Surface multiple wave order reverse time migration imaging method and device
By preprocessing and converting seismic data, combining the source and detector wavefield loading during forward extension and reverse extension, the source normalized imaging conditions are used for imaging, which solves the problem of low surface multiple wave imaging accuracy in the prior art, and achieves high-precision surface multiple wave division order inverse time offset imaging.
Patent Information
- Application Number
- CN202311755967.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-19
- Publication Date
- 2025-06-20
AI Technical Summary
In the prior art, the surface multiple wave order inverse time offset method cannot generate accurate surface multiple waves of each order, resulting in poor imaging accuracy.
By acquiring seismic data, preprocessing is performed and converted into surface multiple waves of independent orders. Then, during the forward and reverse expansion, multiple waves of the surface of each order are loaded as the source and detector wave fields, and the source normalization imaging conditions are used for imaging.
Accurate imaging of multiple waves of each independent order surface is achieved, and the imaging accuracy of reverse-time offset of multiple waves of surface are improved.
Smart Images
Figure CN120178337A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of marine geophysical exploration, and particularly to a surface multiple-order reverse time migration imaging method and apparatus. Background Art
[0002] In marine seismic exploration, surface multiples are one of the main factors affecting the signal-to-noise ratio and resolution of marine seismic data, and are usually regarded as noise and removed. However, surface multiples have a wider illumination range, smaller propagation angles, and richer underground medium information than primary waves. These favorable conditions make it possible to image surface multiples as effective signals. The surface multiple-order reverse time migration methods provided in the related art cannot generate accurate surface multiples of each order, resulting in poor imaging accuracy. Summary of the Invention
[0003] In view of the above problems, this application provides a surface multiple-order reverse time migration imaging method and apparatus, which can improve the imaging accuracy of surface multiple-order reverse time migration.
[0004] This application provides a surface multiple-order reverse time migration imaging method, including:
[0005] Obtaining seismic data, preprocessing the seismic data to obtain preprocessed seismic data;
[0006] Converting the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)-th order surface multiple and the n-th order surface multiple, and n is a positive integer greater than or equal to 1;
[0007] When n is equal to 1, loading the source wavelet as the source wavefield into the forward continuation process, loading the 0-th order surface multiple as the geophone wavefield into the reverse continuation process, and imaging the 0-th order surface multiple using the source-normalized imaging condition;
[0008] When n is greater than 1, loading the (n - 1)-th order surface multiple as the source wavefield into the forward continuation process, loading the n-th order surface multiple as the geophone wavefield into the reverse continuation process, and imaging the n-th order surface multiple using the source-normalized imaging condition to achieve imaging of surface multiples of each independent order.
[0009] In some embodiments, the loading the (n - 1)-th order surface multiple as the source wavefield into the forward continuation process includes:
[0010] Loading the (n - 1)-th order surface multiple as the source wavefield into the forward continuation process using the forward continuation formula, and the forward continuation formula includes:
[0011]
[0012] Among them, R is the free surface reflection operator, δ(·) is the Delta function, is the partial derivative symbol, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface shot source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple order.
[0013] In some embodiments, loading the nth-order surface multiple as the geophone wavefield into the reverse time continuation process includes:
[0014] Loading the nth-order surface multiple as the geophone wavefield into the reverse time continuation process based on the reverse time continuation formula, where the reverse time continuation formula includes:
[0015]
[0016] where p b represents the geophone wavefield.
[0017] In some embodiments, imaging the nth-order surface multiple using the source-normalized imaging condition includes:
[0018] Imaging the nth-order surface multiple using the source-normalized imaging formula, where the source-normalized imaging formula includes:
[0019]
[0020] where I(r) is the imaging result.
[0021] In some embodiments, the preprocessing includes at least one of low-cut filtering, degassing, suppressing swell noise, removing direct waves, suppressing geophone ghosts and source ghosts, near-trace recovery, and regularization.
[0022] An embodiment of the present application provides a surface multiple-order reverse time migration imaging device, including:
[0023] Acquiring seismic data, preprocessing the seismic data to obtain preprocessed seismic data;
[0024] A conversion module for converting the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)th-order surface multiple and the nth-order surface multiple, and n is a positive integer greater than or equal to 1;
[0025] The first imaging module is configured to, when n equals 1, load the source wavelet as the source wavefield into the forward continuation process, load the 0th - order surface multiple wave as the geophone wavefield into the backward continuation process, and image the 0th - order surface multiple wave using the source - normalized imaging condition;
[0026] The second imaging module is configured to, when n is greater than 1, load the (n - 1)th - order surface multiple wave as the source wavefield into the forward continuation process, load the nth - order surface multiple wave as the geophone wavefield into the backward continuation process, and image the nth - order surface multiple wave using the source - normalized imaging condition to achieve imaging of surface multiple waves of each independent order.
