Segmented independent scanning signal design method, device, equipment, medium and product

Abstract

The invention discloses a segmented independent scanning signal design method, device, equipment, medium and product, and the method comprises the steps: obtaining seismic data of a target exploration region, and carrying out the spectrum analysis, and obtaining the spectrum characteristics of a target layer reflection wave; dividing the exploration depth range into a plurality of depth sections according to the geological features of the target exploration area; dividing the frequency range of the scanning signal into a plurality of frequency bands according to the spectrum characteristics and the geological characteristics of the depth section; for each frequency band, determining a scanning parameter of each section of scanning signal according to a frequency spectrum feature and a geological feature corresponding to the frequency band; and according to the segmentation sequence of the frequency band and the scanning parameter of each segment of scanning signal, splicing each segment of scanning signal to obtain a target scanning signal. According to the method, different independent frequency bands are divided according to the accurately analyzed frequency spectrum characteristics of the reflected waves of the target stratum, and the scanning parameters of the scanning signals of the different frequency bands are optimized, so that the seismic data quality is improved, and high-precision exploration of an underground geological structure is realized.

Description

Technical Field

[0001] The present invention relates to the field of seismic exploration technology, and in particular to a design method, device, equipment, medium and product for a segmented independent scanning signal based on the spectrum characteristics of a target layer reflection wave. Background Art

[0002] In the field of seismic exploration, obtaining high-quality seismic data is crucial for accurately detecting underground geological structures and achieving efficient resource exploration. Controllable vibrators offer significant technical advantages in seismic exploration, including economical, efficient, safe, and environmentally friendly excitation. Furthermore, the frequency, phase, and energy of the signals generated by controllable vibrators are controllable. The source signal design can specifically avoid certain interfering frequencies and compensate for the absorption of seismic signals by the strata. When a controllable vibrator is excited, the vibrator emits a long-duration vibration signal into the ground. This signal is generally a sinusoidal function, but the frequency of the sinusoidal function varies over time. This vibration signal is called a sweep signal, also known as a swept frequency signal. If the rate of change of the frequency is constant, the sweep signal is linear; otherwise, it is nonlinear.

[0003] The design of vibroseis scanning signals is a key factor affecting seismic data quality. Traditional scanning signal design methods often struggle to accurately excite reflection waves from target layers and meet the demands of high-resolution exploration when faced with complex geological conditions. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a design method, device, equipment, medium and product for segmented independent scanning signals, divide different independent frequency bands according to the spectral characteristics of the reflected waves of the target layer accurately analyzed, and optimize the scanning parameters of the scanning signals in different frequency bands, thereby improving the quality of seismic data and realizing high-precision exploration of underground geological structures.

[0005] To achieve the above objectives, an embodiment of the present invention provides a method for designing a segmented independent scanning signal, including:

[0006] Acquire seismic data of the target exploration area, and perform spectrum analysis on the seismic data to obtain spectrum characteristics of the target layer reflection wave;

[0007] Dividing the exploration depth range of the target exploration area into a plurality of depth segments according to the geological characteristics of the target exploration area;

[0008] Dividing the frequency range of the scanning signal into several frequency bands according to the frequency spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth section;

[0009] For each of the frequency bands, determining scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0010] According to the segmentation order of the frequency band and the scanning parameters of each scanning signal segment, each scanning signal segment is spliced ​​to obtain a target scanning signal.

[0011] As an improvement to the above solution, the method of acquiring seismic data of the target exploration area and performing spectrum analysis on the seismic data to obtain the spectrum characteristics of the reflection wave of the target layer specifically includes:

[0012] Acquiring seismic data of a target exploration area and preprocessing the seismic data;

[0013] According to the stationarity of the pre-processed seismic data, the corresponding spectrum analysis method is determined;

[0014] The pre-processed seismic data is subjected to spectrum analysis according to the spectrum analysis method to obtain the spectrum characteristics of the target layer reflection wave.

[0015] As an improvement to the above solution, the corresponding spectrum analysis method is determined according to the stationarity of the pre-processed seismic data, specifically including:

[0016] If the pre-processed seismic data is stationary data, discrete Fourier transform is used;

[0017] If the pre-processed seismic data is non-stationary data, continuous wavelet transform is used.

[0018] As an improvement to the above solution, the frequency range of the scanning signal is divided into several frequency bands according to the spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, specifically including:

[0019] Determine the number of frequency bands based on the spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, combined with the attenuation and absorption law of the stratum to signals of different frequencies;

[0020] The frequency range of the scanning signal is divided into a plurality of frequency bands according to the number of frequency bands; wherein the plurality of frequency bands are different non-continuous independent frequency bands.

[0021] As an improvement to the above solution, for each frequency band, determining the scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band specifically includes:

[0022] For each of the frequency bands, determining the frequency range and scanning function of each scanning signal according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0023] The parameters of each scanning signal segment are optimized according to a preset fitness function to obtain optimized scanning parameters; wherein the scanning parameters include a starting frequency, an ending frequency, a frequency change rate, and a scanning time.

