: where t nmo represents the corrected time, t0 is the arrival time at zero offset, x is the offset, and v is the assumed velocity;

[0017] The formula used to calculate the superposition energy is:

[0018]

[0019] E(v)=∑ t (S(t,v)) 2 ;

[0020] Where S(t,v) is the superposition signal at time t and velocity v, d i (t nmo (x i ,v)) is the i-th record at time t nmoThe amplitude value under , N is the number of records in the common center point gather, E(v) is the superposition energy under the assumed velocity v, ∑t represents the sum of all time sampling points;

[0021] C: Plot the superposition energy corresponding to different speeds into a speed spectrum, with the horizontal axis being speed and the vertical axis being time;

[0022] D: Identify the peaks with the highest energy on the speed spectrum. These peaks correspond to the possible true speeds, and select the speed value with the highest energy as the optimal speed for that time period.

[0023] E: According to the optimal speed value, a speed model is constructed, and the speed model is a speed-time curve diagram;

[0024] The migration processing module uses the constructed velocity model to perform time migration processing on the seismic data, convert the data from the time domain to the depth domain, and correct the propagation path of the seismic wave. The program code used during its operation is as follows:

[0025] <Input seismic data and velocity model>

[0026] import seismic_data_handler

[0027] data=seismic_data_handler.load_data('input_data.segy')

[0028] velocity_model=seismic_data_handler.load_velocity_model('velocity_model.txt')

[0029] <Select offset algorithm>

[0030] from seismic_migration import KirchhoffMigration

[0031] migration_processor=KirchhoffMigration(data,velocity_model)

[0032] <Preliminary offset>

[0033] initial_image=migration_processor.run_initial_migration()

[0034] residuals = migration_processor.analyze_residuals(initial_image)

[0035] velocity_model = migration_processor.update_velocity_model(residuals)

[0036] <Refinement processing>

[0037] for i in range(num_iterations):

[0038] image = migration_processor.run_migration(velocity_model)

[0039] residuals = migration_processor.analyze_residuals(image) velocity_model = migration_processor.update_velocity_model(residuals)

[0040] <Final migration processing>

[0041] final_image = migration_processor.run_final_migration(velocity_model)

[0042] attributes = seismic_data_handler.extract_attributes(final_image)

[0043] <Output and storage>

[0044] seismic_data_handler.save_image(final_image,

[0045] 'final_image.segy')

[0046] seismic_data_handler.save_attributes(attributes,

[0047] 'attributes.txt').

[0048] Preferably, the three-dimensional stacking imaging module converts the three-dimensional seismic data into an image of an underground reflection surface by stacking processing, wherein the image of the underground reflection surface is a stacking profile generated by using the data after the stacking processing;

[0049] The X-axis and Y-axis in the stacked section represent the spatial position of the seismic data in the X-direction and Y-direction respectively, and the Z-axis represents the time (i.e., the two-way time of the arrival of the seismic wave). The stacked section shows the reflection information that changes with time, reflecting the preliminary form of the underground structure.

[0050] The reverse time migration module applies the reverse time migration technology and can more accurately restore the underground structure and further improve the imaging quality by simulating the propagation process of seismic waves using the wave equation. The specific steps are as follows:

[0051] (1) Starting from the earthquake source, by numerically solving the wave equation, the propagation of seismic waves in the underground medium is simulated to generate a forward propagating wave field;

[0052] (2) Starting from the receiving point (seismic record), the seismic waves are propagated in the reverse direction of time to generate a wave field that propagates in the reverse direction;

[0053] (3) The forward propagation and reverse propagation wave fields are intersected at each time step to form imaging conditions and generate high-resolution underground structure images;

[0054] The wave equation formula is:

[0055]

[0056] Where u(x,y,z,t) is the displacement at position (x,y,z) and time t, u represents displacement, which indicates the offset of the medium at that point, x, y, z are spatial coordinates, indicating the position in three-dimensional space, and t represents time. The partial derivative symbol represents the derivative with respect to a specific variable. The second-order partial derivative of displacement with respect to time represents acceleration, v represents wave velocity, is the second-order partial derivative of the displacement with respect to the Z coordinate, indicating the bending in the Z direction, is the second-order partial derivative of the displacement with respect to the Y coordinate, indicating the bending in the Y direction, is the second-order partial derivative of the displacement with respect to the z-coordinate, representing the bending in the z-direction.

