Depth domain non-zero phase seismic wavelet extraction method and device

Abstract

The invention discloses a depth domain non-zero phase seismic wavelet extraction method and device. The method may include: decomposing an amplitude spectrum of a depth domain seismic wavelet through a depth-wavenumber spectrum; estimating the phase spectrum of the seismic wavelet according to the phase shift characteristic of the depth domain seismic wavelet; and according to the phase spectrum, through amplitude phase matching fusion, depth domain non-zero phase seismic wavelets are extracted. The depth domain non-zero phase seismic wavelet extraction method can improve the accuracy of depth domain non-zero phase seismic wavelet extraction.

Description

Technical Field

[0001] This invention relates to the field of oil and gas geophysical exploration, and more specifically, to a method and apparatus for extracting non-zero phase seismic wavelets in the depth domain. Background Technology

[0002] The core of depth-domain seismic inversion lies in solving the problem of depth-domain seismic wavelets. Currently, methods for estimating depth-domain seismic wavelets mainly fall into two categories: one involves converting depth-domain seismic data to the time domain or a constant-velocity depth domain using velocity, extracting the seismic wavelet from the converted data, and then converting the wavelet back to the depth domain using velocity; the other involves estimating the amplitude spectrum of the depth-domain seismic wavelet using the data and then using this spectrum to estimate the wavelet. Neither of these methods considers the phase characteristics of the seismic wavelet. However, depth-domain seismic data is typically non-zero phase; therefore, existing methods for estimating depth-domain seismic wavelets exhibit significant errors in practical applications.

[0003] Therefore, it is necessary to develop a method and apparatus for extracting non-zero phase seismic wavelets in the depth domain.

[0004] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention proposes a method and apparatus for extracting non-zero phase seismic wavelets in the depth domain, which can improve the accuracy of extracting non-zero phase seismic wavelets in the depth domain.

[0006] In a first aspect, embodiments of this disclosure provide a method for extracting non-zero phase seismic wavelets in the depth domain, including:

[0007] Amplitude spectra of depth-domain seismic wavelets are decomposed using depth-wavenumber spectral decomposition.

[0008] Based on the phase shift characteristics of the depth-domain seismic wavelet, the phase spectrum of the seismic wavelet is estimated;

[0009] Based on the phase spectrum, non-zero phase seismic wavelets in the depth domain are extracted through amplitude phase matching fusion.

[0010] As a specific implementation of this disclosure, the amplitude spectrum of the depth-domain seismic wavelet is decomposed by the depth-wavenumber spectrum, including:

[0011] The depth-wavenumber spectrum of the depth-domain seismic record is obtained by decomposing the depth-domain seismic record through the depth-domain S-transform.

[0012] The absolute value of the depth-wavenumber spectrum is taken, and the amplitude spectrum of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform.

[0013] As a specific implementation of this disclosure, estimating the phase spectrum of the seismic wavelet based on the phase shift characteristics of the depth-domain seismic wavelet includes:

[0014] The main wavenumbers of the low-pass and high-pass filters are determined based on the wavenumber spectrum, and then the corresponding seismic wavelets are determined.

[0015] Low-pass filtered seismic data and high-pass filtered seismic data are obtained by performing low-pass filtering and high-pass filtering on the seismic wavelets corresponding to low-pass filtering and high-pass filtering, respectively.

[0016] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. The phase rotation was linearly fitted to the depth difference to obtain a linear expression between the peak depth difference and the phase rotation.

[0017] The phase of the depth-domain seismic wavelet is estimated based on the linear expression, and then the phase spectrum is constructed.

[0018] As a specific implementation of this disclosure, wavenumber spectral decomposition is performed on low-pass filtered seismic data and high-pass filtered seismic data respectively, and a linear fit is performed on the phase rotation and depth difference to obtain a linear expression between the peak depth difference and the phase rotation, including:

[0019] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively to determine the dominant wavenumbers k for each. lm and k rm ;

[0020] Calculate the main wave number as k lm and k rm When two depth-domain seismic wavelets rotate with the same phase, the depth difference corresponding to their peaks is obtained by linearly fitting the phase rotation amount to the depth difference, thus obtaining a linear expression between the peak depth difference and the phase rotation amount.

