Method and device for optimizing Kirchhoff prestack depth migration imaging result

Abstract

The invention provides a method and a device for optimizing a Kirchhoff prestack depth migration imaging result. According to the method, the connotation of the Kirchhoff prestack depth migration algorithm is analyzed, and certain improvement is performed on the basis of the Kirchhoff prestack depth migration algorithm to achieve the purpose similar to reverse time migration of a prestack depth migration technology of an advanced algorithm. The imaging result obtained by the method is quite close to reverse time migration, and the efficiency is several times of that of the reverse time migration. The invention aims to obtain an efficient and high-quality pre-stack depth migration algorithm, and the imaging precision of physical model data is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of geophysical seismic exploration, and more particularly to a method and a device for optimizing Kirchhoff prestack depth migration imaging results. Background Art

[0002] In geophysical exploration, the core purpose of data processing is to obtain high-quality imaging profiles. Obtaining high-quality imaging profiles is the core goal of geophysical data processing. Its importance is reflected in at least the following aspects: (1) it can clearly and accurately reflect the stratigraphic structure and identify geological bodies; (2) it can clearly determine the reservoir characteristics and judge the oil and gas reservoir conditions; and (3) it can provide a reliable basis for subsequent drilling. In short, high-quality imaging is directly related to the success or failure of geophysical exploration.

[0003] The best imaging method currently recognized is the reverse time migration method of prestack depth migration. Compared with other methods, the reverse time migration method can provide imaging results with higher resolution and lower noise. However, the reverse time migration method has a complex algorithm and huge amount of calculation, and cannot be used for parameter testing, which limits its application range.

[0004] Kirchhoff integration method is one of the most widely used prestack depth migration algorithms. Compared with the reverse time migration method, Kirchhoff integration method is faster, second only to the high-speed and high-precision imaging method, but the imaging quality is better. Therefore, at this stage, Kirchhoff integration method is mainly used for parameter testing, velocity model establishment and other tasks. These tasks require rapid acquisition of imaging results to determine parameter values, and do not pursue extremely high imaging quality. Therefore, the fast calculation speed of Kirchhoff integration method can meet the needs.

[0005] Kirchhoff integration method also plays a dominant role in the processing of physical simulation data. However, since physical simulation data contains richer information, this places higher demands on the imaging capabilities of the algorithm.

[0006] Compared with actual acquisition, physical simulation can obtain richer geological information in a controlled environment. This leads to more complex and richer data complexity and spectral content obtained from physical simulation, and places higher requirements on imaging algorithms.

[0007] Since the physical model is a collection of many geological bodies, the seismic data collected by the physical model contains a lot of information, and the content that needs to be reflected in the migration imaging increases accordingly, which puts forward better requirements for the imaging of the physical model data, which puts forward high expectations and high demands for efficient, high-quality, and high-precision imaging methods. In particular, when calculating the travel of seismic waves, the conventional ray method has ray shadow areas and caustic areas when calculating the travel, and cannot solve the phenomenon of multiple wave arrivals between the shot points, receiving points, and underground imaging points in complex media areas, resulting in low accuracy of Kirchhoff pre-stack depth migration imaging.

[0008] To this end, the industry urgently needs a new imaging technology that can both ensure imaging speed and provide high-resolution results. Summary of the invention

[0009] In view of this, the present invention discloses a technical solution for optimizing Kirchhoff prestack depth migration imaging results, which significantly improves the imaging accuracy of physical model data, and the imaging speed is much faster than that of the reverse time migration method.

[0010] According to one aspect of the present invention, a method for optimizing Kirchhoff prestack depth migration imaging results is proposed, comprising the following steps:

[0011] Step 1, performing time-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, converting the imaging results in the depth domain into the time domain;

[0012] Step 2, converting the imaging results in the time domain to the frequency domain;

[0013] Step 3, multiplying the frequency domain imaging data by a complex spectrum correction factor to perform complex spectrum correction on the frequency domain imaging result;

[0014] Step 4, performing time-frequency inverse transformation on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain;

[0015] Step 5: Perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

[0016] In some embodiments, step 3 specifically includes:

[0017] If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor;

[0018] If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

[0019] In some embodiments, the first correction factor is iω 2 ; The second correction factor is iω.