[0024] As an improvement to the above solution, for each frequency band, the frequency range and scanning function of each scanning signal are determined according to the spectrum characteristics and geological characteristics corresponding to the frequency band, specifically including:

[0025] For each of the frequency bands, the frequency extension amount is calculated according to the starting frequency and the ending frequency of the reflected wave of the target layer corresponding to the frequency band, and the quality factor of the formation;

[0026] Calculate the starting frequency and ending frequency of each segment of the scanning signal according to the starting frequency and ending frequency of the target layer reflected wave corresponding to the frequency band, and the frequency expansion amount, and obtain the frequency range of each segment of the scanning signal;

[0027] A corresponding scanning function is determined according to the signal change characteristics of the frequency band.

[0028] An embodiment of the present invention further provides a device for designing a segmented independent scanning signal, comprising:

[0029] A spectrum analysis module is used to obtain seismic data of the target exploration area and perform spectrum analysis on the seismic data to obtain the spectrum characteristics of the target layer reflection wave;

[0030] A depth division module is used to divide the exploration depth range of the target exploration area into several depth segments according to the geological characteristics of the target exploration area;

[0031] A frequency band division module, configured to divide the frequency range of the scanning signal into a plurality of frequency bands according to the frequency spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment;

[0032] a parameter determination module, configured to determine, for each frequency band, scanning parameters of each segment of the scanning signal according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0033] The signal synthesis module is used to splice the scanning signals of each segment according to the segmentation order of the frequency band and the scanning parameters of each segment of the scanning signal to obtain a target scanning signal.

[0034] An embodiment of the present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the design method of the segmented independent scanning signal described in any one of the above items is implemented.

[0035] An embodiment of the present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any of the above-mentioned methods for designing segmented independent scanning signals.

[0036] An embodiment of the present invention further provides a computer program product, which includes a computer program or computer instructions. When the computer program or the computer instructions are executed by a processor, the method for designing a segmented independent scanning signal as described above is implemented.

[0037] Compared to the prior art, the advantageous effects of the design method, device, equipment, medium, and product of a segmented independent scanning signal provided by the embodiments of the present invention are as follows: by acquiring seismic data of a target exploration area and performing spectral analysis on the seismic data, the spectral characteristics of the target layer reflection wave are obtained; based on the geological characteristics of the target exploration area, the exploration depth range of the target exploration area is divided into several depth segments; based on the spectral characteristics of the target layer reflection wave and the geological characteristics of the depth segments, the frequency range of the scanning signal is divided into several frequency bands; for each of the frequency bands, the scanning parameters of each segment of the scanning signal are determined based on the spectral characteristics and geological characteristics corresponding to the frequency band; based on the segmentation order of the frequency bands and the scanning parameters of each segment of the scanning signal, the scanning signals of each segment are spliced ​​to obtain the target scanning signal. The embodiments of the present invention divide different independent frequency bands based on the accurately analyzed spectral characteristics of the target layer reflection wave and optimize the scanning parameters of the scanning signals of different frequency bands, thereby improving the quality of seismic data and achieving high-precision exploration of underground geological structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of a preferred embodiment of a method for designing a segmented independent scanning signal provided by the present invention;

[0039] Figure 2 Schematic diagram comparing a segmented independent scanning signal and a conventional scanning signal provided by the present invention;

[0040] Figure 3 This is a schematic diagram of original data in a design method for a segmented independent scanning signal provided by the present invention;

[0041] Figure 4 This is a schematic diagram of the reflection of the target layer reflected wave on the time section in a design method of a segmented independent scanning signal provided by the present invention;

[0042] Figure 5 This is a schematic diagram of comparison results of spectrum of reflected waves of a target layer scanned independently by frequency division in a design method of a segmented independent scanning signal provided by the present invention;

[0043] Figure 6 It is a structural schematic diagram of a preferred embodiment of a device for designing segmented independent scanning signals provided by the present invention;

[0044] Figure 7 It is a structural diagram of a preferred embodiment of a terminal device provided by the present invention. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0046] See also Figure 1 , Figure 1 1 is a flow chart of a preferred embodiment of a method for designing a segmented independent scanning signal provided by the present invention. The method for designing a segmented independent scanning signal includes:

[0047] S1, acquiring seismic data of a target exploration area, and performing spectrum analysis on the seismic data to obtain spectrum characteristics of reflection waves of a target layer;

[0048] S2, dividing the exploration depth range of the target exploration area into a plurality of depth segments according to the geological characteristics of the target exploration area;

[0049] S3, dividing the frequency range of the scanning signal into a plurality of frequency bands according to the frequency spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment;

[0050] S4, for each frequency band, determining scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0051] S5, according to the segmentation order of the frequency band and the scanning parameters of each scanning signal segment, splicing each scanning signal segment to obtain a target scanning signal.

