Seismic data noise suppression method
By conducting spatial intersection analysis of the noise frequency, amplitude energy and signal-to-noise ratio distribution of seismic data, combined with arrangement sheet reconstruction and spatial time window processing, the problem of difficult to effectively suppress seismic data noise in the prior art is solved, and accurate suppression of abnormal amplitude and protection of effective signals are achieved.
Patent Information
- Application Number
- CN202311830678.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-27
- Publication Date
- 2025-06-27
AI Technical Summary
The prior art is difficult to effectively suppress large-area continuous multiple anomaly noise in seismic data, and conventional denoising methods are prone to incorrectly damage strong effective signals.
By conducting background acquisition and noise survey on the target work area, the noise frequency distribution and amplitude energy distribution are determined, combined with the signal-to-noise ratio distribution, seismic data in the spatial intersection area are obtained for targeted noise suppression. The method includes arrangement sheet reconstruction, common channel central sampling and space window processing to identify and suppress abnormal amplitudes.
Accurate suppression of large-area continuous multiple anomaly noises is achieved, avoiding damage to strong effective signals, and improving signal-to-noise ratio and data quality.
Smart Images
Figure CN120214910A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of oil and gas exploration, and in particular to a method for suppressing seismic data noise. Background Art
[0002] The signal-to-noise ratio in seismic data has an important impact on the quality of faults or seismic imaging. Excessive noise energy will not only affect the speed of model establishment, but also generate strong migration arc noise, thus affecting the accuracy of migration imaging and the quality of the resulting data. It further affects the work of structural interpretation, reservoir inversion and oil and gas prediction. During the acquisition process of seismic data, there are many external interferences. In recent years, with the further advancement of exploration work, the work area often passes through some towns, factories and residential gathering points, etc., causing more serious noise to the seismic data. In addition, vibroseis construction is often used in urban areas, that is, the excitation energy is restricted, resulting in weak effective signal energy and strong external interference energy, and then the signal-to-noise ratio of seismic data is extremely low. On the single-shot record of seismic data, the seismic data affected by noise often appears in the form of strong amplitude anomalies. How to suppress the large-area continuous multi-channel abnormal amplitude interference under the premise of signal and amplitude preservation is the focus of attention in the signal processing link. Because in these areas, if stronger denoising parameters are used, it will have a greater impact on the effective signal. On the contrary, if weaker denoising parameters are used, too much noise residue will have a greater impact on the subsequent processing procedures.
[0003] In traditional technologies, for suppressing large-area continuous multi-channel abnormal amplitudes, the general idea is to reconstruct the data, disperse the continuous interference channels, and use moderate denoising parameters to suppress noise. There are mainly two reconstruction methods used more. (1) Data reconstruction denoising based on random functions. Although this method disperses the continuous interference channels, the correlation between channels is weak, and there may be a situation where strong effective channels and weak effective channels are adjacent, resulting in this method misjudging strong effective channels; (2) Common shot-offset domain data rearrangement denoising. This method can highlight the relationship between noise and offset, but it cannot effectively disperse the continuous interference channels, so the noise suppression effect is not obvious; (3) Whether it is the data reconstruction denoising method based on random functions or the common shot-offset domain data rearrangement denoising method, the way to identify noise interference is to judge by a single signal amplitude energy anomaly, so that some effective signals with strong energy are also misjudged as signals with serious interference, resulting in a large loss of strong effective signals.