[0057] Preferably, the three-dimensional visualization module uses professional geophysical software to visualize the stacked three-dimensional seismic data and generate a three-dimensional seismic geological model and a profile diagram;

[0058] The geological interpretation module combines geological knowledge and other geophysical data to perform geological interpretation on the generated three-dimensional seismic geological model and profile, and identifies strata, faults, coal seams and oil and gas reservoirs.

[0059] Preferably, the comprehensive analysis module combines the identified strata, faults, coal seams and oil and gas reservoir locations with multidisciplinary knowledge of geology, geochemistry and geophysics to conduct a comprehensive analysis and assess earthquake risk;

[0060] The early warning module is used to issue an early warning to remind personnel when a high earthquake risk level is detected.

[0061] The present invention also proposes a geophysical prospecting method for seismic survey, comprising the following steps:

[0062] S1: The seismic source and receiving point layout module is used to layout the seismic source points on the surface according to the designed grid, and dense seismic detection wave receiving points are arranged around the seismic source points, and the receiving points form a three-dimensional receiving array;

[0063] S2: The auxiliary equipment uses GPS locator to accurately locate the earthquake source point and the location of the seismic detector;

[0064] S3: According to the designed excitation sequence and time, the seismic sources are excited one by one, and the seismic wave signals of the receiving points are synchronously recorded through the data acquisition module;

[0065] S4: The preprocessing module preprocesses the seismic wave signal received in S3 to improve the data quality, and superimposes the seismic data of multiple excitations through the velocity analysis and superposition processing module to improve the signal-to-noise ratio;

[0066] S5: The offset processing module performs offset processing on the superimposed data, corrects the seismic wave propagation path, and obtains the position of the underground reflection surface;

[0067] S6: The 3D stacking imaging module converts 3D seismic data into images of underground reflection surfaces through stacking processing, and the reverse time migration module applies reverse time migration technology to further improve the imaging quality;

[0068] S7: The 3D visualization module uses professional geophysical software to visualize the stacked 3D seismic data and generate 3D seismic geological models and profiles;

[0069] S8: The geological interpretation module combines geological knowledge to interpret the generated 3D seismic geological model, profile and underground reflection surface images to identify strata, faults, coal seams and oil and gas reservoirs;

[0070] S9: The comprehensive analysis module combines the identified strata, faults, coal seams and oil and gas reservoir locations with multidisciplinary knowledge of geology, geochemistry and geophysics to conduct a comprehensive analysis, assess earthquake risks, and issue timely warnings through the early warning module.

[0071] Preferably, in S1, the seismic source point is a mechanical vibrator, and the designed grid may be a 10x10 grid, with a total of 100 seismic source points, and the spacing between each seismic source point is 100m-120m.

[0072] Preferably, in S3, the excitation is performed point by point according to the arrangement order of the seismic source points, and the excitation duration of each seismic source point is 10 seconds and the interval time is 30 seconds;

[0073] In addition, the activation sequence and schedule are as follows:

[0074] Serial number Epicenter number Excitation time 1 1 08:00:00-08:00:10 2 2 08:00:40-08:00:50 …… …… …… 99 99 09:39:20-09:39:30 100 100 09:40:00-09:40:10 .