[0021] As a specific implementation of this disclosure, the phase of the depth-domain seismic wavelet is:

[0022]

[0023] in, For the phase of the depth-domain seismic wavelet, This represents the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface.

[0024] As a specific implementation of this disclosure, extracting the non-zero phase seismic wavelet in the depth domain through amplitude phase matching fusion based on the phase spectrum includes:

[0025] The amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused.

[0026] An inverse Fourier transform is performed on the matching and fusion results to obtain a non-zero phase seismic wavelet in the depth domain.

[0027] As a specific implementation of this disclosure, the amplitude spectrum and phase spectrum of the depth-domain seismic wavelet are matched and fused using the following formula:

[0028] s(h)=A(h)e -iφ(h)

[0029] Where s(h) is the matching and fusion result.

[0030] Secondly, embodiments of this disclosure also provide a depth-domain non-zero phase seismic wavelet extraction device, comprising:

[0031] The decomposition module decomposes the amplitude spectrum of the depth-domain seismic wavelet using the depth-wavenumber spectrum.

[0032] The estimation module estimates the phase spectrum of the seismic wavelet based on the phase shift characteristics of the depth-domain seismic wavelet;

[0033] The matching and fusion module extracts the non-zero phase seismic wavelet in the depth domain through amplitude phase matching and fusion based on the phase spectrum.

[0034] As a specific implementation of this disclosure, the amplitude spectrum of the depth-domain seismic wavelet is decomposed by the depth-wavenumber spectrum, including:

[0035] The depth-wavenumber spectrum of the depth-domain seismic record is obtained by decomposing the depth-domain seismic record through the depth-domain S-transform.

[0036] The absolute value of the depth-wavenumber spectrum is taken, and the amplitude spectrum of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform.

[0037] As a specific implementation of this disclosure, estimating the phase spectrum of the seismic wavelet based on the phase shift characteristics of the depth-domain seismic wavelet includes:

[0038] The main wavenumbers of the low-pass and high-pass filters are determined based on the wavenumber spectrum, and then the corresponding seismic wavelets are determined.

[0039] Low-pass filtered seismic data and high-pass filtered seismic data are obtained by performing low-pass filtering and high-pass filtering on the seismic wavelets corresponding to low-pass filtering and high-pass filtering, respectively.

[0040] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. The phase rotation was linearly fitted to the depth difference to obtain a linear expression between the peak depth difference and the phase rotation.

[0041] The phase of the depth-domain seismic wavelet is estimated based on the linear expression, and then the phase spectrum is constructed.

[0042] As a specific implementation of this disclosure, wavenumber spectral decomposition is performed on low-pass filtered seismic data and high-pass filtered seismic data respectively, and a linear fit is performed on the phase rotation and depth difference to obtain a linear expression between the peak depth difference and the phase rotation, including:

[0043] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively to determine the dominant wavenumbers k for each. lm and k rm ;

[0044] Calculate the main wave number as k lm and k rm When two depth-domain seismic wavelets rotate with the same phase, the depth difference corresponding to their peaks is obtained by linearly fitting the phase rotation amount to the depth difference, thus obtaining a linear expression between the peak depth difference and the phase rotation amount.

[0045] As a specific implementation of this disclosure, the phase of the depth-domain seismic wavelet is:

[0046]

[0047] in, For the phase of the depth-domain seismic wavelet, This represents the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface.

[0048] As a specific implementation of this disclosure, extracting the non-zero phase seismic wavelet in the depth domain through amplitude phase matching fusion based on the phase spectrum includes:

[0049] The amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused.

[0050] An inverse Fourier transform is performed on the matching and fusion results to obtain a non-zero phase seismic wavelet in the depth domain.

[0051] As a specific implementation of this disclosure, the amplitude spectrum and phase spectrum of the depth-domain seismic wavelet are matched and fused using the following formula:

[0052] s(h)=A(h)e -iφ(h)

[0053] Where s(h) is the matching and fusion result.

