Method and system for suppressing direct wave interference of marine OBN data, and storage medium

Abstract

The application provides a method, system and storage medium for suppressing direct wave interference of marine OBN data. The method comprises the following steps: separating effective signals and noises by using Tau-P transformation; identifying and picking up direct wave noise signals in a three-dimensional Tau-P domain; performing high-precision three-dimensional Tau-P inverse transformation on the picked-up strong energy to obtain a time-domain direct wave noise model; and obtaining the time-domain direct wave noise by performing inverse transformation on the picked-up strong energy. The least square adaptive subtraction technology for multiple wave attenuation is applied to direct wave denoising, the three-dimensional Tau-P transformation technology, adaptive picking and least square adaptive subtraction technology are combined and introduced into OBN data direct wave denoising processing for the first time, the high-precision Tau-P transformation technology, adaptive amplitude picking technology and least square adaptive subtraction technology are optimally combined and applied to direct wave noise attenuation, the limitation of direct denoising of traditional technology is broken, and the fidelity and precision of direct wave denoising containing false frequencies are improved.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration seismic data processing technology, specifically to a method, system, and storage medium for suppressing spurious frequency direct wave interference in marine OBN data. Background Technology

[0002] Compared with traditional narrow azimuth (NAZ) towed cable acquisition, seabed node (OBN) exploration has the advantages of flexible acquisition and construction, ultra-long offset reception, all-round, high coverage, repeatability, and wide frequency and multi-component capabilities. In recent years, it has become a hot technical method in marine seismic exploration and is playing an increasingly important role in the exploration and development of complex marine oil and gas fields and reservoirs, gradually replacing towed cable acquisition.

[0003] In seabed node (OBN) acquisition, three-component geophones for both water and land are buried on the seabed to record pressure and velocity data. Direct wave interference exists in both water and land surveys, especially when shot points are sparse, which can cause strong false frequency interference, seriously affecting data quality, creating structural artifacts, and increasing exploration risks. This interference must be removed during processing.

[0004] However, conventional methods such as FX-domain coherent denoising, FK filtering, and two-dimensional Tau-P domain denoising can effectively remove direct waves without spurious frequency interference, but they are powerless against direct waves containing spurious frequencies. Therefore, the residual spurious frequency interference after denoising by conventional methods directly affects the quality of migration gathers and results. Therefore, it is necessary to study targeted methods to effectively remove direct wave noise with spurious frequency interference.

[0005] Therefore, to address this issue, it is necessary to propose an improved method for suppressing spurious frequency direct wave interference in marine OBN data, thereby providing a reliable data foundation and reducing exploration risks. Summary of the Invention

[0006] In view of this, the purpose of this invention is to propose an improved method, system, and storage medium for suppressing false frequency direct wave interference in marine OBN data, thereby providing a reliable data foundation and reducing exploration risks.

[0007] Currently, OBN seismic exploration processing technology is still in its infancy in China, and the related processing technologies and methods are not yet perfect. Due to the relatively sparse acquisition shot points, the direct wave spurious interference is serious and cannot be completely removed by conventional methods, which directly affects subsequent processing, the final gather quality and the quality of the results. Therefore, it is necessary to develop effective noise reduction methods for spurious direct wave noise, so as to provide a real and reliable data foundation for interpretation and reduce exploration risks.

[0008] To achieve the above objectives, this invention provides a method for suppressing spurious frequency direct wave interference in marine OBN data, wherein the method includes the following steps:

[0009] The effective signal and noise are separated using the Tau-P transform;

[0010] Identification and pickup of direct wave noise signals in the three-dimensional Tau-P domain;

[0011] A high-precision three-dimensional Tau-P inverse transform is performed on the picked-up strong energy to obtain a time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy.

[0012] The least-squares adaptive subtraction technique for multiple wave attenuation is applied to direct wave denoising to form an adaptive direct wave subtraction method.

[0013] In some embodiments of the method for suppressing spurious frequency direct wave interference from marine OBN data according to the present invention, the method further includes:

[0014] Iterative processing is performed to improve the accuracy of the spurious frequency direct wave noise model through multiple iterations, thereby enhancing the denoising effect.