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] 1. By increasing the density of receiving points, improving the coverage and uniformity of signal acquisition, coordinating with the setting of the velocity analysis and stacking processing module, the seismic data of multiple excitations after preprocessing are superimposed to improve the signal-to-noise ratio, and combining with the offset processing module to correct the propagation path of the seismic wave, thus obtaining data with high quality, signal-to-noise ratio and accuracy;

[0077] 2. The three-dimensional stacking imaging module converts the stacked data into an image of the underground reflective surface, and combines the reverse time migration module to accurately restore the underground structure using the reverse time migration technology, thereby improving the imaging quality and facilitating the subsequent interpretation and analysis work of the personnel;

[0078] 3. Through the setting of comprehensive analysis module and early warning module, earthquake risk can be assessed in time and early warning can be issued to personnel, so that personnel can know in time;

[0079] The present invention increases the density of receiving points and combines the velocity analysis and stacking processing module to perform stacking and correction processing on the data, thereby obtaining data with high quality, signal-to-noise ratio and accuracy. At the same time, combined with the reverse time migration technology, the underground structure can be accurately restored, the imaging quality can be improved, and the subsequent interpretation and analysis work of personnel can be more conducive to improving the accuracy of exploration and facilitating personnel to more accurately reveal the underground geological structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 A block diagram of a geophysical exploration system for seismic survey proposed by the present invention;

[0081] Figure 2A block diagram of the connection between a data processing module, a three-dimensional imaging module and a data interpretation module in a geophysical exploration system for seismic survey proposed by the present invention;

[0082] Figure 3 A flow chart of a geophysical prospecting method for seismic survey proposed by the present invention;

[0083] Figure 4 A schematic diagram of the layout of the source point and the receiving point in a geophysical prospecting method for seismic survey proposed by the present invention;

[0084] Figure 5 A schematic diagram of a superimposed section in a geophysical exploration system for seismic survey proposed by the present invention;

[0085] Figure 6 This is a schematic diagram of a velocity spectrum diagram in a geophysical exploration system for seismic survey proposed by the present invention. DETAILED DESCRIPTION

[0086] The present invention will be further explained below in conjunction with specific embodiments.

[0087] Embodiment 1

[0088] Reference Figure 1 , 2 , 5 and 6, this embodiment proposes a geophysical exploration system for seismic survey, including a source and receiving point layout module, a data acquisition module, a data processing module, a three-dimensional imaging module, a data interpretation module, a comprehensive analysis module, auxiliary equipment and an early warning module;

[0089] The seismic source and receiving point layout module is used to arrange mechanical vibrators in a grid on the surface of the coal mine, with the mechanical vibrators serving as seismic source points, and to arrange seismic detector receiving points around the seismic source points, wherein the seismic detectors are arranged in a three-dimensional receiving array, and the seismic detectors convert the mechanical vibrations of the mechanical vibrators into electrical signals, and the distance between two adjacent mechanical vibrators is 100m-120m;

[0090] The auxiliary equipment is a GPS locator, which is installed on each earthquake source point and seismic detector. The GPS locator is used to accurately locate the position of the earthquake source point and the seismic detector;

[0091] The data acquisition module is used to receive the seismic wave signal of the seismic detection wave receiving point and the GPS position of the seismic detection wave;

[0092] The comprehensive analysis module combines the identified strata, faults, coal seams and oil and gas reservoir locations with multidisciplinary knowledge of geology, geochemistry and geophysics to conduct a comprehensive analysis and assess earthquake risks;

[0093] When evaluating, it uses information such as the thickness, depth and lithology of the strata, the location, activity and inclination of the fault plane, the location, size, reserves and development status of coal seams and oil and gas reservoirs, and the established three-dimensional seismic geological model containing strata, faults, coal seams and oil and gas reservoirs to calculate the stress distribution of strata and faults through numerical simulation. Based on the stress distribution, it conducts an earthquake risk level assessment. The risk levels assessed include: low risk: magnitude less than 4.0, low frequency; medium risk: magnitude between 4.0 and 6.0, medium frequency; high risk: magnitude greater than 6.0, high frequency;

[0094] When calculating stress distribution, the program code used is as follows:

[0095] import numpy as npimport scipy.sparse as spimport scipy.sparse.linalgas spla

[0096] def build_global_stiffness_matrix(nodes,elements,E,nu):

[0097] #Calculate the stiffness matrix of each element and assemble the global stiffness matrix

