Scattered wave superposition velocity extraction method and system

Abstract

The application discloses a scattering wave superposition velocity extraction method and system, and the system comprises an acquisition module, a calculation module, a statistical module and an extraction module. First, the acquisition module can acquire common shot gather data, two-way travel time vectors, wave velocity vectors, shot three-dimensional coordinates and detector three-dimensional coordinates. Then, the calculation module introduces the shot three-dimensional coordinates and the detector three-dimensional coordinates, and calculates two-way travel times of all seismic traces at different time and different wave velocities. After that, the statistical module extracts corresponding amplitude values from the common shot gather data according to the two-way travel times, and calculates amplitude absolute average values corresponding to different time and different wave velocities. Finally, the extraction module generates a wave velocity spectrum according to the calculated amplitude absolute average values, and extracts a shot gather corresponding superposition velocity through the wave velocity spectrum. In this way, the superposition velocity of the scattering wave can be directly extracted without height correction, so that the influence of the surface relief can be eliminated.

Description

Technical Field

[0001] This invention relates to the field of earthquake data processing technology, specifically to a method and system for extracting the velocity of superimposed scattered waves. Background Technology

[0002] Velocity extraction is an effective means of obtaining seismic stacking velocities and an indispensable part of seismic data processing. Traditional velocity extraction algorithms are based on horizontal surface conditions. For undulating surfaces, height correction is generally required before velocity extraction to align them with the same reference plane. However, height correction has two serious drawbacks: firstly, it requires obtaining the wave velocity of the shallow low-velocity zone, but this velocity needs to be obtained through other methods, making the exploration work cumbersome; secondly, when this wave velocity is obtained inaccurately, i.e., the undulating surface is not truly calibrated to the same reference plane, it will produce incorrect correction results for shallow scattered wave exploration, the severity of which is far greater than that for deep reflected wave exploration. Therefore, traditional velocity extraction methods are not suitable for extracting scattered wave stacking velocities under undulating surface conditions. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes a method and system for extracting the superposition velocity of scattered waves, applicable to the extraction of superposition velocity of scattered waves under undulating surface conditions. The specific technical solution is as follows:

[0004] Firstly, a method for extracting the superposition velocity of scattered waves is provided, including:

[0005] Acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v);

[0006] Based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, the two-way travel time vector t, and the wave velocity vector v, calculate the two-way travel time corresponding to different times and different wave velocities.

[0007] The corresponding amplitude values ​​are extracted from the common shot point gather data Data based on the corresponding two-way travel time, and the absolute average amplitude of each seismic trace at different times and different wave velocities is calculated.

[0008] The corresponding velocity spectrum is generated based on the absolute average amplitude of all times and all wave velocities, and the superposition velocity corresponding to the shot gather is extracted from the generated velocity spectrum.

[0009] In conjunction with the first aspect, in the first possible implementation of the first aspect, calculating the two-way travel time corresponding to different times and different wave velocities includes:

[0010]

[0011] Among them, CR xCR y CR z These are the three-dimensional coordinates of the detector, CP. x CP y CP z denoted as the three-dimensional coordinates of the shot point, T as the two-way travel time corresponding to the seismic trace, t as the time node in the two-way travel time vector, and v as the wave velocity node in the wave velocity vector.

[0012] In conjunction with the first aspect, in the second possible implementation of the first aspect, the superposition velocity corresponding to the shot gathering is extracted from the velocity spectrum, including:

[0013] The data in each row of the velocity spectrum are normalized respectively;

[0014] Image plots were drawn based on the normalized velocity spectrum;

[0015] The velocity corresponding to the maximum point in the image is selected as the stacking velocity.

[0016] Secondly, a method for extracting the superposition velocity of scattered waves is provided, including:

[0017] Using the scattered wave superposition velocity extraction method provided in the first aspect, the superposition velocities corresponding to different shot collections are extracted;

[0018] An interpolation algorithm is used to interpolate the extracted superposition velocities to generate the superposition velocity matrix VR. itr ;

[0019] According to the superimposed velocity matrix VR itr Determine the layer velocity matrix V and depth matrix H;

[0020] A uniform depth range H is determined using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0021] For the same depth range, the layer velocity matrix V itr The average layer velocity V is obtained by averaging. mean ;

[0022] According to the average layer velocity V mean and uniform depth range H itr Calculate the average round-trip travel time T irt1 ;

[0023] The average layer velocity V corresponding to each shot collection is selected by using the corresponding three-dimensional coordinates of the shot points. mean and average round-trip travel time T irt1 ;

[0024] Based on the selected average round-trip travel time T irt1 Selected average layer velocity V mean Convert to average superposition velocity VR1;

[0025] The average stacking velocity VR1 is interpolated using an interpolation algorithm to obtain the interpolated average stacking velocity VR. mean .

[0026] Thirdly, a method for extracting the superposition velocity of scattered waves is provided, including:

[0027] Using the scattered wave superposition velocity extraction method provided in the first aspect, the superposition velocities corresponding to different shot collections are extracted;

[0028] An interpolation algorithm is used to interpolate the extracted superposition velocities to generate the superposition velocity matrix VR. itr ;

[0029] According to the superimposed velocity matrix VR itr Determine the layer velocity matrix V and depth matrix H;

[0030] A uniform depth range H is determined using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0031] For the layer velocity matrix V itr Smoothing is performed to obtain the smoothing layer velocity V. smooth ;

[0032] According to the smoothing layer speed V smooth and uniform depth range H itr Calculate the smoothed two-way travel time T irt2 ;

[0033] The smoothing layer velocity V corresponding to each shot collection is selected by using the corresponding three-dimensional coordinates of the shot points. smooth And smooth two-way travel T irt2 ;

[0034] Based on smooth two-way travel time T irt2 Select the smoothing layer speed V smooth Convert to smooth overlay speed VR2;

[0035] The smooth stacking velocity VR2 is interpolated using an interpolation algorithm to obtain the interpolated smooth stacking velocity VR. smooth .

