Marchenko-based method for suppressing surface and interlayer multiples in marine streamer seismic data

Abstract

The invention relates to a Marchenko-based method for suppressing surface and interlayer multiples in marine streamer seismic data, and the method comprises the steps: collecting the marine streamer seismic data, and reconstructing a first Green function of a wave field comprising the surface multiples and the interlayer multiples according to the marine streamer seismic data after the completion of detection point data based on a Marchenko equation set comprising a free surface effect; predicting surface multiples through single-channel convolution; and adaptively attenuating the predicted surface multiples from the seismic data of the marine towrope to obtain intermediate reflection data. Inputting the intermediate reflection data into a classical Marchenko equation set, and reconstructing a second Green function comprising interlayer multiples; on the basis of a second Green function, predicting interlayer multiples through single-channel convolution; and adaptively attenuating the interlayer multiples from the intermediate reflection data to obtain reflection wave seismic data in which the surface multiples and the interlayer multiples are suppressed. Compared with the prior art, the method has the advantages of high precision, high adaptability, high robustness and the like.

Description

Technical Field

[0001] This invention relates to the field of geophysical exploration technology, and in particular to a method for suppressing surface and interlayer multiple waves in marine towed seismic data based on Marchenko. Background Technology

[0002] In the field of geophysical exploration technology, multiple reflections have long been a challenge in seismic data processing. Because the presence of multiples can create artifacts in the imaging of primary reflections, introducing significant uncertainty into subsequent seismic interpretation, conventional seismic data processing typically treats multiples as noise and suppresses them.

[0003] Based on their formation mechanisms, multiples can be broadly classified into two categories: free-surface multiples and interlayer multiples. In marine seismic exploration, free-surface multiples are highly developed, but their travel-time relationships are relatively simple, making them easy to identify and suppress. In seismic imaging profiles, artifacts caused by free-surface multiples are usually easily identifiable and eliminated. However, when complex geological structures exist underground (such as hillocks, volcanic bodies, abrupt lithological changes, or unconformities), interlayer multiples are often highly developed. Due to their complex propagation paths, variable travel-time relationships, and superposition with primary reflections, they possess strong concealment, making them difficult to identify and separate in seismic imaging profiles, severely impacting the accuracy of structural interpretation.

[0004] In industry, surface-related multiple elimination (SRME) is commonly used to suppress free surface multiples, and this method has been widely applied. However, for inter-layer multiples, due to their more complex wavefield and kinematic characteristics, effective suppression remains a technical bottleneck in current seismic data processing. The Marchenko method, proposed in recent years, is a data-driven wavefield reconstruction technique. Its core principle is to iteratively solve for the Green's function using wavefield reciprocity, data convolution, and cross-correlation, thereby identifying and suppressing inter-layer multiples. This method does not rely on an accurate velocity model, and therefore has attracted widespread attention in academia.

[0005] However, the current Marchenko method is mainly used for suppressing interlayer multiples, and its theoretical assumption requires that the input data should not contain surface-related multiples. Therefore, in practical applications, it is usually necessary to first remove surface multiples using the SRME method before using the processed data as input to the Marchenko method. This step-by-step processing strategy has the following problems: First, the SRME and Marchenko methods are based on different theoretical assumptions and implementation paths, and their coupling is weak, making it difficult to achieve effective transfer of energy and wavefield information; second, residual surface multiple energy that is not completely suppressed or is incorrectly estimated in the preceding SRME step will be transmitted as errors to the subsequent Marchenko processing stage, causing errors to accumulate gradually and affecting the overall effect of multiple suppression and the fidelity of the primary reflection signal; in addition, step-by-step processing also increases the complexity of the data processing flow, limiting the application potential of the Marchenko method in joint suppression of multiples. Therefore, how to achieve efficient joint suppression of free surface multiples and interlayer multiples in marine towed seismic data within a unified theoretical framework, and avoid the problems of error accumulation and process complexity caused by step-by-step processing, is a technical problem that needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a method for suppressing surface and interlayer multiples in marine towed seismic data based on Marchenko. Within the unified Marchenko theoretical framework, the method directly processes the raw data containing surface multiples by introducing the Marchenko equations with free surface effects, thereby avoiding the theoretical inconsistencies and error accumulation problems caused by the cascade processing of SRME and Marchenko in traditional methods, and achieving integrated and efficient suppression of surface and interlayer multiples.