[0054] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0055] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0056] Figure 1 A flowchart illustrating the steps of a depth-domain non-zero phase seismic wavelet extraction method according to an embodiment of the present invention is shown.

[0057] Figure 2a and Figure 2b Schematic diagrams of depth-domain seismic records and their depth-wavenumber spectra according to an embodiment of the present invention are shown.

[0058] Figure 3 A schematic diagram of the amplitude spectrum estimation results of a depth-domain seismic wavelet according to an embodiment of the present invention is shown.

[0059] Figure 4 A schematic diagram of depth-domain seismic data filtering according to an embodiment of the present invention is shown.

[0060] Figure 5a and Figure 5b Schematic diagrams of the phase shift characteristics and phase spectrum estimation results of a depth-domain seismic wavelet according to an embodiment of the present invention are shown.

[0061] Figure 6 A schematic diagram of a depth-domain non-zero phase seismic wavelet extracted according to an embodiment of the present invention is shown.

[0062] Figure 7 A schematic diagram of depth-domain seismic record comparison results according to an embodiment of the present invention is shown.

[0063] Figure 8 A block diagram of a depth-domain non-zero phase seismic wavelet extraction device according to an embodiment of the present invention is shown.

[0064] Explanation of reference numerals in the attached figures:

[0065] 201. Decomposition module; 202. Estimation module; 203. Matching and fusion module. Detailed Implementation

[0066] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0067] To facilitate understanding of the solutions and effects of the embodiments of the present invention, four specific application examples are given below. Those skilled in the art should understand that these examples are merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0068] Example 1

[0069] Figure 1 A flowchart illustrating the steps of a depth-domain non-zero phase seismic wavelet extraction method according to an embodiment of the present invention is shown.

[0070] like Figure 1 As shown, the depth-domain non-zero phase seismic wavelet extraction method includes:

[0071] Step 101: Decompose the amplitude spectrum of the depth-domain seismic wavelet using the depth-wavenumber spectrum.

[0072] Step 102: Estimate the phase spectrum of the seismic wavelet based on the phase shift characteristics of the depth-domain seismic wavelet;

[0073] Step 103: Based on the phase spectrum, extract the non-zero phase seismic wavelet in the depth domain by amplitude phase matching fusion.

[0074] In one example, the amplitude spectrum of a depth-domain seismic wavelet decomposed by depth-wavenumber spectral decomposition includes:

[0075] The depth-wavenumber spectrum of the depth-domain seismic record is obtained by decomposing the depth-domain seismic record through the depth-domain S-transform.

[0076] By taking the absolute value of the depth-wavenumber spectrum, the amplitude spectrum of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform.

[0077] In one example, the phase spectrum of the seismic wavelet is estimated based on the phase shift characteristics of the depth-domain seismic wavelet, including:

[0078] The main wavenumbers of the low-pass and high-pass filters are determined based on the wavenumber spectrum, and then the corresponding seismic wavelets are determined.

[0079] Low-pass filtered seismic data and high-pass filtered seismic data are obtained by performing low-pass filtering and high-pass filtering on the seismic wavelets corresponding to low-pass filtering and high-pass filtering, respectively.

[0080] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. The phase rotation was linearly fitted to the depth difference to obtain a linear expression between the peak depth difference and the phase rotation.

[0081] The phase of the depth-domain seismic wavelet is estimated based on a linear expression, and then the phase spectrum is constructed.

[0082] In one example, wavenumber spectral decomposition is performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. A linear fit is then performed on the phase rotation and depth difference to obtain the following linear expression between the peak depth difference and the phase rotation:

[0083] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively to determine the dominant wavenumbers k for each. lm and k rm ;

[0084] Calculate the main wave number as k lm and k rm When two depth-domain seismic wavelets rotate with the same phase, the depth difference corresponding to their peaks is obtained by linearly fitting the phase rotation amount to the depth difference, thus obtaining a linear expression between the peak depth difference and the phase rotation amount.

[0085] In one example, the phase of the depth-domain seismic wavelet is:

[0086]

[0087] in, For the phase of the depth-domain seismic wavelet, This represents the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface.

[0088] In one example, based on the phase spectrum, the non-zero phase seismic wavelet in the depth domain is extracted by amplitude-phase matching fusion, including:

[0089] The amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused.