[0027] In some embodiments, the step of loading the (n - 1)th - order surface multiple wave as the source wavefield into the forward continuation process includes:
[0028] Loading the (n - 1)th - order surface multiple wave as the source wavefield into the forward continuation process by using the forward continuation formula, and the forward continuation formula includes:
[0029]
[0030] where R is the free - surface reflection operator, δ(·) is the Delta function, is the partial - derivative symbol, r surf is the free - surface position, c(r) is the medium velocity, the wave - equation operator L acts on the acoustic - pressure field p, s represents the surface - shot source - position vector, r represents the observation - point position vector, r0 represents the geophone - position vector, t represents time, and n represents the order of the surface multiple wave.
[0031] In some embodiments, the step of loading the nth - order surface multiple wave as the geophone wavefield into the backward continuation process includes:
[0032] Loading the nth - order surface multiple wave as the geophone wavefield into the backward continuation process based on the backward continuation formula, where the backward continuation formula includes:
[0033]
[0034] where p b represents the geophone wavefield.
[0035] An embodiment of the present application provides an electronic device, including a memory and a processor. A computer program is stored on the memory, and when the computer program is executed by the processor, it executes the surface - multiple - wave - order - divided reverse - time migration imaging method described in any one of the above.
[0036] An embodiment of the present application provides a storage medium. The computer program stored in the storage medium can be executed by one or more processors and can be used to implement the surface multiple-order reverse time migration imaging method described in any one of the above.
[0037] A surface multiple-order reverse time migration imaging method and device provided by the present application obtain seismic data, preprocess the seismic data to obtain preprocessed seismic data; convert the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)-th order surface multiple and the n-th order surface multiple, and n is a positive integer greater than or equal to 1; when n is equal to 1, the source wavelet is loaded as the source wavefield into the forward continuation process, and the 0-th order surface multiple is loaded as the geophone wavefield into the reverse continuation process, and the 0-th order surface multiple is imaged using the source-normalized imaging condition; when n is greater than 1, the (n - 1)-th order surface multiple is loaded as the source wavefield into the forward continuation process, and the n-th order surface multiple is loaded as the geophone wavefield into the reverse continuation process, and the n-th order surface multiple is imaged using the source-normalized imaging condition to realize the imaging of surface multiples of each independent order, and relatively accurate surface multiples of each order can be obtained, thereby improving the imaging accuracy of surface multiple-order reverse time migration. Description of the Drawings
[0038] In the following, the present application will be described in more detail based on embodiments and with reference to the drawings.
[0039] Figure 1 It is a schematic flowchart of the implementation of a surface multiple-order reverse time migration imaging method provided by an embodiment of the present application;
[0040] Figure 2 It is a schematic flowchart of the implementation of a surface multiple-order reverse time migration imaging method provided by an embodiment of the present application;
[0041] Figure 3 It is a schematic diagram of a test model provided by an embodiment of the present application;
[0042] Figure 4 It is a schematic diagram of single-shot reverse time migration imaging provided by an embodiment of the present application;
[0043] Figure 5 It is a schematic diagram of reflection coefficient comparison provided by an embodiment of the present application;
[0044] Figure 6 It is a schematic diagram of the imaging domain frequency spectrum analysis of full-model reverse time migration imaging provided by an embodiment of the present application;
[0045] Figure 7Schematic diagram of full-model reverse-time migration imaging provided by an embodiment of the present application;
[0046] Figure 8 Schematic diagram of the composition structure of an electronic device provided by an embodiment of the present application.
[0047] In the drawings, the same components are denoted by the same reference numerals, and the drawings are not drawn to actual scale. Detailed implementation manners
[0048] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings. The described embodiments should not be construed as limitations on the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.
[0049] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.
[0050] If similar descriptions such as "first / second / third" appear in the application documents, the following explanation is added. In the following description, the terms "first / second / third" merely distinguish similar objects and do not represent a specific order of the objects. It can be understood that "first / second / third" can be interchanged with a specific order or sequence when permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.
[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.
