Free interface multiple wave prediction method and device, computing device and storage medium

Abstract

The application discloses a free interface multiple wave prediction method and device, a computing device and a storage medium, and the method comprises the following steps: performing prestack time migration processing on a streamer seismic data volume to obtain a prestack time migration data volume; performing reverse migration processing on the prestack time migration data volume to construct a multiple wave prediction seismic trace set; and performing free interface multiple wave prediction on the basis of seabed acquisition data and the multiple wave prediction seismic trace set to obtain a free interface multiple wave record. The scheme provided by the application realizes free interface multiple wave prediction of seabed acquisition data, can predict all free interface multiple wave components in the data, effectively solves the problem that a conventional streamer SRME method cannot be applied to such data, and can significantly improve the multiple wave suppression effect of the P-wave component and the converted wave component data of seabed acquisition data.

Description

Technical Field

[0001] This invention relates to the field of seismic data processing and analysis technology, specifically to a method, apparatus, computing device, and storage medium for predicting multiple waves at a free interface. Background Technology

[0002] In recent years, to obtain high-quality marine seismic data with wide azimuth, high coverage, and small area characteristics, seabed seismic exploration has developed rapidly in my country. Based on differences in signal receiving equipment, seabed seismic exploration can be divided into seabed cable seismic acquisition (OBC) and seabed node seismic acquisition (OBN). Since the sea surface can be approximated as a free interface (reflection coefficient close to -1), in the four-component data obtained from seabed seismic exploration, the P and Z components contain a vast majority of multiples related to the free interface. For the horizontal components X and Y, the P-wave energy reflected from the sea surface and then reflected back by the subsurface interface forms free interface multiples with amplitudes much larger than interlayer multiples (the downflow reflection location is on the seabed or its lower interface), belonging to the converted wave type. Given that the seismic signals mainly used in oil and gas exploration are single-reflection signals, the prediction and suppression of free interface multiples in seabed acquisition data has long been a key and challenging research problem. If effective suppression is not achieved, the free interface multiples will interfere with the velocity analysis process, thereby affecting the authenticity and reliability of seismic imaging and ultimately misleading subsequent seismic geological interpretation tasks.

[0003] In recent years, the free interface multiple attenuation method (SRME) based on feedback loop theory has made significant progress. It can effectively suppress multiple components in seismic records with almost no prior information and has become one of the preferred methods for 2D seismic data processing, and has been extended to multiple suppression of 3D conventional towed cable data. However, this method has encountered severe challenges in processing seabed acquired data. Because seismic signal receiving equipment is deployed on the seabed, seabed seismic acquisition cannot receive primary reflections from the seabed (due to the lack of seabed illumination). Furthermore, the use of observation systems with "few channels, many shots" characteristics results in low and uneven coverage of shallow and mid-situ multiples in the received data, and even the absence of reflection signals from some shallow strata. This severely limits the application effect of the data-driven 3D SRME method. The lack of reflection signals significantly affects the prediction accuracy of multiples, not only failing to predict multiples related to the seabed and shallow interfaces, but also generating significant spatial aliasing, thus affecting the multiple removal effect of seabed acquired data. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a free interface multiple prediction method, apparatus, computing device and storage medium that overcomes or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a method for predicting multiple waves at a free interface is provided, comprising:

[0006] Pre-stack time migration processing is performed on the towed seismic data volume to obtain the pre-stack time migration data volume;

[0007] The pre-stack time migration data volume is subjected to inverse pre-stack time migration processing to construct a multiple wave prediction seismic gather;

[0008] Based on the seabed data and the predicted multiple seismic gathers, multiple predictions of the free interface are performed to obtain the multiple records of the free interface.

[0009] According to another aspect of the present invention, a free interface multiple wave prediction device is provided, comprising:

[0010] The processing module is suitable for performing pre-stack time migration processing on towed seismic data volumes to obtain pre-stack time migration data volumes.

[0011] The construction module is adapted to perform inverse migration processing on the pre-stack time migration data volume to construct a multiple wave prediction seismic gather.