[0098] num_nodes = len(nodes)

[0099] K=sp.lil_matrix((2*num_nodes,2*num_nodes))

[0100] for element in elements:

[0101] K_e=compute_element_stiffness_matrix(element,E,nu)

[0102] for i in range(4):

[0103] for j in range(4):

[0104] K[2*element[i]:2*element[i]+2,2*element[j]:2*element[j]+2]+=K_e[2*i:2*i+2,2*j:2*j+2]

[0105] return K def compute_element_stiffness_matrix(element,E,nu):

[0106] #Calculate the stiffness matrix of a single quadrilateral element

[0107] #The specific implementation is omitted here, assuming that an 8x8 stiffness matrix is ​​returned

[0108] K_e = np.zeros((8,8))

[0109] return K_e

[0110] # Example node and cell data

[0111] nodes=[(0,0),(1,0),(1,1),(0,1)]

[0112] elements = [(0,1,2,3)]

[0113] #Material Properties

[0114] E=210e9#Young's modulus

[0115] nu=0.3#Poisson's ratio

[0116] #Assemble the global stiffness matrix

[0117] K=build_global_stiffness_matrix(nodes,elements,E,nu)

[0118] # Apply boundary conditions and external loads

[0119] F = np.zeros(2*len(nodes))

[0120] u = np.zeros(2*len(nodes)) # Specific implementation is omitted here

[0121] #Solve the linear equations

[0122] u = spla.spsolve(K,F)

[0123] # Post-processing of results # Calculate stress distribution;

[0124] The early warning module is used to issue an early warning to remind personnel when a high earthquake risk level is detected;

[0125] The data processing module includes a pre-processing module, a rapid analysis and overlay processing module, and an offset processing module;

[0126] The pre-processing module in the data processing module is used to remove interference from direct waves and surface waves from the received data using filtering technology, and to remove periodic noise using a frequency domain analysis method of Fourier transform. In addition, static correction is performed based on the arrival time of the first arrival wave to eliminate the influence of surface unevenness and receiver position differences, and a multiple wave removal algorithm is used to remove multiple waves.

[0127] The velocity analysis stacking processing module uses the velocity spectrum analysis method to construct a velocity model and stacks the seismic data of multiple excitations to improve the signal-to-noise ratio. The specific logical steps are as follows:

[0128] A: Select several representative common center point gathers and assume a series of different velocity models in the selected CMP gathers, where the common center point gather refers to the collection of all seismic records with the same center point, which is the midpoint between the source point and the receiving point, for example, the source point S1, the receiving point R1, and the center point M1 = (S1 + R1) / 2;

[0129] B: Perform conventional NMO correction on each assumed velocity, calculate the corrected common center point gathers, and stack the corrected common center point gathers to calculate the stacking energy at different velocities;

[0130] When performing conventional NMO correction, the formula used is: where t nmo represents the corrected time, t0 is the arrival time at zero offset, x is the offset, and v is the assumed velocity;

[0131] The formula used to calculate the superposition energy is:

[0132]

[0133] E(v)=∑ t (S(t,v)) 2 ;

[0134] Where S(t,v) is the superposition signal at time t and velocity v, d i (t nmo (x i ,v)) is the i-th record at time t nmo The amplitude value under , N is the number of records in the common center point gather, E(v) is the superposition energy under the assumed velocity v, ∑t represents the sum of all time sampling points;

[0135] C: Plot the superposition energy corresponding to different speeds into a velocity spectrum (such as Figure 6 As shown), the horizontal axis is speed and the vertical axis is time;

[0136] For example: Assume a series of speed values ​​v1, v2, ..., vm , perform NMO correction on each record in the common center point gather to obtain the corrected data d i (t nmo (x i ,v j )), superimpose the corrected data to obtain the velocity v j The superimposed signal S(t,v j ), for each speed v j , calculate the superposition energy E(v j )=∑ t (S(t,v j )) 2 , the superposition energy E(v j ) is plotted as a velocity spectrum;

[0137] D: Identify the peaks with the highest energy on the speed spectrum. These peaks correspond to the possible true speeds, and select the speed value with the highest energy as the optimal speed for that time period.