[0090] An inverse Fourier transform is performed on the matching and fusion results to obtain a non-zero phase seismic wavelet in the depth domain.

[0091] In one example, the amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused using the following formula:

[0092] s(h)=A(h)e -iφ(h)

[0093] Where s(h) is the matching and fusion result.

[0094] Specifically, the amplitude spectrum of the depth-domain seismic wavelet is estimated by depth-wavenumber spectral decomposition.

[0095] The depth-wavenumber spectrum of the depth-domain seismic record d(h) is obtained by decomposing it using the depth-domain S-transform.

[0096]

[0097] Where g(η-h,k) is the depth-domain Gaussian window function.

[0098] The absolute value of the depth-wavenumber spectrum of the depth-domain seismic record is taken, and the amplitude spectrum A(h) of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform. Since the depth-wavenumber spectrum of the depth-domain seismic record varies with depth, the amplitude spectrum of the depth-domain seismic wavelet also varies with depth.

[0099] The phase spectrum of a seismic wavelet is estimated using the phase shift characteristics of the seismic wavelet in the depth domain.

[0100] Filtering is performed on depth-domain seismic records. The dominant wavenumber k for low-pass filtering is determined based on the wavenumber spectrum of the depth-domain seismic records. l The main wave number k of the high-pass filter r Calculate the main wave number k respectively. l and k r Zero-phase depth domain seismic wavelet:

[0101]

[0102] Using zero-phase depth domain seismic wavelet w l and w r Low-pass and high-pass filters are applied to the depth-domain seismic data d respectively to obtain the low-pass filtered seismic data d. l and high-pass filtered seismic data d r .

[0103] Calculate the phase shift characteristics of the depth-domain seismic wavelet. This is done for the low-pass filtered seismic data d... l and high-pass filtered seismic data d r Wavenumber spectral decomposition was performed to determine the dominant wavenumbers of the two waves as k. lm and k rm Then calculate the main wave number as k. lm and k rm Two depth-domain seismic wavelets rotate with the same phase φ j When (j=1,2,...,m), the depth difference Δh corresponding to the peaks of the two waves. j For (j=1,2,...,m), a linear fit is performed on the phase rotation and depth difference to obtain a linear expression between the peak depth difference Δh and the phase rotation φ:

[0104] φ=c·Δh

[0105] Estimate the phase spectrum of the depth-domain seismic wavelet. Calculate the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface. Phase estimation of depth-domain seismic wavelet based on linear expression

[0106]

[0107] Based on the estimated phase Construct the phase spectrum φ(h) of the seismic wavelet in the depth domain, which does not change with depth.

[0108] Non-zero phase seismic wavelets in the depth domain are extracted based on amplitude-phase matching fusion. The amplitude and phase spectra of the depth-domain seismic wavelets are matched and fused according to the following formula:

[0109] s(h)=A(h)e -iφ(h)

[0110] The inverse Fourier transform of s(h) yields the non-zero phase seismic wavelet in the depth domain.

[0111] Example 2

[0112] The present invention also provides a depth-domain non-zero phase seismic wavelet extraction device, comprising:

[0113] The decomposition module decomposes the amplitude spectrum of the depth-domain seismic wavelet using the depth-wavenumber spectrum.

[0114] The estimation module estimates the phase spectrum of the seismic wavelet based on the phase shift characteristics of the seismic wavelet in the depth domain.

[0115] The matching and fusion module extracts non-zero phase seismic wavelets in the depth domain through amplitude phase matching and fusion based on the phase spectrum.

[0116] In one example, the amplitude spectrum of a depth-domain seismic wavelet decomposed by depth-wavenumber spectral decomposition includes:

[0117] The depth-wavenumber spectrum of the depth-domain seismic record is obtained by decomposing the depth-domain seismic record through the depth-domain S-transform.

[0118] By taking the absolute value of the depth-wavenumber spectrum, the amplitude spectrum of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform.