[0015] In some embodiments of the method for suppressing spurious direct wave interference from marine OBN data according to the present invention, when using the Tau-P transform to separate the effective signal and noise, the two-dimensional Tau-P transform formula is:

[0016]

[0017] In formula (1):

[0018] τ=t-px (2)

[0019]

[0020] Where: V * Let θ represent the apparent velocity, θ represent the incident angle of the seismic wave ray, and v represent the wave velocity in the medium. The three-dimensional Tau-P transformation formula is:

[0021]

[0022] In some embodiments of the method for suppressing spurious direct wave interference in marine OBN data according to the present invention, when separating the effective signal and noise, the direct wave and the reflected wave are also effectively separated by high-precision Tau-P transformation.

[0023] In some embodiments of the method for suppressing spurious direct wave interference in marine OBN data according to the present invention, when identifying and picking up direct wave noise signals in the three-dimensional Tau-P domain, the picking mode is manual picking or automatic picking by setting an energy threshold value.

[0024] Another aspect of the present invention provides a system for suppressing spurious direct wave interference in marine OBN data, comprising:

[0025] The signal-noise separation module uses Tau-P transformation to separate the effective signal from the noise;

[0026] The noise signal identification module is used to identify and pick up direct wave noise signals in the three-dimensional Tau-P domain;

[0027] The three-dimensional Tau-P inverse transform module performs a high-precision three-dimensional Tau-P inverse transform on the picked-up strong energy to obtain a time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy.

[0028] In some embodiments of the marine OBN data spurious frequency direct wave interference suppression system according to the present invention, the system further includes:

[0029] The adaptive direct wave subtraction generation module applies the least-squares adaptive subtraction technique of multiple wave attenuation to direct wave denoising, forming an adaptive direct wave subtraction method.

[0030] In some embodiments of the marine OBN data spurious frequency direct wave interference suppression system according to the present invention, the system further includes:

[0031] The iterative processing module is used to perform iterative processing, which improves the accuracy of the spurious frequency direct wave noise model and enhances the denoising effect through multiple iterations.

[0032] In another aspect, the present invention provides a computer-readable storage medium storing computer program instructions, which, when executed, implement the method for suppressing spurious frequency direct wave interference in marine OBN data.

[0033] This invention has at least the following beneficial technical effects: For the first time, this invention combines three-dimensional Tau-P transform technology with adaptive picking and least-squares adaptive subtraction techniques to denoise OBN data direct waves, targeting the direct wave characteristics of OBN data. It innovatively optimizes and combines high-precision Tau-P transform technology, adaptive amplitude picking technology, and least-squares adaptive subtraction technology for direct wave noise attenuation, breaking through the limitations of traditional direct denoising techniques. This improves the fidelity and accuracy of denoising direct waves containing spurious frequencies, resulting in better denoising fidelity, higher denoising accuracy, and wider applicability.

[0034] After denoising using the method of this application, direct wave noise containing spurious frequencies is effectively suppressed, achieving significant improvement compared to conventional denoising methods. Spurious frequency noise, which conventional methods could not remove regardless of gathers, profiles, or spectra, is significantly improved by the new method. On the one hand, it improves the denoising fidelity, and on the other hand, it improves the data quality, laying a good foundation for subsequent processing, improving the image quality of the data, obtaining processed results that accurately reflect the underground geological conditions, providing a high-fidelity data basis for interpreting well locations, effectively improving the drilling success rate, and reducing exploration risks. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0036] In the diagram:

[0037] Figure 1 A schematic diagram illustrating the implementation process of the method for suppressing spurious frequency direct wave interference in marine OBN data according to the present invention is shown.

[0038] Figure 2 A schematic diagram is shown illustrating the effective separation of direct and reflected waves through high-precision Tau-P transformation.

[0039] Figure 3 This diagram illustrates the Tau-P forward transform and Tau-P domain adaptive picking.

[0040] Figure 4 This diagram illustrates the direct wave noise model obtained by inverse transformation of high-energy direct wave noise.

[0041] Figure 5 The diagram illustrates the process of denoising using least squares adaptive subtraction to obtain the desired denoising result.

[0042] Figure 6 This diagram illustrates how multiple iterations can significantly improve the noise reduction effect.