[0007] The objective of this invention can be achieved through the following technical solutions: According to one aspect of the present invention, a method for suppressing surface and interlayer multiple waves in marine towed seismic data based on Marchenko is provided, the specific steps of which include: S1. Acquire marine towed cable seismic data, and complete the receiver data according to the reciprocity theorem based on the common shot gather, so that the marine towed cable seismic data meets the requirements of shot point and receiver coupling. S2. Based on the Marchenko equations including free surface effects, the first Green's function of the wavefield including surface multiples and interlayer multiples is reconstructed from the ocean towed seismic data supplemented by the receiver data; based on the first Green's function, surface multiples are predicted by single-channel convolution; intermediate reflection data is obtained from the predicted surface multiples in the ocean towed seismic data with adaptive attenuation, wherein the intermediate reflection data includes reflected waves and interlayer multiples; S3. Input the intermediate reflection data into the classical Marchenko equations to reconstruct the second Green's function including interlayer multiples; predict interlayer multiples through single-channel convolution based on the second Green's function; adaptively attenuate interlayer multiples from the intermediate reflection data to obtain reflected seismic data that suppresses surface multiples and interlayer multiples.

[0008] Furthermore, in S2, the specific steps for reconstructing the first Green's function of the wavefield, including surface multiples and interlayer multiples, include: Estimate the seawater depth and select a set depth in the water layer as the first virtual reference interface. Arrange virtual seismic sources as focal points on the first virtual reference interface. Estimate the direct wave corresponding to each of the aforementioned focal points; Based on the Marchenko equations, which include free surface effects, the direct wave is used as the initial condition for iterative solution to obtain the uplink and downlink first Green's functions at each focal point.

[0009] Furthermore, the Marchenko equations, which include the free surface effect, are expressed as follows: in, For seismic data including surface multiples and interlayer multiples, For the focal point position, The location of the actual shot point on the ground or at the tow cable is the integral variable. This refers to a predetermined location on the ground or at the tow cable where the actual blasting point is located. r For the reflection response with a free surface, The boundary of the data acquisition surface. and It is the reconstructed first Green's function for both the uplink and downlink. and It is the uplink and downlink focusing function used for the first Green's function. For the current time, This is the time variable for integration.

[0010] Furthermore, the initial value of the focusing function and Using the time reversal method of direct wave To substitute.

[0011] Furthermore, in S3, the specific steps for reconstructing the second Green's function, which includes interlayer multiples, include: Based on the underground geological structure, at least one second virtual reference interface is selected at the depth where interlayer multiples develop, and a virtual seismic source is arranged on the second virtual reference interface as the focal point. Estimate the direct wave corresponding to each of the aforementioned focal points; Based on the classical Marchenko equations, the direct wave is used as the initial condition for iterative solution to obtain the second Green's function, which includes interlayer multiples, at each focal point.

[0012] Furthermore, the expression for the single-channel convolution is: , in, For the predicted multiple waves, and These are the uplink and downlink Green's functions after removing the direct wave, respectively. This is a virtual reference interface. For the density of the medium, and The location of the excitation point. For the virtual reference interface The integration variable points on the surface.

[0013] Furthermore, the adaptive attenuation method in S2 and S3 is a subtraction method based on amplitude matching.

[0014] Furthermore, after obtaining the first Green's function and the second Green's function, direct wave removal processing is performed on both.

[0015] According to a second aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described thereon.

[0016] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention avoids the accumulation of errors caused by the sequential processing of different theoretical methods, thus improving the overall accuracy of multiple suppression: In the prior art, the SRME method based on wave theory prediction is used to suppress surface multiples first, and then the processed data is input into the Marchenko method based on Green's function reconstruction to process interlayer multiples. This step-by-step strategy means that the residual surface multiple energy that was not completely suppressed or was incorrectly estimated in the preceding SRME step will be transmitted as an error source to the input data of the subsequent Marchenko method, resulting in the introduction and accumulation of errors at the junction of different theoretical frameworks. The invention provides a unified Marchenko theoretical framework, which directly processes the original data containing surface multiples by introducing the Marchenko equations of free surface effects, and sequentially completes the identification and suppression of surface multiples and interlayer multiples under this framework. Since the identification and suppression of all multiples follow the same physical assumption (Green's function reconstruction), it fundamentally avoids the theoretical inconsistency and error propagation problems caused by the step-by-step processing of different theoretical methods, thereby significantly improving the overall accuracy of multiple suppression and the fidelity of the primary reflection wave signal.