[0052] It should be noted that while the currently common segmented nonlinear scanning signal design and discontinuous independent frequency division scanning techniques can improve exploration results to a certain extent, they still have some shortcomings. For example, in spectrum analysis, the accuracy of extracting the spectral characteristics of the target layer's reflected waves needs to be improved, resulting in a lack of sufficient accuracy in the design of scanning signal parameters. The scanning signal parameter calculation process fails to fully consider the complexity of the formation and various interference factors during signal propagation, resulting in a less than ideal match between the scanning signal and the target layer. In the signal synthesis and verification process, there is a lack of a systematic and comprehensive method to ensure the effectiveness and stability of the synthesized signal in actual exploration.

[0053] Based on this, an embodiment of the present invention provides a method for designing segmented, independent scanning signals based on the spectral characteristics of the target layer's reflected waves. First, in the target exploration area, high-resolution seismic exploration equipment is used to collect seismic data according to an optimized acquisition plan. It is important to note that the acquisition plan should fully consider the topography and geological characteristics of the exploration area, as well as the depth and extent of the target layer, to ensure that the collected data comprehensively and accurately reflects the target layer's reflected wave information. Spectral analysis is then performed on the collected seismic data to determine the spectral characteristics of the target layer's reflected waves. Simultaneously, suitable boreholes are identified in the target exploration area, and core sampling is performed. Rock physics analysis methods are used to determine the Young's modulus and Poisson's ratio, and the natural frequencies of different lithologies in different boreholes are calculated. It is important to note that the borehole selection plan should be as evenly distributed as possible within the work area. In cases of special geological conditions, relevant data for at least one borehole should be available. Core selection should cover as many lithologies as possible within the work area. Then, after thoroughly studying geological data, previous exploration results, and the detailed distribution of the target strata, geological modeling techniques were used to divide the exploration depth range of the target exploration area into several depth segments based on the geological characteristics of the target exploration area. Different scanning signals were designed based on the geological characteristics (such as lithology and physical properties) within each depth segment. This approach addresses the differential effects of strata at different depths on signal propagation, such as rapid high-frequency attenuation in shallow layers and strong low-frequency penetration in deep layers. This approach improves full-depth exploration performance through segmented optimization. Each depth segment was divided based on the similarity of geological conditions, ensuring that the lithology, physical properties, and other geological characteristics of the strata within the same depth segment were relatively consistent. The number of segments was determined based on factors such as exploration accuracy requirements, computational complexity, and practical engineering feasibility. A mathematical model was developed to analyze the impact of different segment numbers on exploration accuracy and computing resource consumption. For areas with complex geological conditions, the number of segments was appropriately increased to improve detection accuracy of different strata. For areas with relatively simple geological conditions, the number of segments was reduced to reduce computational complexity and engineering costs. A detailed analysis is conducted on the spectrum response characteristics of the target layer recorded by a single shot. Combined with the attenuation and absorption laws of the stratum for signals of different frequencies, the spectrum analysis software is used to divide the overall frequency range of the scanning signal into several frequency bands. For example, if the target layer has a strong reflection response in the low-frequency band and the high-frequency band, but the signal in the intermediate frequency band is weak, the frequency range is divided into the corresponding low-frequency band, high-frequency band and intermediate frequency band, and the signal design is performed for these frequency bands respectively. Among them, several frequency bands are different non-continuous independent frequency bands. Secondly, for each frequency band, the scanning parameters of each segment of the scanning signal are determined according to the spectral characteristics and geological characteristics corresponding to the frequency band, so as to compensate for the attenuation differences of signals of different frequencies in the propagation of the stratum, enhance the energy of the weak reflection frequency band (such as high-frequency details or low-frequency deep signals), and improve the signal-to-noise ratio and resolution of the entire frequency band.Finally, based on the segmentation order of the frequency bands and the scanning parameters of each scanning signal segment, the scanning signals of each segment are seamlessly spliced ​​together to form a complete segmented independent scanning signal, namely the target scanning signal. During the splicing process, smooth transition technology is used to ensure the continuity and stability of the signal at the splicing point to avoid signal interruption or mutation. The effectiveness and stability of the synthesized signal are verified through simulated seismic exploration and actual field tests. In the simulated seismic exploration, a high-precision seismic simulation system is used to analyze the signal's excitation effect on the target layer under different geological conditions; in the actual field test, actual data acquisition is carried out in the exploration area to check whether the spectral characteristics, signal-to-noise ratio, and resolution of the reflected wave meet the expectations. If the requirements are not met, the scanning parameters of each frequency band are adjusted and optimized according to the actual situation until the geological task requirements are met.

[0054] Through precise spectrum analysis, the embodiments of the present invention can deeply obtain the spectrum characteristics of the reflected waves of the target layer, provide an accurate basis for the design of scanning signal parameters, improve the matching degree between the scanning signal and the target layer, and thus enhance the quality of seismic data and exploration accuracy. In the process of formulating the segmentation strategy and designing the parameters of the scanning signal for each segment, the complexity of the geological conditions, the influence of the stratum on the signal, and the requirements of the geological task are fully considered, making the designed scanning signal more suitable for actual exploration needs and enhancing the pertinence and effectiveness of the exploration. Through simulation and actual testing, the synthetic signal is fully tested and optimized to ensure the reliability and stability of the scanning signal in actual seismic exploration, providing more powerful technical support for geological exploration work.