[0036] Fourthly, a system for extracting the superposition velocity of scattered waves is provided, comprising:

[0037] The acquisition module is configured to acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v).

[0038] The calculation module is configured to calculate the two-way travel time of each seismic trace corresponding to each shot gathering at different times and with different wave velocities, based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, the two-way travel time vector t, and the wave velocity vector v.

[0039] The statistics module is configured to extract the corresponding amplitude values ​​from the common shot point gather data Data based on the corresponding two-way travel time, and calculate the absolute average amplitude values ​​corresponding to different times and different wave velocities.

[0040] The extraction module is configured to generate velocity spectra for each shot collection based on the corresponding absolute average amplitude, and extract the superposition velocity for each shot collection from the generated velocity spectra.

[0041] In conjunction with the second aspect, in the first possible implementation of the second aspect, the calculation module calculates the two-way travel time corresponding to different times and different wave velocities, including:

[0042]

[0043] Among them, CR x CR y CR z These are the three-dimensional coordinates of the detector, CP. x CP y CP z denoted as the three-dimensional coordinates of the shot point, T as the two-way travel time corresponding to the seismic trace, t as the time node in the two-way travel time vector, and v as the wave velocity node in the wave velocity vector.

[0044] In conjunction with the second aspect, in a second possible implementation of the second aspect, the extraction module includes:

[0045] The normalization unit is configured to perform normalization processing on each row of data in the velocity spectrum;

[0046] The image plotting unit is configured to plot an image based on the normalized velocity spectrum.

[0047] The velocity extraction unit is configured to select the velocity corresponding to the maximum point in the image as the stacking velocity.

[0048] Fifthly, a system for extracting the superposition velocity of scattered waves is provided, comprising:

[0049] The scattered wave superposition velocity extraction system provided in the fourth aspect is configured to extract the superposition velocity corresponding to different shot sets, and;

[0050] The matrix generation module is configured to use an interpolation algorithm to interpolate the extracted superposition velocities and generate the superposition velocity matrix VR. itr ;

[0051] The matrix determination module is configured to determine the superimposed velocity matrix VR. itr Determine the layer velocity matrix V and depth matrix H;

[0052] The matrix processing module is configured to determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0053] The averaging module is configured to process the layer velocity matrix V within the same depth range. itr The average layer velocity V is obtained by averaging. mean ;

[0054] The average time calculation module is configured to calculate based on the average layer velocity V. mean and uniform depth range H itr Calculate the average round-trip travel time T irt1 ;

[0055] The average data selection module is configured to select the average layer velocity V corresponding to each shot gather based on the corresponding three-dimensional coordinates of the shot points. mean and average round-trip travel time T irt1 ;

[0056] The average data conversion module is configured to convert data based on the selected average round-trip travel time T. irt1 Selected average layer velocity V mean Convert to average superposition velocity VR1;

[0057] The average velocity calculation module is configured to interpolate the average superimposed velocity VR1 using an interpolation algorithm to obtain the interpolated average superimposed velocity VR. mean .

[0058] Sixthly, a system for extracting the superposition velocity of scattered waves is provided, comprising:

[0059] The scattered wave superposition velocity extraction system provided in the fourth aspect is configured to extract the superposition velocity corresponding to different shot sets, and;

[0060] The matrix generation module is configured to use an interpolation algorithm to interpolate the extracted superposition velocities and generate the superposition velocity matrix VR. itr ;

[0061] The matrix determination module is configured to determine the superimposed velocity matrix VR. itr Determine the layer velocity matrix V and depth matrix H;

[0062] The matrix processing module is configured to determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0063] The smoothing module is configured to process the layer velocity matrix V. itr Smoothing is performed to obtain the smoothing layer velocity V. smooth ;

[0064] The smoothing time calculation module is configured to calculate the smoothing time based on the smoothing layer speed V. smooth and uniform depth range H itr Calculate the smoothed two-way travel time T irt2 ;

[0065] The smoothing data selection module is configured to select the smoothing layer velocity V corresponding to each shot gather based on the corresponding three-dimensional coordinates of the shot points. smooth And smooth two-way travel T irt2 ;

[0066] The smoothing data transformation module is configured to transform data based on the smoothed two-way travel time T. irt2 Select the smoothing layer speed V smooth Convert to smooth overlay speed VR2;

[0067] The smoothed velocity calculation module is configured to interpolate the smoothed superimposed velocity VR2 using an interpolation algorithm to obtain the interpolated smoothed superimposed velocity VR. smooth .

[0068] Beneficial effects: The scattered wave superposition velocity extraction method and system of this invention, using common shot gathers as the extraction object, and by introducing the three-dimensional coordinates of the shot point and the detector, can directly extract the superposition velocity of scattered waves without height correction, thereby eliminating the influence of surface undulations. Simultaneously, through averaging and smoothing processing, the influence of shallow interference on velocity extraction is suppressed. Attached Figure Description

[0069] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0070] Figure 1 This is a flowchart of a method for extracting the superposition velocity of scattered waves according to an embodiment of the present invention;

[0071] Figure 2 To adopt such Figure 1 The flowchart of the computer program for the scattered wave superposition velocity extraction method is shown below.

[0072] Figure 3 A flowchart for extracting the superposition velocity of scattered waves using a computer, provided as an embodiment of the present invention;

[0073] Figure 4 To adopt such Figure 3 The flowchart of the computer program for the scattered wave superposition velocity extraction method is shown below.

