Geological structure imaging method, device, equipment and medium

Abstract

The invention relates to the technical field of seismic exploration, and discloses a geologic structure imaging method, device, equipment and medium, seismic wave velocity distribution data and quality factor distribution data corresponding to a target area can be acquired, and the viscous sound vertical wave number is determined according to the seismic wave velocity distribution data and the quality factor distribution data; inputting the viscous sound vertical wave number into a constructed pressure wave field determination model to determine pressure wave field distribution data corresponding to the target region; wherein the pressure wave field determination model is constructed based on the viscoelastic property of an underground medium and a viscoacoustic propagation operator of matrix decomposition; and performing geologic structure imaging on the target area by using the pressure wave field distribution data to obtain a geologic structure imaging result of the target area. According to the method, wave field information can be reserved to a greater extent, and the imaging resolution of a geological structure and the imaging quality of an underground deep part are improved.

Description

Technical Field

[0001] The present invention relates to the field of seismic exploration technology, and in particular to a geological structure imaging method, device, equipment and medium. Background Art

[0002] With the development of science and technology, seismic exploration technology is constantly improving.

[0003] The relevant technology can be used to conduct seismic exploration in a designated area, send seismic waves to the geological structure in the designated area, collect corresponding seismic wave data, regard the underground medium in the designated area as having completely elastic properties, and perform offset imaging based on the seismic wave data to obtain geological structure imaging. Geological structure imaging can be used to provide detailed information on underground geological structures, helping technicians understand the distribution, thickness, morphology and mutual relationship of strata, and can also be used to determine the location and characteristics of potential reservoirs and ore bodies, and evaluate the reserves and recoverability of resources.

[0004] However, the resolution of geological structure imaging in related technologies is low. Summary of the invention

[0005] The present invention provides a geological structure imaging method, device, equipment and medium, which are used to solve the defect of low resolution of geological structure imaging in related technologies and improve the resolution of geological structure imaging.

[0006] In a first aspect, the present invention provides a geological structure imaging method, comprising: Obtain seismic wave velocity distribution data and quality factor distribution data corresponding to the target area; Determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; Inputting the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; The pressure wave field distribution data is used to perform geological structure imaging of the target area to obtain a geological structure imaging result of the target area.

[0007] Optionally, the seismic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is an acoustic wave medium; The quality factor distribution data includes quality factor data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is an acoustic wave medium.

[0008] Optionally, determining the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data includes: Determine viscoacoustic wave velocity distribution data according to the seismic wave velocity distribution data; wherein the viscoacoustic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is a viscoacoustic medium; determining viscoacoustic parameters according to the quality factor distribution data; The viscoacoustic vertical wave number is determined according to the viscoacoustic wave velocity distribution data and the viscoacoustic parameter.

[0009] Optionally, the process of constructing the pressure wave field determination model includes: Under the condition that the underground medium of the target area is a viscoacoustic medium, a viscoacoustic wave equation for seismic wave propagation is established; Performing Fourier transformation on the viscoacoustic wave equation to obtain a corresponding frequency domain equation; Transforming the frequency domain equation to obtain a viscoacoustic wave equation of a two-dimensional viscoacoustic medium in a frequency domain space domain; Under the condition that the preset assumption conditions are met, the viscoacoustic wave equation of the two-dimensional viscoacoustic medium is decomposed to obtain a decomposed equation; Determining a viscoacoustic Helmholtz operator based on the decomposed equation; Performing eigenvalue decomposition on the viscoacoustic Helmholtz operator to obtain an eigenvalue decomposition result; A pressure wave field value solution equation is determined based on the eigenvalue decomposition result and used as the pressure wave field determination model.

[0010] Optionally, the viscoacoustic wave equation of the two-dimensional viscoacoustic medium is:

[0011]

[0012]

[0013] in, is the pressure field wave, is the coordinate of the depth direction in the underground space, Sampling frequency, is the propagation speed of seismic waves in viscoacoustic media, is an imaginary unit, is the reference frequency of the viscoacoustic medium, is the viscoacoustic parameter, is the horizontal coordinate in the underground space; is the propagation speed of seismic waves in the acoustic medium, is the quality factor.