[0055] In another preferred embodiment, the step S1, acquiring seismic data of a target exploration area and performing spectrum analysis on the seismic data to obtain spectrum characteristics of a reflection wave of a target layer, specifically includes:

[0056] S101, acquiring seismic data of a target exploration area and preprocessing the seismic data;

[0057] S102, determining a corresponding spectrum analysis method according to the stationarity of the pre-processed seismic data;

[0058] S103 , performing spectrum analysis on the pre-processed seismic data according to the spectrum analysis method to obtain spectrum characteristics of the target layer reflection wave.

[0059] Specifically, embodiments of the present invention utilize high-resolution seismic exploration equipment in a target exploration area, using an optimized acquisition scheme to collect seismic data. The collected seismic data is first preprocessed to remove noise and interference signals. Next, an appropriate spectrum analysis method is selected based on the stationarity and frequency characteristics of the preprocessed seismic data. Finally, spectrum analysis is performed on the preprocessed seismic data using the selected spectrum analysis method to determine the spectrum characteristics of the reflection waves from the target layer.

[0060] It is important to note that spectrum analysis reveals the characteristics of the target layer's reflected waves in terms of frequency band, energy distribution, and non-stationarity. By using a segmented, independent scanning strategy to compensate for formation attenuation, a synergistic improvement in low-frequency penetration and high-frequency resolution is achieved. Spectral analysis can determine the target layer's frequency band range and energy distribution characteristics within each band, providing a basis for optimizing scanning duration. The target layer's reflected waves have a dominant frequency distribution in the low- to mid-frequency range (10-40 Hz), but they cover a wide frequency band (5-100 Hz), indicating their potential for high-resolution exploration. The low-frequency band (5-10 Hz) exhibits weak reflected energy but strong penetration, revealing deep geological structures. The high-frequency band (80-100 Hz) exhibits significant reflected energy attenuation (due to formation absorption) but carries high-resolution details. The mid-frequency band (10-80 Hz) offers concentrated energy and a high signal-to-noise ratio, making it the primary frequency band for traditional exploration. Through wavelet transform, it is found that the spectrum of the target layer is non-stationary (changing with time), for example, high-frequency components decay rapidly in the shallow layer, and low-frequency components dominate in the deep layer.

[0061] In another preferred embodiment, the step S102 of determining a corresponding spectrum analysis method based on the stationarity of the pre-processed seismic data specifically includes:

[0062] If the pre-processed seismic data is stationary data, discrete Fourier transform is used;

[0063] If the pre-processed seismic data is non-stationary data, continuous wavelet transform is used.

[0064] Specifically, in the embodiment of the present invention, if the preprocessed seismic data is stationary data, that is, exhibits relatively stable characteristics, the discrete Fourier transform (DFT) is used, and the formula is:

[0065]

[0066] Where X(k) represents the complex representation of the kth frequency component in the frequency domain (including amplitude and phase), which is used to identify the main frequency and bandwidth of the reflection wave of the target layer; x(n) represents the nth sampling point value of the time domain seismic signal, n = 0, 1, 2, ..., N-1; N represents the total number of sampling points of the signal, that is, the signal length; k represents the index of the frequency domain component, k = 0, 1, 2, ..., N-1.

[0067] If the preprocessed seismic data is non-stationary data, that is, it exhibits non-stationary characteristics, the continuous wavelet transform (CWT) is used, and the formula is:

[0068]

[0069] Where a represents the scale parameter; b represents the translation parameter; ψ(t) * Represents the conjugate function of the wavelet mother function ψ(t). By adjusting the values ​​of a and b, the wavelet coefficients W at different scales and positions are obtained. x (a, b) to gain insight into the dynamic change characteristics of the target layer's reflected wave spectrum over time.

[0070] In another preferred embodiment, the step S3 divides the frequency range of the scanning signal into several frequency bands according to the frequency spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, specifically including:

[0071] S301, determining the number of frequency bands based on the spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, combined with the attenuation and absorption law of the stratum for signals of different frequencies;

[0072] S302 : Divide the frequency range of the scanning signal into a plurality of frequency bands according to the number of frequency bands; wherein the plurality of frequency bands are different non-continuous independent frequency bands.

[0073] Specifically, when performing frequency division, the embodiments of the present invention first determine the appropriate number of non-contiguous independent frequency bands based on the spectral characteristics of the target layer's reflected waves and the geological characteristics of the depth segment, combined with the attenuation and absorption patterns of the stratum for signals of different frequencies. Through multiple simulation tests and actual exploration verification, the appropriate number of non-contiguous independent frequency bands is determined. For areas with clear exploration targets and relatively simple geological conditions, fewer frequency bands are allocated to improve exploration efficiency. For areas with complex geology, the number of frequency bands is increased to allow for more detailed exploration of different strata. The frequency range of the scanning signal is then divided into several frequency bands based on the number of frequency bands.