[0018] (2) The processing flow is simplified, and the integration and applicability of the method are enhanced: Traditional methods suppress surface multiples and interlayer multiples separately, requiring the execution of two independent processing flows, SRME and Marchenko, which are cumbersome and poorly coupled. This invention eliminates the preceding SRME step and uses a joint suppression method based on the extended Marchenko equations. Taking the original marine towed seismic data after shot-receiver reciprocity completion as input, and by setting virtual reference interfaces at different depths, the wavefield containing surface multiples is reconstructed and suppressed within the same Marchenko mathematical framework. Then, the wavefield of the remaining data is reconstructed to suppress interlayer multiples. This not only significantly simplifies the data processing flow and reduces operational complexity, but also expands the application scope of the Marchenko method from single interlayer multiple suppression to simultaneous processing of free surface multiples, enhancing the overall applicability to marine towed seismic data.

[0019] (3) Reduced dependence on macroscopic background velocity model and improved robustness of method: When predicting multiple waves, the core step of this invention is to perform single-channel convolution of the reconstructed up and down Green functions. It relies on the wave field propagation path information contained in the reconstructed Green function itself. This information is obtained through data-driven Marchenko iteration process and essentially contains multiple stable phase points of wave propagation in actual complex media. Therefore, even if there is a certain error in the macroscopic background velocity model used, it mainly affects the specific location of the stable phase points and will not fundamentally change the multiple wave prediction path determined by the Green function. This makes the multiple wave prediction and suppression process of this invention insensitive to the accuracy of macroscopic velocity model, making it a more robust multiple wave processing technology, which is conducive to obtaining stable and reliable multiple wave suppression effect in sea areas with complex velocity structure. Attached Figure Description

[0020] Figure 1 This is a flowchart of surface and interlayer multiple wave suppression methods in marine towed seismic data based on Marchenko. Figure 2 Data flow diagrams for surface and interlayer multiple suppression methods in marine towed seismic data based on Marchenko; Figure 3 This is a schematic diagram of a single-shot recording in this embodiment; Figure 4 This is the direct wave simulated at the focal point of the first virtual reference interface at a water depth of 60 meters in this embodiment; Figure 5 This is a schematic diagram of the reconstructed upward and downward Green's functions at different underground depths of 60 meters, 800 meters, and 1500 meters in this embodiment.

[0021] Figure 6 This is a schematic diagram of the predicted multiple waves at different underground depths of 60 meters, 800 meters, and 1500 meters in this embodiment.

[0022] Figure 7 This is a comparison diagram of the suppression effect of multiple waves in this embodiment.

[0023] Figure 8 This is a schematic diagram illustrating the path principle for predicting multiple waves in this embodiment. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] Since the existing Marchenko method is mainly for interlayer multiple suppression, its application presupposes that the input data does not contain free surface multiples. Therefore, in practical processing, it is necessary to rely on the SRME method for preprocessing to suppress surface multiples. This cascade processing strategy of SRME and Marchenko has certain drawbacks: First, the two methods are based on different theoretical assumptions and implementation paths. The residual surface multiple energy that was not completely suppressed in the preceding SRME step will be transmitted as an error source to the subsequent Marchenko processing stage, causing errors to be introduced and accumulated at the junction of the two theoretical frameworks, reducing the overall suppression accuracy. Second, the step-by-step processing increases the complexity of the data processing flow, and the weak coupling between the two makes it difficult to achieve effective transmission of energy and wavefield information, limiting the application potential of the Marchenko method in joint multiple suppression. To address the aforementioned issues, this embodiment provides a method for suppressing surface and interlayer multiples in marine towed seismic data based on Marchenko equations. By introducing Marchenko equations for free surface effects, it sequentially identifies and suppresses surface and interlayer multiples within a unified theoretical framework. This not only avoids theoretical inconsistencies and error accumulation caused by the cascading of different theoretical methods, but also simplifies the processing flow and improves the overall effect and fidelity of multiple suppression.