[0052] Before introducing the embodiments of the present application, a brief introduction to the related technologies is given:
[0053] According to different theoretical bases, surface multiple imaging can be roughly divided into three categories: the first category is the multiple imaging method based on discrete scattering integral (wave propagation-reflection-wave propagation, WRW); the second category is the multiple imaging method based on Green's function; the third category is the multiple imaging method based on wave equation. Among them, the third imaging method avoids the WRW approximation of the first method and the extremely high computational load of the second method, and has predictable practical application value. In related technologies, adjacent-order surface multiples are used as the source and receiver wave fields to achieve the separated-order reverse time migration of surface multiples, avoiding the crosstalk noise generated by non-adjacent-order multiples. In related technologies, separated-order bottom multiples are used to achieve reverse time migration, effectively reducing the crosstalk noise in imaging. In related technologies, the separated-order reverse time migration of surface multiples in a shallow water environment is achieved. These conventional separated-order reverse time migration methods for surface multiples have a common shortcoming: the forward continuation in their reverse time migration cannot correctly handle the reflection of seismic waves at the free surface and cannot generate accurate surface multiples of each order.
[0054] Based on the problems existing in related technologies, an embodiment of the present application provides a separated-order reverse time migration imaging method for surface multiples. The method is applied to an electronic device, and the electronic device can be a computer, a mobile terminal, etc. The functions realized by the separated-order reverse time migration imaging method provided by the embodiment of the present application can be implemented by a processor of the electronic device calling program code, where the program code can be stored in a computer storage medium.
[0055] Example 1
[0056] An embodiment of the present application provides a separated-order reverse time migration imaging method for surface multiples. Figure 1 FIG. is a schematic implementation flowchart of a separated-order reverse time migration imaging method for surface multiples provided by an embodiment of the present application. As Figure 1 shown, it includes:
[0057] Step S101, obtain seismic data, and perform preprocessing on the seismic data to obtain preprocessed seismic data.
[0058] In the embodiment of the present application, the seismic data may be marine seismic data. The seismic data can be obtained in the following ways: the seismic data can be obtained through a seismic monitoring agency, can be obtained by accessing the website of the seismic monitoring agency, or can be obtained through the API interface provided by the website.
[0059] In some embodiments, the seismic data can be obtained through a public data platform.
[0060] In some embodiments, the seismic data can be directly obtained through a measuring device.
[0061] In the embodiments of the present application, the preprocessing includes at least one of low-cut filtering, de-bubbling, suppressing swell noise, removing direct waves, suppressing geophone ghosts and source ghosts, near-trace restoration, and regularization.
[0062] In some embodiments, the data can be cleaned: checking whether there are missing values, outliers, or error values in the data and performing corresponding processing, such as deletion, filling, or correction.
[0063] In some embodiments, the data can also be format-converted: converting the data into a format suitable for analysis, such as converting a timestamp into a date-time format, converting geographical coordinates into latitude and longitude formats, etc. The data can also be smoothed, and seismic data can be smoothed to reduce the influence of noise or burst signals. Common methods include moving average, weighted average, etc. The seismic data can also be standardized so that data of different scales can be compared and analyzed uniformly. Common methods include Z-score standardization, maximum-minimum standardization, etc.
[0064] Step S102: Convert the preprocessed seismic data into surface-related multiples of independent orders, where the surface-related multiples of independent orders include the (n - 1)-th order surface-related multiples and the n-th order surface-related multiples, and n is a positive integer greater than or equal to 1.
[0065] In the embodiments of the present application, the surface-related multiples are removed from the preprocessed seismic data by using the SRME method (Surface-related multiples elimination) to obtain the 0-th order surface-related multiples (primary waves); then, on the basis of the primary waves, the 1-st order surface-related multiples are predicted by using the feedback iteration theory; then, on the basis of the 1-st order surface-related multiples, the 2-nd order surface-related multiples records are predicted by using the feedback iteration theory, and so on, and all surface-related multiples of independent orders can be obtained. At the same time, the hierarchical processing of the surface-related multiples can also be realized by combining the focusing transform with SRME.
[0066] In the case where n is equal to 1, the source wavelet is loaded as the source wavefield into the forward continuation process, and the 0-th order surface-related multiples are loaded as the geophone wavefield into the backward continuation process, and the 0-th order surface-related multiples are imaged by using the source-normalized imaging condition.
[0067] In the embodiments of the present application, the primary waves are regarded as the 0-th order surface-related multiples.