[0074] The embodiments of the present invention require segmented adaptation for formations at different depths where the lithology and physical properties vary significantly. Different frequency signals have different attenuation levels in the formation (high frequency attenuates quickly, low frequency penetrates strongly), so frequency division compensation is required. The segmented focus improves the accuracy of longitudinal exploration to avoid the imbalance of shallow / deep signals caused by "one-size-fits-all" scanning parameters; the frequency division focuses on spectral energy balance to avoid insufficient signal-to-noise ratio in weak frequency bands during unified scanning of the entire frequency band. In exploration in complex areas, such as areas with both vertical stratification and strong frequency band attenuation (such as gas-bearing layers and thin interlayers), both segmentation and frequency division designs need to be adopted. Segmentation reduces the amount of calculation at full depth, and frequency division avoids redundant scanning of the entire frequency band. The combination of the two can effectively improve exploration efficiency.

[0075] In another preferred embodiment, the step S4, for each frequency band, determining the scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band, specifically includes:

[0076] S401, for each frequency band, determining a frequency range and a scanning function of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0077] S402 , optimizing the parameters of each scanning signal segment according to a preset fitness function to obtain optimized scanning parameters; wherein the scanning parameters include a starting frequency, an ending frequency, a frequency change rate, and a scanning time.

[0078] Specifically, the embodiment of the present invention determines the optimal frequency range and scanning time of each non-continuous independent frequency band according to the spectrum response characteristics and geological characteristics of the target layer, and selects appropriate scanning functions and scanning parameters. The influence of different scanning times on the reflected waves of the target layer is verified by simulating seismic exploration and actual field tests. An optimization algorithm (such as a genetic algorithm) is used to gradually maximize the value of the fitness function by continuously adjusting the starting frequency, ending frequency, frequency change rate, scanning time and other parameters of the scanning signal, thereby obtaining the optimal scanning parameters for each scanning signal segment. The fitness function can be defined as:

[0079] F(t)=S(t) / N(t);

[0080] Where: S(t) represents the reflected energy of the scanning signal in the target layer; N(t) represents the noise energy.

[0081] Adjust the scanning time of each frequency band based on simulation and test results. If the signal-to-noise ratio of a frequency band does not meet the requirements, increase the scanning time. If the signal-to-noise ratio of a frequency band already meets the requirements, appropriately reduce the scanning time to improve exploration efficiency. Based on the requirements of the geological task, combined with signal propagation theory and actual exploration experience, quantitatively determine the optimal scanning time for different non-continuous independent frequency bands. For frequency bands with weak reflection signals from the target layer, appropriately increase the scanning time to improve the signal-to-noise ratio; for frequency bands with higher resolution requirements, reasonably adjust the scanning time based on the frequency characteristics and formation conditions to achieve the purpose of widening the target layer frequency band and improving the resolution of seismic exploration.

[0082] In another preferred embodiment, the step S401, for each frequency band, determining the frequency range and scanning function of each scanning signal segment according to the spectral characteristics and geological characteristics corresponding to the frequency band, specifically includes:

[0083] For each of the frequency bands, the frequency extension amount is calculated according to the starting frequency and the ending frequency of the reflected wave of the target layer corresponding to the frequency band, and the quality factor of the formation;

[0084] Calculate the starting frequency and ending frequency of each segment of the scanning signal according to the starting frequency and ending frequency of the target layer reflected wave corresponding to the frequency band, and the frequency expansion amount, and obtain the frequency range of each segment of the scanning signal;

[0085] A corresponding scanning function is determined according to the signal change characteristics of the frequency band.

[0086] Specifically, the embodiment of the present invention calculates the frequency extension for each non-continuous independent frequency band based on the starting and ending frequencies of the target layer's reflected wave corresponding to the frequency band, as well as the formation's quality factor. This is used to compensate for the formation's absorption and attenuation of the signal, ensuring that the effective frequency band reaching the target layer after the scanning signal is excited meets actual coverage requirements. The calculation formula for the frequency extension is:

[0087] ΔF low =α*Q -1 *F start ;

[0088] ΔF high =β*Q -1 *F end ;

[0089] Where, ΔF low Indicates the amount of low-frequency band extension, which is used to enhance deep penetration capability; F start Indicates the starting frequency of the target layer reflection wave; ΔF high Indicates the extension of the high-frequency band, which is used to compensate for the ground absorption loss of high-frequency signals; F end represents the termination frequency of the reflection wave from the target layer; Q represents the quality factor of the formation, which reflects the signal attenuation characteristics (obtained through rock physical analysis or empirical values); α and β are both empirical coefficients (usually 0.2 to 0.5), which are adjusted according to the geological complexity of the exploration area and the signal-to-noise ratio requirements.

[0090] Among them, the target layer reflection wave frequency F start and F end By performing spectrum analysis (DFT or CWT) on the seismic data of the target depth segment, the frequency range where the energy of the target layer reflected wave is significantly higher than the noise is extracted. For example, if the main frequency of the target layer in a certain depth segment is 20Hz and the effective frequency band is 15~45Hz, then F start =15Hz, F end =45Hz.