[0026] like Figure 1 As shown in this embodiment, a surface and interlayer multiple wave suppression method based on Marchenko seismic data of an ocean towed cable is provided. The specific steps include: S1. Acquire marine towed cable seismic data, and complete the receiver data according to the reciprocity theorem based on the common shot gather, so that the marine towed cable seismic data meets the requirements of shot point and receiver coupling. S2. Based on the Marchenko equations including free surface effects, the first Green's function of the wavefield including surface multiples and interlayer multiples is reconstructed from the ocean towed seismic data supplemented by the receiver data; based on the first Green's function, surface multiples are predicted by single-channel convolution; intermediate reflection data is obtained from the surface multiples predicted by adaptive attenuation from the ocean towed seismic data, and the intermediate reflection data includes reflected waves and interlayer multiples. S3. Input the intermediate reflection data into the classical Marchenko equations to reconstruct the second Green's function, which includes interlayer multiples; based on the second Green's function, predict interlayer multiples through single-channel convolution; adaptively attenuate interlayer multiples from the intermediate reflection data to obtain seismic reflection data that suppresses surface multiples and interlayer multiples.

[0027] like Figure 2 The figure shown is a data flow diagram of surface and interlayer multiple wave suppression methods in marine towed seismic data based on Marchenko.

[0028] Specifically, in S2, the specific steps for reconstructing the first Green's function of the wavefield, which includes surface multiples and interlayer multiples, include: Estimate the seawater depth and select a set depth in the water layer as the first virtual reference interface. Arrange virtual seismic sources as focal points on the first virtual reference interface. Estimate the direct wave corresponding to each focal point; Based on the Marchenko equations, which include free surface effects, the first Green's function for both uplink and downlink at each focal point is obtained by iteratively solving the equations using the direct wave as the initial condition.

[0029] The Marchenko equations, including the free surface effect, are expressed as follows: in, For seismic data including surface multiples and interlayer multiples, For the focal point position, The location of the actual shot point on the ground or at the tow cable is the integral variable. This refers to a predetermined location on the ground or at the tow cable where the actual blasting point is located. r For the reflection response with a free surface, The boundary of the data acquisition surface. and It is the reconstructed first Green's function for both the uplink and downlink. and It is the uplink and downlink focusing function used for the first Green's function. For the current time, The time variable is the integral time variable. The initial value of the focusing function. and Using the time reversal method of direct wave To substitute.

[0030] In S3, the specific steps for reconstructing the second Green's function, which includes interlayer multiples, include: Based on the underground geological structure, at least one second virtual reference interface is selected at the depth where interlayer multiples develop, and a virtual seismic source is arranged on the second virtual reference interface as the focal point. Estimate the direct wave corresponding to each focal point; Based on the classical Marchenko equations, the second Green's function, including interlayer multiples, is obtained at each focal point by iteratively solving the problem using the direct wave as the initial condition.

[0031] The expression for a single-channel convolution is: , in, For the predicted multiple waves, and These are the uplink and downlink Green's functions after removing the direct wave, respectively. This is a virtual reference interface. For the density of the medium, and The location of the excitation point. For the virtual reference interface The integration variable points on the surface.

[0032] Furthermore, the adaptive attenuation methods in S2 and S3 are subtraction methods based on amplitude matching. Also, after obtaining the first and second Green's functions, direct wave removal processing is performed in both cases.

[0033] To verify the effectiveness of this method, this embodiment uses actual marine towed cable seismic data collected in a certain sea area for processing. The input marine towed cable seismic data has a sampling interval of 4ms, a sampling time of 4s, a shot-to-shot distance of 25m, and a original trace spacing of 12.5m. For testing convenience, the trace spacing is reduced to 25m. Based on the common shot gathers of this data, the reciprocity theorem is used to complete the receiver data, ensuring that the data meets the coupling requirements between shot and receiver points. Figure 3 The diagram shown is a schematic of a single-shot record in this embodiment. (a) is the original single-shot record, and (b) is the single-shot record completed after shot-receiver exchange. The white box marks the first-order free surface multiples present in the data.

