A method and system for improving seismic profile resolution based on attenuated synthetic records

Abstract

The present application belongs to the field of post-stack reflection seismic data processing technology, and relates to a method, system and readable medium for improving seismic profile resolution based on attenuation synthetic record, comprising: calculating initial absorption parameter value through VSP logging data; generating attenuation synthetic seismic record according to the initial absorption parameter value, reflection coefficient sequence and Ricker wavelet, and selecting the best matching absorption parameter value through the attenuation synthetic seismic record; calculating absorption parameter value based on seismic data according to actual seismic data, calibrating the absorption parameter value based on seismic data through adjusted absorption parameter, and obtaining the best absorption parameter; and processing post-stack seismic data volume through the best absorption parameter to obtain high-resolution seismic profile. The present application can solve the problem of difficulty in obtaining absorption parameter α of seismic data in the prior art.

Description

Technical Field

[0001] This invention relates to a method, system, and readable medium for improving seismic profile resolution based on attenuated synthetic records, belonging to the field of seismic exploration post-stack reflection seismic data processing technology. Background Technology

[0002] Because of the viscoelasticity of the subsurface medium, seismic waves propagating through it cause energy absorption attenuation and phase stretching distortion, reducing the overall resolution of the data. The absorption parameter α is a crucial parameter describing the degree of absorption attenuation in the subsurface medium, and accurately determining α is essential for seismic data absorption attenuation compensation. However, subsurface structures are complex, and many factors influence seismic wave attenuation, making accurate determination of the absorption parameter α difficult. Methods for estimating the absorption parameter α can be broadly categorized based on their principles, such as the centroid frequency shift method and the spectral ratio method. These methods are simple in principle and easy to implement, but are susceptible to data quality issues, resulting in unstable calculation results. Based on data sources, they can also be divided into two main categories: estimating α from seismic data and estimating α from well data. Seismic data has a wide range of sources, but due to thin-layer tuning, the calculation stability, efficiency, and accuracy fluctuate significantly. While well data estimation offers higher accuracy, it is limited by the limited number of wells, making it impossible to obtain α values ​​for locations without wells within the work area. Furthermore, the practicality of combining well and seismic data to determine the absorption parameter α is also limited by the lack of a unified evaluation standard. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a method, system, and readable medium for improving seismic profile resolution based on attenuation synthetic records, which can solve the problem of difficulty in obtaining the seismic data absorption parameter α in the prior art.

[0004] To achieve the above objectives, the present invention proposes the following technical solution: a method for improving seismic profile resolution based on attenuated synthetic records, comprising: calculating initial absorption parameter values ​​using VSP logging data; generating attenuated synthetic seismic records based on the initial absorption parameter values, reflection coefficient sequences, and Ricker wavelets, and selecting optimally matched absorption parameter values ​​using the attenuated synthetic seismic records; calculating absorption parameter values ​​based on actual seismic data, calibrating the absorption parameter values ​​based on seismic data using the adjusted absorption parameters, and obtaining optimal absorption parameters; and processing the post-stack seismic data volume using the optimal absorption parameters to obtain a high-resolution seismic profile.

[0005] Furthermore, the initial absorption parameter values ​​are obtained using the logarithmic spectral ratio method, and the calculation formula is as follows:

[0006]

[0007] Where α is the absorption parameter value, f is the frequency value of the logging data, τ is the time depth of the logging data, A1(f) is the amplitude value of the overlying formation, and A2(f) is the amplitude value of the current formation.

[0008] Furthermore, the dominant frequency of shallow seismic data is used as the dominant frequency of the Rick wavelet.

[0009] Furthermore, the method for selecting the best matching absorption parameter value is as follows: generating waveforms corresponding to each different absorption parameter value; marking the peak positions in the attenuated synthetic seismic record; comparing the peak positions in the waveforms corresponding to each different absorption parameter value with the peak positions in the attenuated synthetic seismic record, and selecting the waveforms whose peak positions are the same as those in the attenuated synthetic seismic record; and using the absorption parameter value corresponding to the selected waveform as the best matching absorption parameter value.

[0010] Furthermore, the different absorption parameter values ​​are obtained by multiplying the initial absorption parameter value by a set of preset coefficients.

[0011] Furthermore, the formula for calculating the absorption parameter value based on actual seismic data is as follows:

[0012] α = 14v 2.2

[0013] Where α is the absorption parameter value and v is the root mean square velocity of the seismic data.

[0014] Furthermore, the optimally matched absorption parameter value is denoted as α. w The absorption parameter value based on seismic data is denoted as α. s , will α w α corresponding to its time depth s By dividing each value one by one, the correction coefficient is obtained, and the formula is as follows:

[0015]

[0016] Where η is the correction coefficient, spatial interpolation smoothing is performed on the correction coefficient η, and the spatially interpolated and smoothed correction coefficient η is multiplied by α. s This allows us to obtain the optimal absorption parameters.