[0091] According to the starting frequency and ending frequency of the target layer reflection wave corresponding to the frequency band, as well as the frequency expansion amount, the starting frequency and ending frequency of each segment of the scanning signal are calculated to obtain the frequency range of each segment of the scanning signal. The calculation formula is:

[0092] F scan_low =Fstart -ΔF low ;

[0093] F scan_high =F end +ΔF high ;

[0094] Where, F scan_low Indicates the starting frequency of the scanning signal; F scan_high Indicates the end frequency of the sweep signal.

[0095] Determine the corresponding sweep function based on the signal variation characteristics of the frequency band. For example, if the signal in a certain frequency band requires linear variation, select the linear sweep function. If nonlinear variation is required, determine the specific parameter values ​​based on the sweep function parameter calculation method used in segmented nonlinear sweep, taking into account the start frequency, end frequency, and sweep duration of each frequency band.

[0096] For example, the nonlinear scanning function is selected as exponential scanning:

[0097] S(t)==A(t)·sin(2π*(F scan_high -F scan_low ) / (γ*T)*(e γt / T -1)+2πF scan_low *t);

[0098] Where γ is the nonlinear coefficient that controls the frequency change rate; T is the sweep time.

[0099] Polynomial Sweep:

[0100] f(t)==F scan_low +(F scan_high -F scan_low )*(a1*t+a2*t2+…);

[0101] Wherein, coefficients a1, a2, ... are determined by optimization algorithm.

[0102] Parameter optimization (taking index scanning as an example)

[0103] Optimization goal: maximize the target layer reflection energy S(t) and minimize the noise N(t).

[0104] Fitness function:

[0105] Fitness=(∫ Fstart Fend ∣X scan(f) ∣df) / (∫0 FNyquist ∣X noise (f) | df);

[0106] Where, Xscan (f) represents the spectrum of the scanning signal; X noise (f) represents the noise spectrum.

[0107] Optimization method:

[0108] Genetic Algorithm: Adjusting γ, T, ΔF low , ΔF high ;

[0109] Gradient descent: Locally optimize the sweep parameters.

[0110] See also Figure 2 , Figure 2 This is a schematic diagram comparing a segmented independent scanning signal provided by the present invention and a conventional scanning signal. Figure 2 In the figure, a is a conventional linear scanning signal, b is a conventional nonlinear scanning signal, and c is a segmented independent scanning signal. It should be noted that the non-continuous independent frequency division scanning technology, for conventional vibroseis scanning, divides the entire scanning frequency range into several continuous and independent frequency bands, and each frequency band adopts a different scanning method. The integration of different frequency bands is a non-continuous scanning form, but it is different from the conventional nonlinear scanning method. Its scanning method is as follows: Figure 2 shown.

[0111] See also Figure 3 , Figure 3 This is a schematic diagram of the original data in the design method of a segmented independent scanning signal provided by the present invention. The embodiment of the present invention selects a high-density three-dimensional seismic exploration area in a certain area of ​​XJZD for research. The original single shot data is as follows: Figure 3 As shown, Figure 3 b is the original single shot target layer ( Figure 3 The spectrum analysis results are shown in the red and green curves in a. By analyzing the spectrum curve, it is found that the frequency band of the controllable source is 5 to 100 Hz, and the four independent frequency bands are divided into Figure 3 Figures ①, ②, ③, and ④ represent 5-10 Hz, 10-40 Hz, 40-80 Hz, and 80-100 Hz, respectively. The entire frequency band was scanned, with a nonlinear upscaling sweep of 5-100 Hz and a sweep time of 12 seconds. The sweep time for 5-10 Hz was 2 seconds; for 10-40 Hz, 3 seconds; for 40-80 Hz, 3 seconds; and for 80-120 Hz, 4 seconds. The record length was 2 seconds. By stacking the individual, segmented, nonlinear scanning single-shot records, the low- and high-frequency reflections from the target layer were enhanced to varying degrees.

[0112] See also Figure 4 and Figure 5 , Figure 4This is a schematic diagram of the reflection of the target layer reflected wave on the time section in a design method of a segmented independent scanning signal provided by the present invention. Figure 5 This is a schematic diagram of the comparison results of the spectrum of the target layer reflection wave in the design method of the segmented independent scanning signal provided by the present invention. Figure 4 As shown in the figure, the comparison and analysis of the target layer spectrum difference is as follows: Figure 5 As shown, it can be seen that there are different degrees of improvement in the low-frequency and high-frequency parts, and the bandwidth is improved accordingly, achieving the purpose of improving resolution.

[0113] Correspondingly, the present invention also provides a device for designing a segmented independent scanning signal, which can implement all the processes of the method for designing a segmented independent scanning signal in the above embodiment.

[0114] See also Figure 6 , Figure 6 1 is a schematic structural diagram of a preferred embodiment of a device for designing a segmented independent scanning signal provided by the present invention. The device for designing a segmented independent scanning signal comprises:

[0115] The spectrum analysis module 601 is used to obtain seismic data of the target exploration area and perform spectrum analysis on the seismic data to obtain the spectrum characteristics of the reflection wave of the target layer;

[0116] A depth division module 602 is configured to divide the exploration depth range of the target exploration area into a plurality of depth segments according to the geological characteristics of the target exploration area;

[0117] The frequency band division module 603 is used to divide the frequency range of the scanning signal into several frequency bands according to the frequency spectrum characteristics of the reflection wave of the target layer and the geological characteristics of the depth segment;

[0118] A parameter determination module 604 is configured to determine, for each frequency band, scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0119] The signal synthesis module 605 is configured to combine the scanning signals of each segment according to the segmentation order of the frequency band and the scanning parameters of each segment of the scanning signal to obtain a target scanning signal.