[0012] The prediction module is adapted to perform free interface multiple wave prediction based on seabed data and the multiple wave prediction seismic gather, and obtain the free interface multiple wave record.

[0013] According to another aspect of the present invention, a computing device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;

[0014] The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the free interface multiple wave prediction method described above.

[0015] According to another aspect of the present invention, a computer storage medium is provided, the storage medium storing at least one executable instruction that causes a processor to perform an operation corresponding to the free interface multiple wave prediction method described above.

[0016] According to the solution provided by the present invention, free interface multiple prediction of seabed data is realized. It can predict all free interface multiple components in the data, effectively solving the problem that the conventional towed cable SRME method cannot be applied to this type of data, and can significantly improve the multiple suppression effect of P-wave and converted wave components in seabed data.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0019] Figure 1 A flowchart illustrating a free interface multiple wave prediction method according to an embodiment of the present invention is shown.

[0020] Figure 2 This is a schematic diagram of the ray tracing process for a "straight ray" model of pre-stack time migration.

[0021] Figure 3 This is a schematic diagram of the ray tracing process of temporal Kirchhoff inverse offset;

[0022] Figure 4 This is a schematic diagram of the pre-stack time migration velocity field of conventional towed seismic data.

[0023] Figure 5 A schematic diagram of the pre-stack time migration data volume of conventional towed seismic data;

[0024] Figure 6 A schematic diagram of multiple wave prediction seismic gathers constructed for time-domain Kirchhoff inverse migration;

[0025] Figure 7 A schematic diagram of the gun collection record;

[0026] Figure 8 A schematic diagram of the predicted free interface multiple wave record;

[0027] Figure 9 A schematic diagram of a free interface multiple wave prediction device according to an embodiment of the present invention is shown.

[0028] Figure 10A schematic diagram of a computing device according to an embodiment of the present invention is shown. Detailed Implementation

[0029] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0030] Figure 1 A flowchart illustrating a free interface multiple wave prediction method according to an embodiment of the present invention is shown. Figure 1 As shown, the method includes the following steps:

[0031] Step S101: Perform pre-stack time migration processing on the towed seismic data volume to obtain the pre-stack time migration data volume.

[0032] Specifically, pre-stack time migration refers to the process in seismic exploration of shifting towed seismic data in time to align the reflected waves at the same time, thereby correcting time differences in the seismic record to obtain more accurate information about the underground structure.

[0033] Towed cable seismic data refers to seismic data collected by a cable towed by a geophysical exploration vessel. This data is existing data in the work area. Pre-stack time migration processing is performed on the towed cable seismic data volume to obtain a pre-stack time-migrated data volume. Preferably, during pre-stack time migration processing, the migration velocity field of the towed cable seismic data can be obtained. A preset pre-stack time migration algorithm is then used to perform pre-stack time migration processing on the towed cable seismic data volume based on the migration velocity field, resulting in the pre-stack time-migrated data volume. For example, the Kirchhoff pre-stack time migration algorithm can be used. Of course, other pre-stack time migration algorithms can also be used, which will not be listed here.

[0034] Step S102: Perform inverse migration processing of the pre-stack time migration data volume to construct a multiple wave prediction seismic gather.

[0035] Specifically, after obtaining the pre-stack time migration data volume according to step S101, the pre-stack time migration data volume is subjected to inverse migration processing. Through inverse migration processing, it can be back-migrated to the seabed acquisition reference surface and reflection coefficient. Through inverse migration processing, a multiple wave prediction seismic gather that meets the prediction accuracy of free interface multiple waves is constructed. The constructed multiple wave prediction seismic gather is a common receiver point gather. The common receiver point is located at the seabed acquisition reference surface, and the acquisition method is the same as the seabed acquisition method.

[0036] Step S103: Based on the seabed data and the predicted multiple seismic gathers, perform free interface multiple prediction to obtain the free interface multiple record.