[0004] Therefore, a more effective method for suppressing seismic data noise for large-area continuous multi-channel abnormal amplitudes is urgently needed in the art. Summary of the Invention
[0005] In order to be able to suppress the noise of large - area continuous multi - trace abnormal amplitudes and avoid damaging the seismic data of strong effective traces, in the first aspect of the present invention, a seismic data noise suppression method is proposed. The method includes: performing background acquisition and noise investigation on the target work area, determining the noise frequency distribution in the target work area, and determining a first spatial region according to a preset noise main frequency range; obtaining the interval - sampled single - shot records of the target work area, determining the amplitude - energy distribution of the seismic data in the single - shot records, and determining a second spatial region where the amplitude energy is greater than the preset amplitude - energy threshold according to the preset amplitude - energy threshold; determining the signal - to - noise ratio distribution according to the noise frequency distribution and the amplitude - energy distribution, and determining a third spatial region where the signal - to - noise ratio is less than the preset signal - to - noise ratio threshold according to the preset signal - to - noise ratio threshold; finding the spatial intersection of the first spatial region, the second spatial region, and the third spatial region, and performing targeted noise suppression on the seismic data in the intersection spatial region.
[0006] In one or more embodiments, the method further includes, before performing targeted noise suppression, performing arrangement - slice reconstruction on the seismic data in the intersection spatial region. The arrangement - slice reconstruction includes: forming seismic traces from the seismic data in the intersection spatial region according to the source of geophones; reconstructing the seismic traces with the same geophone serial number in all geophone lines into the same arrangement slice.
[0007] In one or more embodiments, when there are multiple shot points near the intersection spatial region, multiple common - shot gather are formed based on the seismic data in the intersection spatial region, and each of the common - shot gather contains multiple of the arrangement slices.
[0008] In one or more embodiments, the method further includes: sampling the multiple common - shot gather; determining the number of abnormal traces with continuous abnormal amplitudes in the common - shot gather sampling; determining the size of the spatial time window according to the number of abnormal traces, where the size of the spatial time window should be greater than or equal to 2 times the number of abnormal traces and less than or equal to the total number of traces in an arrangement slice in the common - shot gather sampling.
[0009] In one or more embodiments, the targeted noise suppression of the seismic data in the intersection spatial region includes processing the seismic traces in each common - shot gather after arrangement - slice reconstruction as follows: continuously extracting multiple seismic traces starting from the first seismic trace data in the common - shot gather according to the size of the spatial time window; determining the abnormal - trace seismic data to be processed in the multiple seismic traces according to a preset algorithm; sliding the spatial time window to the next starting point, and sequentially processing the multiple common - shot gather until all the abnormal - trace seismic data to be processed in all the common - shot gather are determined; performing targeted noise suppression processing on the abnormal - trace seismic data according to the noise frequencies within the noise main frequency range.
[0010] In one or more embodiments, determining the abnormal channel seismic data to be processed in the multi-channel seismic data according to a preset algorithm includes: calculating the average energy of each channel of seismic data, and the calculation formula is:
[0011]
[0012] Where Ei is the average amplitude energy of the i-th seismic data, n i is the number of vertical spatial time windows used to process the i-th seismic data, A ij is the amplitude value of the jth seismic data in the ith channel; determines the median Em of the average amplitude energy of the multi-channel seismic data in the spatial time window; calculates the threshold value according to the preset threshold coefficient k and the median Em, and the calculation formula is:
[0013] Et=k*Em
[0014] Wherein, Et is a threshold value; the average amplitude energy of each seismic data in the space time window is compared with the threshold value; when Ei≥Et, the seismic data is judged to be abnormal seismic data.
[0015] In one or more embodiments, the method for determining the threshold coefficient k includes: determining the threshold coefficient k under the premise of removing noise as much as possible and without damaging valid seismic trace data.
[0016] In one or more embodiments, the targeted noise suppression processing of the abnormal channel seismic data according to the noise frequency within the noise main frequency range includes: determining the noise interference area through which the seismic data passes according to the area where the detection points receiving the seismic channel data are located and the area where the corresponding shot points of the common shot set are located; and targeted noise suppression of the seismic channel data according to the noise main frequency and noise energy in the noise interference area.
[0017] In one or more embodiments, the method further comprises: reorganizing the seismic traces in the common shot gather after noise suppression into arrangement slices according to the detection line sequence number.
[0018] In one or more embodiments, the method further includes: performing seismic data imaging processing based on the arrangement slices reorganized according to the detection line numbers.