[0120] Preferably, the spectrum analysis module 601 specifically includes:

[0121] A data acquisition unit, configured to acquire seismic data of a target exploration area and pre-process the seismic data;

[0122] A method determination unit, configured to determine a corresponding spectrum analysis method according to the stationarity of the pre-processed seismic data;

[0123] The spectrum analysis unit is used to perform spectrum analysis on the pre-processed seismic data according to the spectrum analysis method to obtain the spectrum characteristics of the target layer reflection wave.

[0124] Preferably, the method determining unit is specifically configured to:

[0125] If the pre-processed seismic data is stationary data, discrete Fourier transform is used;

[0126] If the pre-processed seismic data is non-stationary data, continuous wavelet transform is used.

[0127] Preferably, the frequency band division module 603 specifically includes:

[0128] a number determination unit, configured to determine the number of frequency bands based on the spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, combined with the attenuation and absorption law of the stratum for signals of different frequencies;

[0129] The frequency band division unit is used to divide the frequency range of the scanning signal into a plurality of frequency bands according to the number of frequency bands; wherein the plurality of frequency bands are different non-continuous independent frequency bands.

[0130] Preferably, the parameter determination module 604 specifically includes:

[0131] a function determination unit, configured to determine, for each frequency band, a frequency range and a scanning function of each scanning signal according to the spectrum characteristics and geological characteristics corresponding to the frequency band;

[0132] The parameter optimization unit is used to optimize the parameters of each segment of the scanning signal according to a preset fitness function to obtain optimized scanning parameters; wherein the scanning parameters include the starting frequency, the ending frequency, the frequency change rate and the scanning time.

[0133] Preferably, the function determination unit is specifically configured to:

[0134] For each of the frequency bands, the frequency extension amount is calculated according to the starting frequency and the ending frequency of the reflected wave of the target layer corresponding to the frequency band, and the quality factor of the formation;

[0135] Calculate the starting frequency and ending frequency of each segment of the scanning signal according to the starting frequency and ending frequency of the target layer reflected wave corresponding to the frequency band, and the frequency expansion amount, and obtain the frequency range of each segment of the scanning signal;

[0136] A corresponding scanning function is determined according to the signal change characteristics of the frequency band.

[0137] In specific implementation, the working principle, control process and technical effect of the design device of the segmented independent scanning signal provided by the embodiment of the present invention are the same as those of the design method of the segmented independent scanning signal in the above embodiment, and will not be repeated here.

[0138] See also Figure 7 , Figure 7 7 is a schematic diagram of a preferred embodiment of a terminal device provided by the present invention. The terminal device includes a processor 701, a memory 702, and a computer program stored in the memory 702 and configured to be executed by the processor 701. When the processor 701 executes the computer program, it implements the method for designing segmented independent scanning signals described in any of the above embodiments.

[0139] Preferably, the computer program can be divided into one or more modules / units (e.g., computer program 1, computer program 2, ...), which are stored in the memory 702 and executed by the processor 701 to implement the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0140] The processor 701 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor, or the processor 701 can be any conventional processor. The processor 701 is the control center of the terminal device, and uses various interfaces and lines to connect the various parts of the terminal device.

[0141] The memory 702 mainly includes a program storage area and a data storage area. The program storage area can store an operating system, at least one application required for a function, and the data storage area can store related data. In addition, the memory 702 can be a high-speed random access memory or a non-volatile memory, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, and a Flash Card. Alternatively, the memory 702 can be other volatile solid-state memory devices.

[0142] It should be noted that the above terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that Figure 7 The structural diagram is only an example of the above-mentioned terminal device and does not constitute a limitation on the above-mentioned terminal device. It may include more or fewer components than shown in the figure, or combine certain components, or different components.

[0143] An embodiment of the present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the method for designing a segmented independent scanning signal as described in any of the above embodiments.

[0144] An embodiment of the present invention further provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, the method for designing a segmented independent scanning signal described in any of the above embodiments is implemented.

[0145] Embodiments of the present invention provide a design method, apparatus, device, medium, and product for a segmented independent scanning signal. The method comprises acquiring seismic data from a target exploration area and performing spectrum analysis on the seismic data to obtain the spectrum characteristics of the target layer's reflected waves. The method further comprises dividing the exploration depth range of the target exploration area into a plurality of depth segments based on the geological characteristics of the target exploration area. The method further comprises dividing the frequency range of the scanning signal into a plurality of frequency bands based on the spectrum characteristics of the target layer's reflected waves and the geological characteristics of the depth segments. For each frequency band, the scanning parameters of each segment of the scanning signal are determined based on the spectrum characteristics and geological characteristics corresponding to the frequency band. The scanning signals of each segment are then spliced ​​together based on the segmentation order of the frequency bands and the scanning parameters of each segment of the scanning signal to obtain a target scanning signal. The embodiment of the present invention divides different independent frequency bands based on the precisely analyzed spectrum characteristics of the target layer's reflected waves and optimizes the scanning parameters of the scanning signals of the different frequency bands, thereby improving the quality of seismic data and achieving high-precision exploration of underground geological structures.

