Seismic data surface wave suppression method and device

Abstract

The invention discloses a surface wave suppression method and device for seismic data. The method comprises the following steps: acquiring original seismic data; separating low-frequency data containing surface waves by using a band-pass filtering method; performing gain processing on the low-frequency data containing the surface waves to determine the surface wave noise data; and according to the determined surface wave noise data, generating seismic data after surface wave suppression.

Description

Technical Field

[0001] The present invention relates to the field of exploration geophysical technology, and in particular to a surface wave suppression method and device for seismic data. Background Art

[0002] Under certain conditions, seismic exploration will excite seismic waves propagating along the ground or interface, namely surface waves. They are characterized by strong amplitude, low velocity, and low frequency, generally with a frequency range of several Hz to more than ten Hz. Surface waves are spread out in a "broom-like" manner on monitoring records, and decay rapidly with the increase of propagation distance. In addition, the strong phase of the surface waves gradually shifts backward, with dispersion, and multiple groups of surface waves are presented. The time-distance curve of the surface wave is a set of straight lines of energy intensity conversion (change of the phase axis), and the envelope of its amplitude is a curve. The observed surface wave velocity is actually the propagation velocity of the synthetic wave, that is, the group velocity. Its characteristic parameters are generally: apparent velocity varies from 200m / s to 800m / s, and frequency varies from 7Hz to 10Hz. Surface waves are actually interference waves, which are not conducive to seismic imaging and need to be removed in seismic data processing. Usually, combined detection, combined excitation, and low-cut filtering methods are used in field acquisition to weaken them to a certain extent, but the surface waves on seismic records are often still very strong. There are also many methods for suppressing surface rolls in indoor processing, but some are more complicated to implement, and the surface rolls are dispersed, the phase and amplitude characteristics vary greatly, and the denoising parameters are difficult to accurately determine, which often results in poor suppression effects and has a great impact on the fidelity and amplitude preservation of seismic imaging.

[0003] In order to solve the difficulties in the process of surface roll suppression, it is urgent to propose a surface roll suppression method. Summary of the invention

[0004] The present application provides a method and device for suppressing surface rolls in seismic data. The method separates surface rolls and effective wave data from original seismic data by using a bandpass filtering method, and adopts a gain processing method to determine the noise data of the surface rolls, and finally obtains the seismic data after suppressing the surface rolls. The method can improve the accuracy of seismic imaging and enhance the fidelity and amplitude preservation of seismic imaging.

[0005] In a first aspect, the present application provides a surface wave suppression method for seismic data, the method comprising:

[0006] Obtaining raw seismic data;

[0007] Separating low-frequency data including surface waves from the original seismic data using a bandpass filtering method;

[0008] Performing gain processing on the low-frequency data containing the surface roll to determine the surface roll noise data;

[0009] Based on the determined surface wave noise data, seismic data after surface wave suppression is generated.

[0010] In an exemplary embodiment, the step of separating low-frequency data including surface waves from the original seismic data by using a bandpass filtering method comprises:

[0011] Performing frequency scanning on the original seismic data to determine the frequency range of surface waves and the frequency range of effective waves in the original seismic data;

[0012] According to the frequency range of the surface roll, a bandpass filtering method is used to separate low-frequency data containing the surface roll from the original seismic data.

[0013] In an exemplary embodiment, according to the frequency range of the effective wave, a bandpass filtering method is used to separate the effective wave data within a predetermined frequency band from the original seismic data.

[0014] In an exemplary embodiment, performing gain processing on the low-frequency data containing the surface roll to determine the surface roll noise data includes:

[0015] Performing gain processing on the low-frequency data including the surface roll and the effective wave data within the predetermined frequency band to obtain the low-frequency data after gain processing, and determining a maximum scale factor record;

[0016] Performing inverse gain processing on the gain-processed low-frequency data according to the determined maximum scale factor record to obtain low-frequency data after surface roll suppression;

[0017] The noise data of the surface roll is obtained by performing a subtraction process on the low-frequency data containing the surface roll and the low-frequency data after suppressing the surface roll.

[0018] In an exemplary embodiment, the process of determining the maximum scale factor record is as follows:

[0019] Performing root mean square gain processing on the low-frequency data containing surface rolls and the effective wave data within the predetermined frequency band, respectively, to determine a root mean square gain proportional factor for each sampling point of the two;

[0020] Compare the root mean square gain proportional factor of the low-frequency data containing surface waves at the same channel number and the same sampling point with the root mean square gain proportional factor of the effective wave data within the predetermined frequency band to determine the larger gain proportional factor of the two;

[0021] Generate a maximum scale factor record based on the largest gain scale factor corresponding to all sampling points.