[0068] In the case where n is equal to 1, it is the 0-th order surface-related multiples. In the embodiments of the present application, the 0-th order surface-related multiples are imaged by using the primary-wave reverse-time migration imaging method.
[0069] In the embodiments of the present application, the reverse time migration imaging method is a commonly used imaging method, which can perform high-resolution imaging of underground structures. For the 0th-order surface multiple waves, the reverse time migration imaging method can be used for imaging. Reverse time migration calculations can be performed based on the underground model and actual wave field data. Reverse time migration refers to inverting the received wave field data in the time domain of the wave equation to obtain the imaging result of the underground structure. According to the target to be imaged, a suitable imaging domain is selected. For the 0th-order surface multiple waves, a suitable depth range can be selected for imaging. According to the actual situation, imaging parameters are adjusted, including imaging aperture, imaging step, imaging speed, etc. Thus, imaging of the 0th-order surface multiple waves is achieved.
[0070] In the embodiments of the present application, loading the source wavelet as the source wave field into the forward continuation process includes:
[0071] Loading the source wavelet as the source wave field into the forward continuation process based on the forward continuation formula, where the forward continuation formula includes:
[0072] Lp(s,r,t) = f(t);
[0073] Where the wave equation operator L acts on the acoustic pressure field p, f represents the source wavelet, s represents the surface shot source position vector, r represents the observation point position vector, and t represents time.
[0074] In the embodiments of the present application, loading the 0th-order surface multiple waves as the detector wave field into the backward continuation process includes:
[0075] Loading the 0th-order surface multiple waves as the detector wave field into the backward continuation process based on the backward continuation formula, where the backward continuation formula includes:
[0076]
[0077] Where p b represents the detector wave field.
[0078] Step S104, when n is greater than 1, loading the (n - 1)th-order surface multiple waves as the source wave field into the forward continuation process, and loading the nth-order surface multiple waves as the detector wave field into the backward continuation process, and imaging the nth-order surface multiple waves using the source normalization imaging condition to achieve imaging of each independent order of surface multiple waves.
[0079] Loading the (n - 1)th-order surface multiple waves as the source wave field into the forward continuation process includes:
[0080] Loading the (n - 1)th-order surface multiple waves as the source wave field into the forward continuation process using the forward continuation formula, and the forward continuation formula includes:
[0081]
[0082] wherein, R is the free surface reflection operator, δ(·) is the Delta function, is the partial derivative symbol, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface shot source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple order.
[0083] In the embodiment of the present application, due to the dipole approximation of the free surface, the free surface reflection operator R is introduced, and the incident wave and the reflected wave at the free surface are simultaneously loaded into the surface shot source, so that the forward continuation can simulate accurate surface multiples of each order.
[0084] Loading the nth-order surface multiple into the reverse continuation process as the geophone wave field includes:
[0085] Loading the nth-order surface multiple into the reverse continuation process as the geophone wave field based on the reverse continuation formula, wherein the reverse continuation formula includes:
[0086]
[0087] wherein, p b represents the geophone wave field.
[0088] In the embodiment of the present application, the source-normalized imaging formula is used to image the target nth-order surface multiple, wherein the source-normalized imaging formula includes:
[0089]
[0090] wherein, I(r) is the imaging result.
[0091] Continuing from the above example, the imaging corresponding to the first-order surface multiple can be obtained. By looping in this way, the imaging of surface multiples of each independent order is realized.
[0092] A surface multiple-order reverse time migration imaging method and apparatus provided by the present application obtain seismic data, preprocess the seismic data to obtain preprocessed seismic data; convert the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)th-order surface multiple and the nth-order surface multiple, and n is a positive integer greater than or equal to 1; when n is equal to 1, load the source wavelet as the source wavefield into the forward continuation process, and load the 0th-order surface multiple (primary wave) as the detector wavefield into the reverse continuation process, and image the 0th-order surface multiple using the source-normalized imaging condition; when n is greater than 1, load the (n - 1)th-order surface multiple as the source wavefield into the forward continuation process, and load the nth-order surface multiple as the detector wavefield into the reverse continuation process, and image the nth-order surface multiple using the source-normalized imaging condition, so as to realize the imaging of surface multiples of each independent order and improve the imaging accuracy of surface multiple-order reverse time migration.