[0020] In some embodiments, the threshold is the area of ​​a circle with a diameter of 20 meters.

[0021] According to another aspect of the present invention, a device for optimizing Kirchhoff prestack depth migration imaging results is provided, comprising:

[0022] A time-to-depth conversion unit is used to perform time-to-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, and convert the imaging results in the depth domain into the time domain;

[0023] A time-frequency conversion unit, used for converting the imaging result in the time domain into the frequency domain;

[0024] A complex spectrum correction unit, used for multiplying the imaging data in the frequency domain by a complex spectrum correction factor to perform complex spectrum correction on the imaging result in the frequency domain;

[0025] An inverse time-frequency conversion unit is used to perform an inverse time-frequency conversion on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain;

[0026] The inverse time-depth conversion unit is used to perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

[0027] In some implementations, the complex spectrum correction unit is specifically used to:

[0028] If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor;

[0029] If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

[0030] In some embodiments, the first correction factor is iω 2 ; The second correction factor is iω.

[0031] In some embodiments, the threshold is the area of ​​a circle with a diameter of 20 meters.

[0032] According to another aspect of the present invention, an electronic device is also provided, the electronic device comprising:

[0033] A memory storing executable instructions;

[0034] A processor is used to execute the executable instructions in the memory to implement the method for optimizing Kirchhoff prestack depth migration imaging results as described above.

[0035] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the method for optimizing Kirchhoff prestack depth migration imaging results described above is implemented.

[0036] The present invention introduces a technical solution for efficiently optimizing the imaging results of Kirchhoff prestack depth migration. The method analyzes the connotation of the Kirchhoff prestack depth migration algorithm and makes certain improvements on the basis of the algorithm to achieve a purpose similar to the reverse time migration of the advanced algorithm prestack depth migration technology. Not only is the result quite close to that of reverse time migration, but the efficiency is several times that of reverse time migration. The purpose of the present invention is to obtain an efficient and high-quality prestack depth migration algorithm, which significantly improves the imaging accuracy of physical model data. The advantages of this technical solution are further analyzed in detail below.

[0037] 1. Improved high-frequency resolution of physical simulation data

[0038] The present invention adopts spectrum correction technology and significantly enhances high-frequency details through the designed complex spectrum correction factor, which enables complex physical simulation data to retain richer geological information and is conducive to improving the resolution of imaging.

[0039] 2. Guaranteed computational efficiency

[0040] Compared with the reverse time migration algorithm, the present invention retains the Kirchhoff prestack migration operation on the basis of spectrum processing, which inherits the speed advantage of the Kirchhoff method, has high calculation efficiency, and is more suitable for large-scale data processing.

[0041] 3. Easy to integrate existing workflows

[0042] The present invention is organically combined with the original Kirchhoff method, which is beneficial to be established on the basis of mature products, has low transformation cost and is easy to implement.

[0043] 4. Providing imaging quality that exceeds existing Kirchhoff methods

[0044] Through the optimization at the spectrum level, the present invention provides an imaging result with higher quality than the Kirchhoff method while ensuring the calculation speed, and its imaging level is close to that of the reverse time migration method.

[0045] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0047] Figure 1A flow chart of a method for optimizing Kirchhoff prestack depth migration imaging results according to an embodiment of the present invention is shown.

[0048] 2(a), (b) and (c) respectively show the imaging results of a physical model using a conventional Kirchhoff algorithm, the imaging results using a reverse time migration algorithm and the imaging results using an embodiment of the present invention.

[0049] FIG3 (a) and (b) are schematic diagrams showing the spectrum of imaging results using the reverse time migration algorithm and according to the present invention, respectively. DETAILED DESCRIPTION

[0050] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0051] Here, the concept of the present invention is further described.

[0052] First, the characteristics of conventional prestack depth migration technology are introduced.