[0022] In an exemplary embodiment, the root mean square gain factor is:

[0023]

[0024] Among them, Ai is the RMS gain scaling factor, B is the desired RMS amplitude level, N is the total number of samples in the i-th time window, X j is the amplitude value of the jth sample point in the i-th time window.

[0025] In an exemplary embodiment, performing subtraction processing on the low-frequency data containing the surface roll and the low-frequency data after suppressing the surface roll to obtain the noise data of the surface roll includes:

[0026] Adaptively subtract the low-frequency data containing the surface roll from the low-frequency data after suppressing the surface roll to obtain noise data of the surface roll.

[0027] In an exemplary embodiment, generating the seismic data after suppressing the surface roll according to the determined surface roll noise data comprises:

[0028] The surface roll noise data is subtracted from the original seismic data to generate seismic data after surface roll suppression.

[0029] In a second aspect, an embodiment of the present invention further provides a surface wave suppression device for seismic data, the device comprising: a memory and a processor; the memory is used to store a program for performing surface wave suppression on seismic data, the processor is used to read and execute the program for performing surface wave suppression on seismic data, and execute any one of the methods described in the above embodiments.

[0030] In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a data processing program is stored, and the data processing program is executed by a processor to perform any of the methods in the above embodiments.

[0031] Compared with the related art, the present application provides a surface wave suppression method and device for seismic data, the method comprising: obtaining original seismic data; separating low-frequency data containing surface waves by bandpass filtering method; performing gain processing on the low-frequency data containing surface waves to determine the surface wave noise data; and generating seismic data after surface wave suppression according to the determined surface wave noise data. The present application separates surface waves and effective wave data from original seismic data by bandpass filtering method, determines the noise data of surface waves by gain processing method, and finally obtains seismic data after surface wave suppression.

[0032] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0034] Figure 1 A flow chart of a surface wave suppression method for seismic data according to an embodiment of the present application;

[0035] Figure 2 A schematic diagram of a surface wave suppression device for seismic data according to an embodiment of the present application;

[0036] Figure 3 A flow chart of a surface roll suppression method based on scale factor selection interchange in some exemplary embodiments;

[0037] Figure 4 is a schematic diagram of raw seismic data in some exemplary embodiments;

[0038] Figure 5 is a schematic diagram of low-frequency data including surface waves in some exemplary embodiments;

[0039] Figure 6 A schematic diagram of effective wave data within a predetermined frequency band in some exemplary embodiments;

[0040] Figure 7 is a schematic diagram of surface wave noise data in some exemplary embodiments;

[0041] Figure 8 A schematic diagram of seismic data after surface wave suppression in some exemplary embodiments;

[0042] Fig. 9 FIG. 4 is a schematic diagram of dominant frequency bands in some exemplary embodiments. DETAILED DESCRIPTION

[0043] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0044] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0045] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0046] The embodiment of the present invention provides a surface wave suppression method for seismic data, such as Figure 1 As shown, the method includes steps S100-S130:

[0047] S100: obtaining original seismic data;

[0048] S110: Separating low-frequency data including surface waves from the original seismic data using a bandpass filtering method;

[0049] S120: performing gain processing on the low-frequency data including the surface roll to determine the surface roll noise data;

[0050] S130: Generate seismic data after suppressing surface waves according to the determined surface wave noise data.

[0051] In this embodiment, the original seismic data refers to seismic data collected in the field without any processing.

[0052] In an exemplary embodiment, the low-frequency data including surface waves are separated from the original seismic data by using a bandpass filtering method, including:

[0053] Performing frequency scanning on the original seismic data to determine the frequency range of surface waves and the frequency range of effective waves in the original seismic data;

[0054] According to the frequency range of the surface roll, a bandpass filtering method is used to separate low-frequency data containing the surface roll from the original seismic data.

[0055] In an exemplary embodiment, according to the frequency range of the effective wave, a bandpass filtering method is used to separate the effective wave data within a predetermined frequency band from the original seismic data.

[0056] The predetermined frequency band in this embodiment is called a dominant frequency band in the earthquake field, such as Fig. 9 Shown is a schematic diagram of the dominant frequency band: a seismic data record contains seismic wave signals of different frequencies ranging from 0 to several hundred Hz, among which the amplitude is greater than a certain value, or relatively speaking, the amplitude is larger than other frequencies. The seismic wave frequency range that plays a major role in seismic wave imaging is called the dominant frequency band, which is a relative frequency range.