[0043] Figure 7 The comparison diagrams of gathers and FK spectra before and after denoising are shown;

[0044] Figure 8 The diagram shows a comparison of the denoising profiles and spectra before and after denoising using the method and conventional methods.

[0045] Figure 9 A schematic diagram of the structure of the marine OBN data spurious frequency direct wave interference suppression system according to the present invention is shown. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0047] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two different entities or different parameters with the same name. Therefore, "first" and "second" are merely for convenience of expression and should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as other steps or units inherent in a process, method, system, product, or device that includes a series of steps or units.

[0048] Currently, OBN seismic exploration processing technology is still in its infancy in China, and the related processing technologies and methods are not yet perfect. Due to the relatively sparse acquisition shot points, the direct wave spurious interference is serious and cannot be completely removed by conventional methods, which directly affects subsequent processing, the final gather quality and the quality of the results. Therefore, it is necessary to develop effective noise reduction methods for spurious direct wave noise, so as to provide a real and reliable data foundation for interpretation and reduce exploration risks.

[0049] In short, this invention proposes a method for suppressing spurious direct wave interference in ocean OBN data. Targeting the characteristics of direct waves in OBN data, this invention, for the first time, combines three-dimensional Tau-P transform technology with adaptive picking and least-squares adaptive subtraction techniques to denoise OBN data direct waves. It innovatively optimizes and combines high-precision Tau-P transform technology, adaptive amplitude picking technology, and least-squares adaptive subtraction technology for direct wave noise attenuation, overcoming the limitations of traditional direct denoising techniques. This improves the fidelity and accuracy of denoising direct waves containing spurious frequencies, resulting in better denoising fidelity, higher denoising accuracy, and wider applicability. Compared with conventional denoising methods, the new method significantly improves imaging quality. This, in turn, improves the quality of the final processed data, effectively reduces structural artifacts, and increases drilling success rate.

[0050] Therefore, in a first aspect, the present invention provides a method for suppressing spurious frequency direct wave interference in marine OBN data. Figure 1 A schematic block diagram illustrating an embodiment of the method for suppressing spurious frequency direct wave interference in marine OBN data according to the present invention is shown. In such... Figure 1 In the illustrated embodiment, the method includes:

[0051] Step S1: Use Tau-P transform to separate the effective signal and noise.

[0052] Step S2: Identify and pick up the direct wave noise signal in the three-dimensional Tau-P domain.

[0053] Step S3: Perform a high-precision three-dimensional Tau-P inverse transform on the picked-up strong energy to obtain the time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy.

[0054] Step S4: The least squares adaptive subtraction technique for multiple wave attenuation is applied to direct wave denoising to form an adaptive direct wave subtraction method.

[0055] For example, the least-squares adaptive subtraction technique of multiple-wave attenuation technology is applied to direct-wave denoising, innovatively forming an adaptive direct-wave subtraction technique. Using this adaptive subtraction technique, high-fidelity denoising results can be obtained. Figure 5 The diagram illustrates the process of denoising using least squares adaptive subtraction to obtain the desired denoising result.

[0056] Considering the energy difference between the noise model and the original data, noise reduction is performed using least squares adaptive subtraction, thus obtaining a more ideal noise reduction result.

[0057] Step S5 involves iterative processing to improve the accuracy of the spurious frequency direct wave noise model and enhance the denoising effect through multiple iterations.

[0058] For example, such as Figure 6 As shown, a schematic diagram illustrates how multiple iterations can significantly improve the denoising effect, such as... Figure 7 and Figure 8 As shown, Figure 8 The diagram shows a comparison of the denoising profiles and spectra before and after denoising using the method and conventional methods. Figure 7 The comparison images of gathers and FK spectra before and after denoising are shown, demonstrating a significant improvement in imaging quality from the new method. This, in turn, enhances the quality of the final processed data, effectively reduces structural artifacts, and increases drilling success rate.

[0059] In step S1, when separating the effective signal and noise, a high-precision Tau-P transformation is also used to effectively separate the direct wave from the reflected wave.