[0074] Figure 5 A flowchart for extracting the superposition velocity of scattered waves using a computer, provided as an embodiment of the present invention;

[0075] Figure 6 To adopt such Figure 5 The flowchart of the computer program for the scattered wave superposition velocity extraction method is shown below.

[0076] Figure 7 This is a system block diagram of a scattered wave superposition velocity extraction system provided in an embodiment of the present invention;

[0077] Figure 8 This is a system block diagram of a scattered wave superposition velocity extraction system provided in an embodiment of the present invention;

[0078] Figure 9 This is a system block diagram of a scattered wave superposition velocity extraction system provided in an embodiment of the present invention. Detailed Implementation

[0079] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0080] Example 1

[0081] like Figure 1 The flowchart shown illustrates a method for extracting the superposition velocity of scattered waves. This method includes:

[0082] Step A1: Obtain common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v);

[0083] Step A2: Calculate the two-way travel time of each seismic trace at different times and with different wave velocities based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, the two-way travel time vector t, and the wave velocity vector v.

[0084] Step A3: Extract the corresponding amplitude value Amp from the common shot point gather data Data based on the corresponding two-way travel time. r And calculate the absolute average amplitude corresponding to different times and different wave velocities.

[0085] Where r is the channel number and n is the channel number.

[0086] Step A4: Generate the corresponding velocity spectrum based on the absolute average amplitude of all times and all wave velocities, and extract the superposition velocity corresponding to the shot gather through the generated velocity spectrum.

[0087] Specifically, first, obtain the common shot point gather data Data and the two-way travel time vector t(t1,t2,t3......t) n ) and wave velocity vector v(v1,v2,v3......v n Simultaneously, by introducing the three-dimensional coordinates of the shot point and the three-dimensional coordinates of the detector, and combining the two-way travel time vector t and the wave velocity vector v, the two-way travel time corresponding to different times and different wave velocities in the common shot point gather data Data is calculated.

[0088] Subsequently, based on the calculated two-way travel time for each seismic trace, the amplitude values ​​corresponding to different seismic traces can be extracted from the common shot gather data (Data), and the absolute average amplitude values ​​corresponding to different times and wave velocities can be calculated respectively. Finally, a wave velocity spectrum is generated based on the calculated absolute average amplitude values ​​corresponding to all times and all wave velocities, and the stacking velocity corresponding to the shot gather is extracted from the wave velocity spectrum. In this way, the stacking velocity of scattered waves can be extracted directly without height correction, thereby eliminating the influence of surface undulations.

[0089] In this embodiment, optionally, in step 2, calculating the round-trip travel time corresponding to different times and different wave velocities includes:

[0090]

[0091] Among them, CR x CR y CR z These are the three-dimensional coordinates of the detector, CP.x CP y CP z denoted as the three-dimensional coordinates of the shot point, T as the two-way travel time corresponding to the seismic trace, t as the time node in the two-way travel time vector, and v as the wave velocity node in the wave velocity vector.

[0092] In this embodiment, optionally, in step 4, the superposition velocity corresponding to the shot gathering is extracted from the velocity spectrum, including:

[0093] The data in each row of the velocity spectrum are normalized, and the specific calculation formula is as follows:

[0094]

[0095] Where (a,b) is the normalization interval, and Amp max and Amp min This represents the maximum and minimum values ​​of Amp in this row. nor This is the result after normalization;

[0096] Image plots were drawn based on the normalized velocity spectrum;

[0097] The velocity corresponding to the maximum point in the image is selected as the stacking velocity.

[0098] The following will combine Figure 2 The steps for extracting the velocity of superimposed scattered waves using a computer are explained in detail.

[0099] In this embodiment, the step of the computer performing velocity extraction by overlaying the common shot point gather data (Data) includes:

[0100] S1. Input common shot point gather Data, input shot point 3D coordinates, detector 3D coordinates, and two-way travel time vector t(t1,t2,t3......t) n ) and wave velocity vector v(v1,v2,v3......v n );

[0101] S2. Let the initial cycle number i = 1 for the two-way travel time vector t;

[0102] S3. Set the initial cycle number j = 1 for the wave velocity vector v;

[0103] S4. Set the initial cycle number k = 1 for the common shot point gather Data.

[0104] S5. Calculate the round-trip travel time T for the k-th route using the above formula;

[0105] S6. Extract and record the amplitude value at time T of the k-th trace from the common shot point gather Data;

[0106] S7. Determine if k is less than the maximum number of common shot point gathers Data; if not, proceed to the next step; if yes, let k = k + 1 and repeat S5-S7.

[0107] S8. Calculate the absolute average of all extracted amplitude values ​​and save the result to the corresponding position (i, j) in Amp;

[0108] S9. Determine if j is less than the maximum index of the wave velocity vector v; if not, proceed to the next step; if yes, let j = j + 1, and repeat S4-S9.

[0109] S10. Normalize the i-th row of Amp, as shown in the following formula:

[0110]

[0111] S11. Determine if i is less than the maximum index of the round-trip travel time vector t; if not, proceed to the next step; if yes, let i = i + 1, and repeat S3-S11.

[0112] S12. Draw an image map based on Amp, select the maximum points in the image map, and save the coordinates corresponding to each maximum point, with the horizontal axis representing the stacking velocity v. r The vertical axis represents the round-trip travel time t0.