[0093] Example 2
[0094] Based on the foregoing embodiments, the embodiments of the present application further provide a surface multiple-order reverse time migration imaging method. By preprocessing marine seismic data, including but not limited to low-cut filtering, de-bubbling, suppressing swell noise, removing direct waves, suppressing detector ghosts and source ghosts, near-offset recovery, regularization, etc., and converting the preprocessed data into surface multiples of independent orders, where the primary wave is regarded as the 0th-order surface multiple. Then, use the conventional reverse time migration method to image the primary wave. Finally, repeatedly apply the improved surface multiple-order reverse time migration method to image surface multiples of each order respectively.
[0095] Figure 2 It is a schematic flow chart of the implementation of a surface multiple-order reverse time migration imaging method provided by the embodiments of the present application, as Figure 2 shown, including:
[0096] Step 1: Preprocess seismic data and convert the preprocessed seismic data into surface multiples of independent orders;
[0097] Step 2: Use the source wavelet as the source wavefield and the 0th-order surface multiple (i.e., the primary wave) as the detector wavefield, and image the 0th-order surface multiple (i.e., the primary wave) using the source-normalized imaging formula.
[0098] Step 3: Load the 0th-order surface multiple (i.e., the primary wave) as the source wavefield into the improved forward continuation formula.
[0099] In the embodiments of the present application, the forward continuation formula includes:
[0100]
[0101] Among them, R is the free surface reflection operator, δ(·) is the Delta function, is the symbol of partial derivative, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface gun source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple order.
[0102] Step Four: Load the first-order surface multiple as the geophone wave field into the reverse continuation formula.
[0103] In the embodiment of the present application, the reverse continuation formula includes:
[0104]
[0105] Among them, p b represents the geophone wave field.
[0106] Step Five: Image the first-order surface multiple using the source-normalized imaging formula.
[0107] In the embodiment of the present application, the source-normalized imaging formula includes:
[0108]
[0109] Among them, I(r) is the imaging result.
[0110] Step Six: Repeat Steps Three to Five in a loop to sequentially achieve the hierarchical imaging of the second-order and higher-order surface multiples.
[0111] Verify the method provided by the present application. Figure 3 is a schematic diagram of a test model provided by the embodiment of the present application, as Figure 3 shown. The size of the test model is set to 34800m×7000m, the spatio-temporal sampling interval of numerical calculation is (0.5ms, 5m), and the total sampling time is 8s. The time-domain source function is a 30Hz Ricker wavelet, and the main wave number of the space-domain Ricker wavelet after time-depth conversion is 0.02m -1 . The observation system is set as follows: the starting position of the shot point is 2000m, the starting position of the geophone array is 0 - 3450m, the same-shift spacing of the shot row is 500m, and there are 63 shots in total. Figure 4 is a schematic diagram of single-shot reverse time migration imaging provided by the embodiment of the present application, as Figure 4 shown. Figure 4 (a) is the single-shot imaging of the primary wave. Figure 4(b) is the improved first-order surface multiple single-shot imaging, Figure 4 (c) is the conventional first-order surface multiple single-shot imaging. It can be seen that the first-order surface multiple single-shot imaging has a wider illumination range and weaker low-frequency noise. To further illustrate the advantages of the improved method, extract the seismic trace at the black dashed line in Figure 4 and compare it with the reflection coefficient of the true velocity model, and plot it as Figure 5 , Figure 5 is a schematic diagram of the reflection coefficient comparison provided by the embodiment of the present application. Figure 5 (a) Comparison of the reflection coefficient of the primary wave imaging with the true reflection coefficient, Figure 5 (b) Comparison of the reflection coefficient of the improved first-order multiple wave imaging with the true reflection coefficient, Figure 5 (c) Comparison of the reflection coefficient of the conventional first-order multiple wave imaging with the true reflection coefficient. It can be seen that Figure 5 the improved first-order surface multiple single-shot imaging in (b) is better at depicting the reflection coefficient than Figure 5 the conventional first-order multiple wave single-shot imaging in (c) and Figure 5 the primary wave single-shot imaging in (a). Further, perform spectral analysis in the image domain on the extracted data in Figure 4 . Figure 6 is a schematic diagram of the spectral analysis in the image domain of the full model reverse time migration imaging provided by the embodiment of the present application. As shown in Figure 6 , spectral analysis in the image domain. Figure 6 (a) and (b) are the amplitude spectrum and phase spectrum of the seismic trace in the image domain selected from Figure 4 the dashed line in (b); Figure 6 (c) and (d) are the amplitude spectrum and phase spectrum of the seismic trace in the image domain selected from Figure 4 the dashed line in (c). In Figure 6 , the vertical dashed line represents the average dominant wave number of the Ricker wavelet in the image domain. The improved first-order multiple wave imaging has a wider frequency band range than the conventional first-order multiple wave imaging. Figure 7 is a schematic diagram of the full model reverse time migration imaging provided by the embodiment of the present application. As shown in Figure 7 , Figure 7 (a) Reverse time migration imaging of the primary wave, Figure 7 (b) Reverse time migration imaging of the improved first-order multiple waves, Figure 7 (c) Reverse time migration imaging of the conventional first-order multiple waves. Figure 7 The improved first-order multiple wave imaging in (b) is better at depicting the structural interface than the conventional first-order multiple wave imaging, and has less low-frequency interference than the primary wave imaging. Figure 7 (a) and Figure 7 (b) together constitute the imaging result of the improved surface multiple wave hierarchical reverse time migration imaging.