[0019] The beneficial effects of the present invention include: the method of the present invention takes into account the spatial distribution of noise, the spatial distribution of amplitude energy and the spatial distribution of signal-to-noise ratio in the process of determining the abnormal amplitude, and by obtaining the spatial intersection of the three, it can more accurately determine the seismic data of the abnormal channel and effectively avoid accidentally damaging the strong effective channel, and the arrangement piece reconstruction makes the adjacent seismic channels have a certain correlation, which is helpful for the continuous extraction of the abnormal channel. Brief Description of the Drawings
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other embodiments can also be obtained based on these drawings.
[0021] Figure 1 It is a flowchart of the working process of a seismic data noise suppression method according to an embodiment of the present invention;
[0022] Figure 2 It is a main frequency distribution diagram of noise at geophone points in the first embodiment of the present invention;
[0023] Figure 3 It is a noise energy distribution diagram at geophone points in the first embodiment of the present invention;
[0024] Figure 4 It is a signal-to-noise ratio distribution diagram of the whole area in the first embodiment of the present invention;
[0025] Figure 5 It is a schematic diagram of the seismic data arrangement in the traditional common shot gather in the first embodiment of the present invention;
[0026] Figure 6 It is a schematic diagram of the seismic data arrangement in the reconstructed common shot gather in the first embodiment of the present invention;
[0027] Figure 7 It is an amplitude energy distribution diagram of the seismic data in the traditional common shot gather in the first embodiment of the present invention;
[0028] Figure 8 It is an amplitude energy distribution diagram of the seismic data in the reconstructed common shot gather in the first embodiment of the present invention;
[0029] Figure 9 It is a comparison diagram before and after denoising of the reconstructed data in the first embodiment of the present invention;
[0030] Figure 10 It is a comparison diagram of the single-shot record before denoising (left), the single-shot record after conventional abnormal amplitude suppression (middle), and the single-shot record after abnormal amplitude suppression by seismic data arrangement slice reconstruction in the first embodiment of the present invention. Detailed Embodiments
[0031] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the following will further elaborate on the embodiments of the present invention in detail with reference to specific embodiments and the accompanying drawings.
[0032] It should be noted that in the embodiments of the present invention, all expressions using "first" and "second" are for distinguishing two entities or parameters with the same name but different identities. It can be seen that "first" and "second" are only for the convenience of expression and should not be construed as a limitation on the embodiments of the present invention. This will not be elaborated one by one in the subsequent embodiments.
[0033] Please refer to Figure 1 , which shows the workflow of a seismic data noise suppression method according to an embodiment of the present invention, including:
[0034] Step S1: Perform background acquisition and noise investigation on the target work area, determine the noise frequency distribution in the target work area, and determine the first spatial region according to the preset main noise frequency range.
[0035] Specifically, for work areas passing through towns, factories, and residential gathering points, since the sources of noise interference are complex and the main frequency distribution is wide, it is necessary to perform background acquisition and noise investigation on the target work area in advance to determine the main frequency distribution of noise in the target work area, so as to fully understand the distribution of the main noise frequency. Among them, according to the different energies of single-shot excitation, the noise frequencies that have the greatest impact on single-shot records will also be different. Therefore, it is necessary to pre-determine the main noise frequency range that has the greatest interference on the records according to the excitation energy of the single shot. Please refer to Figure 2 , which shows the main noise frequency distribution in the geophone point domain of the first embodiment of the present invention, Figure 2 The color blocks with different depths in Figure 2 represent noises of different frequencies. Among them, the main noise frequency with the largest proportion is the noise with a frequency between 60 and 80 Hz, accounting for 30%. And the frequency range that has the greatest impact on the current seismic data can be the noise with a frequency of 40 - 60 Hz, that is,
[0036] The light-colored strip area in
[0037] is the main interference area. When seismic data passes through these areas, the probability of it being abnormal data is greater. On the contrary, the probability of data that has not passed through these areas being strong effective channels is relatively large.