[0138] E: According to the optimal speed value, a speed model is constructed, and the speed model is a speed-time curve diagram;

[0139] The migration processing module uses the constructed velocity model to perform time migration processing on the seismic data, convert the data from the time domain to the depth domain, and correct the propagation path of the seismic wave. The program code used during its operation is as follows:

[0140] <Input seismic data and velocity model>

[0141] import seismic_data_handler

[0142] data=seismic_data_handler.load_data('input_data.segy')

[0143] velocity_model=seismic_data_handler.load_velocity_model('velocity_model.txt')

[0144] <Select offset algorithm>

[0145] from seismic_migration import KirchhoffMigration

[0146] migration_processor=KirchhoffMigration(data,velocity_model)

[0147] <Initial offset>

[0148] initial_image = migration_processor.run_initial_migration()

[0149] residuals = migration_processor.analyze_residuals(initial_image)

[0150] velocity_model = migration_processor.update_velocity_model(residuals)

[0151] <Refinement processing>

[0152] for i in range(num_iterations):

[0153] image = migration_processor.run_migration(velocity_model)

[0154] residuals = migration_processor.analyze_residuals(image) velocity_model = migration_processor.update_velocity_model(residuals)

[0155] <Final offset processing>

[0156] final_image = migration_processor.run_final_migration(velocity_model)

[0157] attributes = seismic_data_handler.extract_attributes(final_image)

[0158] <Output and storage>

[0159] seismic_data_handler.save_image(final_image,

[0160] 'final_image.segy')

[0161] seismic_data_handler.save_attributes(attributes,

[0162] 'attributes.txt');

[0163] Through the above program code, the constructed velocity model can be effectively used to perform time migration processing, convert seismic data from the time domain to the depth domain, correct the propagation path of seismic waves, and finally obtain high-precision underground structure imaging results;

[0164] The three-dimensional imaging module includes a three-dimensional superposition imaging module and a reverse time migration module;

[0165] The three-dimensional stacking imaging module converts the three-dimensional seismic data into an image of the underground reflection surface by stacking processing, wherein the image of the underground reflection surface is a stacking profile generated by using the data after stacking processing, (such as Figure 5 The X-axis and Y-axis in the stacked section represent the spatial position of the seismic data in the X-direction and Y-direction respectively, and the Z-axis represents the time (i.e., the two-way time of the arrival of the seismic wave). The stacked section shows the reflection information that changes with time, reflecting the preliminary form of the underground structure.

[0166] The reverse time migration module applies the reverse time migration technology and can more accurately restore the underground structure and further improve the imaging quality by simulating the propagation process of seismic waves using the wave equation. The specific steps are as follows:

[0167] (1) Starting from the earthquake source, by numerically solving the wave equation, the propagation of seismic waves in the underground medium is simulated to generate a forward propagating wave field, the order of which is: earthquake source point -> bottom layer -> reflection surface -> seismic detector;

[0168] (2) Starting from the receiving point (seismic record), the seismic waves are propagated in the reverse direction of time to generate the reverse propagating wave field, the order of which is: seismic detector -> reflection surface -> bottom layer -> source point;

[0169] (3) The forward propagation and reverse propagation wave fields are intersected at each time step to form imaging conditions and generate high-resolution underground structure images;

[0170] The wave equation formula is:

[0171]

[0172] Where u(x,y,z,t) is the displacement at position (x,y,z) and time t, u represents displacement, which indicates the offset of the medium at that point, x, y, z are spatial coordinates, indicating the position in three-dimensional space, and t represents time. The partial derivative symbol represents the derivative with respect to a specific variable. The second-order partial derivative of displacement with respect to time represents acceleration, v represents wave velocity, is the second-order partial derivative of the displacement with respect to the Z coordinate, indicating the bending in the Z direction, is the second-order partial derivative of the displacement with respect to the Y coordinate, indicating the bending in the Y direction, is the second-order partial derivative of the displacement with respect to the z coordinate, representing the bending in the z direction;