[0053] Kirchhoff integral method prestack depth migration uses the Kirchhoff integral solution of the wave equation to achieve reverse propagation and imaging of the seismic wave field. It is the most widely used prestack depth migration method in industrial production. The theoretical starting point of Kirchhoff integral method prestack depth migration is the weighted diffraction stacking of seismic records. The input data can be either common center point gathers or common shot point gathers. For example, the common shot point gather Kirchhoff integral method prestack depth migration can be expressed as

[0054]

[0055] Among them, x s , x r , x is the position of the shot point, receiving point and imaging point respectively, t is the time, t s and t r are the travel time from the shot point and the receiving point to the imaging point, respectively, U(x r , x s , t) is the received wave field, W is the weighting function, δ represents the Dirac function, and the single-shot imaging result I(x, x s ) is the superposition of all imaging values.

[0056] According to formula (1), Kirchhoff prestack depth migration includes two processes: one is to calculate the travel time t based on the velocity field. s +t r, and secondly, t s +t r The amplitude at each moment is weighted summed. Therefore, the key lies in the calculation of the travel time of seismic waves. The conventional ray method has ray shadow areas and caustic areas when calculating travel time, and cannot solve the phenomenon of multiple wave arrivals between the shot point, receiving point and underground imaging point in complex medium areas, resulting in low accuracy of Kirchhoff prestack depth migration imaging.

[0057] Prestack reverse time migration is to reverse time migrate the single shot record data, and then superimpose the imaging results of each shot to obtain the final imaging profile. For a single shot record, it takes the wave field at the last sampling moment of the shot record as the starting plane, reverses in time, and uses the seismic profile data as the boundary condition for each long step to obtain the wave field value at time zero, and then applies the imaging condition to obtain the final migration result. At present, cross-correlation imaging conditions are widely used. The imaging result of reverse time migration is better than that of Kirchhoff prestack depth migration, but it uses a finite difference recursive algorithm, which is computationally intensive and time-consuming, which is a major drawback.

[0058] Figure 2(a) shows the imaging result of the physical model data after conventional Kirchhoff depth migration processing. From the section shown in Figure 2(a), it can be seen that there are some low-frequency background noises in the imaging section, and the resolution is low, which makes some special geological bodies involved in the physical model unclear, and even some relatively small geological bodies are not reflected. Such results are very unfavorable for subsequent interpretation and analysis.

[0059] Figure 2(b) shows the reverse time migration imaging result of prestack depth migration. Its imaging effect is obviously better than the conventional Kirchhoff prestack depth migration result in Figure 2(a), but it consumes a lot of calculation.

[0060] After in-depth research, the inventors have improved the Kirchhoff prestack depth migration imaging method and introduced a complex spectrum correction factor in the frequency domain, which can make the effect of Kirchhoff prestack depth migration imaging equivalent to that of reverse time migration, and the computational efficiency is much better than the reverse time migration technology.

[0061] Example 1

[0062] Figure 1 A flow chart of a method for optimizing Kirchhoff prestack depth migration imaging results according to an embodiment of the present invention is shown. As shown in the figure, the method includes steps 1 to 5.

[0063] Step 1: Perform time-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, and convert the imaging results in the depth domain into the time domain.

[0064] A physical model usually refers to a simplified model made of artificial materials under laboratory conditions that simulates actual geological conditions. Seismic wave propagation experiments are conducted on this model to obtain seismic data.

[0065] The physical model is mainly used to: simulate the propagation law of seismic waves under complex geological conditions to verify earthquake theories; provide experimental data for testing seismic data processing algorithms; control geological conditions and wave source parameters to obtain ideal and complete seismic records, which is conducive to method development; and visualize the seismic wave propagation process to better understand the physical mechanism of earthquakes.

[0066] Usually, physical models can be made of materials such as plexiglass and shale powder, and the parameters of the materials are strictly controlled to match the acoustic characteristics of different strata. Geological structures such as geological bodies and faults can also be artificially introduced into the model. Compared with the actual collected data, physical model experiments can obtain more complete and idealized records and provide a lot of valuable information.

[0067] The imaging results of Kirchhoff prestack depth migration can be converted from the depth domain to the time domain by using two-dimensional grid lookup method, one-dimensional wavenumber integration method, finite difference method or ray tracing method.