[0037] Specifically, the seabed acquisition data refers to data collected during seabed seismic exploration. The receiving point during seabed acquisition is located on the seabed, and the seabed acquisition data includes ocean bottom cable (OBC) seismic acquisition data and ocean bottom node (OBN) seismic acquisition data. Using the multiple prediction seismic gather constructed in step S102 as the prediction factor required for free interface multiple prediction, free interface multiple prediction is performed based on the seabed acquisition data and the multiple prediction seismic gather, resulting in the multiple record of the free interface, where the free interface is the sea surface.

[0038] In one optional embodiment of the present invention, the seabed acquisition data includes P-wave component data. Therefore, the step of performing free-interface multiple prediction based on the seabed acquisition data and the multiple prediction seismic gather to obtain the free-interface multiple record can be further implemented by the following method: performing frequency domain transformation processing on the P-wave component data in the seabed acquisition data and the multiple prediction seismic gather; performing free-interface multiple prediction based on the frequency domain transformation result to obtain the free-interface multiple record.

[0039] Specifically, both the P-wave component data and the predicted multiple seismic gathers are in the time domain, meaning they are represented using the time axis as the coordinate. To facilitate multiple prediction, the P-wave component data and the predicted multiple seismic gathers in the seabed acquisition data can first be converted to the frequency domain, i.e., represented using the frequency axis as the coordinate. Then, based on the frequency domain conversion result, free interface multiple prediction is performed to obtain the free interface multiple records.

[0040] More preferably, the receiver point of the P-wave and the shot point of the multiple wave prediction seismic trace are the same point. Therefore, the P-wave and the target multiple wave prediction trace for multiple wave prediction can be determined based on the spatial coordinates of the receiver point of the P-wave and the spatial coordinates of the shot point of the multiple wave prediction seismic trace. Specifically, the multiple wave prediction seismic trace set is queried based on the spatial coordinates of the receiver point of any P-wave in the P-wave component data. The target multiple wave prediction trace set with the same shot point spatial coordinates as the receiver point spatial coordinates of the P-wave is obtained. The P-wave and the target multiple wave prediction trace are multiplied, and the multiplication results are summed to obtain the multiple wave record of the free interface.

[0041] Multiple prediction of free interfaces can be performed using the three-dimensional free interface multiple prediction equation (1):

[0042]

[0043] Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. P These are the multiple wave records of the predicted P-wave components at the free interface, where P is the P-wave component data and H is the predicted multiple wave gather; x k With y k This represents the spatial coordinates of the receiver points in the P-wave component data P and the spatial coordinates of the shot points in the multiple prediction seismic gather H, which are involved in the summation operation. The main process involves spatial convolution of the P-wave component data and the multiple prediction seismic gather to obtain the multiple records of the free interface.

[0044] In one optional embodiment of the present invention, the seabed acquisition data includes converted wave component data, which is shear wave component data. The step of performing free interface multiple wave prediction based on the seabed acquisition data and the multiple wave prediction seismic gather to obtain the free interface multiple wave record further includes: performing frequency domain conversion processing on the wavefield-separated converted wave component data in the seabed acquisition data and the multiple wave prediction seismic gather.

[0045] Based on the frequency domain conversion results, multiple wave prediction of the free interface is performed to obtain the multiple wave record of the free interface.

[0046] Specifically, both the converted wave component data and the predicted multiple seismic gathers are in the time domain, meaning they are represented using the time axis as the coordinate. To facilitate multiple prediction, the converted wave component data and the predicted multiple seismic gathers in the seabed acquisition data can first be converted to the frequency domain, i.e., represented using the frequency axis as the coordinate. Then, based on the frequency domain conversion result, free interface multiple prediction is performed to obtain the free interface multiple records.

[0047] More preferably, the receiver point of the converted wave and the shot point of the multiple wave prediction seismic trace are the same point. Therefore, the converted wave and the target multiple wave prediction trace for multiple wave prediction can be determined based on the spatial coordinates of the receiver point of the converted wave and the spatial coordinates of the shot point of the multiple wave prediction seismic trace. Specifically, the multiple wave prediction seismic trace set is queried based on the spatial coordinates of the receiver point of any converted wave in the converted wave component data. The target multiple wave prediction trace set with the same shot point spatial coordinates as the receiver point spatial coordinates of the converted wave is obtained. The converted wave and the target multiple wave prediction trace are multiplied, and the multiplication results are summed to obtain the multiple wave record of the free interface.

