Intelligent multiple suppression method

Abstract

The invention discloses a multiple intelligent suppression method, which comprises the following steps: S1, data preprocessing: carrying out dynamic correction processing on VSP seismic data by using zero offset seismic velocity information to obtain seismic data after dynamic correction processing, and then carrying out first arrival removal on the data to obtain first preprocessed data; performing data removal and corridor superposition on the first pre-processed data by selecting a time window to obtain second pre-processed data; s2, performing normalization and phase reversal processing on the second pre-processed data to obtain pressing processing parameters; and S3, performing pressing processing on the first pre-processed data by using the pressing processing parameters to obtain final pressing data. According to the method, the multiple noise component in the seismic data can be greatly reduced, the goodness of fit with the seismic data without multiple waves is higher, it is proved that the method has a good multiple wave suppression effect, the signal-to-noise ratio and fidelity of the data are improved, the reliability is higher, and the method is suitable for efficient and intelligent multiple wave suppression in seismic data processing.

Description

Technical Field

[0001] The invention belongs to the field of seismic data processing, in particular to a multiple wave intelligent suppression method. Background Art

[0002] Multiple waves are a type of interference wave that exists in seismic waves. Multiple waves are generated because some reflection interfaces with large reflection coefficients on the surface or underground cause the primary reflection wave to be reflected back underground. Therefore, in order to improve the signal-to-noise ratio and fidelity of the signal, multiple waves need to be suppressed after obtaining seismic wave data.

[0003] There are many methods for analyzing and suppressing multiple waves in seismic data, and the more representative ones are: 1. In 1973, Cassano et al. proposed the optimal filtering and stacking method, which used the least squares method to solve the filtering factor of each stacking channel so that the stacking can achieve the best suppression of multiple waves and thus the best approximation of the primary wave; 2. The deconvolution suppression method proposed by Lokshtanov et al. is based on a one-dimensional and two-dimensional reflection model. In the frequency and slowness domain, a deconvolution operator is calculated to suppress the multiple waves; 3. Doicin et al. proposed a specific micro-bend multiple wave attenuation method, which uses the spatial matrix filtering method in the fx domain to obtain the model of multiple waves.

[0004] The above-mentioned wave suppression methods mostly use ground seismic data to extract suppression parameters. The data obtained by this method has uncertainty, which will produce errors and affect the suppression effect. For some complex seismic data, multiple waves and noise may not be effectively suppressed. In addition, the effect of multiple wave suppression using ground seismic data is also easily affected by underground geological conditions. For example, the complexity and inhomogeneity of the underground medium, or the presence of geological structures such as interfaces and faults, will affect the suppression effect and accuracy of the multiple wave suppression method. Summary of the invention

[0005] In order to solve the above deficiencies in the prior art, the present invention aims to provide a multiple wave intelligent suppression method to achieve the purpose of efficiently and intelligently suppressing multiple waves and preserving the fidelity of seismic data.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A multiple wave intelligent suppression method comprises the following steps: S1. Data preprocessing, obtaining first preprocessed data and second preprocessed data, including the following operations: a. Select VSP seismic data and use zero-bias seismic velocity information to perform dynamic correction processing to obtain seismic data after dynamic correction processing; b. Perform first-arrival removal on the seismic data after the NMO correction processing to obtain VSP seismic data after first-arrival removal, which is recorded as the first preprocessed data; c. Select a suitable time window, perform data removal and corridor superposition on the first preprocessed data, and obtain the second preprocessed data; S2. Extraction of compression processing parameters, including the following operations, d. normalizing the second preprocessed data obtained in step S1 to obtain normalized data; e. performing inversion processing on the obtained normalized data to obtain suppression processing parameters; S3. Multiple Suppression The first pre-processed data in S1 is subjected to compression processing using the compression processing parameters obtained in S2 to obtain final compression result data.

[0007] As a limitation of the present invention: the zero-bias velocity information described in step S1a refers to the first arrival parameters and well-source distance parameters picked up using the original data, which are calculated based on Geoeast software; The dynamic correction processing described in step a of step S1 refers to the process of correcting the original one-way time profile to a two-way time profile.

[0008] As another limitation of the present invention: the selection of a suitable time window in step S1 c means that the excision position needs to retain a time window range containing multiple waves, that is, the excision position is ≤ 200ms; The data removal described in step S1c refers to removing the data within 200ms from the well point position using the selected time window on the first pre-processed data; The corridor superposition described in step S1 c refers to superimposing the data after excision at the same time. After the data is superimposed, the same number of channels as the first pre-processed data are copied and generated.