[0113] Example 2

[0114] like Figure 3 The flowchart shown illustrates a method for extracting the superposition velocity of scattered waves. This method includes:

[0115] Step B1: Using the above-mentioned method for extracting the superposition velocity of scattered waves, extract the superposition velocity corresponding to different shot collections;

[0116] Step B2: Interpolate the extracted superposition velocities using an interpolation algorithm to generate the superposition velocity matrix VR. itr ;

[0117] Step B3: Based on the superimposed velocity matrix VR itr Determine the layer velocity matrix V and the depth matrix H, where the formula for calculating the layer velocity matrix V is as follows:

[0118]

[0119] Where I is the superimposed velocity matrix VR itr The serial number of each column.

[0120] The formula for calculating the depth matrix H is as follows:

[0121]

[0122] Where J is the index of each column of the layer velocity matrix V, CP z This is the Z-coordinate of the shot point corresponding to this column of data.

[0123] Step B4: Determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0124] Step B5: For the layer velocity matrix V within the same depth range itr The average layer velocity V is obtained by averaging. mean ;

[0125] Step B6: Based on the average layer velocity V mean and uniform depth range H itr Calculate the average round-trip travel time T irt1 The specific calculation formula is as follows:

[0126]

[0127] Where K represents the uniform depth range H itr The serial number of each column.

[0128] Step B7: Select the average layer velocity V corresponding to each shot collection using the corresponding three-dimensional coordinates of the shot points. mean and average round-trip travel time T irt1 Specifically:

[0129] Within a uniform depth range H itr The search function retrieves the Z-coordinate (CP) of the shot point corresponding to each column of data. z The position number corresponds to the average layer velocity V in each column. mean Retain the data within the range from this sequence number to the end; the corresponding average round-trip travel time T in each column. itr1 Retain the data within the range from the beginning to the end of the sequence number, and then subtract the data value corresponding to the sequence number from the retained data in turn.

[0130] Step B8: Based on the selected average round-trip travel time T irt1 Selected average layer velocity V mean The conversion to average superposition velocity VR1 is calculated using the following formula:

[0131]

[0132] Where l is the average layer velocity V mean The serial number of each column.

[0133] Step B9: Interpolate the average stacking velocity VR1 using an interpolation algorithm to obtain the interpolated average stacking velocity VR. mean .

[0134] Specifically, it should be understood that in shallow scattered wave exploration, strong interference in the shallow layer can significantly reduce the accuracy of velocity extraction. When extracting the stacked velocity distribution of the shallow low-velocity zone, the extraction method described in Example 1 can be used first to directly extract the stacked velocity corresponding to each shot gather from the common shot point gather data Data corresponding to multiple different shot gathers without height correction. Then, the extraction results of each shot gather are regarded as the velocity distribution below that shot point, and the extraction results of all shot gathers are interpolated and averaged to suppress the influence of shallow interference on velocity extraction and obtain a more accurate stacked velocity distribution.

[0135] The following will combine Figure 4 The steps for extracting the velocity of superimposed scattered waves using a computer are explained in detail.

[0136] In this embodiment, the steps for extracting the superimposed velocity by the computer include:

[0137] SS1. Input common shot point gather Data, including the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, and the two-way travel time vector t(t1, t2, t3, ..., t4). n ) and wave velocity vector v(v1,v2,v3......v n );

[0138] SS2. Let the initial cycle number i = 1 for the two-way travel time vector t;

[0139] SS3. Set the initial cycle number j of the wave velocity vector v to 1;

[0140] SS4. Set the initial cycle number k = 1 for the common shot point gather Data.

[0141] SS5. Calculate the round-trip travel time T for the k-th route using the above formula;

[0142] SS6. Extract and record the amplitude value at time T of the k-th trace from the common shot gather Data;

[0143] SS7. Determine if k is less than the maximum number of common shot point gathers Data; if not, proceed to the next step; if yes, let k = k + 1, and repeat SS5-SS7.

[0144] SS8. Calculate the absolute average of all extracted amplitude values ​​and save the result to the corresponding position (i, j) of Amp;

[0145] SS9. Determine if j is less than the maximum index of the wave velocity vector v; if not, proceed to the next step; if yes, let j = j + 1, and repeat SS4-SS9.

[0146] SS10. Normalize the i-th row of Amp;

[0147] SS11. Determine if i is less than the maximum index of the round-trip travel time vector t; if not, proceed to the next step; if yes, let i = i + 1, and repeat SS3-SS11.

[0148] SS12. Draw an image map based on Amp, select the maxima points in the image map, and save the coordinates corresponding to each maxima point, with the horizontal axis representing the stacking velocity v. r The vertical axis represents the round-trip travel time t0.

[0149] SS13. Select the next shot set and repeat steps SS1-SS12 until all shot sets have been processed and proceed to the next step.

[0150] SS14. Input the three-dimensional coordinates of all shot points;

[0151] SS15, sequentially for each group (v) r ,t0) is interpolated in one dimension according to the two-way travel time vector t;

[0152] SS16, v r The interpolation results are arranged according to the X coordinate of the corresponding shot point;

[0153] SS17, regarding the permuted v r The matrix is ​​interpolated in two dimensions according to the X coordinates of all shot points to obtain the superimposed velocity matrix VR. itr ;

[0154] SS18. Calculate the superimposed velocity matrix VR sequentially. itr The layer velocities corresponding to each column form the layer velocity matrix V;

[0155] SS19. Calculate the superimposed velocity matrix VR sequentially. itr The depth corresponding to each column forms a depth matrix H;

[0156] SS20. Interpolate the layer velocity matrix V from different depth ranges to a uniform depth range H. itr The layer velocity matrix V is obtained. itr ;

[0157] SS21, Calculate the layer velocity matrix V itr The average layer velocity V is obtained by averaging the values ​​at the same depth. mean ;

[0158] SS22, based on the average layer velocity V meanand uniform depth range H itr Calculate the average round-trip travel time T itr1 ;

[0159] SS23. Determine the average layer velocity V below each shot based on its Z-coordinate. mean Range and average round-trip travel time T itr1 Scope;

[0160] SS24. Based on the determined average round-trip travel time T itr1 The range will be determined sequentially by the average layer velocity V mean Average layer velocity V in each column within the range mean Convert back to average superposition velocity VR1;

[0161] SS25. Sequentially interpolate each column of the average superposition velocity VR1 according to the two-way travel time vector t to obtain the interpolated average superposition velocity VR. mean And save it.