[0048] Multiple prediction of free interfaces can be performed using the three-dimensional free interface multiple prediction equation (2):

[0049]

[0050] Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. X The predicted converted wave component data are the multiple wave records at the free interface, where X is the converted wave component data and H is the predicted multiple wave seismic gather; x k With y k This represents the spatial coordinates of the receiver point in the converted wave component X participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

[0051] In an optional embodiment of the present invention, when constructing the multiple prediction seismic gather required for free-interface multiple prediction of seabed acquired data by performing inverse migration of pre-stack time migration, a seismic wavelet different from the current source is introduced. In order to improve the accuracy and recording resolution of the multiple prediction results, the influence of this wavelet should be eliminated. The method further includes: calculating the free-interface factor based on the introduced seismic wavelet different from the current source and the free-interface reflection coefficient, wherein the reflection coefficient of the free interface (sea surface) can be set to -1; combining the elimination of the wavelet influence with the multiple recording phase correction, the free-interface factor calculation expression in the frequency domain is obtained as follows:

[0052] A(f) = [W(f)] -1 ·(-1)=-[W(f)] -1

[0053] In the formula: W(f) is the Fourier transform of the seismic wavelet w(t) extracted based on the inverse migration record, and f and t represent frequency and time, respectively.

[0054] After calculating the free interface factor, the step of performing free interface multiple wave prediction based on seabed data and the multiple wave prediction seismic gather to obtain the free interface multiple wave record can be further achieved by the following method: performing free interface multiple wave prediction based on seabed data, the multiple wave prediction seismic gather, and the free interface factor to obtain the free interface multiple wave record.

[0055] In an optional embodiment of the present invention, the method further includes: eliminating the multiple wave records of the free interface, for example, by eliminating the multiple wave records of the free interface through an adaptive attenuation method.

[0056] Area A is a shallow water region with a relatively flat seabed and a depth of approximately 40 meters. Seismic waves were continuously generated by a towed air gun source, and the seismic signals were received using ocean bottom cables (OBC). During seismic acquisition, eight cables (1920 in total) were laid on the seabed, and seismic signals were generated sequentially through 24 shot lines, with the distance between the receiving line and the shot line set at 400 meters and their directions perpendicular to each other. The sampling interval and recording length of the seismic data were 0.004 seconds and 8 seconds, respectively. Because both the sea surface and seabed are strong wave impedance interfaces, the corresponding seismic records contain a large number of high-amplitude free interface multiples, which severely affects the imaging quality of subsurface structures and can mislead subsequent geological interpretation and analysis. Therefore, the free interface multiple prediction method provided in this invention is needed for free interface multiple prediction.

[0057] In a specific embodiment of the present invention, the free interface multiple prediction method is implemented in the following five steps: 1) pre-stack time migration processing of conventional towed seismic data volume to obtain pre-stack time migration data volume; 2) inverse migration processing of the pre-stack time migration data volume to construct multiple prediction seismic gathers; 3) calculation of the free interface factor; 4) free interface multiple prediction based on the P-wave component data in the seabed acquisition data and the multiple prediction seismic gathers; 5) free interface multiple prediction based on the converted wave component data in the seabed acquisition data and the multiple prediction seismic gathers.

[0058] The above implementation method is described in detail below:

[0059] 1) Pre-stack time migration processing of conventional towed seismic data volumes to obtain pre-stack time migration data volumes.

[0060] The work area contains conventional towed seismic data acquired in the early stages. This data is input into the preprocessed shot gather, based on... Figure 4The wave velocity field shown is used for migration imaging. Kirchhoff pre-stack time migration is a mature migration imaging method currently in production. Given a migration velocity field, it can generate pre-stack time migration data volumes based on conventional towed seismic data volumes. These pre-stack time migration data volumes are then stacked to obtain pre-stack time migration profiles. Kirchhoff pre-stack migration in the shot gather domain can be expressed as an integral summation process of the following form:

[0061]

[0062] In the formula: I represents the pre-stack time offset data volume, η is the coordinates of the data volume sample points; W I S is the weighting factor for the Kirchhoff integral migration, τ represents the sum of the travel times of the ray from the shot point to the imaging point and from the imaging point to the receiver point, (S m G n D represents the coordinates of a gun-check pair; m This is the shot set record for towed cable data, where m and n are the shot number and track number, respectively, t represents the travel time, and M and N are the number of shots and tracks applied during offset, respectively.