[0068] Two-dimensional grid lookup table method: Establish a two-dimensional lookup table of the time-depth correspondence, obtain the corresponding time value according to the depth coordinate of the imaging point, and realize the conversion from depth to time. The two-dimensional grid lookup table method is simple and intuitive, and is suitable for simple velocity fields.

[0069] One-dimensional wavenumber integration method: superimpose the corresponding points of the same offset integral diagram of different shot points to obtain the offset-time matrix, and obtain the time according to the offset table to achieve conversion. The one-dimensional wavenumber integration method is suitable for models with more complex wave velocities.

[0070] Finite difference method: By establishing a mathematical model of the wave equation in the time-depth domain, the finite difference algorithm is used to solve the wave field distribution and realize the conversion between the depth and time domains. The finite difference method has a large amount of calculation but high accuracy.

[0071] Ray tracing method: The time-depth mapping relationship can be determined according to the wave propagation law, and time and depth can be accurately converted through a large number of ray tracing integrals. The ray tracing method has a huge amount of calculation but the result is the most accurate.

[0072] Those skilled in the art may choose to use applicable technical means to perform time-depth conversion according to actual conditions, and the present invention is not limited to this.

[0073] Step 2: Convert the imaging results in the time domain to the frequency domain.

[0074] Fourier transform, wavelet transform, Hilbert transform, Wigner-Ville distribution, Z transform, etc. can be used for time-frequency transform to transform the Kirchhoff prestack depth migration imaging results in the time domain into the frequency domain.

[0075] Fourier transform: It is the most famous and widely used time-frequency analysis method. Its basic principle is to represent the signal as a superposition of sine waves and cosine waves of different frequencies. Fourier transform converts the time information in the original signal into amplitude and phase information in the frequency domain through the integral kernel to obtain the spectrum expression. Fourier transform has good processing effect and stable computing performance.

[0076] Wavelet transform: Wavelet transform is similar to Fourier transform, which can transform the signal from time domain to time-frequency domain and analyze the time-frequency characteristics of the signal. However, wavelet transform is complex to implement and requires the selection of a suitable wavelet basis.

[0077] Hilbert transform: Hilbert transform maps the signal to Hilbert space to obtain the frequency content of the signal. The local characteristics of the spectrum after Hilbert transform will be preserved very well.

[0078] Wigner-Ville distribution: This is one of the important methods of time-frequency analysis. It can directly display the time-frequency distribution of the signal and display the global frequency distribution of the signal through integration. Wigner-Ville distribution is easy to use but will produce cross-spectral aliasing.

[0079] Z transform: This is a frequency domain analysis method similar to Laplace transform, mainly used in spectrum analysis of sampled data and discrete signals. Z transform is very convenient to use and the results are very stable.

[0080] In one example, Fourier transform may be used to implement time-frequency conversion.

[0081] Step 3: multiply the frequency domain imaging data by the complex spectrum correction factor to perform complex spectrum correction on the frequency domain imaging result.

[0082] As mentioned above, when calculating the travel of seismic waves, the conventional ray method has ray shadow areas and caustic areas, and cannot solve the phenomenon of multiple wave arrivals between the shot points, receiving points and underground imaging points in complex medium areas, resulting in low Kirchhoff prestack depth migration imaging accuracy. According to the present invention, by designing a specific complex spectrum correction factor, the frequency domain amplitude spectrum shape is adjusted to improve the resolution of the imaging result in the frequency domain and enhance the detail expression of the image.

[0083] In some embodiments, this step specifically includes:

[0084] If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor;

[0085] If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

[0086] Because the size of a geological body is related to the frequency component of seismic wave propagation, according to this embodiment, matching complex spectrum correction factors are selected for geological bodies of different sizes to perform corresponding corrections.

[0087] In some embodiments, the first correction factor is iω 2 , the second correction factor is iω.

[0088] According to this embodiment, the amplitudes of the first correction factor and the second correction factor are designed to increase with frequency. In this way, the spectrum amplitude of the signal can be significantly enhanced by dot multiplication, thereby obtaining a high-resolution spectrum distribution.