[0112] It can be seen that the method provided by the embodiments of the present application can reasonably handle the reflection of seismic waves at the free surface, simulate relatively accurate surface multiples of each order, and effectively image the surface multiples of each order, improving both the imaging accuracy and the frequency band width.
[0113] The method provided by the embodiments of the present application introduces a free surface reflection operator in its forward continuation by performing a dipole approximation on the free surface, thereby being able to reasonably handle the reflection of seismic waves at the free surface, simulate relatively accurate surface multiples of each order, improve the imaging accuracy of surface multiple split-step reverse time migration, and expand the effective frequency band of the imaging domain. The imaging results of the model data verify that the present method can effectively image the surface multiples of each order, improving both the imaging accuracy and the frequency band width.
[0114] Example 3
[0115] Based on the foregoing embodiments, the embodiments of the present application provide a surface multiple split-step reverse time migration imaging device. Each module included in the device, as well as each unit included in each module, can be implemented by a processor in a computer device; of course, it can also be implemented by specific logic circuits; during implementation, the processor can be a central processing unit (CPU), a microprocessor unit (MPU), a digital signal processor (DSP), or a field programmable gate array (FPGA), etc.
[0116] The embodiments of the present application provide a surface multiple split-step reverse time migration imaging device, which includes:
[0117] An acquisition module, configured to acquire seismic data and preprocess the seismic data to obtain preprocessed seismic data;
[0118] A conversion module, configured to convert the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)-th order surface multiple and the n-th order surface multiple, and n is a positive integer greater than or equal to 1;
[0119] A first imaging module, configured to, when n is equal to 1, load the source wavelet as the source wavefield into the forward continuation process, load the 0-th order surface multiple as the geophone wavefield into the reverse continuation process, and image the 0-th order surface multiple using the source normalization imaging condition;
[0120] The second imaging module is configured to, when n>1, load the (n - 1)-th order surface multiple wave as the source wavefield into the forward continuation process, and load the n-th order surface multiple wave as the geophone wavefield into the reverse continuation process, and image the n-th order surface multiple wave by using the source-normalized imaging condition, so as to realize the imaging of surface multiple waves of each independent order.
[0121] In some embodiments, loading the (n - 1)-th order surface multiple wave as the source wavefield into the forward continuation process includes:
[0122] Loading the (n - 1)-th order surface multiple wave as the source wavefield into the forward continuation process by using the forward continuation formula, where the forward continuation formula includes:
[0123]
[0124] where R is the free surface reflection operator, δ(·) is the Delta function, is the partial derivative symbol, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface gun source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple wave order.
[0125] In some embodiments, loading the n-th order surface multiple wave as the geophone wavefield into the reverse continuation process includes:
[0126] Loading the n-th order surface multiple wave as the geophone wavefield into the reverse continuation process based on the reverse continuation formula, where the reverse continuation formula includes:
[0127]
[0128] where p b represents the geophone wavefield.
[0129] In some embodiments, imaging the target n-th order surface multiple wave by using the source-normalized imaging condition includes:
[0130] Imaging the target n-th order surface multiple wave by using the source-normalized imaging formula, where the source-normalized imaging formula includes:
[0131]
[0132] where I(r) is the imaging result
[0133] In some embodiments, the preprocessing includes at least one of low-cut filtering, de-bubbling, suppressing surge noise, removing direct waves, suppressing geophone ghosts and source ghosts, near-trace recovery, and regularization.