[0014] Optionally, the viscoacoustic Helmholtz operator is:

[0015] in, is the viscoacoustic Helmholtz operator.

[0016] Optionally, the pressure wave field determination model is:

[0017]

[0018] in, is the depth step, is the wavefield propagation operator, is the viscoacoustic vertical wave number.

[0019] In a second aspect, the present invention provides a geological structure imaging device, comprising: An acquisition unit, used to acquire seismic wave velocity distribution data and quality factor distribution data corresponding to the target area; A determination unit, configured to determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; An input unit, used for inputting the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; An imaging unit is used to perform geological structure imaging of the target area using the pressure wave field distribution data to obtain a geological structure imaging result of the target area.

[0020] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the geological structure imaging method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0021] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the geological structure imaging method of the first aspect or any corresponding embodiment thereof.

[0022] The geological structure imaging method, device, equipment and medium provided by the present invention can obtain the seismic wave velocity distribution data and quality factor distribution data corresponding to the target area, determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; input the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; use the pressure wave field distribution data to perform geological structure imaging on the target area, and obtain the geological structure imaging result of the target area. The present invention can retain the wave field information to a greater extent, improve the resolution of geological structure imaging and the quality of deep underground imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A flow chart of a geological structure imaging method provided by an embodiment of the present invention; Figure 2 A velocity model of a two-dimensional undulation model provided by an embodiment of the present invention; Figure 3 A quality factor model of a two-dimensional fluctuation model provided by an embodiment of the present invention; Figure 4 An underground structure imaging result generated according to acoustic wave data and an acoustic wave propagation operator based on matrix decomposition is provided in an embodiment of the present invention; Figure 5 An underground structure imaging result generated by a viscoacoustic propagation operator based on viscoacoustic data and matrix decomposition is provided in an embodiment of the present invention; Figure 6 An underground structure imaging result generated by an acoustic wave propagation operator based on viscoacoustic data and matrix decomposition is provided in an embodiment of the present invention; Figure 7 A waveform comparison schematic diagram provided by an embodiment of the present invention; Figure 8 Another waveform comparison schematic diagram provided for an embodiment of the present invention; Fig. 9 Another waveform comparison schematic diagram provided for an embodiment of the present invention; Fig.10 A schematic diagram of another waveform comparison provided by an embodiment of the present invention; Fig.11A schematic structural diagram of a geological structure imaging device provided by an embodiment of the present invention; Fig.12 A schematic diagram of the structure of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Combine the following Figure 1-Figure 10 The geological structure imaging method of the present invention is described.

[0027] like Figure 1 As shown, this embodiment proposes a first geological structure imaging method, which may include the following steps: S101. Obtain seismic wave velocity distribution data and quality factor distribution data corresponding to the target area.

[0028] The target area is a region where geological structure imaging is required. It is understandable that in this embodiment, geological structure imaging can be performed on the target area.

[0029] Optionally, the seismic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area.

[0030] The quality factor distribution data includes the quality factor data at different spatial positions during the propagation of seismic waves in the underground medium of the target area.

[0031] Specifically, in this embodiment, seismic detectors and exciting seismic wave sources can be arranged in the target area, seismic waves can be emitted to the geological structure of the target area, and information about the propagation of seismic waves underground can be recorded to achieve seismic exploration of the target area. Afterwards, in this embodiment, seismic instruments can be used to collect seismic wave data, including data such as the arrival time and amplitude of the seismic waves. In this embodiment, the collected seismic wave data can be preprocessed, including operations such as removing noise, correcting signals, and extracting features, so as to improve data quality and availability.

[0032] Specifically, this embodiment can use the wave propagation time and distance information in the preprocessed seismic wave data to calculate the propagation velocity of the seismic wave at each spatial position in the underground medium through velocity analysis, wherein the velocity analysis method can be ray tracing and wave equations.

[0033] Specifically, this embodiment can process the preprocessed seismic wave data based on amplitude attenuation, frequency change or seismic wave propagation characteristics to obtain the quality factor of the seismic wave at each spatial position in the underground medium.

[0034] S102. Determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data.