[0089] According to this embodiment, for a geological body with a small volume, a first correction factor iω is assigned to it. 2 , in order to obtain a higher resolution, correction is performed using the square attenuation law; for geological bodies with larger volumes, a second correction factor of iω is assigned to them, and correction is performed using the linear attenuation law.

[0090] In some embodiments, the threshold is the area of ​​a circle with a diameter of about 20 meters. For example, if the diameter of the geological body included in the physical model is less than 20 meters, iω is selected. 2 As the complex spectrum correction factor, spectrum correction is performed; if the diameter of the geological body contained in the physical model is greater than 20 meters, iω is selected as the complex spectrum correction factor for spectrum correction.

[0091] Step 4: Perform time-frequency inverse transformation on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain.

[0092] Here, an inverse transform corresponding to step 2 may be used. For example, if Fourier transform is used in step 2 to transform the imaging result in the time domain into the frequency domain, then in step 4, an inverse Fourier transform may be used to transform the imaging result in the frequency domain into the time domain.

[0093] Step 5: Perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

[0094] Here, the inverse transformation corresponding to step 1 can be used to obtain the restored depth domain imaging result.

[0095] This embodiment introduces a technical method for efficiently optimizing the Kirchhoff prestack depth migration imaging results. This method analyzes the connotation of the Kirchhoff prestack depth migration algorithm, and makes certain improvements on the basis of its algorithm to achieve a purpose similar to the reverse time migration of the advanced algorithm prestack depth migration technology. Not only is the result quite close to the reverse time migration, but the efficiency is several times that of the reverse time migration. The purpose of the present invention is to obtain an efficient and high-quality prestack depth migration algorithm, which significantly improves the imaging accuracy of the physical model data. The advantages of this technical solution are further analyzed in detail below.

[0096] 1. Improved high-frequency resolution of physical simulation data

[0097] The present invention adopts spectrum correction technology and significantly enhances high-frequency details through the designed complex spectrum correction factor, which enables complex physical simulation data to retain richer geological information and is conducive to improving the resolution of imaging.

[0098] 2. Guaranteed computational efficiency

[0099] Compared with the reverse time migration algorithm, the present invention retains the Kirchhoff prestack migration operation on the basis of spectrum processing, which inherits the speed advantage of the Kirchhoff method, has high calculation efficiency, and is more suitable for large-scale data processing.

[0100] 3. Easy to integrate existing workflows

[0101] The present invention is organically combined with the original Kirchhoff method, which is beneficial to be established on the basis of mature products, has low transformation cost and is easy to implement.

[0102] 4. Providing imaging quality that exceeds existing Kirchhoff methods

[0103] Through the optimization at the spectrum level, the present invention provides an imaging result with higher quality than the Kirchhoff method while ensuring the calculation speed, and its imaging level is close to that of the reverse time migration method.

[0104] Example 2

[0105] According to an embodiment of the present invention, a device for optimizing Kirchhoff prestack depth migration imaging results includes:

[0106] A time-to-depth conversion unit is used to perform time-to-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, and convert the imaging results in the depth domain into the time domain;

[0107] A time-frequency conversion unit, used for converting the imaging result in the time domain into the frequency domain;

[0108] A complex spectrum correction unit, used for multiplying the imaging data in the frequency domain by a complex spectrum correction factor to perform complex spectrum correction on the imaging result in the frequency domain;

[0109] An inverse time-frequency conversion unit is used to perform an inverse time-frequency conversion on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain;

[0110] The inverse time-depth conversion unit is used to perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

[0111] The time-to-depth conversion unit can convert the imaging results of Kirchhoff prestack depth migration from the depth domain to the time domain by using a two-dimensional grid lookup method, a one-dimensional wavenumber integration method, a finite difference method or a ray tracing method.

[0112] The time-frequency conversion unit can use Fourier transform, wavelet transform, Hilbert transform, Wigner-Ville distribution, Z transform, etc. to perform time-frequency transformation to transform the Kirchhoff prestack depth migration imaging results in the time domain into the frequency domain.

[0113] In some implementations, the complex spectrum correction unit is specifically used to:

[0114] If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor;

[0115] If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

[0116] In some embodiments, the first correction factor is iω 2 ; The second correction factor is iω.