[0017] Furthermore, the post-stack seismic data volume is processed using the following formula:

[0018]

[0019] Where w(t) is the earthquake data amplitude, It is the inverse Fourier transform, w(ω) is the Fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, and α is the absorption parameter.

[0020] This invention also discloses a system for improving seismic profile resolution based on attenuated synthetic records, comprising: an initial absorption parameter value acquisition module for calculating initial absorption parameter values ​​using VSP logging data; an optimal matching absorption parameter value acquisition module for generating attenuated synthetic seismic records based on the initial absorption parameter values, reflection coefficient sequences, and Ricker wavelets, and selecting optimal matching absorption parameter values ​​using the attenuated synthetic seismic records; an optimal absorption parameter acquisition module for calculating absorption parameter values ​​based on actual seismic data, calibrating the absorption parameter values ​​based on seismic data using adjusted absorption parameters, and obtaining optimal absorption parameters; and a seismic profile acquisition module for processing the post-stack seismic data volume using the optimal absorption parameters to obtain high-resolution seismic profiles.

[0021] The present invention also discloses a computer-readable storage medium storing a computer program, which is executed by a processor to implement any of the above-described methods for improving seismic profile resolution based on attenuated synthetic records.

[0022] The present invention has the following advantages due to the adoption of the above technical solutions:

[0023] 1. This invention models the absorption parameter α based on attenuated synthetic records, and achieves the optimal determination of the absorption parameter α by waveform matching between attenuated synthetic seismic records and well-side seismic data. It features a simple method, ease of implementation, and high accuracy.

[0024] 2. This invention utilizes the acquired absorption parameter α field to compensate for the attenuation of high-frequency signals in post-stack seismic data, broaden the frequency band of seismic data, and effectively improve the resolution of seismic data. Attached Figure Description

[0025] Figure 1 This is a flowchart of a method for improving seismic profile resolution based on attenuated synthetic records in one embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a method for selecting the best matching absorption parameter value in one embodiment of the present invention;

[0027] Figure 3 This is a high-resolution post-stack seismic profile before processing by the method in this invention;

[0028] Figure 4 This is a high-resolution post-stack seismic profile before processing by the method in this invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is described in detail through specific embodiments. However, it should be understood that the specific embodiments are provided only for a better understanding of the present invention and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terminology used is for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] To address the problems in existing technologies where absorption parameter calculations are easily affected by data quality, resulting in unstable calculation results; significant fluctuations in calculation stability, efficiency, and accuracy; limitations due to a small number of wells, making it impossible to obtain absorption parameter α values ​​for locations without wells in the work area; and the lack of a unified evaluation standard for absorption parameter α, this invention proposes a method and system for improving seismic profile resolution based on attenuated synthetic records. First, initial absorption parameter α values ​​are obtained using VSP (Vertical Seismic Profiling) well logging data and the logarithmic spectral ratio method. Then, attenuated synthetic seismic records are generated using the initial absorption parameter α values, and the absorption parameter α values ​​are adjusted based on the waveform similarity between the attenuated synthetic seismic records and the well-side seismic data traces. Absorption parameter α values ​​derived from seismic data are calculated. The optimal absorption parameter is obtained through adjustment. Finally, high-resolution processing is performed on the post-stack seismic data volume using the optimal absorption parameter to compensate for high-frequency signal attenuation caused by energy dissipation during seismic wave propagation, resulting in a subsurface structural image with improved resolution. The following detailed description of the invention, with reference to the accompanying drawings, illustrates the scheme in detail through embodiments.

[0031] Example 1:

[0032] This implementation discloses a method for improving seismic profile resolution based on attenuated synthetic records, such as... Figure 1 As shown, it includes the following steps:

[0033] In this embodiment, three-dimensional post-stack seismic data from a block in the eastern oilfield is used as an example. The sampling interval of this data is 1ms, the recording duration of the seismic signal is 3s, and the trace spacing is 20m.

[0034] S1 calculates the initial absorption parameter values ​​using VSP logging data.

[0035] The initial absorption parameter values ​​were obtained using the logarithmic spectral ratio method, and the calculation formula is as follows:

[0036]

[0037] Where α is the absorption parameter value, f is the frequency value of the logging data, τ is the time depth of the logging data, A1(f) is the amplitude value of the overlying formation, and A2(f) is the amplitude value of the current formation.

[0038] After inputting the amplitude values ​​of the overlying strata and the current stratum, the initial absorption parameter value α0 can be obtained layer by layer using the above formula. This step is repeated for all VSP wells in the work area to obtain the initial absorption parameter value α0 for all VSP wells.