[0009] As another limitation of the present invention: the normalization processing described in step S2d refers to taking out the maximum value in the data and dividing the second pre-processed data by the maximum value to obtain normalized processed data; The inversion processing described in step S2e refers to subtracting the normalized processing data from 1 to obtain the inversion processed data, which is the suppression processing parameter.

[0010] As another limitation of the present invention: the pressing process described in step S3 includes two steps, specifically: f. The first step is a multiplication operation. In step S1, the first preprocessed data is processed with the suppression processing parameters obtained in step S2 for different depths to obtain the first step of the suppression processing data; g. The second step is a subtraction operation, which uses the first pre-processed data to subtract the first step of the compression processing data in f to obtain the final compression result data.

[0011] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: The present invention performs multiple wave suppression processing on VSP seismic data. VSP, namely Vertical Seismic Profile, is a seismic observation method. Vertical profile is relative to ground seismic profile. This method observes seismic wave fields in a well and places seismic detectors at different depths in the well to record seismic signals generated by ground sources. Therefore, VSP has higher signal-to-noise ratio and resolution than conventional ground seismic methods and is widely used. In addition, the VSP method can simultaneously observe downgoing waves and upgoing waves of multiple waves, which has unique advantages in tracking the occurrence and propagation of multiple waves. The present invention preprocesses the VSP data to obtain first preprocessed data and second preprocessed data in sequence; then normalizes and inverts the second preprocessed data to obtain suppression processing parameters; finally, suppresses the first preprocessed data using the suppression processing parameters to obtain final suppression result data; the suppression data obtained by the method is compared with simulated seismic data without multiple waves, and the two have a high degree of consistency, which proves that the method has a good multiple wave suppression effect and improves the signal-to-noise ratio and fidelity of the seismic data.

[0012] In summary, the present invention can reduce the noise in seismic data and has a higher degree of consistency with seismic data without multiple waves, which proves that this embodiment has a good multiple wave suppression effect, improves the signal-to-noise ratio and fidelity of the data, and has higher reliability. It is suitable for seismic data processing and is used to efficiently and intelligently suppress multiple waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 The seismic data after the simulated VSP dynamic correction processing in the embodiment of the present invention; Figure 2 is the first pre-processed data in the embodiment of the present invention; Figure 3 The second pre-processed data in the embodiment of the present invention; Figure 4 The first step of data compression processing in the embodiment of the present invention; Figure 5 The second step data is compressed and processed in the embodiment of the present invention; Figure 6This is simulation data without multiple waves in the embodiment of the present invention. DETAILED DESCRIPTION

[0015] The preferred embodiment of the present invention is described below in conjunction with the accompanying drawings. It should be understood that the multiple wave intelligent suppression method described here is a preferred embodiment, which is only used to illustrate and explain the present invention and does not constitute a limitation of the present invention.

[0016] Embodiment A multiple wave intelligent suppression method This embodiment is a multiple wave intelligent suppression method, including data preprocessing, suppression parameter extraction, and multiple wave suppression. It can realize efficient and intelligent multiple wave suppression, and provide a new technical means for seismic data fidelity processing. The embodiment will be further described in detail below in conjunction with the accompanying drawings. It should be noted that: Figure 1 to Figure 6 The horizontal coordinates are all depths, in meters; the vertical coordinates are all time, in milliseconds.

[0017] The specific method of this embodiment is: S1. Data Preprocessing Select VSP seismic data that need to be subjected to multiple wave suppression, and perform preprocessing according to the following operations a to c to obtain first and second preprocessed data after preprocessing; a. For the selected VSP seismic data, use the zero-bias seismic velocity information to perform dynamic correction processing to obtain the seismic data after dynamic correction processing, see Figure 1 ; Among them, zero-bias seismic velocity information refers to the parameters such as first arrival and well-source distance picked up by raw data, which are calculated based on the existing Geoeast software; Dynamic correction processing is a conventional processing step of VSP processing, which refers to the process of correcting the original one-way time profile to a two-way time profile.

[0018] In particular, the selected VSP seismic data may be single-component data or one of three-component data; at the same time, it may be data before amplitude or frequency compensation or data after corresponding compensation.