[0035] Optionally, step S102 may include: Determine viscoacoustic wave velocity distribution data according to the seismic wave velocity distribution data; wherein the viscoacoustic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is a viscoacoustic medium; Determine viscoacoustic parameters based on quality factor distribution data; The viscoacoustic vertical wave number is determined based on the viscoacoustic wave velocity distribution data and viscoacoustic parameters.

[0036] S103, inputting the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition.

[0037] The inventor of the present invention has found that in the related art, when performing underground structure imaging, the viscoelastic information of the underground medium is ignored, and the underground medium is regarded as an ideal medium to process the underground structure imaging of seismic wave data, resulting in a low resolution of underground structure imaging, which may even affect the seismic interpretation work in serious cases. This embodiment no longer regards the underground medium as an ideal medium, but introduces viscoacoustic properties to fully grasp the medium information, constructs a wave equation formula for viscoacoustic media, improves the resolution of underground structure imaging, and retains wave field information to a greater extent, and significantly improves the quality of deep underground imaging.

[0038] Specifically, in this embodiment, a pressure wave field determination model may be constructed first. Optionally, the process of constructing the pressure wave field determination model includes: Considering that the underground medium in the target area is a viscoacoustic medium, the viscoacoustic wave equation of seismic wave propagation is established; Perform Fourier transform on the viscoacoustic wave equation to obtain the corresponding frequency domain equation; The frequency domain equation is transformed to obtain the viscoacoustic wave equation of the two-dimensional viscoacoustic medium in the frequency space domain; Under the condition that the preset assumptions are met, the viscoacoustic wave equation of the two-dimensional viscoacoustic medium is decomposed to obtain the decomposed equation; Determine the viscoacoustic Helmholtz operator based on the decomposed equation; Perform eigenvalue decomposition on the viscoacoustic Helmholtz operator to obtain the eigenvalue decomposition result; The pressure wave field value solution equation is determined based on the eigenvalue decomposition result and used as the pressure wave field determination model.

[0039] The inventors of the present invention have found that the underground medium is not an ideal homogeneous medium, nor does it have completely elastic properties. Therefore, in seismic exploration, the propagation of seismic waves underground often causes energy attenuation and dispersion. This is reflected in seismic records as amplitude drop and waveform distortion. If these seismic records are directly used for migration processing without considering viscoelastic attenuation, the quality and resolution of the imaging will be reduced. In severe cases, it will lead to insufficient lighting in the attenuation area and below, and incorrect migration depth. Therefore, in the process of migration imaging, it is very necessary to perform attenuation compensation for the strong attenuation medium area.

[0040] Specifically, this embodiment can consider the viscoelastic properties of the underground medium and establish the viscoacoustic wave equation for seismic wave propagation:

[0041]

[0042]

[0043] in, is the pressure field wave, For time, is the viscoacoustic parameter, is the propagation speed of seismic waves in viscoacoustic media. is the reference frequency of the visco-acoustic medium and is the standard frequency value of the set visco-acoustic medium. is the Laplace operator. is the propagation speed of seismic waves in the acoustic medium. is the quality factor.

[0044] Among them, when As it approaches infinity, is 0. At this time, the formula degenerates into the acoustic wave equation in the related art.

[0045] Specifically, in this embodiment, formula (1) can be transformed into the frequency domain by Fourier transform to obtain the corresponding frequency domain equation:

[0046] in, Is an imaginary unit.

[0047] Afterwards, this embodiment can transform formula (4) to obtain the viscoacoustic wave equation of the two-dimensional viscoacoustic medium in the frequency space domain:

[0048] in, is the coordinate of the depth direction in the underground space, Sampling frequency, It is the horizontal coordinate in the underground space.

[0049] It should be noted that the acoustic wave equation in the related art is:

[0050] Comparing formula (5) with formula (6), the derived viscoacoustic wave equation realizes viscoacoustic compensation by introducing the viscoacoustic compensation term.