[0146] It should be noted that the system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the system embodiment provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement the present invention without inventive work.

[0147] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A design method for segmented independent scanning signals, characterized in that: include: Acquire seismic data of the target exploration area, and perform spectrum analysis on the seismic data to obtain spectrum characteristics of the target layer reflection wave; Dividing the exploration depth range of the target exploration area into a plurality of depth segments according to the geological characteristics of the target exploration area; Dividing the frequency range of the scanning signal into several frequency bands according to the frequency spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth section; For each of the frequency bands, determining scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band; According to the segmentation order of the frequency band and the scanning parameters of each scanning signal segment, each scanning signal segment is spliced ​​to obtain a target scanning signal.

2. The method for designing a segmented independent scanning signal according to claim 1, wherein: The acquiring of seismic data of the target exploration area and performing spectrum analysis on the seismic data to obtain spectrum characteristics of the target layer reflection wave specifically includes: Acquiring seismic data of a target exploration area and preprocessing the seismic data; According to the stationarity of the pre-processed seismic data, the corresponding spectrum analysis method is determined; The pre-processed seismic data is subjected to spectrum analysis according to the spectrum analysis method to obtain the spectrum characteristics of the target layer reflection wave.

3. The method for designing a segmented independent scanning signal according to claim 2, wherein: Determining a corresponding spectrum analysis method based on the stationarity of the pre-processed seismic data specifically includes: If the pre-processed seismic data is stationary data, discrete Fourier transform is used; If the pre-processed seismic data is non-stationary data, continuous wavelet transform is used.

4. The method for designing a segmented independent scanning signal according to claim 3, wherein: The frequency range of the scanning signal is divided into several frequency bands according to the spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, specifically including: Determine the number of frequency bands based on the spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment, combined with the attenuation and absorption law of the stratum to signals of different frequencies; The frequency range of the scanning signal is divided into a plurality of frequency bands according to the number of frequency bands; wherein the plurality of frequency bands are different non-continuous independent frequency bands.

5. The method for designing a segmented independent scanning signal according to claim 4, wherein: For each frequency band, determining the scanning parameters of each scanning signal segment according to the spectrum characteristics and geological characteristics corresponding to the frequency band specifically includes: For each of the frequency bands, determining the frequency range and scanning function of each scanning signal according to the spectrum characteristics and geological characteristics corresponding to the frequency band; The parameters of each scanning signal segment are optimized according to a preset fitness function to obtain optimized scanning parameters; wherein the scanning parameters include a starting frequency, an ending frequency, a frequency change rate, and a scanning time.

6. The method for designing a segmented independent scanning signal according to claim 5, wherein: For each frequency band, determining the frequency range and scanning function of each scanning signal according to the spectrum characteristics and geological characteristics corresponding to the frequency band specifically includes: For each of the frequency bands, the frequency extension amount is calculated according to the starting frequency and the ending frequency of the reflected wave of the target layer corresponding to the frequency band, and the quality factor of the formation; Calculate the starting frequency and ending frequency of each segment of the scanning signal according to the starting frequency and ending frequency of the target layer reflected wave corresponding to the frequency band, and the frequency expansion amount, and obtain the frequency range of each segment of the scanning signal; A corresponding scanning function is determined according to the signal change characteristics of the frequency band.

7. A device for designing segmented independent scanning signals, characterized in that: include: A spectrum analysis module is used to obtain seismic data of the target exploration area and perform spectrum analysis on the seismic data to obtain the spectrum characteristics of the target layer reflection wave; A depth division module is used to divide the exploration depth range of the target exploration area into several depth segments according to the geological characteristics of the target exploration area; A frequency band division module, configured to divide the frequency range of the scanning signal into a plurality of frequency bands according to the frequency spectrum characteristics of the reflected wave of the target layer and the geological characteristics of the depth segment; a parameter determination module, configured to determine, for each frequency band, scanning parameters of each segment of the scanning signal according to the spectrum characteristics and geological characteristics corresponding to the frequency band; The signal synthesis module is used to splice the scanning signals of each segment according to the segmentation order of the frequency band and the scanning parameters of each segment of the scanning signal to obtain a target scanning signal.

8. A terminal device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory and configured to be executed by the processor, and wherein the processor implements the method for designing a segmented independent scanning signal according to any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, wherein when the device where the computer-readable storage medium is located executes the computer program, the method for designing a segmented independent scanning signal according to any one of claims 1 to 6 is implemented.

10. A computer program product, characterized in that The computer program product includes a computer program or computer instructions, and when the computer program or the computer instructions are executed by a processor, the method for designing a segmented independent scanning signal according to any one of claims 1 to 6 is implemented.

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