[0063] Kirchhoff pre-stack time migration employs a ray tracing process using a "straight ray" model (see appendix). Figure 2 Therefore, the weighting factor W in equation (3) I (S m G n ,η) and travel time τ(S) m G n The calculation process of η is significantly simplified, and the two can be expressed as follows:

[0064]

[0065] In the formula: v(η) is the offset velocity of the first wave, cosθ represents the tilt factor, r0 is the distance from the shot point to the imaging point, and r is the distance from the imaging point to the shot point.

[0066] Based on the offset imaging processing according to formulas (3) and (4), the following was obtained: Figure 5 The offset data volume shown.

[0067] 2) Perform inverse pre-stack time migration processing on the pre-stack time migration data volume to construct multiple wave prediction seismic gathers.

[0068] Using the inverse process of Kirchhoff pre-stack time migration, a multiple prediction seismic gather that meets the prediction accuracy of free interface multiples is constructed. The pre-stack time migration data volume I(η) generated according to formula (3) is input, and the ray tracing process of the "straight ray" model of pre-stack time migration is introduced. Then, the time-domain Kirchhoff inverse migration formula can be expressed as:

[0069]

[0070] In the formula: H is the predicted seismic gather for multiple waves, x k With y k The x represents the spatial coordinates of the shot point with the reverse offset. r With y r The receiver's spatial coordinates represent the inverse migration; I(η) represents the pre-stack time migration data volume, where η is the coordinates of the profile sample points; ds represents the integration surface element; W H τ is the weighting factor for Kirchhoff reverse migration, and τ represents the sum of the travel times of the ray from the shot point to point η and from point η to the receiver point.

[0071] When performing multiple wave predictions based on a single shot concentration data point, x r With y r It is a fixed value, while x k With y k It is variable, therefore H(x) k ,y k ,x r ,y r ,t) represents the common receiver point gather record. It is important to note the integration weighting factor W during the reverse migration process. H (η,x k ,y k ,x r ,y r This differs somewhat from that in time-lapse imaging, and should be calculated using a more accurate Kirchhoff integral diffraction superposition method (see appendix). Figure 3 ),Right now

[0072]

[0073] In the formula: l0 and l are the propagation distances of the incident ray and the diffracted ray, respectively; θ0 and θ are the angles between l0, l and the surface element normal vector n, respectively; v(η) represents the seismic wave velocity, and η is the coordinate of the data volume sample point.

[0074] Input as follows Figure 4 The offset velocity field shown is as follows Figure 5 The conventional tow cable data offset data volume shown is constructed based on the time-domain Kirchhoff inverse offset of formulas (5) and (6) as follows. Figure 6 The earthquake records shown can be used as free interface multiples predictors in the prediction of free interface multiples in seabed data.

[0075] 3) Calculation of the free interface factor

[0076] When inputting the migration velocity field and imaging data volume of conventional towed cable data, and constructing the prediction factor required for multiple prediction of the free interface of seabed acquired data using time-domain Kirchhoff inverse migration, a seismic wavelet different from the current source will be introduced. To improve the accuracy and recording resolution of the multiple prediction results, the influence of this wavelet should be eliminated. The reflection coefficient of the free interface (sea surface) in marine seismic exploration can be set to -1, and phase correction is performed on the multiple prediction results accordingly. Combining the elimination of wavelet influence with the phase correction of multiple recordings yields the expression for calculating the free interface factor in the frequency domain.

[0077] A(f) = [W(f)] -1 ·(-1)=-[W(f)] -1 (7)

[0078] In the formula: W(f) is the Fourier transform of the seismic wavelet w(t) extracted based on the inverse migration record, and f and t represent frequency and time, respectively.