[0051] Taking the derived viscoacoustic wave equation of a two-dimensional viscoacoustic medium as an example, usually only the depth direction is considered as the main propagation direction of the seismic wave. When the seismic wave extends downward at a certain depth interval, within a depth step interval, the velocity of the medium only changes horizontally but not vertically. Based on this assumption, formula (5) can be decomposed into:

[0052] Take the following traveling wave propagation equation as an example, which is written as:

[0053] Therefore, the viscoacoustic vertical wave number is defined as:

[0054] The vertical wave number of the sound wave based on the sound wave equation in the relevant technology is:

[0055] By comparing the viscoacoustic vertical wave number with the acoustic wave vertical wave number of the acoustic wave equation in the related art, the viscoacoustic vertical wave number defined in this embodiment realizes viscoacoustic compensation by introducing a viscoacoustic compensation term.

[0056] In this embodiment, the Helmholtz operator can be defined as L Written as:

[0057] Combining the acoustic wave vertical wave number and the Helmholtz operator of the acoustic wave equation in the relevant technology, we can get:

[0058] At this time, the viscoacoustic Helmholtz operator based on the viscoacoustic medium It can be written as:

[0059] in, is the viscoacoustic Helmholtz operator.

[0060] Specifically, in this embodiment, the parameters can be determined based on the seismic velocity distribution data and the quality factor distribution data. and , then the parameters and Substituting into the formula, we can obtain the viscoacoustic Helmholtz operator.

[0061] It should be noted that the viscoacoustic Helmholtz operator is a symmetric matrix, and its eigenvalue decomposition is expressed as:

[0062] During the calculations, positive eigenvalues ​​are retained while negative eigenvalues ​​are removed in order to suppress evanescent waves.

[0063] The extrapolation equation of the wave field along the depth is written as:

[0064] in, is the depth step, is the wavefield propagation operator.

[0065] Specifically, in this embodiment, the eigenvalue decomposition formula of the viscoacoustic Helmholtz operator can be substituted into the extrapolation equation of the wave field along the depth, so as to obtain the pressure wave field at any depth.

[0066] In addition, substituting the Euler formula into the formula, the extrapolation equation of the wave field along the depth can be written in another form:

[0067] It can be understood that the pressure wave field determination model includes:

[0068]

[0069] In this embodiment, the viscoacoustic vertical wave number can be input into the constructed pressure wave field determination model, so that the pressure wave field distribution data obtained by the pressure wave field determination model through calculation can be obtained.

[0070] S104: Use the pressure wave field distribution data to perform geological structure imaging of the target area to obtain a geological structure imaging result of the target area.

[0071] Specifically, after obtaining the pressure wave field distribution data, this embodiment can perform offset imaging based on the pressure wave field distribution data to obtain geological structure imaging of the target area, improve the resolution of geological structure imaging, and retain the wave field information to a greater extent, thereby significantly improving the quality of deep underground imaging.

[0072] The geological structure imaging method proposed in this embodiment can obtain the seismic wave velocity distribution data and quality factor distribution data corresponding to the target area, determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; input the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; use the pressure wave field distribution data to perform geological structure imaging on the target area, and obtain the geological structure imaging result of the target area. This embodiment can retain the wave field information to a greater extent, improve the resolution of geological structure imaging and the quality of deep underground imaging.

[0073] In order to better introduce the geological structure imaging method proposed in this embodiment, this embodiment proposes the following Example 1, which applies the geological structure imaging method of this embodiment to a two-dimensional undulating model and explains the application process.

[0074] Example 1, Figure 2 and Figure 3 They are the velocity model of the two-dimensional undulation model and the corresponding quality factor model, Figure 2 and Figure 3 The x in the figure represents the horizontal coordinate, and the depth represents the depth coordinate. Figure 2 The filling color in the figure indicates the magnitude of the phase velocity. Different colors correspond to different magnitudes of phase velocities. The phase velocity indicates the propagation speed of seismic waves in the acoustic wave medium. Figure 3 The filling color in represents the size of the quality factor, and different colors correspond to different sizes of quality factors. The size of the two-dimensional undulation model is 1250 meters in depth and 1000 meters in the horizontal direction. The two-dimensional undulation model contains multiple layers of undulating interfaces, and the speed of each layer is uniform. The minimum speed of the model is 1500 meters per second and the maximum speed is 2300 meters per second. The gun set records a total of 100 guns, with a gun spacing of 2 channels. Each gun is equipped with 60 detectors, the channel spacing is 5 meters, the minimum gun detection distance is 0 meters, the sampling time interval is 0.0005 seconds, the sampling length is 2 seconds, the velocity model grid spacing is 5 meters in depth and 5 meters in horizontal length, and the extension depth is 1250 meters. The source uses a Ricker wavelet with a main wavelet frequency of 20 Hz, and determines the underground structure imaging results corresponding to the two-dimensional undulation model based on the relevant technology and the geological structure imaging method of this embodiment.