[0162] Example 3

[0163] like Figure 5 The flowchart shown illustrates a method for extracting the superposition velocity of scattered waves. This method includes:

[0164] Step C1: Using the above-mentioned method for extracting the superposition velocity of scattered waves, extract the superposition velocity corresponding to different shot collections;

[0165] Step C2: Interpolate the extracted superposition velocities using an interpolation algorithm to generate the superposition velocity matrix VR. itr ;

[0166] Step C3: Based on the superimposed velocity matrix VR itr Determine the layer velocity matrix V and depth matrix H;

[0167] Step C4: Determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0168] Step C5: For the layer velocity matrix V... itr Smoothing is performed to obtain the smoothing layer velocity V. smooth ;

[0169] Step C6: Based on the smoothing layer speed V smooth and uniform depth range H itr Calculate the smoothed two-way travel time T irt2 ;

[0170] Step C7: Select the smoothing layer velocity V corresponding to each shot collection using the corresponding three-dimensional coordinates of the shot points. smooth And smooth two-way travel T irt2 ;

[0171] Step C8, based on the smooth two-way travel time T irt2 Select the smoothing layer speed V smooth Convert to smooth overlay speed VR2;

[0172] Step C9: Interpolate the smooth superposition velocity VR2 using an interpolation algorithm to obtain the interpolated smooth superposition velocity VR. smooth .

[0173] Specifically, when extracting the stacking velocity distribution of the shallow low-velocity zone, the extraction method described in Example 1 can be used first to directly extract the stacking velocity corresponding to each shot set from the common shot point gather data Data corresponding to multiple different shot sets without height correction. Then, the extraction results of each shot set are regarded as the velocity distribution below that shot point, and interpolation and smoothing are performed on the extraction results of all shot sets to suppress the influence of shallow interference on velocity extraction and obtain a more accurate stacking velocity distribution.

[0174] The following will combine Figure 6 The steps for extracting the velocity of superimposed scattered waves using a computer are explained in detail.

[0175] In this embodiment, the steps for extracting the superimposed velocity by the computer include:

[0176] SSS1, Input common shot point gather Data, input shot point 3D coordinates, detector 3D coordinates, and two-way travel time vector t(t1,t2,t3......t n ) and wave velocity vector v(v1,v2,v3......v n );

[0177] SSS2, Let the initial cycle number i = 1 for the two-way travel time vector t;

[0178] SSS3, Let the initial cycle number j = 1 for the wave velocity vector v;

[0179] SSS4, set the initial cycle number k = 1 for the common shot point gather Data;

[0180] SSS5. Calculate the round-trip travel time T for the k-th route using the above formula;

[0181] SSS6. Extract and record the amplitude value at time T of the k-th trace from the common shot point gather Data;

[0182] SSS7. Determine if k is less than the maximum number of common shot point gathers Data; if not, proceed to the next step; if yes, let k = k + 1, and repeat SSS5-SSS7.

[0183] SSS8. Calculate the absolute average of all extracted amplitude values ​​and save the result to the corresponding position (i, j) in Amp;

[0184] SSS9. Determine if j is less than the maximum index of the wave velocity vector v; if not, proceed to the next step; if yes, let j = j + 1, and repeat SSS4-SSS9.

[0185] SSS10, Normalize the i-th row of Amp;

[0186] SSS11. Determine if i is less than the maximum index of the round-trip travel time vector t; if not, proceed to the next step; if yes, let i = i + 1, and repeat SSS3-SSS11.

[0187] SSS12. Draw an image map based on Amp, select the maxima points in the image map, and save the coordinates corresponding to each maxima point, with the horizontal axis representing the stacking velocity v. r The vertical axis represents the round-trip travel time t0.

[0188] SSS13. Select the next shot set and repeat steps SSS1-SSS12 until all shot sets have been processed and proceed to the next step.

[0189] SSS14. Input the three-dimensional coordinates of all shot points;

[0190] SSS15, sequentially process each group (v) r ,t0) is interpolated in one dimension according to the two-way travel time vector t;

[0191] SSS16, v r The interpolation results are arranged according to the X coordinate of the corresponding shot point;

[0192] SSS17, regarding the arranged v r The matrix is ​​interpolated in two dimensions according to the X coordinates of all shot points to obtain the superimposed velocity matrix VR. itr ;

[0193] SSS18, Calculate the superimposed velocity matrix VR sequentially. itr The layer velocities corresponding to each column form the layer velocity matrix V;

[0194] SSS19, Calculate the superimposed velocity matrix VR sequentially. itr The depth corresponding to each column forms a depth matrix H;

[0195] SSS20: Interpolate the layer velocity matrix V from different depth ranges to a uniform depth range H.itr The layer velocity matrix V is obtained. itr ;

[0196] SSS21, Layer velocity matrix V itr Smoothing is performed to obtain the smoothing layer velocity V. smooth ;

[0197] SSS22, based on the smoothing layer velocity V smooth and uniform depth range H itr Calculate the smoothed two-way travel time T irt2 The specific calculation formula is as follows:

[0198]

[0199] Where L is the smoothing layer velocity V smooth The serial number of each column.