[0060] Understandably, after denoising using the method of this application, direct wave noise containing spurious frequencies is effectively suppressed, achieving a significant improvement compared to conventional denoising methods. Spurious frequency noise, which conventional methods could not remove regardless of gathers, profiles, or spectra, is significantly improved by the new method. On the one hand, it improves the denoising fidelity, and on the other hand, it improves the data quality, laying a good foundation for subsequent processing, improving the data imaging quality, obtaining processed results that accurately reflect the underground geological conditions, providing a high-fidelity data basis for interpreting well locations, effectively improving drilling success rate, and reducing exploration risks.

[0061] For example, when using the Tau-P transform to separate the effective signal and noise, the two-dimensional Tau-P transform formula is:

[0062] In formula (1):

[0063] τ=t-px (2)

[0064]

[0065] At the same time, such as Figure 2 The diagram illustrates how high-precision Tau-P transformation effectively separates direct and reflected waves. Figure 2 Analysis shows that direct wave noise becomes a point after Tau-P transformation, while effective reflection becomes an ellipse, making them clearly separable spatially. This is beneficial for signal and noise separation and pickup in the Tau-P domain, and the method can be easily extended to three dimensions. Figure 2 In the middle, signal analysis of the time domain signal (left) and the Tau-P domain signal (right).

[0066] (a): tx domain 3 sets of reflected waves (1, 2, 3), direct wave A and surface wave B.

[0067] (b): The three sets of elliptical arcs (1, 2, 3) and two separation points (A, B) corresponding to the τ-p domain.

[0068] Where: V * Let θ represent the apparent velocity, θ represent the incident angle of the seismic wave ray, and v represent the wave velocity in the medium. The three-dimensional Tau-P transformation formula is:

[0069]

[0070] like Figure 3 As shown, a schematic diagram of Tau-P positive transform and Tau-P domain adaptive picking is illustrated. For example, when identifying and picking up direct wave noise signals in the three-dimensional Tau-P domain, the picking mode is manual picking or automatic picking by setting an energy threshold value.

[0071] Furthermore, in step S3, the three-dimensional Tau-P inverse transform formula is:

[0072]

[0073] For example, such as Figure 4 As shown, a schematic diagram of the direct wave noise model obtained by inverse transformation of high-energy direct wave noise is presented.

[0074] A second aspect of the present invention provides a system for suppressing spurious frequency direct wave interference in marine OBN data. Figure 9A schematic block diagram of an embodiment of a marine OBN data spurious frequency direct wave interference suppression system according to the present invention is shown. Figure 9 In the illustrated embodiment, the system includes:

[0075] The signal-noise separation module 100 uses Tau-P transformation to separate the effective signal and noise;

[0076] The noise signal identification module 200 is used to identify and pick up direct wave noise signals in the three-dimensional Tau-P domain;

[0077] The 3D Tau-P inverse transform module 300 performs a high-precision 3D Tau-P inverse transform on the picked-up strong energy to obtain a time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy.

[0078] The adaptive direct wave subtraction forming module 400 applies the least-squares adaptive subtraction technique of multiple wave attenuation to direct wave denoising, forming an adaptive direct wave subtraction method.

[0079] The iterative processing module 500 is used to perform iterative processing, which improves the accuracy of the spurious frequency direct wave noise model and enhances the denoising effect through multiple iterations.

[0080] This invention also discloses a computer-readable storage medium storing computer program instructions. When these computer program instructions are executed, they implement the method for suppressing spurious direct wave interference in marine OBN data. The specific execution steps are as follows:

[0081] Step S1: Use Tau-P transform to separate the effective signal and noise.

[0082] Step S2: Identify and pick up the direct wave noise signal in the three-dimensional Tau-P domain.

[0083] Step S3: Perform a high-precision three-dimensional Tau-P inverse transform on the picked-up strong energy to obtain the time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy.

[0084] Step S4: The least squares adaptive subtraction technique for multiple wave attenuation is applied to direct wave denoising to form an adaptive direct wave subtraction method.

[0085] Step S5 involves iterative processing to improve the accuracy of the spurious frequency direct wave noise model and enhance the denoising effect through multiple iterations.

[0086] For example, a computer program can be divided into one or more modules, one or more of which are stored in memory and executed by a processor to perform the present invention. One or more modules can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in a terminal device. For example, the aforementioned computer program can be divided into units or modules of the berth status display system provided in the various system embodiments described above.