[0075] The final offset result is Figure 4 , Figure 5 and Figure 6 As shown, Figure 4 , Figure 5 and Figure 6 The x in the figure represents the horizontal coordinate, the depth represents the depth coordinate, and the grayscale intensity represents the amplitude of the imaging result. The darker the color, the larger the amplitude. Figure 4is the underground structure imaging result generated based on the acoustic wave data and the acoustic wave propagation operator based on matrix decomposition (i.e., the underground structure imaging result generated by the related technology), Figure 5 is an underground structure imaging result generated based on viscoacoustic data and a viscoacoustic propagation operator based on matrix decomposition (that is, an underground structure imaging result generated by the geological structure imaging method proposed in this embodiment), Figure 6 It is the underground structure imaging result generated based on viscoacoustic data and the acoustic wave propagation operator based on matrix decomposition (the underground structure imaging result generated by combining the relevant technology and the geological structure imaging method proposed in this embodiment). It can be seen that for the two-dimensional undulating model, the migration results of the viscoacoustic propagation operator based on matrix decomposition and the acoustic wave propagation operator based on matrix decomposition can accurately reflect the actual situation of the stratum.

[0076] However, the results obtained from the viscoacoustic data and the acoustic wave propagation operator based on matrix decomposition show that the imaging energy is weak in the deep. In order to intuitively show the compensation effect of the viscoacoustic propagation operator based on matrix decomposition on the attenuated seismic waveform, the waveforms with horizontal coordinates of 400 and 800 meters can be selected for comparison. The waveform comparison display of 400 meters can be seen in Figure 7 and Figure 8 , Figure 7 and Figure 8 The vertical axis amplitude represents the amplitude. Figure 7 Waveform comparison for x=400m (a) Schematic diagram of the visco-acoustic compensation effect (the blue line is the acoustic wave data using the acoustic wave propagation operator based on matrix decomposition, and the red line is the visco-acoustic data using the visco-acoustic propagation operator based on matrix decomposition). Figure 8 The following is an illustration of the result without compensation (the blue line is the acoustic wave data using the acoustic wave propagation operator based on matrix decomposition, and the red line is the visco-acoustic data using the acoustic wave propagation operator based on matrix decomposition).

[0077] The waveform comparison display of 800 meters can be seen in Fig. 9 and Fig.10 . Fig. 9 Waveform comparison for x=800m (a) Schematic diagram of visco-acoustic compensation effect (the blue line is the acoustic wave data using the acoustic wave propagation operator based on matrix decomposition, and the red line is the visco-acoustic data using the visco-acoustic propagation operator based on matrix decomposition). Fig.10 The following is an illustration of the result without compensation (the blue line is the acoustic wave data using the acoustic wave propagation operator based on matrix decomposition, and the red line is the visco-acoustic data using the acoustic wave propagation operator based on matrix decomposition).

[0078] It can be seen that the waveform of the viscoacoustic propagation operator based on matrix decomposition is very close to the acoustic wave propagation operator based on matrix decomposition, which means that the viscoacoustic propagation operator based on matrix decomposition has a good compensation effect on the attenuated seismic waveform. At the same time, the viscoacoustic data is processed using the program of the acoustic wave propagation operator based on matrix decomposition in the related technology, and the resolution of the obtained offset result is significantly reduced. The failure to use the viscoacoustic propagation operator based on matrix decomposition for compensation causes the waveform information of the seismic wave to be seriously distorted. Further analysis Figure 8 and Fig.10 The waveform of the viscoacoustic data was found to have not only amplitude attenuation, but also phase dispersion when the viscoacoustic propagation operator based on matrix decomposition was used to obtain the results. This is due to the viscoelasticity of the formation, so the migration results are not accurate. This shows that the viscoacoustic propagation operator based on matrix decomposition has a positive effect on compensating the attenuated seismic waveform. After considering the viscosity of the medium, the corresponding viscoacoustic propagation operator based on matrix decomposition must also be used for processing to obtain accurate migration results.