[0200] SSS23. Determine the velocity V of the smoothing layer below each shot based on its Z-coordinate. smooth The range and smooth two-way travel time T irt2 The scope is as follows:

[0201] In H itr The search function retrieves the Z-coordinate (CP) of the shot point corresponding to each column of data. z The position number, corresponding to each column V smooth Retain the data within the range from this sequence number to the end; each corresponding column T itr2 Retain the data within the range from the beginning to the end of the sequence number, and then subtract the data value corresponding to the sequence number from the retained data in turn.

[0202] SSS24, based on the determined smooth two-way travel time T irt2 The range will be determined sequentially by the smoothing layer velocity V smooth The speed V of each smoothing layer in the range smooth The conversion back to the smooth superposition velocity VR2 is calculated as follows:

[0203]

[0204] Where f is the smoothing layer velocity V smooth The serial number of each column.

[0205] SSS25. Sequentially interpolate each column of the smoothed superimposed velocity VR2 according to the two-way travel time vector t to obtain the interpolated smoothed superimposed velocity VR. smooth And save it.

[0206] Example 4

[0207] like Figure 7The system block diagram shown is for the scattered wave superposition velocity extraction system. The extraction system includes:

[0208] The acquisition module is configured to acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v).

[0209] The calculation module is configured to calculate the two-way travel time of each seismic trace at different times and with different wave velocities based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, the two-way travel time vector t, and the wave velocity vector v.

[0210] The statistics module is configured to extract the corresponding amplitude values ​​from the common shot point gather data Data based on the corresponding two-way travel time, and calculate the absolute average amplitude values ​​corresponding to different times and different wave velocities.

[0211] The extraction module is configured to generate a velocity spectrum based on the absolute average amplitude of all times and all velocities, and extract the superposition velocity corresponding to the shot gather from the generated velocity spectrum.

[0212] Specifically, the extraction system consists of an acquisition module, a calculation module, a statistics module, and an extraction module. The acquisition module can acquire common shot point gather data (Data), two-way travel time vectors t(t1, t2, t3, ..., t...). n ) and wave velocity vector v(v1,v2,v3......v n ), as well as the three-dimensional coordinates of the shot point and the three-dimensional coordinates of the detector.

[0213] The calculation module can calculate the two-way travel time of all seismic traces in the common shot gather data Data at different times and with different wave velocities, based on the three-dimensional coordinates of the shot point and the three-dimensional coordinates of the detector, combined with the two-way travel time vector t and the wave velocity vector v.

[0214] The statistics module can extract the amplitude values ​​corresponding to different seismic traces from the common shot gather data Data based on the calculated two-way travel time of each seismic trace, and calculate the absolute average amplitude values ​​corresponding to different times and different wave velocities.

[0215] The extraction module can generate a wave velocity spectrum based on the calculated absolute average amplitude of all wave velocities at all times, and then extract the stacking velocity corresponding to the shot gather from the wave velocity spectrum. In this way, the stacking velocity of the scattered waves can be extracted directly without height correction, thereby eliminating the influence of surface undulations.

[0216] In this embodiment, when the calculation module calculates the two-way travel time corresponding to different times and different wave speeds, it includes:

[0217]

[0218] Among them, CR x CR y CR z These are the three-dimensional coordinates of the detector, CP. x CP y CP z denoted as the three-dimensional coordinates of the shot point, T as the two-way travel time corresponding to the seismic trace, t as the time node in the two-way travel time vector, and v as the wave velocity node in the wave velocity vector.

[0219] In this embodiment, optionally, the extraction module includes:

[0220] The normalization unit is configured to perform normalization processing on each row of data in the velocity spectrum;

[0221] The image plotting unit is configured to plot an image based on the normalized velocity spectrum.

[0222] The velocity extraction unit is configured to select the velocity corresponding to the maximum point in the image as the stacking velocity.

[0223] Example 5

[0224] like Figure 8 The system block diagram shown is for the scattered wave superposition velocity extraction system. The extraction system includes:

[0225] The aforementioned scattered wave superposition velocity extraction system is configured to extract the superposition velocity corresponding to different shot sets, and;

[0226] The matrix generation module is configured to use an interpolation algorithm to interpolate the extracted superposition velocities and generate the superposition velocity matrix VR. itr ;

[0227] The matrix determination module is configured to determine the superimposed velocity matrix VR. itr Determine the layer velocity matrix V and depth matrix H;

[0228] The matrix processing module is configured to determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0229] The averaging module is configured to process the layer velocity matrix V within the same depth range. itr The average layer velocity V is obtained by averaging. mean ;

[0230] The average time calculation module is configured to calculate based on the average layer velocity V. mean and uniform depth range H itr Calculate the average round-trip travel time T irt1 ;

[0231] The average data selection module is configured to select the average layer velocity V corresponding to each shot gather based on the corresponding three-dimensional coordinates of the shot points. mean and average round-trip travel time T irt1 ;

[0232] The average data conversion module is configured to convert data based on the selected average round-trip travel time T. irt1 Selected average layer velocity V mean Convert to average superposition velocity VR1;

[0233] The average velocity calculation module is configured to interpolate the average superimposed velocity VR1 using an interpolation algorithm to obtain the interpolated average superimposed velocity VR. mean .

[0234] Specifically, when extracting the stacking velocity distribution of the shallow low-velocity zone, the extraction system described in Example 4 can be used to directly extract the stacking velocity corresponding to each shot set from the common shot point gather data Data corresponding to multiple different shot sets without height correction. The matrix generation module, matrix processing module, and averaging module can treat the extraction results of each shot set as the velocity distribution below that shot point, and perform interpolation and averaging processing on the extraction results of all shot sets, thereby suppressing the influence of shallow interference on velocity extraction and obtaining a more accurate stacking velocity distribution.