[0173] The data interpretation module includes a three-dimensional visualization module and a geological interpretation module;

[0174] The three-dimensional visualization module uses professional geophysical software to visualize the stacked three-dimensional seismic data and generate a three-dimensional seismic geological model and profile;

[0175] The geological interpretation module combines geological knowledge and other geophysical data to perform geological interpretation on the generated three-dimensional seismic geological model and profile, and identifies strata, faults, coal seams and oil and gas reservoirs;

[0176] This embodiment increases the density of receiving points and combines the velocity analysis and stacking processing module to perform stacking and correction processing on the data, thereby obtaining data with high quality, signal-to-noise ratio and accuracy. At the same time, combined with the reverse time migration technology, the underground structure can be accurately restored, the imaging quality can be improved, and the subsequent interpretation and analysis work of personnel can be more conducive to improving the accuracy of exploration and facilitating personnel to more accurately reveal the underground geological structure.

[0177] Embodiment 2

[0178] Reference Figure 3-4 This embodiment proposes a geophysical exploration method for seismic survey, comprising the following steps:

[0179] S1: The seismic source and receiving point layout module is used to layout the seismic source points on the surface according to the designed grid, and dense seismic detection wave receiving points are arranged around the seismic source points. The receiving points form a three-dimensional receiving array, where the seismic source point is a mechanical vibrator, and the designed grid can be a 10x10 grid, with a total of 100 seismic source points, and the spacing between each seismic source point is 100m-120m;

[0180] S2: The auxiliary equipment uses GPS locator to accurately locate the earthquake source point and the location of the seismic detector;

[0181] S3: According to the designed excitation sequence and time, the seismic sources are excited one by one, and the seismic wave signals of the receiving points are synchronously recorded through the data acquisition module. The seismic sources are excited point by point according to the arrangement order of the seismic source points, and the excitation duration of each seismic source point is 10 seconds, with an interval of 30 seconds;

[0182] In addition, the activation sequence and schedule are as follows:

[0183] Serial number Epicenter number Excitation time 1 1 08:00:00-08:00:10 2 2 08:00:40-08:00:50 …… …… …… 99 99 09:39:20-09:39:30 100 100 09:40:00-09:40:10 ;

[0184] S4: The preprocessing module preprocesses the seismic wave signal received in S3 to improve the data quality, and superimposes the seismic data of multiple excitations through the velocity analysis and superposition processing module to improve the signal-to-noise ratio;

[0185] S5: The offset processing module performs offset processing on the superimposed data, corrects the seismic wave propagation path, and obtains the position of the underground reflection surface;

[0186] S6: The 3D stacking imaging module converts 3D seismic data into images of underground reflection surfaces through stacking processing, and the reverse time migration module applies reverse time migration technology to further improve the imaging quality;

[0187] S7: The 3D visualization module uses professional geophysical software to visualize the stacked 3D seismic data and generate 3D seismic geological models and profiles;

[0188] S8: The geological interpretation module combines geological knowledge to interpret the generated 3D seismic geological model, profile and underground reflection surface images to identify strata, faults, coal seams and oil and gas reservoirs;

[0189] S9: The comprehensive analysis module combines the identified strata, faults, coal seams and oil and gas reservoir locations with multidisciplinary knowledge of geology, geochemistry and geophysics to conduct a comprehensive analysis, assess earthquake risks, and issue timely warnings through the early warning module.

[0190] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A geophysical exploration system for seismic survey, characterized in that: It includes the module for setting up the source and receiving points, the module for data acquisition, the module for data processing, the module for three-dimensional imaging, the module for data interpretation, the module for comprehensive analysis, the auxiliary equipment and the module for early warning; The data processing module includes a pre-processing module, a rapid analysis and overlay processing module, and an offset processing module; The three-dimensional imaging module includes a three-dimensional superposition imaging module and a reverse time migration module; The data interpretation module includes a three-dimensional visualization module and a geological interpretation module.