[0079] This embodiment can be verified by using the Marmousi model. Combined with the velocity model and quality factor of the Marmousi model, the size of the Marmousi model is 1875 meters in depth and 12,500 meters in the horizontal direction. The model includes complex structures such as faults and synclines. The minimum velocity of the model is 1500m / s and the maximum velocity is 5500m / s. The shot collection records a total of 120 shots, with 8 tracks between shots, 240 detectors for each shot, 8m between tracks, the minimum shot offset is 0m, the sampling interval is 0.0005s, the sampling length is 3s, the velocity model grid spacing is 8m in depth and 8m in horizontal length, and the extension depth is 1875m. The source uses a Ricker wavelet with a main wavelet frequency of 20Hz, and determines the underground structure imaging results corresponding to the two-dimensional undulation model based on the relevant technology and the geological structure imaging method of this embodiment.

[0080] According to the final migration results, it can be seen that for the Marmousi model, the migration results of the viscoacoustic propagation operator based on matrix decomposition are basically consistent with the migration effect of the acoustic wave propagation operator based on matrix decomposition in the related art, and both can accurately reflect the actual situation of the underground medium, and the details are clear. In addition, the migration results of the viscoacoustic propagation operator based on matrix decomposition are significantly better than the acoustic wave propagation operator based on matrix decomposition in the imaging of complex structures. However, the results obtained by using the acoustic wave propagation operator based on matrix decomposition with viscoacoustic data show that the imaging energy at the deep complex structure is weak, and the resolution is significantly reduced. In order to intuitively reflect the compensation effect of the viscoacoustic propagation operator based on matrix decomposition on the attenuated seismic waveform, the present embodiment can select waveforms with horizontal coordinates of 4800, 5600, and 6400m for comparison. According to the comparison results, it can be determined that for complex models, the waveform of the viscoacoustic propagation operator based on matrix decomposition can also be close to the acoustic wave propagation operator based on matrix decomposition, which means that the viscoacoustic propagation operator based on matrix decomposition has practical value and has a certain accuracy. At the same time, the resolution of the migration results obtained by processing the viscoacoustic data using the program of the acoustic wave propagation operator based on matrix decomposition in the relevant technology is significantly reduced, and the deep information is almost invisible. The failure to use the viscoacoustic propagation operator based on matrix decomposition for compensation causes the waveform information of the seismic wave to be seriously distorted, making its migration results inaccurate. This is consistent with the conclusion drawn from the two-dimensional undulation model.

[0081] Finally, when this embodiment is applied to actual seismic data, the velocity model and quality factor model corresponding to the actual data can be combined. The size of the model is 8605 meters in depth and 15850 meters in horizontal direction. The shot collection records a total of 445 shots, each shot has 360 geophones, the sampling interval is 0.002s, the sampling length is 5.004s, and the velocity model grid spacing is , the extension depth is 8605m. The source uses a Ricker wavelet with a wavelet main frequency of 14Hz, and determines the underground structure imaging results corresponding to the two-dimensional undulation model based on the actual data data based on the relevant technology and the geological structure imaging method of this embodiment. According to the final offset result, it can be determined that for the actual seismic data, the viscoacoustic propagation operator based on matrix decomposition and the acoustic wave propagation operator based on matrix decomposition both reflect the actual situation of the underground medium. The results obtained by the acoustic wave propagation operator based on matrix decomposition are worse than those of the viscoacoustic propagation operator based on matrix decomposition. From the overall point of view, the resolution of the acoustic wave propagation operator based on matrix decomposition is also significantly lower than that of the viscoacoustic propagation operator based on matrix decomposition. This shows that the geological structure imaging method proposed in this embodiment has certain practical value, and to a certain extent can obtain offset results that are equivalent to or even better in local imaging effects than the acoustic wave propagation operator based on matrix decomposition in the relevant technology.