[0057] In an exemplary embodiment, performing gain processing on the low-frequency data containing the surface roll to determine the surface roll noise data includes:

[0058] Performing gain processing on the low-frequency data including the surface roll and the effective wave data within the predetermined frequency band to obtain the low-frequency data after gain processing, and determining a maximum scale factor record;

[0059] Performing inverse gain processing on the gain-processed low-frequency data according to the determined maximum scale factor record to obtain low-frequency data after surface roll suppression;

[0060] The noise data of the surface roll is obtained by performing a subtraction process on the low-frequency data containing the surface roll and the low-frequency data after suppressing the surface roll.

[0061] In an exemplary embodiment, the process of determining the maximum scale factor record is as follows:

[0062] Performing root mean square gain processing on the low-frequency data containing surface rolls and the effective wave data within the predetermined frequency band, respectively, to determine a root mean square gain proportional factor for each sampling point of the two;

[0063] Compare the root mean square gain proportional factor of the low-frequency data containing surface waves at the same channel number and the same sampling point with the root mean square gain proportional factor of the effective wave data within the predetermined frequency band to determine the larger gain proportional factor of the two;

[0064] Generate a maximum scale factor record based on the largest gain scale factor corresponding to all sampling points.

[0065] In an exemplary embodiment, the root mean square gain factor is:

[0066]

[0067] Among them, A i is the RMS gain scaling factor, B is the desired RMS amplitude level, N is the total number of samples in the i-th time window, X j is the amplitude value of the jth sample point in the i-th time window.

[0068] In an exemplary embodiment, performing subtraction processing on the low-frequency data containing the surface roll and the low-frequency data after suppressing the surface roll to obtain the noise data of the surface roll includes:

[0069] Adaptively subtract the low-frequency data containing the surface roll from the low-frequency data after suppressing the surface roll to obtain noise data of the surface roll.

[0070] In an exemplary embodiment, generating the seismic data after suppressing the surface roll according to the determined surface roll noise data comprises:

[0071] The surface roll noise data is subtracted from the original seismic data to generate seismic data after surface roll suppression.

[0072] The embodiment of the present invention provides a surface wave suppression device for seismic data, such as Figure 2 As shown, the device includes: a memory 200 and a processor 210; the memory is used to store a program for surface wave suppression of seismic data, and the processor is used to read and execute the program for surface wave suppression of seismic data, and execute any one of the methods in the above embodiments.

[0073] An embodiment of the present invention further provides a computer-readable storage medium, on which a data processing program is stored. The data processing program is executed by a processor to perform the surface wave suppression method for seismic data described in any one of the above embodiments.

[0074] Example 1

[0075] Surface wave suppression methods for seismic data based on scaling factors, such as Figure 3 As shown, the process is as follows:

[0076] Step 301, obtaining original seismic data;

[0077] The original seismic data is the original data collected in the field and has not been processed. Figure 4 Shown is a schematic diagram of the original seismic data.

[0078] Step 302, performing frequency scanning on the original seismic data to respectively determine the frequency range of surface waves in the original seismic data and the frequency range of effective waves in the original seismic data;

[0079] Step 303: Separate low-frequency data containing surface waves from the original seismic data using a bandpass filtering method according to the frequency range of the surface waves. Figure 5 Shown are low-frequency data containing surface waves.

[0080] Step 304: Based on the frequency range of the effective wave, separate the effective wave data within a predetermined frequency band from the original seismic data using a bandpass filtering method. Figure 6 As shown, it is the effective wave data within the predetermined frequency band.

[0081] Step 305, performing root mean square gain processing on the low-frequency data including surface waves and the effective wave data within the predetermined frequency band, and recording the gain proportional factor of each sample point of the seismic data in the gain processing;

[0082] Step 306, comparing the gain proportional factors of the low-frequency data containing surface waves and the sampling points corresponding to the effective wave data within the predetermined frequency band at the same sampling points with the same channel number and time, and selecting the one with the largest proportional factor among the two sampling points with the same channel number and time;

[0083] Step 307, generating a maximum scale factor record according to the large gain scale factors corresponding to all sampling points;

[0084] Step 308, performing inverse gain processing on the gain-processed low-frequency data according to the determined maximum scale factor record to obtain low-frequency data after surface roll suppression;

[0085] Step 309, adaptively subtracting the low-frequency data containing the surface roll from the low-frequency data after suppressing the surface roll to obtain noise data of the surface roll; Figure 7 Shown is the surface wave noise data obtained by adaptive subtraction.