2. A geophysical exploration system for seismic survey according to claim 1, characterized in that: The seismic source and receiving point layout module is used to arrange mechanical vibrators in a grid on the surface of the coal mine, with the mechanical vibrators serving as seismic source points, and to arrange seismic detector receiving points around the seismic source points, wherein the seismic detectors are arranged in a three-dimensional receiving array, and the seismic detectors convert the mechanical vibrations of the mechanical vibrators into electrical signals, and the distance between two adjacent mechanical vibrators is 100m-120m; The auxiliary equipment is a GPS locator, which is installed on each earthquake source point and seismic detector. The GPS locator is used to accurately locate the position of the earthquake source point and the seismic detector.

3. A geophysical exploration system for seismic survey according to claim 1, characterized in that: The data acquisition module is used to receive the seismic wave signal of the seismic detection wave receiving point and the GPS position of the seismic detection wave; The preprocessing module in the data processing module is used to remove the interference of direct waves and surface waves from the received data by using filtering technology, and to remove periodic noise by using the frequency domain analysis method of Fourier transform, and to perform static correction according to the arrival time of the first arrival wave to eliminate the influence of the uneven surface and the difference in the position of the receiver, and to remove multiple waves by using the multiple wave removal algorithm; The velocity analysis stacking processing module uses the velocity spectrum analysis method to construct a velocity model and stacks the seismic data of multiple excitations to improve the signal-to-noise ratio. The specific logical steps are as follows: A: Select several representative common center point gathers and assume a series of different velocity models in the selected CMP gathers, where the common center point gather refers to the collection of all seismic records with the same center point, which is the midpoint between the source point and the receiving point, for example, the source point S1, the receiving point R1, and the center point M1 = (S1 + R1) / 2; B: Perform conventional NMO correction on each assumed velocity, calculate the corrected common center point gathers, and stack the corrected common center point gathers to calculate the stacking energy at different velocities; When performing conventional NMO correction, the formula used is: where t nmo represents the corrected time, t0 is the arrival time at zero offset, x is the offset, and v is the assumed velocity; The formula used to calculate the superposition energy is: E(v)=∑ t (S(t,v)) 2 ; Where S(t, v) is the superposition signal at time t and velocity v, d i (t nmo (x i , v)) is the i-th record at time t nmo The amplitude value under , N is the number of records in the common center point gather, E(v) is the superposition energy under the assumed velocity v, ∑t represents the sum of all time sampling points; C: Plot the superposition energy corresponding to different speeds into a speed spectrum, with the horizontal axis being speed and the vertical axis being time; D: Identify the peaks with the highest energy on the speed spectrum. These peaks correspond to the possible true speeds, and select the speed value with the highest energy as the optimal speed for that time period. E: According to the optimal speed value, a speed model is constructed, and the speed model is a speed-time curve diagram; The migration processing module uses the constructed velocity model to perform time migration processing on the seismic data, convert the data from the time domain to the depth domain, and correct the propagation path of the seismic wave.