[0235] Example 6

[0236] like Figure 9 The system block diagram shown is for the scattered wave superposition velocity extraction system. The extraction system includes:

[0237] The scattered wave superposition velocity extraction system as described in Example 4, and;

[0238] The matrix generation module is configured to use an interpolation algorithm to interpolate the extracted superposition velocities and generate the superposition velocity matrix VR. itr ;

[0239] The matrix determination module is configured to determine the superimposed velocity matrix VR. itr Determine the layer velocity matrix V and depth matrix H;

[0240] The matrix processing module is configured to determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itrOne-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ;

[0241] The smoothing module is configured to process the layer velocity matrix V. itr Smoothing is performed to obtain the smoothing layer velocity V. smooth ;

[0242] The smoothing time calculation module is configured to calculate the smoothing time based on the smoothing layer speed V. smooth and uniform depth range H itr Calculate the smoothed two-way travel time T irt2 ;

[0243] The smoothing data selection module is configured to select the smoothing layer velocity V corresponding to each shot gather based on the corresponding three-dimensional coordinates of the shot points. smooth And smooth two-way travel T irt2 ;

[0244] The smoothing data transformation module is configured to transform data based on the smoothed two-way travel time T. irt2 Select the smoothing layer speed V smooth Convert to smooth overlay speed VR2;

[0245] The smoothed velocity calculation module is configured to interpolate the smoothed superimposed velocity VR2 using an interpolation algorithm to obtain the interpolated smoothed superimposed velocity VR. smooth .

[0246] Specifically, when extracting the stacking velocity distribution of the shallow low-velocity zone, the extraction system described in Example 4 can be used to directly extract the stacking velocity corresponding to each shot set from the common shot point gather data Data corresponding to multiple different shot sets without height correction. The matrix generation module, matrix processing module, and smoothing module can treat the extraction results of each shot set as the velocity distribution below that shot point, and perform interpolation and smoothing processing on the extraction results of all shot sets, thereby suppressing the influence of shallow interference on velocity extraction and obtaining a more accurate stacking velocity distribution.

[0247] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for extracting the velocity of superimposed scattered waves, characterized in that, include: Extract the stacking velocity corresponding to different gun sets, including: Acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v); Based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the geophone, the two-way travel time vector t, and the wave velocity vector v, the two-way travel time corresponding to each seismic trace at different times and with different wave velocities is calculated. Based on the corresponding two-way travel time, the corresponding amplitude values ​​are extracted from the common shot point gather data Data, and the absolute average amplitude values ​​corresponding to different times and different wave velocities are calculated. The corresponding velocity spectrum is generated based on the absolute average amplitude of all times and all wave velocities, and the superposition velocity corresponding to the shot gather is extracted from the generated velocity spectrum. The interpolation algorithm is used to interpolate the extracted superimposed acceleration to generate a superimposed acceleration matrix VR itr ; According to the superimposed velocity matrix VR itr determining a velocity matrix V and a depth matrix H; determining a uniform depth range H from the depth matrix H itr and in accordance with the uniform depth range H itr one-dimensionally interpolating the interval velocity matrix V to obtain an interval velocity matrix V of the same depth range itr ; A matrix of interval velocities V for the same depth range itr The average interval velocity V is obtained by averaging mean ; According to the average interval velocity V mean and the unified depth range H itr the average two-way travel time T irt1 is calculated The average interval velocity V and average two-way travel time T corresponding to each shot point are selected by corresponding shot point three-dimensional coordinates mean and average two-way travel time T irt1 ; According to the selected average two-way travel time T irt1 The selected average interval velocity V mean is converted to an average stacking velocity VR1; The interpolation algorithm is used to interpolate the average stacking velocity VR1 to obtain the interpolated average stacking velocity VR mean .

2. A method for extracting the velocity of superimposed scattered waves, characterized in that, include: Extract the stacking velocity corresponding to different gun sets, including: Acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v); Based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the geophone, the two-way travel time vector t, and the wave velocity vector v, the two-way travel time corresponding to each seismic trace at different times and with different wave velocities is calculated. Based on the corresponding two-way travel time, the corresponding amplitude values ​​are extracted from the common shot point gather data Data, and the absolute average amplitude values ​​corresponding to different times and different wave velocities are calculated. The corresponding velocity spectrum is generated based on the absolute average amplitude of all times and all wave velocities, and the superposition velocity corresponding to the shot gather is extracted from the generated velocity spectrum. The interpolation algorithm is used to interpolate the extracted superimposed acceleration to generate a superimposed acceleration matrix VR itr ; According to the superimposed velocity matrix VR itr determining a velocity matrix V and a depth matrix H; determining a unified depth range H from the depth matrix H itr and in accordance with the unified depth range H itr one-dimensionally interpolating the interval velocity matrix V to obtain an interval velocity matrix V of the same depth range itr ; The layer velocity matrix V itr is smoothed to obtain a smoothed layer velocity V smooth ; According to the smoothed layer velocities V smooth and the unified depth range H itr the smoothed two-way travel times T irt2 are calculated; The smooth layer velocity V corresponding to each shot gather is selected through the corresponding shot point three-dimensional coordinate smooth and the smooth two-way travel time T irt2 ; According to the smoothed two-way travel time T irt2 The selected smoothed interval velocities V smooth are converted to smoothed stacking velocities VR2; The interpolation algorithm is used to interpolate the smoothed stacking velocity VR2 to obtain the interpolated smoothed stacking velocity VR smooth .