[0082] It should be noted that the migration imaging of the acoustic wave propagation operator based on matrix decomposition in the related technology will result in a low resolution of the migration result due to the neglect of the viscoelastic information of the underground medium, which may even affect the seismic interpretation work in serious cases. Based on the acoustic wave equation, this embodiment no longer regards the underground medium as an ideal medium, but introduces the viscoacoustic property to fully grasp the medium information and construct the wave equation formula of the viscoacoustic medium. The application of numerical experiments on the two-dimensional undulation model and the Marmousi model shows that this method can improve the resolution of the migration imaging. The viscoacoustic propagation operator based on matrix decomposition proposed in this embodiment can effectively obtain imaging results equivalent to the acoustic wave equation of the related technology. The application of actual seismic data confirms the beneficial effects of the geological structure imaging method of this embodiment, further confirms the practical value of the viscoacoustic propagation operator based on matrix decomposition, can effectively improve the resolution of underground imaging, and retain the wave field information to a greater extent, and the quality of deep underground imaging is significantly improved. The geological structure imaging method of this embodiment is a development of the wave equation migration theory, which expands the application value of the fractional wave equation.

[0083] like Fig.11 As shown, this embodiment provides a geological structure imaging device, which may include: An acquisition unit 101 is used to acquire seismic wave velocity distribution data and quality factor distribution data corresponding to a target area; A determination unit 102, for determining a viscoacoustic vertical wave number according to seismic wave velocity distribution data and quality factor distribution data; An input unit 103 is used to input the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; The imaging unit 104 is used to perform geological structure imaging of the target area using the pressure wave field distribution data to obtain a geological structure imaging result of the target area.

[0084] It should be noted that the processing of the acquisition unit 101, the determination unit 102, the input unit 103 and the imaging unit 104 and the beneficial effects thereof can be respectively referred to in Figure 1 Steps S101 to S104 in the above are not described in detail.

[0085] Optionally, the seismic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is an acoustic wave medium; The quality factor distribution data includes quality factor data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is an acoustic wave medium.

[0086] Optionally, the determining unit 102 is further configured to: Determine viscoacoustic wave velocity distribution data according to the seismic wave velocity distribution data; wherein the viscoacoustic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is a viscoacoustic medium; Determine viscoacoustic parameters based on quality factor distribution data; The viscoacoustic vertical wave number is determined based on the viscoacoustic wave velocity distribution data and viscoacoustic parameters.

[0087] Optionally, construct a pressure wave field determination model and set it as: Considering that the underground medium in the target area is a viscoacoustic medium, the viscoacoustic wave equation of seismic wave propagation is established; Perform Fourier transform on the viscoacoustic wave equation to obtain the corresponding frequency domain equation; The frequency domain equation is transformed to obtain the viscoacoustic wave equation of the two-dimensional viscoacoustic medium in the frequency space domain; Under the condition that the preset assumptions are met, the viscoacoustic wave equation of the two-dimensional viscoacoustic medium is decomposed to obtain the decomposed equation; Determine the viscoacoustic Helmholtz operator based on the decomposed equation; Perform eigenvalue decomposition on the viscoacoustic Helmholtz operator to obtain the eigenvalue decomposition result; The pressure wave field value solution equation is determined based on the eigenvalue decomposition result and used as the pressure wave field determination model.

[0088] Optionally, the viscoacoustic wave equation of a two-dimensional viscoacoustic medium is:

[0089]

[0090]

[0091] in, is the pressure field wave, is the coordinate of the depth direction in the underground space, Sampling frequency, is the propagation speed of seismic waves in viscoacoustic media, is an imaginary unit, is the reference frequency of the viscoacoustic medium, is the viscoacoustic parameter, is the horizontal coordinate in the underground space; is the propagation speed of seismic waves in the acoustic medium, is the quality factor.

[0092] Optionally, the viscoacoustic Helmholtz operator is:

[0093] in, is the viscoacoustic Helmholtz operator.

[0094] Optionally, the pressure wave field determination model is:

[0095]

[0096] in, is the depth step, is the wavefield propagation operator, is the viscoacoustic vertical wave number.