[0037] Specifically, since for work areas passing through towns, factories and mining areas as well as residential gathering points, vibroseis construction with restricted excitation energy is often adopted, the energy of the seismic waves excited by shot points is limited. After the energy loss during the formation reflection process, the amplitude energy of the seismic data (i.e., seismic wave data) received by geophone points is small. As a result, the seismic data affected by noise often shows abnormal conditions with strong amplitudes. Therefore, most of the interference signals can be effectively identified through this abnormal condition of excessive amplitude energy. However, in order to avoid the situation in the traditional technology where some effective signals with strong energy are misjudged as signals with serious interference, in the subsequent step S4 of this application, the spatial intersection of the first spatial region determined in step S1 and the second spatial region determined in step S2 needs to be calculated, so that only when the seismic data in the spatial region where the main frequency of the noise is greater than the noise frequency threshold shows abnormal amplitudes will it be determined as abnormal seismic data (i.e., interference signal). Please refer to Figure 3 , which shows the noise energy distribution in the geophone point domain of the first embodiment of the present invention, Figure 3 The color blocks with different depths in it represent different average amplitude energies. Among them, the average amplitude energy with the largest proportion is the average amplitude energy between 0.001 and 0.005, and the proportion reaches 70%.
[0038] By comparing Figure 2 and Figure 3 it can be found that Figure 2 and Figure 3 The noise frequency distribution and the average amplitude energy distribution in are similar but not exactly the same. Therefore, neither the single noise frequency distribution nor the single average amplitude energy distribution can accurately determine the influence of noise on the amplitude of seismic waves. Therefore, the accuracy of the abnormal seismic data determined by this method by calculating the spatial intersection of the two is higher.
[0039] Step S3: Determine the signal-to-noise ratio distribution according to the main frequency distribution of the noise and the amplitude energy distribution of the seismic data, and determine the third spatial region where the signal-to-noise ratio is less than the signal-to-noise ratio threshold according to the preset signal-to-noise ratio threshold.
[0040] Specifically, the signal quality of the seismic data ultimately needs to be judged by the signal-to-noise ratio. The higher the signal-to-noise ratio, the better the signal quality. In the embodiment of the present invention, only the signals with low signal-to-noise ratio need to be subjected to noise suppression. Therefore, in the subsequent steps, it is necessary to calculate the spatial intersection of the first spatial region, the second spatial region and the third spatial region. Please refer to Figure 4 , which shows the signal-to-noise ratio distribution of the whole region of the first embodiment of the present invention, Figure 4 The color blocks with different depths in it represent different signal-to-noise ratio values. In an optional embodiment, only the abnormal seismic data in the region where the signal-to-noise ratio is less than 1 or 1.2 is subjected to noise suppression.
[0041] Step S4: Calculate the spatial intersection of the first spatial region, the second spatial region, and the third spatial region, and perform targeted noise suppression on the seismic data within the intersection spatial region.
[0042] Specifically, since the seismic waves passing through different regions are disturbed to different degrees, and the main frequency distribution and signal-to-noise ratio distribution of the noise have been statistically analyzed in the foregoing embodiments of the present invention, the present invention can perform targeted noise suppression on the seismic data within the intersection spatial region, so as to perform noise suppression on the seismic data within different intersection spatial regions to different degrees, thereby achieving the best suppression effect. In an alternative embodiment, the method for calculating the spatial intersection includes determining the spatial ranges of the first spatial region, the second spatial region, and the third spatial region based on the spatial coordinates of each geophone, and then solving the spatial intersection based on the spatial coordinates.
[0043] In addition, it should be noted that, as can be seen from the above embodiments, the present invention realizes the screening of seismic data based on the noise frequency threshold, the amplitude energy threshold, and the signal-to-noise ratio threshold by calculating the spatial intersection. Compared with directly screening the seismic data according to the above three thresholds, the advantage of the method based on calculating the spatial intersection of the present invention is that it also realizes spatial limitation at the same time, so that only when the seismic data passing through the spatial region where the main frequency of the noise is greater than the noise frequency threshold shows abnormal amplitude will it be judged as abnormal seismic data, thereby making the judgment of abnormal seismic data more accurate.