3. The method for extracting the superposition velocity of scattered waves according to claim 1 or 2, characterized in that, Calculating the round-trip travel time for different times and different wave speeds includes: ； in, , , These are the three-dimensional coordinates of the detector. , , denoted as the three-dimensional coordinates of the shot point, T as the two-way travel time corresponding to the seismic trace, t as the time node in the two-way travel time vector, and v as the wave velocity node in the wave velocity vector.

4. The method for extracting the superposition velocity of scattered waves according to claim 1 or 2, characterized in that, The superposition velocity corresponding to the shot set is extracted from the velocity spectrum, including: The data in each row of the velocity spectrum are normalized respectively; Image plots were drawn based on the normalized velocity spectrum; The velocity corresponding to the maximum point in the image is selected as the stacking velocity.

5. A system for extracting the velocity of superimposed scattered waves, characterized in that, include: A scattered wave superposition velocity extraction system is configured to extract the superposition velocities corresponding to different shot sets, including: The acquisition module is configured to acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v). The calculation module is configured to calculate the two-way travel time of each seismic trace at different times and with different wave velocities based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, the two-way travel time vector t, and the wave velocity vector v. The statistics module is configured to extract the corresponding amplitude values ​​from the common shot point gather data Data based on the corresponding two-way travel time, and calculate the absolute average amplitude values ​​corresponding to different times and different wave velocities. The extraction module is configured to generate a corresponding velocity spectrum based on the absolute average amplitude of all time and all wave velocities, and extract the superposition velocity corresponding to the shot gather from the generated velocity spectrum. as well as; The matrix generating module is configured to generate a superimposed velocity matrix VR by interpolating the extracted superimposed velocity using an interpolation algorithm itr ; a matrix determination module configured to determine a velocity matrix V and a depth matrix H from the stack velocity matrix VR itr determine a velocity matrix V and a depth matrix H from the stack velocity matrix VR a matrix processing module configured to determine a unified depth range H from the depth matrix H itr and to determine layer velocity matrices V for the same depth range H itr performing one-dimensional interpolation on the layer velocity matrices V itr ; The averaging module is configured to process the layer velocity matrix V within the same depth range. itr The average layer velocity V is obtained by averaging. mean ; The average time calculation module is configured to calculate based on the average layer velocity V. mean and uniform depth range H itr Calculate the average round-trip travel time T irt1 ; The average data selection module is configured to select the average layer velocity V corresponding to each shot point based on the corresponding three-dimensional coordinates of the shot point. mean and average round-trip travel time T irt1 ; The average data conversion module is configured to convert data based on the selected average round-trip travel time T. irt1 Selected average layer velocity V mean Convert to average superposition velocity VR1; The average velocity calculation module is configured to interpolate the average superimposed velocity VR1 using an interpolation algorithm to obtain the interpolated average superimposed velocity VR. mean .

6. A system for extracting the velocity of superimposed scattered waves, characterized in that, include: The acquisition module is configured to acquire common shot gather data (Data), three-dimensional coordinates of the shot point, three-dimensional coordinates of the detector, two-way travel time vector (t), and wave velocity vector (v). The calculation module is configured to calculate the two-way travel time of each seismic trace at different times and with different wave velocities based on the three-dimensional coordinates of the shot point, the three-dimensional coordinates of the detector, the two-way travel time vector t, and the wave velocity vector v. The statistics module is configured to extract the corresponding amplitude values ​​from the common shot point gather data Data based on the corresponding two-way travel time, and calculate the absolute average amplitude values ​​corresponding to different times and different wave velocities. The extraction module is configured to generate a corresponding velocity spectrum based on the absolute average amplitude of all time and all wave velocities, and extract the superposition velocity corresponding to the shot gather from the generated velocity spectrum. as well as; The matrix generation module is configured to use an interpolation algorithm to interpolate the extracted superposition velocities and generate the superposition velocity matrix VR. itr ; The matrix determination module is configured to determine the superimposed velocity matrix VR. itr Determine the layer velocity matrix V and depth matrix H; The matrix processing module is configured to determine a uniform depth range H using the depth matrix H. itr and according to the unified depth range H itr One-dimensional interpolation is performed on the layer velocity matrix V to obtain layer velocity matrices V within the same depth range. itr ; The smoothing module is configured to process the layer velocity matrix V. itr Smoothing is performed to obtain the smoothing layer velocity V. smooth ; The smoothing time calculation module is configured to calculate the smoothing time based on the smoothing layer speed V. smooth and uniform depth range H itr Calculate the smoothed two-way travel time T irt2 ; The smoothing data selection module is configured to select the smoothing layer velocity V corresponding to each shot gather based on the corresponding three-dimensional coordinates of the shot points. smooth And smooth two-way travel T irt2 ; The smoothing data transformation module is configured to transform data based on the smoothed two-way travel time T. irt2 Select the smoothing layer speed V smooth Convert to smooth overlay speed VR2; The smoothed velocity calculation module is configured to interpolate the smoothed superimposed velocity VR2 using an interpolation algorithm to obtain the interpolated smoothed superimposed velocity VR. smooth .

7. The scattered wave superposition velocity extraction system according to claim 5 or 6, characterized in that, The calculation module calculates the round-trip travel time at different times and different wave speeds, including: ； in, , , These are the three-dimensional coordinates of the detector. , , denoted as the three-dimensional coordinates of the shot point, T as the two-way travel time corresponding to the seismic trace, t as the time node in the two-way travel time vector, and v as the wave velocity node in the wave velocity vector.

8. The scattered wave superposition velocity extraction system according to claim 5 or 6, characterized in that, The extraction module includes: The normalization unit is configured to perform normalization processing on each row of data in the velocity spectrum; The image plotting unit is configured to plot an image based on the normalized velocity spectrum. The velocity extraction unit is configured to select the velocity corresponding to the maximum point in the image as the stacking velocity.

Images