[0034] To estimate the seawater depth, a depth of 60 meters is selected as the first virtual reference interface within the water column. Virtual seismic sources are then positioned on this interface as focal points, and the direct wave corresponding to each focal point is estimated. For example... Figure 4 The figure shows a simulated direct wave at the focal point of a first virtual reference interface at a water depth of 60 meters. Based on the Marchenko equations, which include free surface effects, the direct wave is used as the initial condition for iterative solution to obtain the uplink and downlink first Green's functions at each focal point. Direct wave removal is then applied to the reconstructed first Green's functions.

[0035] Surface multiples are predicted using the first Green's function after removing the direct wave, through single-channel integration. Then, the predicted surface multiples are subtracted from the raw ocean towed seismic data using an amplitude-matched adaptive attenuation method to obtain intermediate reflection data, including reflected waves and interlayer multiples.

[0036] Based on the underground geological structure and the depths where interlayer multiples develop, this embodiment selects depths of 800 meters and 1500 meters to establish second virtual reference interfaces. Virtual seismic sources are placed on these interfaces as focal points, and the direct wave corresponding to each focal point is estimated. Intermediate reflection data are input into the classical Marchenko equations, and the direct waves are used as initial conditions for iterative solving to obtain the second Green's function at each focal point. Similarly, the reconstructed second Green's function is subjected to direct wave removal. Figure 5 The diagram shows the reconstructed upward and downward Green's functions at different underground depths (60 meters, 800 meters, and 1500 meters).

[0037] Using the second Green's function after removing the direct wave, interlayer multiples are predicted through single-channel integration. For example... Figure 6 The diagram shows predicted multiples at different depths underground. (a) shows the predicted surface multiples at a depth of 60 meters, and (b) and (c) show the predicted inter-layer multiples at depths of 800 meters and 1500 meters, respectively. The red and green arrows indicate the multiples. Subsequently, the predicted inter-layer multiples are subtracted from the intermediate reflection data using an adaptive attenuation method based on amplitude matching, ultimately yielding the primary reflection seismic data that suppresses both surface and inter-layer multiples.

[0038] like Figure 7 The image shows a comparison of the multiple wave suppression effect, where (a) and (c) show the comparison of the common offset gathers before and after suppression, respectively, and (b) and (d) show the corresponding autocorrelation spectra. It can be seen that the multiple wave signal was successfully attenuated, and the autocorrelation spectrum results further verify the reliability of this method. Figure 8 This is a schematic diagram of the path principle for predicting multiple waves in this embodiment. The red and green asterisks represent the stable phase points in the single-channel integral calculation. This method utilizes the information of multiple stable phase points contained in the reconstructed Green's function, making the prediction insensitive to macroscopic background velocity errors. It mainly changes the position of the stable phase points without changing the predicted wave path, demonstrating the robustness of the method.

[0039] In existing technologies, there is a problem of error accumulation due to inconsistencies in theoretical foundations. SRME and Marchenko methods are based on different theoretical assumptions and implementation paths. When these two methods are cascaded, residual surface multiple energy that was not fully suppressed or was incorrectly estimated in the preceding SRME step will be passed on as an error source to the input data of the subsequent Marchenko method. This causes errors to be introduced and accumulated at the intersection of different theoretical frameworks, reducing the accuracy of the subsequent Marchenko method in suppressing interlayer multiples. In addition, the processing flow has poor coupling: the final effect of this step-by-step cascade strategy is limited by the suppression accuracy of the preceding SRME step, and the two cannot achieve integrated coupling processing.

[0040] Because this invention treats both types of multiples uniformly within a single, self-consistent Marchenko theoretical framework, the identification and suppression of all multiples follow the same physical assumption (Green's function reconstruction). This fundamentally avoids the theoretical inconsistencies and error propagation accumulation problems caused by the step-by-step processing of different theoretical methods in the prior art. Furthermore, this invention extends the application of the Marchenko method from treating only inter-layer multiples to simultaneously treating free-surface multiples, achieving integrated suppression of both major types of multiples.

[0041] Therefore, by processing surface and interlayer multiples sequentially within the same Marchenko theoretical framework, this invention effectively avoids the problems of error accumulation and process redundancy in traditional cascade methods, improves the multiple suppression accuracy and processing efficiency of marine towed seismic data, and can provide a more reliable high-fidelity data foundation for seismic imaging and tectonic interpretation in complex marine areas, which is of positive significance for promoting the advancement of seismic exploration data processing technology.