[0044] In a further embodiment, the seismic data noise suppression method of the present invention further includes, before performing targeted noise suppression, performing arrangement slice reconstruction on the seismic data within the intersection spatial region. The arrangement slice reconstruction includes: forming seismic traces from the seismic data within the intersection spatial region according to the source of the geophones; reconstructing the seismic traces with the same geophone serial number among all geophone lines within the same arrangement slice.
[0045] Specifically, in the traditional technology, generally, common shot gathers are formed with the same geophone line numbers, and then the data is arranged based on the geophone point numbers within the common shot gathers. However, in this data arrangement method, since the seismic data of adjacent channels is received by different geophones on the same geophone line, when there are abnormal channels, the abnormal channels will be relatively concentrated and strong de-noising processing needs to be adopted, which will inevitably misjudge strong effective channels (i.e., seismic channels with a relatively high signal-to-noise ratio). Therefore, in this embodiment, the seismic data in the common shot gathers will be arranged and reconstructed into slices, and multiple seismic data with the same geophone point number will form a common shot gather, so that the seismic data of adjacent channels in each common shot gather comes from geophones at the same position on different geophone lines. This not only ensures the correlation of adjacent channels but also effectively disperses the abnormal channels, avoiding the problem of misjudging strong effective channels during the noise suppression process due to the excessive concentration of abnormal channels. And after the continuous strong interference channels (i.e., abnormal channels) are effectively dispersed, a smaller spatial time window can be used in the subsequent steps, which can further avoid setting the spatial time window too large in order to include all the abnormal channel data into the spatial time window, thus including too much effective channel data and causing a greater range of misjudgment of the effective channels, and further avoiding reducing the accuracy of identifying abnormal channels. And the more dispersed abnormal channel data helps to achieve more targeted noise suppression. Among them, a common shot gather refers to all the seismic data in the gather that comes from the seismic waves excited by the same shot point and is received by different geophone points after being reflected by different formation interfaces. And during the transmission of seismic waves, due to the different depths of the formation interfaces, the lengths of the reflection paths are also different, so that the same geophone can receive multiple seismic wave data reflected at different times within the geophone detection period.
[0046] More specifically, please refer to Figure 5 and Figure 6 , which respectively show the seismic data arrangement method in the traditional common shot gather of the first embodiment of the present invention and the seismic data arrangement method in the reconstructed common shot gather of the first embodiment of the present invention. Figure 5 and Figure 6 Each black dot (such as A33) in represents a seismic data, and each seismic data is represented in the form of Aij in the arrangement slice, where i is the geophone line number in the arrangement slice and j is the geophone point number in the arrangement slice. As Figure 5 shown, in the traditional common shot gather, it will form arrangement slices for the seismic data according to the same geophone line number. For example, A11 - A15 is taken as an arrangement slice, and the seismic data is sorted according to the geophone point number within the arrangement slice, and then the arrangement slices are sorted according to the geophone line number. After A11 - A15, it is A21 - A25, and so on. The specific arrangement of the seismic channels is as shown in the right view of Figure 5 ; while in the present invention, as Figure 6As shown, the data reconstruction of the present invention reconstructs the common shot gather on the condition that the detection point numbers j are the same, so that A11 - A51 form a permutation slice, and then sorts each permutation slice according to the detection point number j. For example, after A11 - A51 comes A12 - A52. The formed seismic trace permutation is specifically as shown in Figure 6 the right view in
[0047] More specifically, please refer to Figure 7 and Figure 8 , which respectively show the amplitude energy distribution of the seismic data in the traditional common shot gather of the first embodiment of the present invention and the amplitude energy distribution of the seismic data in the reconstructed common shot gather of the first embodiment of the present invention under the condition of the same total number of traces. Among them, the darker the color, the higher the amplitude energy. By comparing Figure 7 and Figure 8 , it can be found that the strong amplitude energy in the present invention is more dispersed.