[0119] In one example, the phase spectrum of the seismic wavelet is estimated based on the phase shift characteristics of the depth-domain seismic wavelet, including:

[0120] The main wavenumbers of the low-pass and high-pass filters are determined based on the wavenumber spectrum, and then the corresponding seismic wavelets are determined.

[0121] Low-pass filtered seismic data and high-pass filtered seismic data are obtained by performing low-pass filtering and high-pass filtering on the seismic wavelets corresponding to low-pass filtering and high-pass filtering, respectively.

[0122] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. The phase rotation was linearly fitted to the depth difference to obtain a linear expression between the peak depth difference and the phase rotation.

[0123] The phase of the depth-domain seismic wavelet is estimated based on a linear expression, and then the phase spectrum is constructed.

[0124] In one example, wavenumber spectral decomposition is performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. A linear fit is then performed on the phase rotation and depth difference to obtain the following linear expression between the peak depth difference and the phase rotation:

[0125] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively to determine the dominant wavenumbers k for each. lm and k rm ;

[0126] Calculate the main wave number as k lm and k rm When two depth-domain seismic wavelets rotate with the same phase, the depth difference corresponding to their peaks is obtained by linearly fitting the phase rotation amount to the depth difference, thus obtaining a linear expression between the peak depth difference and the phase rotation amount.

[0127] In one example, the phase of the depth-domain seismic wavelet is:

[0128]

[0129] in, For the phase of the depth-domain seismic wavelet, This represents the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface.

[0130] In one example, based on the phase spectrum, the non-zero phase seismic wavelet in the depth domain is extracted by amplitude-phase matching fusion, including:

[0131] The amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused.

[0132] An inverse Fourier transform is performed on the matching and fusion results to obtain a non-zero phase seismic wavelet in the depth domain.

[0133] In one example, the amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused using the following formula:

[0134] s(h)=A(h)e -iφ(h)

[0135] Where s(h) is the matching and fusion result.

[0136] Specifically, the amplitude spectrum of the depth-domain seismic wavelet is estimated by depth-wavenumber spectral decomposition.

[0137] The depth-wavenumber spectrum of the depth-domain seismic record d(h) is obtained by decomposing it using the depth-domain S-transform.

[0138]

[0139] Where g(η-h,k) is the depth-domain Gaussian window function.

[0140] The absolute value of the depth-wavenumber spectrum of the depth-domain seismic record is taken, and the amplitude spectrum A(h) of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform. Since the depth-wavenumber spectrum of the depth-domain seismic record varies with depth, the amplitude spectrum of the depth-domain seismic wavelet also varies with depth.

[0141] The phase spectrum of a seismic wavelet is estimated using the phase shift characteristics of the seismic wavelet in the depth domain.

[0142] Filtering is performed on depth-domain seismic records. The dominant wavenumber k for low-pass filtering is determined based on the wavenumber spectrum of the depth-domain seismic records. l The main wave number k of the high-pass filter r Calculate the main wave number k respectively. l and k r Zero-phase depth domain seismic wavelet:

[0143]

[0144] Using zero-phase depth domain seismic wavelet w l and w r Low-pass and high-pass filters are applied to the depth-domain seismic data d respectively to obtain the low-pass filtered seismic data d. l and high-pass filtered seismic data d r .

[0145] Calculate the phase shift characteristics of the depth-domain seismic wavelet. This is done for the low-pass filtered seismic data d... l and high-pass filtered seismic data d r Wavenumber spectral decomposition was performed to determine the dominant wavenumbers of the two waves as k. lm and k rm Then calculate the main wave number as k.lm and k rm Two depth-domain seismic wavelets rotate with the same phase φ j When (j=1,2,...,m), the depth difference Δh corresponding to the peaks of the two waves. j For (j=1,2,...,m), a linear fit is performed on the phase rotation and depth difference to obtain a linear expression between the peak depth difference Δh and the phase rotation φ:

[0146] φ=c·Δh

[0147] Estimate the phase spectrum of the depth-domain seismic wavelet. Calculate the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface. Phase estimation of depth-domain seismic wavelet based on linear expression

[0148]

[0149] Based on the estimated phase Construct the phase spectrum φ(h) of the seismic wavelet in the depth domain, which does not change with depth.