[0097] The geological structure imaging device proposed in this embodiment can obtain the seismic wave velocity distribution data and quality factor distribution data corresponding to the target area, determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; input the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; use the pressure wave field distribution data to perform geological structure imaging on the target area, and obtain the geological structure imaging result of the target area. This embodiment can retain the wave field information to a greater extent, improve the resolution of geological structure imaging and the quality of deep underground imaging.

[0098] The geological structure imaging device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0099] The embodiment of the present invention also provides a computer device having the above Fig.11 The geological structure imaging device shown.

[0100] See also Fig.12, a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.12 A processor 10 is taken as an example.

[0101] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0102] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0103] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function. The data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0104] The memory 20 may include a volatile memory, such as a random access memory. The memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive. The memory 20 may also include a combination of the above-mentioned types of memory.

[0105] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0106] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A geological structure imaging method, characterized in that: include: Obtain seismic wave velocity distribution data and quality factor distribution data corresponding to the target area; Determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; Inputting the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; The pressure wave field distribution data is used to perform geological structure imaging of the target area to obtain a geological structure imaging result of the target area.

2. The method according to claim 1, characterized in that The seismic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is an acoustic wave medium; The quality factor distribution data includes quality factor data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is an acoustic wave medium.

3. The method according to claim 1, characterized in that The determining of the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data comprises: Determine viscoacoustic wave velocity distribution data according to the seismic wave velocity distribution data; wherein the viscoacoustic wave velocity distribution data includes propagation velocity data at different spatial positions during the propagation of seismic waves in the underground medium of the target area, assuming that the underground medium of the target area is a viscoacoustic medium; determining viscoacoustic parameters according to the quality factor distribution data; The viscoacoustic vertical wave number is determined according to the viscoacoustic wave velocity distribution data and the viscoacoustic parameter.

4. The method according to claim 1, characterized in that The process of constructing the pressure wave field determination model includes: Under the condition that the underground medium of the target area is a viscoacoustic medium, a viscoacoustic wave equation for seismic wave propagation is established; Performing Fourier transformation on the viscoacoustic wave equation to obtain a corresponding frequency domain equation; Transforming the frequency domain equation to obtain a viscoacoustic wave equation of a two-dimensional viscoacoustic medium in a frequency domain space domain; Under the condition that the preset assumption conditions are met, the viscoacoustic wave equation of the two-dimensional viscoacoustic medium is decomposed to obtain a decomposed equation; Determining a viscoacoustic Helmholtz operator based on the decomposed equation; Performing eigenvalue decomposition on the viscoacoustic Helmholtz operator to obtain an eigenvalue decomposition result; A pressure wave field value solution equation is determined based on the eigenvalue decomposition result and used as the pressure wave field determination model.

5. The method according to claim 4, characterized in that The viscoacoustic wave equation of the two-dimensional viscoacoustic medium is: in, is the pressure field wave, is the coordinate of the depth direction in the underground space, Sampling frequency, is the propagation speed of seismic waves in viscoacoustic media, is an imaginary unit, is the reference frequency of the viscoacoustic medium, is the viscoacoustic parameter, is the horizontal coordinate in the underground space; is the propagation speed of seismic waves in the acoustic medium, is the quality factor.

6. The method according to claim 5, characterized in that The viscoacoustic Helmholtz operator is: in, is the viscoacoustic Helmholtz operator.

7. The method according to claim 6, characterized in that The pressure wave field determination model is: in, is the depth step, is the wavefield propagation operator, is the viscoacoustic vertical wave number.

8. A geological structure imaging device, characterized in that: include: An acquisition unit, used to acquire seismic wave velocity distribution data and quality factor distribution data corresponding to the target area; A determination unit, configured to determine the viscoacoustic vertical wave number according to the seismic wave velocity distribution data and the quality factor distribution data; An input unit, used for inputting the viscoacoustic vertical wave number into the constructed pressure wave field determination model to determine the pressure wave field distribution data corresponding to the target area; wherein the pressure wave field determination model is constructed based on the viscoelastic properties of the underground medium and the viscoacoustic propagation operator of matrix decomposition; An imaging unit is used to perform geological structure imaging of the target area using the pressure wave field distribution data to obtain a geological structure imaging result of the target area.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the geological structure imaging method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the geological structure imaging method according to any one of claims 1 to 7.

Images