[0048] Please refer to Figure 9 , which shows the comparison before and after denoising of the reconstructed data of the first embodiment of the present invention. Among them, by comparing before denoising (upper) and after denoising (lower), it can be found that the present implementation method greatly reduces the amplitude energy of the abnormal amplitude energy (dark concentrated area), while having little impact on the amplitude energy of other areas.
[0049] Please refer to Figure 10 , which shows the comparison of the single-shot record before denoising (left), the single-shot record after conventional abnormal amplitude suppression (middle), and the single-shot record after abnormal amplitude suppression by seismic data permutation slice reconstruction of the first embodiment of the present invention. As shown in Figure 10 , the result after abnormal amplitude suppression after seismic data permutation slice reconstruction is significantly better than the result of conventional abnormal amplitude suppression, and the seismic data with abnormal amplitude energy (dark concentrated area) is significantly reduced.
[0050] In a further embodiment, when there are multiple shot points near the intersection space region, multiple common shot gathers are formed based on the seismic data in the intersection space region, and each common shot gather contains multiple permutation slices. Specifically, since the present invention uses interval sampling single-shot records, that is, multiple single-shot excitations are carried out at intervals, so when there are multiple shot points near the intersection space region, multiple common shot gathers can be formed.
[0051] In a further embodiment, the seismic data noise suppression method of the present invention further includes: extracting common shot gather samples from multiple common shot gathers; determining the number of abnormal traces with continuous abnormal amplitudes in the common shot gather samples; determining the size of the spatial time window according to the number of abnormal traces, where the size of the spatial time window should be greater than or equal to 2 times the number of abnormal traces and less than or equal to the total number of traces in a permutation slice in the common shot gather samples.
[0052] Specifically, the size of the spatio-temporal window will affect the determination of the median value Em of the average amplitude energy of multi-channel seismic data within the spatio-temporal window in subsequent steps. In order to include all abnormal trace data in the abnormal trace set position but avoid including too much normal trace data, the size of the spatio-temporal window should be greater than or equal to 2 times the number of abnormal traces and less than or equal to the total number of traces in one spread segment of the common shot gather sampling according to the number of abnormal traces in the common shot gather sampling.
[0053] In a further embodiment, the targeted noise suppression of the seismic data in the intersection space region of the present invention includes processing the seismic traces in each common shot gather reconstructed by spread segment reconstruction as follows: continuously extracting multi-channel seismic data starting from the first seismic trace data in the common shot gather according to the size of the spatio-temporal window; determining the abnormal trace seismic data to be processed in the multi-channel seismic data according to a preset algorithm; sliding the spatio-temporal window to the next starting point and processing multiple common shot gathers in sequence until all the abnormal trace seismic data to be processed in all common shot gathers are determined; performing targeted noise suppression processing on the abnormal trace seismic data according to the noise frequencies within the main frequency range of the noise.
[0054] In a further embodiment, determining the abnormal trace seismic data to be processed in the multi-channel seismic data according to a preset algorithm includes: calculating the average energy of each seismic trace, and the calculation formula is
[0055]
[0056] where Ei is the average amplitude energy of the i-th seismic trace, ni is the number of longitudinal spatio-temporal windows used when processing the i-th seismic trace, and A ij is the amplitude value of the j-th seismic data in the i-th trace; determining the median value Em of the average amplitude energy of the multi-channel seismic data in the spatio-temporal window; calculating the threshold value according to a preset threshold coefficient k and the median value Em, and the calculation formula is
[0057] Et = k * Em
[0058] where Et is the threshold value; comparing the average amplitude energy of each seismic trace in the spatio-temporal window with the threshold value; when Ei ≥ Et, determining that the seismic data is abnormal seismic data.