[0150] Non-zero phase seismic wavelets in the depth domain are extracted based on amplitude-phase matching fusion. The amplitude and phase spectra of the depth-domain seismic wavelets are matched and fused according to the following formula:

[0151] s(h)=A(h)e -iφ(h)

[0152] The inverse Fourier transform of s(h) yields the non-zero phase seismic wavelet in the depth domain.

[0153] Example 3

[0154] This embodiment uses simulated depth-domain seismic data as an example to extract non-zero phase seismic wavelets in the depth domain using this method.

[0155] Figure 2a and Figure 2b Schematic diagrams of depth-domain seismic records and their depth-wavenumber spectra according to an embodiment of the present invention are shown.

[0156] Figure 2a and Figure 2b This is a depth-domain seismic record and its depth-wavenumber spectrum for a model. The depth-domain seismic record is obtained by convolving the depth-domain seismic wavelet with the reflection coefficient at a phase of 40 degrees. The depth-wavenumber spectrum of the seismic record is calculated using the depth-domain S-transform.

[0157] Figure 3 A schematic diagram of the amplitude spectrum estimation results of a depth-domain seismic wavelet according to an embodiment of the present invention is shown.

[0158] Figure 3 The amplitude spectrum of a depth-domain seismic wavelet is estimated using the depth-wavenumber spectrum of depth-domain seismic data.

[0159] Figure 4 A schematic diagram of depth-domain seismic data filtering according to an embodiment of the present invention is shown.

[0160] Figure 4 The images show the low-pass and high-pass filtering results for depth-domain seismic data, with filtering factors of 6 and 55 for zero-phase seismic wavelets, respectively. The blue line represents the low-pass filtering result, and the red line represents the high-pass filtering result.

[0161] Figure 5a and Figure 5b Schematic diagrams of the phase shift characteristics and phase spectrum estimation results of a depth-domain seismic wavelet according to an embodiment of the present invention are shown.

[0162] Figure 5a and Figure 5b This demonstrates the phase shift characteristics of the depth-domain seismic wavelet, showing a linear relationship between the peak depth difference and the phase of the seismic wavelet in low-pass and high-pass filtered seismic data. Therefore, by calculating... Figure 4 The peak depth difference between low-pass filtered data and high-pass filtered data at the same interface can be used to estimate the phase of the depth-domain seismic wavelet, and thus obtain the phase spectrum of the depth-domain seismic wavelet.

[0163] Figure 6 A schematic diagram of a depth-domain non-zero phase seismic wavelet extracted according to an embodiment of the present invention is shown. It can be seen that the seismic wavelet varies with depth; the shallow seismic wavelet has a shorter duration and a higher dominant wave number, while the deep seismic wavelet has a longer duration and a lower dominant wave number. Furthermore, the seismic wavelets at each depth point are asymmetrical, reflecting the influence of non-zero phase on the depth-domain seismic wavelet.

[0164] Figure 7 A schematic diagram illustrating the comparison results of depth-domain seismic records according to an embodiment of the present invention is shown. The black line in the diagram represents the actual seismic record, and the red line represents the synthetic seismic record obtained by convolving the extracted depth-domain non-zero-phase seismic wavelet with the reflection coefficient. It can be seen that the synthetic seismic record matches the actual seismic record very well, demonstrating the accuracy of the depth-domain non-zero-phase seismic wavelet extraction and the effectiveness of the proposed method.

[0165] Example 4

[0166] Figure 8 A block diagram of a depth-domain non-zero phase seismic wavelet extraction device according to an embodiment of the present invention is shown.

[0167] like Figure 8 As shown, the depth-domain non-zero phase seismic wavelet extraction device includes:

[0168] Decomposition module 201 decomposes the amplitude spectrum of the depth domain seismic wavelet using the depth-wavenumber spectrum.

[0169] Estimation module 202 estimates the phase spectrum of the seismic wavelet based on the phase shift characteristics of the depth-domain seismic wavelet;

[0170] The matching and fusion module 203 extracts the non-zero phase seismic wavelet in the depth domain by amplitude phase matching and fusion based on the phase spectrum.