[0079] 4) Perform free interface multiple prediction based on the P-wave component data and multiple prediction seismic gathers in the seabed acquisition data.

[0080] Input P-wave component data (see) Figure 7 Using the time-domain Kirchhoff back-migration constructed seismic gathers for predicting multiples at free interfaces as predictors, both are transformed to the frequency domain and substituted into the three-dimensional free interface multiple prediction equation (1). The free interface multiple prediction process for the P-wave component is then as follows:

[0081]

[0082] Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. P These are the multiple wave records of the predicted P-wave components at the free interface, where P is the P-wave component data and H is the predicted multiple wave gather; x k With y k This represents the spatial coordinates of the receiver point in the P-wave component data P participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

[0083] The free interface factor A(f) calculated by introducing equation (7) can be further expressed as:

[0084]

[0085] Equation (8) is the multiple prediction equation that incorporates the multiple prediction factor and the free interface factor. This process is carried out in the frequency domain. After obtaining the multiple record based on Equation (8), the multiples in the P-wave component data P can be eliminated by the adaptive attenuation method.

[0086] Input P-wave component data (see) Figure 7 ), using time-domain Kirchhoff inverse migration to construct multiple wave prediction seismic gathers (see Figure 6 As the predictor factor required for free interface multiple prediction, free interface multiple prediction based on formula (8) was realized using seabed-acquired data, and the following results were obtained: Figure 8 The multiple wave records shown contain rich multiple wave information. A comparison reveals that, as... Figure 7 and Figure 8 The travel times of the multiple phase axes in the two records shown are basically the same, which proves the effectiveness of the free interface multiple prediction method.

[0087] 5) Perform free interface multiple prediction based on converted wave component data and multiple prediction seismic gathers from seabed acquisition data.

[0088] Inputting the converted wave component data from wavefield separation, and using the multiple prediction seismic gathers constructed from time-domain Kirchhoff inverse migration as the predictor factors required for free-interface multiple prediction, both are transformed to the frequency domain and substituted into the three-dimensional free-interface multiple prediction equation. The free-interface multiple prediction process for the converted wave components is then as follows:

[0089]

[0090] Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. X The predicted converted wave component data are the multiple wave records at the free interface, where X is the converted wave component data and H is the predicted multiple wave seismic gather; x k With y k This represents the spatial coordinates of the receiver point in the converted wave component X participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

[0091] The free interface factor A(f) calculated by introducing equation (7) can be further expressed as:

[0092]

[0093] Equation (9) is the multiple prediction equation that incorporates the multiple prediction factor and the free interface factor. This process is carried out in the frequency domain. After obtaining the multiple record based on Equation (9), the multiples in the converted wave component data X can be eliminated by the adaptive attenuation method.

[0094] The solution provided by this invention enables three-dimensional free-interface multiple prediction of P-wave and converted-wave components in seabed-acquired data. This effectively solves the problem that conventional towed SRME methods cannot be applied to this type of data, and significantly improves the multiple suppression effect of P-wave and converted-wave components in seabed-acquired data. Compared with wavefield extrapolation-based multiple prediction techniques, this method has a significant accuracy advantage. This is because the former can only predict a portion of the free-interface multiples—ghost waves and seabed multiples (full-range seabed multiples and seabed-related micro-bending multiples), while this invention can predict all free-interface multiple components in the data, thus inevitably further improving the accuracy of multiple removal.

[0095] Figure 9 A schematic diagram of a free interface multiple wave prediction device according to an embodiment of the present invention is shown. Figure 9 As shown, the device includes:

[0096] Processing module 901 is adapted to perform pre-stack time migration processing on towed seismic data volumes to obtain pre-stack time migration data volumes;

[0097] The construction module 902 is adapted to perform inverse migration processing of the pre-stack time migration data volume to construct a multiple wave prediction seismic gather.

[0098] The prediction module 903 is adapted to perform free interface multiple prediction based on seabed data and the multiple prediction seismic gathers, and obtain the free interface multiple record.