[0059] More specifically, the explanations for ni include: the detection point has the number of samplings, sampling duration, and sampling frequency. For example, if the number of samplings per detection point is 6, the sampling duration is 1 s, and the sampling frequency is 100, then a total of 600 samplings will be collected in 6 samplings. These 600 samplings will form a seismic trace. Therefore, when processing seismic trace data using a spatial time window, not only the number of seismic traces extracted in the horizontal direction by the spatial time window needs to be considered, but also the amount of data extracted from each seismic trace in the vertical (time axis) direction needs to be considered. Among them, the size of the spatial time window is used to determine the number of seismic traces to be extracted in the horizontal direction, and the number of vertical spatial time windows is used to determine the amount of data to be extracted from each seismic trace. For example, in this embodiment, a seismic trace needs to be divided into 6 segments for processing, and each segment includes 100 seismic data.
[0060] As can be seen from the above solution, in this embodiment, the key parameters affecting the determination of abnormal seismic data (or abnormal amplitude energy) include not only the size of the spatial time window but also the threshold coefficient k. In an alternative embodiment, the threshold coefficient k needs to be determined through a threshold coefficient test. The core idea of the test is to start from the perspective of protecting valid signals, perform quality control on the records and noise before and after denoising, and select the optimal threshold value coefficient to avoid damaging valid signals while removing noise as much as possible.
[0061] In a further embodiment, targeted noise suppression processing is performed on the abnormal trace seismic data according to the noise frequencies within the main frequency range of the noise, including: determining the noise interference area through which the seismic data passes according to the area where the detection points of the received seismic trace data are located and the area where the corresponding shot points of the common shot gather are located; performing targeted noise suppression on the seismic data according to the main frequency and noise energy within the noise interference area.
[0062] In a further embodiment, obtaining the interval sampling single-shot record of the target work area includes: obtaining the medium-interval uniform sampling single-shot record of the target work area. Using the medium-interval uniform sampling single-shot record can obtain an appropriate amount of seismic data.
[0063] In a further embodiment, the seismic data in the common shot gather after noise suppression is re-sorted based on the geophone line number to restore the original arrangement order of the seismic data. That is, the seismic traces in the common shot gather after noise suppression are re-organized into arrangement slices according to the geophone line number; the seismic data after restoring the original arrangement will be used for seismic data imaging processing, and further used to realize fault interpretation to judge the possible storage locations of oil and gas.
[0064] Based on the above embodiments, the present invention proposes a solution for screening seismic records with large-area continuous interference channels through a multi-attribute (multiple threshold) intersection recognition method. By means of the screening step based on average amplitude energy, it is realized that only the shot points (the excited seismic data) with severe interference are processed, thereby forming a certain protection mechanism for single-shot records with high signal-to-noise ratio. And an arrangement for reconstructing seismic data within the array is designed, which effectively disperses continuous interference channels and ensures that the effective signal energies of adjacent channels have a certain correlation. On this basis, abnormal amplitudes are suppressed, which can denoise to a greater extent and better retain effective signals.
[0065] The above are exemplary embodiments disclosed by the present invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments disclosed by the present invention as defined by the claims. The functions, steps, and / or actions of the method claims according to the disclosed embodiments herein do not need to be executed in any specific order. In addition, although the elements disclosed by the embodiments of the present invention can be described or claimed in individual form, they can also be understood as multiple unless explicitly limited to the singular.
[0066] It should be understood that, as used herein, unless the context clearly supports exceptions, the singular form "a" is also intended to include the plural form. It should also be understood that the "and / or" used herein refers to any and all possible combinations of one or more of the related listed items.
[0067] The serial numbers of the disclosed embodiments of the present invention above are only for description and do not represent the superiority or inferiority of the embodiments.
[0068] Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the embodiments disclosed by the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features between the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included in the protection scope of the embodiments of the present invention.