[0171] In one example, the amplitude spectrum of a depth-domain seismic wavelet decomposed by depth-wavenumber spectral decomposition includes:

[0172] The depth-wavenumber spectrum of the depth-domain seismic record is obtained by decomposing the depth-domain seismic record through the depth-domain S-transform.

[0173] By taking the absolute value of the depth-wavenumber spectrum, the amplitude spectrum of the depth-domain seismic wavelet is constructed based on the symmetry of the Fourier transform.

[0174] In one example, the phase spectrum of the seismic wavelet is estimated based on the phase shift characteristics of the depth-domain seismic wavelet, including:

[0175] The main wavenumbers of the low-pass and high-pass filters are determined based on the wavenumber spectrum, and then the corresponding seismic wavelets are determined.

[0176] Low-pass filtered seismic data and high-pass filtered seismic data are obtained by performing low-pass filtering and high-pass filtering on the seismic wavelets corresponding to low-pass filtering and high-pass filtering, respectively.

[0177] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. The phase rotation was linearly fitted to the depth difference to obtain a linear expression between the peak depth difference and the phase rotation.

[0178] The phase of the depth-domain seismic wavelet is estimated based on a linear expression, and then the phase spectrum is constructed.

[0179] In one example, wavenumber spectral decomposition is performed on low-pass filtered seismic data and high-pass filtered seismic data respectively. A linear fit is then performed on the phase rotation and depth difference to obtain the following linear expression between the peak depth difference and the phase rotation:

[0180] Wavenumber spectral decomposition was performed on low-pass filtered seismic data and high-pass filtered seismic data respectively to determine the dominant wavenumbers k for each. lm and k rm ;

[0181] Calculate the main wave number as klm and k rm When two depth-domain seismic wavelets rotate with the same phase, the depth difference corresponding to their peaks is obtained by linearly fitting the phase rotation amount to the depth difference, thus obtaining a linear expression between the peak depth difference and the phase rotation amount.

[0182] In one example, the phase of the depth-domain seismic wavelet is:

[0183]

[0184] in, For the phase of the depth-domain seismic wavelet, This represents the peak depth difference between low-pass filtered and high-pass filtered seismic data at the same interface.

[0185] In one example, based on the phase spectrum, the non-zero phase seismic wavelet in the depth domain is extracted by amplitude-phase matching fusion, including:

[0186] The amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused.

[0187] An inverse Fourier transform is performed on the matching and fusion results to obtain a non-zero phase seismic wavelet in the depth domain.

[0188] In one example, the amplitude and phase spectra of the depth-domain seismic wavelet are matched and fused using the following formula:

[0189] s(h)=A(h)e -iφ(h)

[0190] Where s(h) is the matching and fusion result.

[0191] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.

[0192] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for extracting a deep domain non-zero phase seismic wavelet, characterized in that, The method comprises the following steps: decomposing the amplitude spectrum of the depth domain seismic wavelet by depth-wavenumber spectrum; estimating the phase spectrum of the seismic wavelet according to the phase shift characteristics of the depth domain seismic wavelet; extracting the depth domain non-zero phase seismic wavelet by amplitude-phase matching fusion according to the phase spectrum.

2. The depth domain non-zero phase seismic wavelet extraction method of claim 1, wherein, The decomposing the amplitude spectrum of the depth domain seismic wavelet by depth-wavenumber spectrum comprises: decomposing the depth domain seismic record by depth domain S transform to obtain the depth-wavenumber spectrum of the depth domain seismic record; taking the absolute value of the depth-wavenumber spectrum to construct the amplitude spectrum of the depth domain seismic wavelet according to the symmetry of Fourier transform.

3. The depth domain non-zero phase seismic wavelet extraction method of claim 1, wherein, The estimating the phase spectrum of the seismic wavelet according to the phase shift characteristics of the depth domain seismic wavelet comprises: determining the main wavenumber of low-pass filtering and high-pass filtering respectively according to the wavenumber spectrum, and then determining the corresponding seismic wavelet; respectively performing low-pass filtering and high-pass filtering on the corresponding seismic wavelet by low-pass filtering and high-pass filtering to obtain low-pass filtered seismic data and high-pass filtered seismic data; respectively performing wavenumber spectrum decomposition on the low-pass filtered seismic data and the high-pass filtered seismic data, and linearly fitting the phase rotation amount and the depth difference to obtain a linear expression between the peak depth difference and the phase rotation amount; estimating the phase of the depth domain seismic wavelet according to the linear expression, and then constructing the phase spectrum.