[0099] Optionally, the prediction module is further adapted to: perform frequency domain conversion processing on the P-wave component data in the seabed acquisition data and the predicted multiple wave seismic gathers;

[0100] Based on the frequency domain conversion results, multiple wave prediction of the free interface is performed to obtain the multiple wave record of the free interface.

[0101] Optionally, the prediction module is further adapted to: perform free interface multiple prediction using the three-dimensional free interface multiple prediction equation (1):

[0102]

[0103] Where, x s With y s The spatial coordinates of the shot point, x r With y rThe spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. P These are the multiple wave records of the predicted P-wave components at the free interface, where P is the P-wave component data and H is the predicted multiple wave gather; x k With y k This represents the spatial coordinates of the receiver point in the P-wave component data P participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

[0104] Optionally, the prediction module is further adapted to: perform frequency domain conversion processing on the wavefield-separated converted wave component data and the multiple wave prediction seismic gathers in the seabed acquisition data;

[0105] Based on the frequency domain conversion results, multiple wave prediction of the free interface is performed to obtain the multiple wave record of the free interface.

[0106] Optionally, the prediction module is further adapted to: perform free interface multiple prediction using the three-dimensional free interface multiple prediction equation (2):

[0107]

[0108] Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. X The predicted converted wave component data are the multiple wave records at the free interface, where X is the converted wave component data and H is the predicted multiple wave seismic gather; x k With y k This represents the spatial coordinates of the receiver point in the converted wave component X participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

[0109] Optionally, the device further includes: a calculation module adapted to calculate the free interface factor based on the introduced seismic wavelet different from the current source and the free interface reflection coefficient;

[0110] The prediction module is further adapted to: perform free interface multiple prediction based on seabed data, the predicted multiple seismic gathers, and the free interface factor, to obtain the free interface multiple record.

[0111] Optionally, the apparatus further includes an elimination module adapted to eliminate multiple wave records of the free interface.

[0112] The solution provided by this invention enables three-dimensional free-interface multiple prediction of P-wave and converted-wave components in seabed-acquired data. This effectively solves the problem that conventional towed SRME methods cannot be applied to this type of data, and significantly improves the multiple suppression effect of P-wave and converted-wave components in seabed-acquired data. Compared with wavefield extrapolation-based multiple prediction techniques, this method has a significant accuracy advantage. This is because the former can only predict a portion of the free-interface multiples—ghost waves and seabed multiples (full-range seabed multiples and seabed-related micro-bending multiples), while this invention can predict all free-interface multiple components in the data, thus inevitably further improving the accuracy of multiple removal.

[0113] This application also provides a non-volatile computer storage medium storing at least one executable instruction that can execute the free interface multiple wave prediction method in any of the above method embodiments.

[0114] Figure 10 A schematic diagram of a computing device according to an embodiment of the present invention is shown. The specific embodiments of the present invention do not limit the specific implementation of the computing device.

[0115] like Figure 10 As shown, the computing device may include: a processor 1002, a communications interface 1004, a memory 1006, and a communications bus 1008.

[0116] The processor 1002, communication interface 1004, and memory 1006 communicate with each other via communication bus 1008.

[0117] Communication interface 1004 is used to communicate with other network elements such as clients or other servers.

[0118] The processor 1002 is used to execute program 1010, which can specifically execute the relevant steps in the above-described free interface multiple wave prediction method embodiment.

[0119] Specifically, program 1010 may include program code that includes computer operation instructions.

[0120] The processor 1002 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The computing device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0121] Memory 1006 is used to store program 1010. Memory 1006 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0122] Specifically, program 1010 can be used to cause processor 1002 to execute the free interface multiple wave prediction method in any of the above method embodiments. The specific implementation of each step in program 1010 can be found in the corresponding descriptions of the steps and units in the above free interface multiple wave prediction embodiments, and will not be repeated here. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the devices and modules described above can be referred to the corresponding process descriptions in the foregoing method embodiments, and will not be repeated here.