4. A geophysical exploration system for seismic survey according to claim 1, characterized in that: The three-dimensional stacking imaging module converts the three-dimensional seismic data into an image of an underground reflection surface by stacking processing, wherein the image of the underground reflection surface is a stacking profile generated by using the data after the stacking processing; The X-axis and Y-axis in the stacked section represent the spatial position of the seismic data in the X-direction and Y-direction respectively, and the Z-axis represents the time (i.e., the two-way time of the arrival of the seismic wave). The stacked section shows the reflection information that changes with time, reflecting the preliminary form of the underground structure. The reverse time migration module applies the reverse time migration technology and can more accurately restore the underground structure and further improve the imaging quality by simulating the propagation process of seismic waves using the wave equation. The specific steps are as follows: (1) Starting from the earthquake source, by numerically solving the wave equation, the propagation of seismic waves in the underground medium is simulated to generate a forward propagating wave field; (2) Starting from the receiving point (seismic record), the seismic waves are propagated in the reverse direction of time to generate a wave field that propagates in the reverse direction; (3) The forward propagation and reverse propagation wave fields are intersected at each time step to form imaging conditions and generate high-resolution underground structure images; The wave equation formula is: Where u(x, y, z, t) is the displacement at position (x, y, z) and time t, u represents displacement, which indicates the offset of the medium at that point, x, y, z are spatial coordinates, indicating the position in three-dimensional space, and t represents time. The partial derivative symbol represents the derivative with respect to a specific variable. The second-order partial derivative of displacement with respect to time represents acceleration, v represents wave velocity, is the second-order partial derivative of the displacement with respect to the Z coordinate, indicating the bending in the Z direction, is the second-order partial derivative of the displacement with respect to the Y coordinate, indicating the bending in the Y direction, is the second-order partial derivative of the displacement with respect to the z-coordinate, representing the bending in the z-direction.

5. A geophysical exploration system for seismic survey according to claim 1, characterized in that: The three-dimensional visualization module uses professional geophysical software to visualize the stacked three-dimensional seismic data and generate a three-dimensional seismic geological model and a profile diagram; The geological interpretation module combines geological knowledge and other geophysical data to perform geological interpretation on the generated three-dimensional seismic geological model and profile, and identifies strata, faults, coal seams and oil and gas reservoirs.

6. A geophysical exploration system for seismic survey according to claim 1, characterized in that: The comprehensive analysis module combines the identified strata, faults, coal seams and oil and gas reservoir locations with multidisciplinary knowledge of geology, geochemistry and geophysics to conduct a comprehensive analysis and assess earthquake risks; The early warning module is used to issue an early warning to remind personnel when a high earthquake risk level is detected.

7. A geophysical method for seismic survey, characterized in that: The following steps are involved: S1: The seismic source and receiving point layout module is used to layout the seismic source points on the surface according to the designed grid, and dense seismic detection wave receiving points are arranged around the seismic source points, and the receiving points form a three-dimensional receiving array; S2: The auxiliary equipment uses GPS locator to accurately locate the earthquake source point and the location of the seismic detector; S3: According to the designed excitation sequence and time, the seismic sources are excited one by one, and the seismic wave signals of the receiving points are synchronously recorded through the data acquisition module; S4: The preprocessing module preprocesses the seismic wave signal received in S3 to improve the data quality, and superimposes the seismic data of multiple excitations through the velocity analysis and superposition processing module to improve the signal-to-noise ratio; S5: The offset processing module performs offset processing on the superimposed data, corrects the seismic wave propagation path, and obtains the position of the underground reflection surface; S6: The 3D stacking imaging module converts 3D seismic data into images of underground reflection surfaces through stacking processing, and the reverse time migration module applies reverse time migration technology to further improve the imaging quality; S7: The 3D visualization module uses professional geophysical software to visualize the stacked 3D seismic data and generate 3D seismic geological models and profiles; S8: The geological interpretation module combines geological knowledge to interpret the generated 3D seismic geological model, profile and underground reflection surface images to identify strata, faults, coal seams and oil and gas reservoirs; S9: The comprehensive analysis module combines the identified strata, faults, coal seams and oil and gas reservoir locations with multidisciplinary knowledge of geology, geochemistry and geophysics to conduct a comprehensive analysis, assess earthquake risks, and issue timely warnings through the early warning module.

8. A geophysical prospecting method for seismic survey according to claim 7, characterized in that: In the S1, the seismic source point is a mechanical vibrator, and the designed grid may be a 10x10 grid, with a total of 100 seismic source points, and the spacing between each seismic source point is 100m-120m.

9. A geophysical exploration method for seismic survey according to claim 7, characterized in that: In S3, the earthquake source points are excited point by point according to the arrangement order of the earthquake source points, and the excitation duration of each earthquake source point is 10 seconds and the interval time is 30 seconds; In addition, the activation sequence and schedule are as follows: 。

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