4. The depth domain non-zero phase seismic wavelet extraction method of claim 3, wherein, The respectively performing wavenumber spectrum decomposition on the low-pass filtered seismic data and the high-pass filtered seismic data, and linearly fitting the phase rotation amount and the depth difference to obtain a linear expression between the peak depth difference and the phase rotation amount comprises: The wave number spectrum decomposition is respectively performed on the low-pass filtered seismic data and the high-pass filtered seismic data, and main wave numbers of the two are respectively determined as k lm and k rm ; The main wave number is k lm and k rm The peak depth difference of two depth domain seismic wavelets with the same phase rotation is obtained by linear fitting the phase rotation and the depth difference.

5. The depth domain non-zero phase seismic wavelet extraction method of claim 3, wherein, the phase of the depth domain seismic wavelet is: wherein, is the phase of the seismic wavelet in the depth domain, is the peak depth difference of the low-pass filtered seismic data and the high-pass filtered seismic data at the same interface.

6. The depth domain non-zero phase seismic wavelet extraction method of claim 1, wherein, The extracting the depth domain non-zero phase seismic wavelet by amplitude-phase matching fusion according to the phase spectrum comprises: matching and fusing the amplitude spectrum and the phase spectrum of the depth domain seismic wavelet; performing inverse Fourier transform on the matching and fusion result to obtain the depth domain non-zero phase seismic wavelet.

7. The depth domain non-zero phase seismic wavelet extraction method of claim 6, wherein, The matching and fusing the amplitude spectrum and the phase spectrum of the depth domain seismic wavelet by the following formula: s(h) = A(h) e -iφ(h) wherein, s(h) is the matching and fusion result.

8. A device for extracting a deep domain non-zero phase seismic wavelet, characterized by, The method comprises the following steps: a decomposing module, which decomposes the amplitude spectrum of the depth domain seismic wavelet by depth-wavenumber spectrum; an estimating module, which estimates the phase spectrum of the seismic wavelet according to the phase shift characteristics of the depth domain seismic wavelet; a matching and fusion module, which extracts the depth domain non-zero phase seismic wavelet by amplitude-phase matching fusion according to the phase spectrum.

9. The depth domain non-zero phase seismic wavelet extraction apparatus of claim 8, wherein, The decomposing the amplitude spectrum of the depth domain seismic wavelet by depth-wavenumber spectrum comprises: decomposing the depth domain seismic record by depth domain S transform to obtain the depth-wavenumber spectrum of the depth domain seismic record; taking the absolute value of the depth-wavenumber spectrum to construct the amplitude spectrum of the depth domain seismic wavelet according to the symmetry of Fourier transform.

10. The depth domain non-zero phase seismic wavelet extraction apparatus of claim 8, wherein, The estimating the phase spectrum of the seismic wavelet according to the phase shift characteristics of the depth domain seismic wavelet comprises: determining the main wavenumber of low-pass filtering and high-pass filtering respectively according to the wavenumber spectrum, and then determining the corresponding seismic wavelet; respectively performing low-pass filtering and high-pass filtering on the corresponding seismic wavelet by low-pass filtering and high-pass filtering to obtain low-pass filtered seismic data and high-pass filtered seismic data; respectively performing wavenumber spectrum decomposition on the low-pass filtered seismic data and the high-pass filtered seismic data, and linearly fitting the phase rotation amount and the depth difference to obtain a linear expression between the peak depth difference and the phase rotation amount; The wave number spectrum decomposition is respectively performed on low-pass filtered seismic data and high-pass filtered seismic data, linear fitting is performed on phase rotation amount and depth difference, and a linear expression between peak depth difference and phase rotation amount is obtained; According to the linear expression, the phase of the depth domain seismic wavelet is estimated, and then the phase spectrum is constructed.

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