[0123] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, the embodiments of the present invention are not directed to any particular programming language. It should be understood that the content of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0124] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0125] Similarly, it should be understood that, in order to simplify the invention and aid in understanding one or more of the various inventive aspects, features of the embodiments of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the above description of exemplary embodiments of the invention. However, this disclosure should not be construed as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0126] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0127] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0128] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components according to the embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0129] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.

Claims

1. A free-interface multiple wave prediction method, comprising: Pre-stack time migration processing is performed on the towed seismic data volume to obtain the pre-stack time migration data volume; The pre-stack time migration data volume is subjected to inverse pre-stack time migration processing to construct a multiple wave prediction seismic gather; Based on the seabed data and the predicted multiple seismic gathers, multiple predictions of the free interface are performed to obtain the multiple records of the free interface.

2. The method according to claim 1, wherein, The step of performing free-interface multiple prediction based on seabed data and the multiple prediction seismic gathers to obtain the free-interface multiple record further includes: Frequency domain conversion processing is performed on the P-wave component data in the seabed acquisition data and the predicted seismic gathers of the multiple waves. Based on the frequency domain conversion results, multiple wave prediction of the free interface is performed to obtain the multiple wave record of the free interface.

3. The method according to claim 2, wherein, The step of predicting multiple waves of the free interface based on the frequency domain conversion result to obtain the multiple wave record of the free interface further includes: Free interface multiple prediction is performed using the three-dimensional free interface multiple prediction equation (1): Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. P These are the multiple wave records of the predicted P-wave components at the free interface, where P is the P-wave component data and H is the predicted multiple wave gather; x k With y k This represents the spatial coordinates of the receiver point in the P-wave component data P participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

4. The method according to any one of claims 1-3, wherein, The step of performing free-interface multiple prediction based on seabed data and the multiple prediction seismic gathers to obtain the free-interface multiple record further includes: Frequency domain conversion processing is performed on the wavefield-separated transformed wave component data and the predicted seismic gathers of the multiple waves in the seabed acquisition data. Based on the frequency domain conversion results, multiple wave prediction of the free interface is performed to obtain the multiple wave record of the free interface.

5. The method according to claim 4, wherein, The step of predicting multiple waves of the free interface based on the frequency domain conversion result to obtain the multiple wave record of the free interface further includes: Free interface multiple prediction is performed using the three-dimensional free interface multiple prediction equation (2): Where, x s With y s The spatial coordinates of the shot point, x r With y r The spatial coordinates of the receiving point are represented by f, and the frequency is represented by M. X The predicted converted wave component data are the multiple wave records at the free interface, where X is the converted wave component data and H is the predicted multiple wave seismic gather; x k With y k This represents the spatial coordinates of the receiver point in the converted wave component X participating in the summation operation, and the spatial coordinates of the shot point in the multiple wave prediction seismic gather H.

6. The method according to any one of claims 1-3, wherein, The method further includes: calculating the free interface factor based on the introduced seismic wavelet different from the current seismic source and the free interface reflection coefficient; The step of performing free-interface multiple prediction based on seabed data and the multiple prediction seismic gathers to obtain the free-interface multiple record further includes: Based on seabed data, the predicted multiple seismic gathers, and the free interface factor, free interface multiple prediction is performed to obtain the free interface multiple record.

7. The method according to any one of claims 1-3, wherein, The method further includes: eliminating the multiple wave records of the free interface.

8. A free-interface multiple wave prediction device, comprising: The processing module is suitable for performing pre-stack time migration processing on towed seismic data volumes to obtain pre-stack time migration data volumes. The construction module is adapted to perform inverse migration processing on the pre-stack time migration data volume to construct a multiple wave prediction seismic gather. The prediction module is adapted to perform free interface multiple wave prediction based on seabed data and the multiple wave prediction seismic gather, and obtain the free interface multiple wave record.

9. A computing device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation corresponding to the free interface multiple wave prediction method as described in any one of claims 1-7.

10. A computer storage medium storing at least one executable instruction that causes a processor to perform an operation corresponding to the free interface multiple wave prediction method as described in any one of claims 1-7.

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