Claims
1. A method for suppressing seismic data noise, characterized in that, The method includes: Performing background collection and noise investigation on the target work area, determining the noise frequency distribution within the target work area, and determining a first spatial region according to a preset main noise frequency range; Obtaining the interval sampling single-shot records of the target work area, determining the amplitude energy distribution of the seismic data in the single-shot records, and determining a second spatial region where the amplitude energy is greater than the preset amplitude energy threshold according to the preset amplitude energy threshold; Determining the signal-to-noise ratio distribution according to the noise frequency distribution and the amplitude energy distribution, and determining a third spatial region where the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold according to the preset signal-to-noise ratio threshold; Finding the spatial intersection of the first spatial region, the second spatial region, and the third spatial region, and performing targeted noise suppression on the seismic data within the intersection spatial region.
2. The seismic data noise suppression method according to claim 1, characterized in that The method further includes, before performing targeted noise suppression, performing arrangement slice reconstruction on the seismic data within the intersection spatial region, and the arrangement slice reconstruction includes: Forming seismic traces from the seismic data within the intersection spatial region according to the source of geophones; Reconstructing the seismic traces with the same geophone serial number in all geophone lines into the same arrangement slice.
3. The seismic data noise suppression method according to claim 2, wherein When there are multiple shot points near the intersection spatial region, forming multiple common shot gather based on the seismic data within the intersection spatial region, and each of the common shot gather contains multiple of the arrangement slices.
4. The seismic data noise suppression method according to claim 3, characterized in that, The method further includes: Sampling the multiple common shot gather; Determining the number of abnormal traces with continuous abnormal amplitudes in the common shot gather sampling; Determining the size of the spatial time window according to the number of abnormal traces, where the size of the spatial time window should be greater than or equal to 2 times the number of abnormal traces and less than or equal to the total number of traces in one arrangement slice in the common shot gather sampling.
5. The seismic data noise suppression method according to claim 4, wherein The targeted noise suppression of the seismic data within the intersection spatial region includes processing the seismic traces in each common shot gather that has undergone arrangement slice reconstruction as follows: Continuously extracting multiple traces of seismic data starting from the first trace of seismic data in the common shot gather according to the size of the spatial time window; Determining the abnormal trace seismic data to be processed in the multiple traces of seismic data according to a preset algorithm; Sliding the spatial time window to the next starting point, and sequentially processing the multiple common shot gather until all the abnormal trace seismic data to be processed in all the common shot gather are determined; Performing targeted noise suppression processing on the abnormal trace seismic data according to the noise frequencies within the main noise frequency range.
6. The seismic data noise suppression method according to claim 5, wherein, The determining of the abnormal trace seismic data to be processed in the multiple traces of seismic data according to the preset algorithm includes: Calculating the average energy of each trace of seismic data, and the calculation formula is where Ei is the average amplitude energy of the i-th seismic data, n i is the number of longitudinal spatial time windows used when processing the i-th seismic data, A ij is the amplitude value of the j-th seismic data in the i-th trace; Determining the median Em of the average amplitude energy of the multiple traces of seismic data in the spatial time window; Calculating the threshold value according to a preset threshold coefficient k and the median Em, and the calculation formula is Et = k * Em where Et is the threshold value; Comparing the average amplitude energy of each trace of seismic data in the spatial time window with the threshold value; When Ei ≥ Et, determining that the seismic data is abnormal trace seismic data.
7. The seismic data noise suppression method according to claim 6, characterized in that The determining method of the threshold coefficient k includes: Determine the threshold coefficient k on the premise of removing noise as much as possible without damaging the effective seismic trace data.
8. The seismic data noise suppression method according to claim 5, characterized in that, The targeted noise suppression processing of the abnormal trace seismic data according to the noise frequencies within the main noise frequency range includes: Determine the noise interference area through which the seismic data passes according to the area where the geophone point receiving the seismic trace data is located and the area where the corresponding shot point of the common shot gather is located; Perform targeted noise suppression on the seismic trace data according to the main noise frequency and noise energy within the noise interference area.
9. The seismic data noise suppression method according to claim 2, wherein The method further includes: Re-organize the seismic traces in the common shot gather after noise suppression into patches according to the geophone line numbers.
10. The seismic data noise suppression method according to claim 9, characterized in that, The method further includes: Perform seismic data imaging processing based on the patches re-organized according to the geophone line numbers.