[0117] In some embodiments, the threshold is the area of ​​a circle with a diameter of 20 meters.

[0118] This embodiment introduces a technical solution for efficiently optimizing the imaging results of Kirchhoff prestack depth migration. This solution analyzes the connotation of the Kirchhoff prestack depth migration algorithm and makes certain improvements on the basis of its algorithm to achieve a purpose similar to the reverse time migration of the advanced algorithm prestack depth migration technology. Not only is the result quite close to that of reverse time migration, but the efficiency is several times that of reverse time migration. The purpose of this embodiment is to obtain an efficient and high-quality prestack depth migration algorithm, which significantly improves the imaging accuracy of physical model data. The advantages of this technical solution are further analyzed in detail below.

[0119] 1. Improved high-frequency resolution of physical simulation data

[0120] The present invention adopts spectrum correction technology and significantly enhances high-frequency details through the designed complex spectrum correction factor, which enables complex physical simulation data to retain richer geological information and is conducive to improving the resolution of imaging.

[0121] 2. Guaranteed computational efficiency

[0122] Compared with the reverse time migration algorithm, the present invention retains the Kirchhoff prestack migration operation on the basis of spectrum processing, which inherits the speed advantage of the Kirchhoff method, has high calculation efficiency, and is more suitable for large-scale data processing.

[0123] 3. Easy to integrate existing workflows

[0124] The present invention is organically combined with the original Kirchhoff method, which is beneficial to be established on the basis of mature products, has low transformation cost and is easy to implement.

[0125] 4. Providing imaging quality that exceeds existing Kirchhoff methods

[0126] Through the optimization at the spectrum level, the present invention provides an imaging result with higher quality than the Kirchhoff method while ensuring the calculation speed, and its imaging level is close to that of the reverse time migration method.

[0127] For other detailed descriptions and advantages of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0128] Example 3

[0129] According to another aspect of the present invention, an electronic device is provided. The electronic device comprises:

[0130] Memory, which stores executable instructions:

[0131] A processor runs the executable instructions in the memory to implement the method for optimizing Kirchhoff prestack depth migration imaging results according to the present invention.

[0132] Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc.

[0133] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present invention, the processor is used to run the computer-readable instructions stored in the memory.

[0134] The method for optimizing Kirchhoff prestack depth migration imaging results comprises the following steps:

[0135] Step 1, performing time-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, converting the imaging results in the depth domain into the time domain;

[0136] Step 2, converting the imaging results in the time domain to the frequency domain;

[0137] Step 3, multiplying the frequency domain imaging data by a complex spectrum correction factor to perform complex spectrum correction on the frequency domain imaging result;

[0138] Step 4, performing time-frequency inverse transformation on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain;

[0139] Step 5: Perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

[0140] In some embodiments, step 3 specifically includes:

[0141] If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor;

[0142] If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

[0143] In some embodiments, the first correction factor is iω 2 ; The second correction factor is iω.

[0144] In some embodiments, the threshold is the area of ​​a circle with a diameter of 20 meters.

[0145] This embodiment introduces a technical solution for efficiently optimizing the imaging results of Kirchhoff prestack depth migration. This solution analyzes the connotation of the Kirchhoff prestack depth migration algorithm and makes certain improvements on the basis of its algorithm to achieve a purpose similar to the reverse time migration of the advanced algorithm prestack depth migration technology. Not only is the result quite close to that of reverse time migration, but the efficiency is several times that of reverse time migration. The purpose of this embodiment is to obtain an efficient and high-quality prestack depth migration algorithm, which significantly improves the imaging accuracy of physical model data. The advantages of this technical solution are further analyzed in detail below.

[0146] 1. Improved high-frequency resolution of physical simulation data

[0147] The present invention adopts spectrum correction technology and significantly enhances high-frequency details through the designed complex spectrum correction factor, which enables complex physical simulation data to retain richer geological information and is conducive to improving the resolution of imaging.

[0148] 2. Guaranteed computational efficiency

[0149] Compared with the reverse time migration algorithm, the present invention retains the Kirchhoff prestack migration operation on the basis of spectrum processing, which inherits the speed advantage of the Kirchhoff method, has high calculation efficiency, and is more suitable for large-scale data processing.