[0134] Example 4
[0135] An embodiment of the present application provides an electronic device; Figure 8 As shown in the schematic diagram of the composition structure of the electronic device provided by the embodiment of the present application, Figure 8 as shown, the electronic device 700 includes: a processor 701, at least one communication bus 702, a user interface 703, at least one external communication interface 704, and a memory 705. Among them, the communication bus 702 is configured to realize the connection and communication between these components. Among them, the user interface 703 may include a display screen, and the external communication interface 704 may include a standard wired interface and a wireless interface. The processor 701 is configured to execute the program of the surface multiple-order reverse time migration imaging method stored in the memory to implement the steps in the surface multiple-order reverse time migration imaging method provided in the above embodiments.
[0136] The present application provides a surface multiple-order reverse time migration imaging method, including:
[0137] Obtain seismic data, perform preprocessing on the seismic data to obtain preprocessed seismic data;
[0138] Convert the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)-th order surface multiple and the n-th order surface multiple, and n is a positive integer greater than or equal to 1;
[0139] When n is equal to 1, load the source wavelet as the source wavefield into the forward continuation process, and load the 0-th order surface multiple as the geophone wavefield into the reverse continuation process, and image the 0-th order surface multiple using the source-normalized imaging condition;
[0140] When n is greater than 1, load the (n - 1)-th order surface multiple as the source wavefield into the forward continuation process, and load the n-th order surface multiple as the geophone wavefield into the reverse continuation process, and image the n-th order surface multiple using the source-normalized imaging condition to achieve imaging of surface multiples of each independent order.
[0141] In some embodiments, the step of loading the (n - 1)-th order surface multiple as the source wavefield into the forward continuation process includes:
[0142] The (n-1)th order surface multiple wave is loaded as a source wavefield into the forward continuation process using the forward continuation formula, and the forward continuation formula includes:
[0143]
[0144] where R is the free surface reflection operator, δ(·) is the Delta function, is the partial derivative symbol, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface gun source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple order.
[0145] In some embodiments, loading the nth order surface multiple wave as a geophone wavefield into the reverse continuation process includes:
[0146] Loading the nth order surface multiple wave as a geophone wavefield into the reverse continuation process based on the reverse continuation formula, where the reverse continuation formula includes:
[0147]
[0148] where p b represents the geophone wavefield.
[0149] In some embodiments, imaging the nth order surface multiple wave using the source-normalized imaging condition includes:
[0150] Imaging the target nth order surface multiple wave using the source-normalized imaging formula, where the source-normalized imaging formula includes:
[0151]
[0152] where I(r) is the imaging result.
[0153] In some embodiments, the preprocessing includes at least one of low-cut filtering, degassing, suppressing swell noise, removing direct waves, suppressing geophone ghosts and source ghosts, near-trace recovery, and regularization.
[0154] Example 5
[0155] In the embodiments of the present application, if the above-mentioned surface multiple wave hierarchical reverse time migration imaging method is implemented in the form of software function modules and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories (ROM, Read Only Memory), magnetic disks, or optical discs. Thus, the embodiments of the present application are not limited to any specific combination of hardware and software.
[0156] Correspondingly, the embodiments of the present application provide a storage medium, on which a computer program is stored, and is characterized in that when the computer program is executed by a processor, it implements the steps in the surface multiple wave hierarchical reverse time migration imaging method provided in the above embodiments.
[0157] The descriptions of the above electronic device and storage medium embodiments are similar to the descriptions of the above method embodiments and have beneficial effects similar to those of the method embodiments. For the technical details not disclosed in the computer device and storage medium embodiments of the present application, please refer to the descriptions of the method embodiments of the present application for understanding.
[0158] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures, or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "in one embodiment" or "in an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The serial numbers of the embodiments of the present application above are only for description and do not represent the advantages or disadvantages of the embodiments.
[0159] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element.
[0160] In several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical functional division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the couplings, direct couplings, or communication connections between the components shown or discussed can be through some interfaces. The indirect couplings or communication connections of devices or units can be electrical, mechanical, or other forms.
[0161] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units; they can be located in one place or distributed to multiple network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0162] In addition, each functional unit in the embodiments of this application can be all integrated in one processing unit, or each unit can be separately a unit, or two or more units can be integrated in one unit; the above-mentioned integrated units can be implemented in the form of hardware, or in the form of a combination of hardware and software functional units.
[0163] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes: various media such as removable storage devices, read-only memory (ROM, Read Only Memory), magnetic disks, or optical discs that can store program codes.
[0164] Alternatively, if the above integrated units of the present application are implemented in the form of software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a controller to execute all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media such as removable storage devices, ROMs, magnetic disks, or optical discs that can store program codes.