[0039] S2 generates attenuated synthetic seismic records based on initial absorption parameter values, reflection coefficient sequences, and Ricker wavelets, and selects the best-matching absorption parameter values ​​through the attenuated synthetic seismic records.

[0040] S2.1 Generate a synthetic seismic record without attenuation. In this embodiment, the dominant frequency of shallow seismic data can be used as the dominant frequency of the Ricker wavelet. In this embodiment, the dominant frequency is selected as 25Hz.

[0041] S2.2 Different absorption parameter values ​​are obtained by multiplying the initial absorption parameter value by a set of preset coefficients. In this embodiment, a set of preset coefficients is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5, generating 11 different absorption parameter values.

[0042] S2.3 generates waveforms corresponding to various absorption parameter values, such as... Figure 2 As shown, channel 0 is the attenuated synthetic seismic record, channel 1 is the waveform obtained by multiplying the initial absorption parameter value by 0.5, channel 2 is the waveform obtained by multiplying the initial absorption parameter value by 0.6, and so on, with channel 11 being the waveform obtained by multiplying the initial absorption parameter value by 1.5. The six peak positions of the attenuated synthetic seismic record in channel 0 are used as reference waveforms, and the start and end points of the peaks are marked with dashed lines. The intersection of the two dashed lines with the waveform of channel 0 has an amplitude of 0. The six peaks represent six strata.

[0043] The peak positions in the waveforms corresponding to different absorption parameter values ​​are compared with the peak positions in the attenuated synthetic seismic records. Specifically, the two dashed lines corresponding to each peak are extended from channel 0 to channel 11.

[0044] Waveforms with peak positions matching those in the attenuated composite seismic records are selected. The absorption parameter values ​​corresponding to the selected waveforms are taken as the optimal matching absorption parameter values. In other words, the optimal absorption parameter value is determined by whether the two dashed lines intersect with the waveforms corresponding to different absorption parameter values ​​at the point where the amplitude is 0. Figure 2 The six black boxes in the middle indicate the locations of the best-matched absorption parameter values.

[0045] S3 calculates the absorption parameter values ​​based on actual earthquake data, and calibrates the absorption parameter values ​​based on earthquake data using the adjusted absorption parameters to obtain the optimal absorption parameters.

[0046] The formula for calculating the absorption parameter value based on actual seismic data is as follows:

[0047] α = 14v 2.2

[0048] Where α is the absorption parameter value and v is the root mean square velocity of the seismic data.

[0049] The optimal absorption parameter value is denoted as α. w The absorption parameter value based on seismic data is denoted as α. s , will α w α corresponding to its time depth s By dividing each value one by one, the correction coefficient is obtained, and the formula is as follows:

[0050]

[0051] Where η is the correction coefficient, spatial interpolation smoothing is performed on the correction coefficient η, and the spatially interpolated correction coefficient η is multiplied by α. s This allows us to obtain the optimal absorption parameters.

[0052] S4 processes the post-stack seismic data volume using optimal absorption parameters to obtain high-resolution seismic profiles.

[0053] The post-stack seismic data volume is processed using the following formula:

[0054]

[0055] Where w(t) is the earthquake data amplitude, It is the inverse Fourier transform, w(ω) is the Fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, and α is the absorption parameter.

[0056] Figure 3 This is a post-stack seismic profile before high-resolution processing. Figure 4 This is a high-resolution processed post-stack seismic profile. Figure 3 and Figure 4 Comparing the post-stack seismic profiles in the data, it can be seen that after using the absorption parameters obtained in this embodiment... Figure 4 The resolution of the seismic profiles is significantly improved, the previously superimposed phase axes are better separated, and the lateral continuity of the phase axes is improved.

[0057] Example 2:

[0058] Based on the same inventive concept, this embodiment discloses a system for improving seismic profile resolution based on attenuation synthetic records, including:

[0059] The initial absorption parameter value acquisition module is used to calculate the initial absorption parameter value using VSP logging data;

[0060] The module for obtaining the best-matched absorption parameter value is used to generate attenuated synthetic seismic records based on the initial absorption parameter value, reflection coefficient sequence and Ricker wavelet, and to select the best-matched absorption parameter value through the attenuated synthetic seismic records.

[0061] The optimal absorption parameter acquisition module is used to calculate the absorption parameter value based on the actual seismic data, and to obtain the optimal absorption parameter by calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter.

[0062] The seismic profile acquisition module is used to process the post-stack seismic data volume using optimal absorption parameters to obtain high-resolution seismic profiles.

[0063] The post-stack seismic data volume is processed using the following formula:

[0064]

[0065] Where w(t) is the earthquake data amplitude, It is the inverse Fourier transform, w(ω) is the Fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, and α is the absorption parameter.