[0086] Step 310: subtract the surface roll noise data from the original seismic data to generate seismic data after surface roll suppression. Figure 8 This is a schematic diagram of seismic data after surface wave suppression. Figure 8 It can be seen that after suppressing the surface wave, the surface wave interference of a single shot is effectively removed, the effective wave event axis masked by the surface wave is highlighted, and the signal-to-noise ratio is improved.

[0087] The embodiment of the present invention provides a surface roll suppression method and device based on proportional factor selection exchange, which is used to solve the influence of strong energy surface rolls on imaging in exploration seismic data, can effectively and quickly suppress the interference of strong energy surface rolls, improve the signal-to-noise ratio of seismic data, and can better keep the low-frequency components from being damaged.

[0088] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A surface wave suppression method for seismic data, characterized in that: The method comprises: Obtaining raw seismic data; Separating low-frequency data including surface waves from the original seismic data using a bandpass filtering method; Performing gain processing on the low-frequency data containing the surface roll to determine the surface roll noise data; Based on the determined surface wave noise data, seismic data after surface wave suppression is generated.

2. The surface wave suppression method of seismic data according to claim 1, characterized in that: The method of separating low-frequency data including surface waves from the original seismic data by using a bandpass filtering method comprises: Performing frequency scanning on the original seismic data to determine the frequency range of surface waves and the frequency range of effective waves in the original seismic data; According to the frequency range of the surface roll, a bandpass filtering method is used to separate low-frequency data containing the surface roll from the original seismic data.

3. The surface wave suppression method of seismic data according to claim 2, characterized in that: The method also includes: According to the frequency range of the effective wave, the effective wave data within a predetermined frequency band is separated from the original seismic data using a bandpass filtering method.

4. The surface wave suppression method of seismic data according to claim 3, characterized in that: The step of performing gain processing on the low-frequency data containing the surface roll to determine the surface roll noise data comprises: Performing gain processing on the low-frequency data including the surface roll and the effective wave data within the predetermined frequency band to obtain the low-frequency data after gain processing, and determining a maximum scale factor record; Performing inverse gain processing on the gain-processed low-frequency data according to the determined maximum scale factor record to obtain low-frequency data after surface roll suppression; The noise data of the surface roll is obtained by performing a subtraction process on the low-frequency data containing the surface roll and the low-frequency data after suppressing the surface roll.

5. The surface wave suppression method of seismic data according to claim 4, characterized in that: The determination process of the maximum scale factor record is: Performing root mean square gain processing on the low-frequency data containing surface rolls and the effective wave data within the predetermined frequency band, respectively, to determine a root mean square gain proportional factor for each sampling point of the two; Compare the root mean square gain proportional factor of the low-frequency data containing surface waves at the same channel number and the same sampling point with the root mean square gain proportional factor of the effective wave data within the predetermined frequency band to determine the larger gain proportional factor of the two; Generate a maximum scale factor record based on the largest gain scale factor corresponding to all sampling points.

6. The surface wave suppression method of seismic data according to claim 5, characterized in that: The rms gain factor is: Among them, A i is the RMS gain scaling factor, B is the desired RMS amplitude level, N is the total number of samples in the i-th time window, X j is the amplitude value of the jth sample point in the i-th time window.

7. The surface wave suppression method of seismic data according to claim 4, characterized in that: The subtraction processing is performed on the low-frequency data containing the surface roll and the low-frequency data after the surface roll is suppressed to obtain the noise data of the surface roll, including: Adaptively subtract the low-frequency data containing the surface roll from the low-frequency data after suppressing the surface roll to obtain noise data of the surface roll.

8. The surface wave suppression method of seismic data according to claim 4, characterized in that: The step of generating seismic data after suppressing surface waves according to the determined surface wave noise data comprises: The surface roll noise data is subtracted from the original seismic data to generate seismic data after surface roll suppression.

9. A surface wave suppression device for seismic data, characterized in that: The device comprises: a memory and a processor; the memory is used to store a program for surface wave suppression of seismic data, and the processor is used to read and execute the program for surface wave suppression of seismic data, and execute the method described in any one of claims 1-8.

10. A computer-readable storage medium having a data processing program stored thereon, wherein the data processing program is executed by a processor to implement the surface wave suppression method for seismic data according to any one of claims 1 to 9.

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