[0165] As described above, the above are only the implementation manners of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A surface multiple wave hierarchical reverse time migration imaging method, characterized in that, Including: Obtain seismic data, perform preprocessing on the seismic data to obtain preprocessed seismic data; Convert the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)th order surface multiples and the nth order surface multiples, and n is a positive integer greater than or equal to 1; When n equals 1, load the source wavelet as the source wavefield into the forward continuation process, and load the 0th order surface multiples as the geophone wavefield into the backward continuation process, and image the 0th order surface multiples using the source-normalized imaging condition; When n is greater than 1, load the (n - 1)th order surface multiples as the source wavefield into the forward continuation process, and load the nth order surface multiples as the geophone wavefield into the backward continuation process, and image the nth order surface multiples using the source-normalized imaging condition to achieve imaging of the surface multiples of each independent order.
2. The method according to claim 1, characterized in that, The step of loading the (n - 1)th order surface multiples as the source wavefield into the forward continuation process includes: Loading the (n - 1)th order surface multiples as the source wavefield into the forward continuation process using the forward continuation formula, and the forward continuation formula includes: where R is the free surface reflection operator, δ(·) is the Delta function, is the partial derivative symbol, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface gun source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple order.
3. The method according to claim 2, characterized in that, The step of loading the nth order surface multiples as the geophone wavefield into the backward continuation process includes: Loading the nth order surface multiples as the geophone wavefield into the backward continuation process based on the backward continuation formula, where the backward continuation formula includes: where p b represents the geophone wave field.
4. The method according to claim 3, characterized in that, The step of imaging the nth order surface multiples using the source-normalized imaging condition includes: Imaging the nth order surface multiples using the source-normalized imaging formula, where the source-normalized imaging formula includes: where I(r) is the imaging result.
5. The method according to any one of claims 1 to 4, characterized in that, The preprocessing includes at least one of low-cut filtering, de-bubbling, suppressing swell noise, removing direct waves, suppressing geophone ghosts and source ghosts, near-offset trace recovery, and regularization.
6. A surface multiple wave hierarchical reverse time migration imaging device, characterized in that, Including: An acquisition module for obtaining seismic data, performing preprocessing on the seismic data to obtain preprocessed seismic data; A conversion module for converting the preprocessed seismic data into surface multiples of independent orders, where the surface multiples of independent orders include: the (n - 1)th order surface multiples and the nth order surface multiples, and n is a positive integer greater than or equal to 1; A first imaging module for, when n equals 1, loading the source wavelet as the source wavefield into the forward continuation process, and loading the 0th order surface multiples as the geophone wavefield into the backward continuation process, and imaging the 0th order surface multiples using the source-normalized imaging condition; A second imaging module for, when n is greater than 1, loading the (n - 1)th order surface multiples as the source wavefield into the forward continuation process, and loading the nth order surface multiples as the geophone wavefield into the backward continuation process, and imaging the nth order surface multiples using the source-normalized imaging condition to achieve imaging of the surface multiples of each independent order.
7. The surface multiple wave hierarchical reverse time migration imaging device according to claim 6, characterized in that, The step of loading the (n - 1)th order surface multiples as the source wavefield into the forward continuation process includes: The (n-1)th order surface multiple wave is loaded into the forward continuation process as the source wavefield by using the forward continuation formula, and the forward continuation formula includes: where R is the free surface reflection operator, δ(·) is the Delta function, is the partial derivative symbol, r surf is the free surface position, c(r) is the medium velocity, the wave equation operator L acts on the acoustic pressure field p, s represents the surface shot source position vector, r represents the observation point position vector, r0 represents the geophone position vector, t represents time, and n represents the surface multiple order.
8. The surface multiple wave hierarchical reverse time migration imaging device according to claim 7, characterized in that, Loading the nth order surface multiple wave into the reverse continuation process as the geophone wavefield includes: Based on the reverse continuation formula, the nth order surface multiple wave is loaded into the reverse continuation process as the geophone wavefield, where the reverse continuation formula includes: where p b represents the geophone wavefield.
9. An electronic device, characterized in that, It includes a memory and a processor. A computer program is stored on the memory. When the computer program is executed by the processor, it executes the surface multiple wave hierarchical reverse time migration imaging method according to any one of claims 1 to 5.
10. A storage medium, characterized in that, The computer program stored in the storage medium can be executed by one or more processors and can be used to implement the surface multiple wave hierarchical reverse time migration imaging method according to any one of claims 1 to 5.