[0066] Example 3:

[0067] Based on the same inventive concept, this embodiment discloses a computer-readable storage medium storing a computer program, which is executed by a processor to implement any of the above-mentioned methods for improving seismic profile resolution based on attenuated synthetic records.

[0068] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0070] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0071] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific embodiments of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention. The above content is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for improving seismic profile resolution based on attenuated synthetic records, characterized in that, include: Calculate the initial absorption parameter values ​​using VSP logging data; Attenuated synthetic seismic records are generated based on the initial absorption parameter values, reflection coefficient sequence, and Ricker wavelet, and the best-matching absorption parameter values ​​are selected through the attenuated synthetic seismic records. The absorption parameter values ​​based on actual earthquake data are calculated, and the optimal absorption parameters are obtained by calibrating the absorption parameter values ​​based on earthquake data using the adjusted absorption parameters. High-resolution seismic profiles are obtained by processing the post-stack seismic data volume using the optimal absorption parameters. The method for selecting the best-matching absorption parameter value is as follows: Generate waveforms corresponding to different absorption parameter values; The positions of the wave crests in the attenuated synthetic seismic records are marked; The peak positions in the waveforms corresponding to different absorption parameter values ​​are compared with the peak positions in the attenuated synthetic seismic record, and the waveforms with the same peak positions as those in the attenuated synthetic seismic record are selected. The absorption parameter value corresponding to the selected waveform is taken as the best matching absorption parameter value; The different absorption parameter values ​​are obtained by multiplying the initial absorption parameter value by a set of preset coefficients.

2. The method for improving seismic profile resolution based on attenuated synthetic records as described in claim 1, characterized in that, The initial absorption parameter values ​​are obtained using the logarithmic spectral ratio method, and the calculation formula is as follows: in, For the absorption parameter value, It is the frequency value of the well logging data. It refers to the time depth of the well logging data. It is the amplitude value of the overlying strata. It is the amplitude value of the current stratum.

3. The method for improving seismic profile resolution based on attenuated synthetic records as described in claim 1, characterized in that, The dominant frequency of shallow seismic data is used as the dominant frequency of the Rick wavelet.

4. The method for improving seismic profile resolution based on attenuated synthetic records as described in any one of claims 1-3, characterized in that, The formula for calculating the absorption parameter value based on actual earthquake data is as follows: in, Here, v represents the absorption parameter value, and v is the root mean square velocity of the seismic data.

5. The method for improving seismic profile resolution based on attenuated synthetic records as described in any one of claims 1-3, characterized in that, The optimally matched absorption parameter value is denoted as The absorption parameter value based on the seismic data is denoted as ,Will Corresponding to its time depth By dividing each value one by one, the correction coefficient is obtained, and the formula is as follows: in, For the correction coefficient, the correction coefficient Perform spatial interpolation smoothing, and then apply the correction coefficients after spatial interpolation smoothing. Multiply This allows us to obtain the optimal absorption parameters.

6. The method for improving seismic profile resolution based on attenuated synthetic records as described in any one of claims 1-3, characterized in that, The post-stack seismic data volume is processed using the following formula: in, It is the amplitude of earthquake data. It is the inverse Fourier transform. It is the Fourier transform result of the seismic data. It is angular frequency. It's about time depth. It is the absorption parameter.

7. A system for improving seismic profile resolution based on attenuated synthetic records, characterized in that, include: The initial absorption parameter value acquisition module is used to calculate the initial absorption parameter value using VSP logging data; The optimal matching absorption parameter value acquisition module is used to generate attenuated synthetic seismic records based on the initial absorption parameter values, reflection coefficient sequence and Ricker wavelet, and select the optimal matching absorption parameter values ​​through the attenuated synthetic seismic records; The optimal absorption parameter acquisition module is used to calculate the absorption parameter value based on the actual seismic data, and calibrate the absorption parameter value based on the seismic data through the adjusted absorption parameter to obtain the optimal absorption parameter; The seismic profile acquisition module is used to process the post-stack seismic data volume using the optimal absorption parameters to obtain a high-resolution seismic profile. The method for selecting the best-matching absorption parameter value is as follows: Generate waveforms corresponding to different absorption parameter values; The positions of the wave crests in the attenuated synthetic seismic records are marked; The peak positions in the waveforms corresponding to different absorption parameter values ​​are compared with the peak positions in the attenuated synthetic seismic record, and the waveforms with the same peak positions as those in the attenuated synthetic seismic record are selected. The absorption parameter value corresponding to the selected waveform is taken as the best matching absorption parameter value; The different absorption parameter values ​​are obtained by multiplying the initial absorption parameter value by a set of preset coefficients.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that is executed by a processor to implement the method for improving seismic profile resolution based on attenuated synthetic records as described in any one of claims 1-6.

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