[0150] 3. Easy to integrate existing workflows

[0151] The present invention is organically combined with the original Kirchhoff method, which is beneficial to be established on the basis of mature products, has low transformation cost and is easy to implement.

[0152] 4. Providing imaging quality that exceeds existing Kirchhoff methods

[0153] Through the optimization at the spectrum level, the present invention provides an imaging result with higher quality than the Kirchhoff method while ensuring the calculation speed, and its imaging level is close to that of the reverse time migration method.

[0154] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0155] Example 4

[0156] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the method for optimizing Kirchhoff prestack depth migration imaging results according to the present invention is implemented.

[0157] The computer-readable storage medium according to the embodiment of the present invention stores non-transitory computer-readable instructions, and when the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the above-mentioned methods of the embodiments of the present invention are executed.

[0158] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0159] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present invention.

[0160] The method for optimizing Kirchhoff prestack depth migration imaging results comprises the following steps:

[0161] Step 1, performing time-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, converting the imaging results in the depth domain into the time domain;

[0162] Step 2, converting the imaging results in the time domain to the frequency domain;

[0163] Step 3, multiplying the frequency domain imaging data by a complex spectrum correction factor to perform complex spectrum correction on the frequency domain imaging result;

[0164] Step 4, performing time-frequency inverse transformation on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain;

[0165] Step 5: Perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

[0166] In some embodiments, step 3 specifically includes:

[0167] If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor;

[0168] If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

[0169] In some embodiments, the first correction factor is iω 2 ; The second correction factor is iω.

[0170] In some embodiments, the threshold is the area of ​​a circle with a diameter of 20 meters.

[0171] This embodiment introduces a technical solution for efficiently optimizing the imaging results of Kirchhoff prestack depth migration. This solution analyzes the connotation of the Kirchhoff prestack depth migration algorithm and makes certain improvements on the basis of its algorithm to achieve a purpose similar to the reverse time migration of the advanced algorithm prestack depth migration technology. Not only is the result quite close to that of reverse time migration, but the efficiency is several times that of reverse time migration. The purpose of this embodiment is to obtain an efficient and high-quality prestack depth migration algorithm, which significantly improves the imaging accuracy of physical model data. The advantages of this technical solution are further analyzed in detail below.

[0172] 1. Improved high-frequency resolution of physical simulation data

[0173] The present invention adopts spectrum correction technology and significantly enhances high-frequency details through the designed complex spectrum correction factor, which enables complex physical simulation data to retain richer geological information and is conducive to improving the resolution of imaging.

[0174] 2. Guaranteed computational efficiency

[0175] Compared with the reverse time migration algorithm, the present invention retains the Kirchhoff prestack migration operation on the basis of spectrum processing, which inherits the speed advantage of the Kirchhoff method, has high calculation efficiency, and is more suitable for large-scale data processing.

[0176] 3. Easy to integrate existing workflows

[0177] The present invention is organically combined with the original Kirchhoff method, which is beneficial to be established on the basis of mature products, has low transformation cost and is easy to implement.

[0178] 4. Providing imaging quality that exceeds existing Kirchhoff methods

[0179] Through the optimization at the spectrum level, the present invention provides an imaging result with higher quality than the Kirchhoff method while ensuring the calculation speed, and its imaging level is close to that of the reverse time migration method.

[0180] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0181] Example 5

[0182] The effects of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0183] 2(a), (b) and (c) respectively show the imaging results of a physical model using a conventional Kirchhoff algorithm, the imaging results using a reverse time migration algorithm and the imaging results using an embodiment of the present invention.

[0184] FIG3 (a) and (b) are schematic diagrams showing the spectrum of imaging results using the reverse time migration algorithm and according to the present invention, respectively.

[0185] Figure 2(a) shows the imaging result of conventional Kirchhoff depth migration after the physical model data is processed. It can be seen from the figure that there is some low-frequency background noise and the resolution is low, which makes some special geological bodies involved in the physical model not obvious, and even some relatively small geological bodies are not reflected. Such results are not conducive to subsequent interpretation and analysis.