[0087] Those skilled in the art will understand that the above description of the terminal device is merely an example and does not constitute a limitation on the terminal device. It may include more or fewer components than described above, or a combination of certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0088] This invention targets the direct wave characteristics of OBN data, and for the first time introduces a combination of three-dimensional Tau-P transform technology with adaptive picking and least squares adaptive subtraction techniques into the denoising processing of OBN data direct waves. It innovatively combines high-precision Tau-P transform technology, adaptive amplitude picking technology and least squares adaptive subtraction technology in an optimized combination for direct wave noise attenuation, breaking through the limitations of traditional direct denoising techniques, improving the denoising fidelity and accuracy of direct waves containing spurious frequencies, resulting in better denoising fidelity, higher denoising accuracy and wider applicability.

[0089] After denoising using the method of this application, direct wave noise containing spurious frequencies is effectively suppressed, achieving significant improvement compared to conventional denoising methods. Spurious frequency noise, which conventional methods could not remove regardless of gathers, profiles, or spectra, is significantly improved by the new method. On the one hand, it improves the denoising fidelity, and on the other hand, it improves the data quality, laying a good foundation for subsequent processing, improving the image quality of the data, obtaining processed results that accurately reflect the underground geological conditions, providing a high-fidelity data basis for interpreting well locations, effectively improving the drilling success rate, and reducing exploration risks.

[0090] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0091] It should be understood that, as used herein, the singular form "a" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the associatedly listed items. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0092] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for suppressing spurious frequency direct wave interference in ocean OBN data, characterized in that, Includes the following steps: The effective signal and noise are separated using the Tau-P transform; Identification and pickup of direct wave noise signals in the three-dimensional Tau-P domain; A high-precision three-dimensional Tau-P inverse transform is performed on the picked-up strong energy to obtain a time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy. The least-squares adaptive subtraction technique for multiple wave attenuation is applied to direct wave denoising to form an adaptive direct wave subtraction method. Iterative processing is performed to improve the accuracy of the spurious frequency direct wave noise model through multiple iterations, thereby improving the denoising effect. When identifying and picking up direct wave noise signals in the three-dimensional Tau-P domain, the picking mode is manual picking or automatic picking by setting an energy threshold value.

2. The method according to claim 1, characterized in that, When using the Tau-P transform to separate the effective signal from the noise, the two-dimensional Tau-P transform formula is: （1） In formula (1): （2） （3） in: Indicates apparent speed. The angle of incidence of the seismic wave ray is given by ν, where v represents the wave velocity in the medium. The three-dimensional Tau-P transform formula is: （4）。 3. The method according to claim 1 or 2, characterized in that, When separating the effective signal and noise, a high-precision Tau-P transformation is also used to effectively separate the direct wave from the reflected wave.

4. The method according to claim 1, characterized in that, The formula for the three-dimensional Tau-P inverse transform is: （5）。 5. A system for suppressing aliased direct wave interference in ocean OBN data based on the method for suppressing aliased direct wave interference as described in any one of claims 1 to 4, characterized in that, The ocean OBN data spurious frequency direct wave interference suppression system includes: The signal-noise separation module uses Tau-P transformation to separate the effective signal from the noise; The noise signal identification module is used to identify and pick up direct wave noise signals in the three-dimensional Tau-P domain. When identifying and picking up direct wave noise signals in the three-dimensional Tau-P domain, the picking mode is manual picking or automatic picking by setting an energy threshold value. The three-dimensional Tau-P inverse transform module performs a high-precision three-dimensional Tau-P inverse transform on the picked-up strong energy to obtain a time-domain direct-wave noise model. The time-domain direct-wave noise can be obtained by performing an inverse transform on the picked-up strong energy. The adaptive direct wave subtraction generation module applies the least-squares adaptive subtraction technique of multiple wave attenuation to direct wave denoising, forming an adaptive direct wave subtraction method. The iterative processing module is used to perform iterative processing, which improves the accuracy of the spurious frequency direct wave noise model and enhances the denoising effect through multiple iterations.

6. A computer-readable storage medium, characterized in that, The device stores computer program instructions, which, when executed, implement the method for suppressing spurious frequency direct wave interference in marine OBN data as described in any one of claims 1-4.

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