[0042] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0043] The electronic device of this invention includes a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (ROM) or loaded from a storage unit into random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0044] Multiple components in the device are connected to an I / O interface, including: input units such as a keyboard, mouse, etc.; output units such as various types of displays, speakers, etc.; storage units such as disks, optical disks, etc.; and communication units such as network interface cards, modems, wireless transceivers, etc. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks. The processing unit performs the various methods and processes described above, such as the method of the present invention. For example, in some embodiments, the method of the present invention may be implemented as a computer software program tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or the communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of the method of the present invention described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute the method of the present invention by any other suitable means (e.g., by means of firmware).

[0045] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0046] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0047] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for suppressing surface and interlayer multiple waves in marine towed seismic data based on Marchenko, characterized in that, The specific steps include: S1. Acquire marine towed cable seismic data, and complete the receiver data according to the reciprocity theorem based on the common shot gather, so that the marine towed cable seismic data meets the requirements of shot point and receiver coupling. S2. Based on the Marchenko equations including free surface effects, the first Green's function of the wavefield including surface multiples and interlayer multiples is reconstructed from the ocean towed seismic data supplemented by the receiver data; based on the first Green's function, surface multiples are predicted by single-channel convolution; intermediate reflection data is obtained from the predicted surface multiples in the ocean towed seismic data with adaptive attenuation, wherein the intermediate reflection data includes reflected waves and interlayer multiples; S3. Input the intermediate reflection data into the classical Marchenko equations to reconstruct the second Green's function including interlayer multiples; predict interlayer multiples through single-channel convolution based on the second Green's function; adaptively attenuate interlayer multiples from the intermediate reflection data to obtain reflected seismic data that suppresses surface multiples and interlayer multiples.

2. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 1, is characterized in that... In step S2, the specific steps for reconstructing the first Green's function of the wavefield, which includes surface multiples and interlayer multiples, include: Estimate the seawater depth and select a set depth in the water layer as the first virtual reference interface. Arrange virtual seismic sources as focal points on the first virtual reference interface. Estimate the direct wave corresponding to each of the aforementioned focal points; Based on the Marchenko equations, which include free surface effects, the direct wave is used as the initial condition for iterative solution to obtain the uplink and downlink first Green's functions at each focal point.

3. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 2, is characterized in that... The Marchenko equations, which include the free surface effect, are expressed as follows: in, For seismic data including surface multiples and interlayer multiples, For the focal point position, The location of the actual shot point on the ground or at the tow cable is the integral variable. This refers to a predetermined location on the ground or at the tow cable where the actual blasting point is located. r For the reflection response with a free surface, The boundary of the data acquisition surface. and It is the reconstructed first Green's function for both the uplink and downlink. and It is the uplink and downlink focusing function used for the first Green's function. For the current time, This is the time variable for integration.

4. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 3, is characterized in that... The initial value of the focusing function and Using the time reversal method of direct wave To substitute.

5. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 1, is characterized in that... In step S3, the specific steps for reconstructing the second Green's function, which includes interlayer multiples, include: Based on the underground geological structure, at least one second virtual reference interface is selected at the depth where interlayer multiples develop, and a virtual seismic source is arranged on the second virtual reference interface as the focal point. Estimate the direct wave corresponding to each of the aforementioned focal points; Based on the classical Marchenko equations, the direct wave is used as the initial condition for iterative solution to obtain the second Green's function, which includes interlayer multiples, at each focal point.

6. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 1, is characterized in that... The expression for the single-channel convolution is: ， in, For the predicted multiple waves, and These are the uplink and downlink Green's functions after removing the direct wave, respectively. This is a virtual reference interface. For the density of the medium, and The location of the excitation point. For the virtual reference interface The integration variable points on the surface.

7. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 1, is characterized in that... The adaptive attenuation method in S2 and S3 is a subtraction method based on amplitude matching.

8. The surface and interlayer multiple wave suppression method for marine towed seismic data based on Marchenko, as described in claim 1, is characterized in that... After obtaining the first Green's function and the second Green's function, direct wave removal processing is performed on both.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 8.

Images