[0186] Figure 2(b) shows the reverse time migration imaging result of prestack depth migration, and its imaging effect is obviously better than Figure 1 Kirchhoff prestack depth migration results.

[0187] Figure 2(c) is an imaging result obtained by the optimization method according to an embodiment of the present invention. According to the present invention, the Kirchhoff prestack depth migration imaging method is improved, and a factor is introduced in the frequency domain, so that the effect of Kirchhoff prestack depth migration imaging can be equivalent to that of reverse time migration, and the calculation efficiency is much better than the reverse time migration technology.

[0188] Figure 3(a) is a schematic diagram of the spectrum of imaging results obtained by using the reverse time migration algorithm, and Figure 3(b) is a schematic diagram of the spectrum of imaging results obtained according to an embodiment of the present invention. It can be seen from Figures 3(a) and (b) that their spectrum results are basically the same.

[0189] It can be understood that the above embodiments mentioned in the present disclosure can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present disclosure will not repeat them. It can be understood by those skilled in the art that in the above methods of the specific implementation, the specific execution order of each step should be determined according to its function and possible internal logic.

[0190] Note that, unless otherwise directly stated, all features disclosed in this specification (including any attached claims, abstracts and drawings) may be replaced by alternative features for achieving the same, equivalent or similar purposes. Therefore, unless otherwise explicitly stated, each feature disclosed is only an example of a group of equivalent or similar features. Where used, further, preferably, further and more preferably are simple beginnings for elaborating another embodiment based on the aforementioned embodiment, and the content of the further, preferably, further or more preferably followed by the combination with the aforementioned embodiment constitutes a complete construction of another embodiment. Several further, preferably, further or more preferably settings following the same embodiment can be arbitrarily combined to form another embodiment.

[0191] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure 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 replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for optimizing Kirchhoff prestack depth migration imaging results. It is characterized in that The method comprises: Step 1, performing time-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, converting the imaging results in the depth domain into the time domain; Step 2, converting the imaging results in the time domain to the frequency domain; Step 3, multiplying the frequency domain imaging data by a complex spectrum correction factor to perform complex spectrum correction on the frequency domain imaging result; Step 4, performing time-frequency inverse transformation on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain; Step 5: Perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

2. The method according to claim 1, It is characterized in that The step 3 specifically includes: If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor; If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

3. The method according to claim 2, Features: The first correction factor is iω 2 ; The second correction factor is iω.

4. The method according to claim 3, Features: The threshold is the area of ​​a circle with a diameter of 20 meters.

5. A device for optimizing Kirchhoff prestack depth migration imaging results, It is characterized in that The device comprises: A time-to-depth conversion unit is used to perform time-to-depth conversion on the Kirchhoff prestack depth migration imaging results of the physical model, and convert the imaging results in the depth domain into the time domain; A time-frequency conversion unit, used for converting the imaging result in the time domain into the frequency domain; A complex spectrum correction unit, used for multiplying the imaging data in the frequency domain by a complex spectrum correction factor to perform complex spectrum correction on the imaging result in the frequency domain; An inverse time-frequency conversion unit is used to perform an inverse time-frequency conversion on the imaging result after complex spectrum correction to obtain a corrected imaging result in the time domain; The inverse time-depth conversion unit is used to perform time-depth inverse conversion on the corrected imaging result in the time domain to obtain the corrected imaging result in the depth domain.

6. The device according to claim 5, It is characterized in that The complex spectrum correction unit is specifically used for: If the size of the geological body included in the object model is smaller than a threshold, selecting a first correction factor as the complex spectrum correction factor; If the size of the geological body included in the object model is greater than a threshold, the second correction factor is selected as the complex spectrum correction factor.

7. The device according to claim 6, Features: The first correction factor is iω 2 ; The second correction factor is iω.

8. The device according to claim 7, Features: The threshold is the area of ​​a circle with a diameter of 20 meters.

9. An electronic device, It is characterized in that The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method according to any one of claims 1 to 4.

10. A computer-readable storage medium storing a computer program, wherein the computer program implements the method according to any one of claims 1 to 4 when executed by a processor.

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