[0019] b. Perform first-arrival removal on the seismic data after the dynamic correction processing obtained in operation a to obtain the VSP seismic data after the first-arrival removal, which is recorded as the first preprocessed data, see Figure 2 ; c. Select a suitable time window, perform data removal and corridor superposition on the first preprocessed data obtained in operation b, and obtain the second preprocessed data, see Figure 3 ; Among them, when selecting a suitable time window, the excision position needs to retain the time window range containing multiple waves, which is usually no more than 200ms; Data excision refers to using the selected time window to excise the data within 200ms from the well point location on the first preprocessed data.

[0020] Corridor superposition refers to superimposing the above-mentioned excised data at the same time. Different from the conventional corridor superposition, after the data is superimposed, this embodiment duplicates and generates the same number of channels as the first pre-processed data.

[0021] S2. Extraction of compression processing parameters Performing mathematical calculation on the second pre-processed data in step S1 to obtain the compression processing parameters specifically includes the following operations: d. normalizing the second preprocessed data, specifically: taking out the maximum value in the data, and dividing the second preprocessed data by the maximum value to obtain normalized data; e. Perform inversion processing on the obtained normalized data, specifically: subtract the normalized data in operation d from 1 to obtain the inverted data, which is the suppression processing parameter required in this embodiment.

[0022] S3. Multiple wave intelligent suppression Using the compression processing parameters obtained in step S2, the first pre-processed data in step S1 is compressed to obtain the final intelligent compression result data, which specifically includes the following operations: f. The first step of the suppression process is a multiplication operation: on the first preprocessed data in step S1, the suppression process parameters obtained in step S2 are used for different depths to obtain the first step of the suppression process data, see Figure 4 ; g. The second step of the suppression process is a subtraction operation. The first step of the suppression process data in operation f is subtracted from the first preprocessed data to obtain the first step of the suppression process data, which is the final intelligent suppression result data, see Figure 5 .

[0023] Figure 6 The data obtained by direct simulation without multiple waves is different from the data obtained in this embodiment. Figure 5 In comparison, the suppression method of the present invention can reduce the noise in the seismic data and has a higher degree of consistency with the seismic data without multiple waves, which proves that this embodiment has a good multiple wave suppression effect, improves the signal-to-noise ratio and fidelity of the data, and has higher reliability.

[0024] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A multiple wave intelligent suppression method, characterized in that: The following steps are involved: S1. Data preprocessing, obtaining first preprocessed data and second preprocessed data, including the following operations: a. Select VSP seismic data and use zero-bias seismic velocity information to perform dynamic correction processing to obtain seismic data after dynamic correction processing; b. Perform first-arrival removal on the seismic data after the NMO correction processing to obtain VSP seismic data after first-arrival removal, which is recorded as the first preprocessed data; c. Select a suitable time window, perform data removal and corridor superposition on the first preprocessed data, and obtain the second preprocessed data; S2. Extraction of compression processing parameters, including the following operations, d. normalizing the second preprocessed data obtained in step S1 to obtain normalized data; e. performing inversion processing on the obtained normalized data to obtain suppression processing parameters; S3. Multiple Suppression The first pre-processed data in S1 is subjected to compression processing using the compression processing parameters obtained in S2 to obtain final compression result data.

2. The multiple wave intelligent suppression method according to claim 1, characterized in that: The zero-bias velocity information described in step S1a refers to the first arrival parameters and well-source distance parameters picked up using the original data, which are calculated based on Geoeast software; The dynamic correction processing described in step a of step S1 refers to the process of correcting the original one-way time profile to a two-way time profile.

3. The multiple wave intelligent suppression method according to claim 1, characterized in that: The selection of a suitable time window in step S1 c means that the excision position needs to retain a time window range containing multiple waves, that is, the excision position is ≤ 200ms; The data removal described in step S1c refers to removing the data within 200ms from the well point position using the selected time window on the first pre-processed data; The corridor superposition described in step S1 c refers to superimposing the data after excision at the same time. After the data is superimposed, the same number of channels as the first pre-processed data are copied and generated.

4. The multiple wave intelligent suppression method according to claim 1, characterized in that: The normalization processing described in step S2d refers to taking out the maximum value in the data and dividing the second pre-processed data by the maximum value to obtain normalized processed data; The inversion processing described in step S2e refers to subtracting the normalized processing data from 1 to obtain the inversion processed data, which is the suppression processing parameter.

5. The multiple wave intelligent suppression method according to claim 1, characterized in that: The pressing process described in step S3 includes two steps, specifically: f. The first step is a multiplication operation. In step S1, the first preprocessed data is processed with the suppression processing parameters obtained in step S2 for different depths to obtain the first step of the suppression processing data; g. The second step is a subtraction operation, which uses the first pre-processed data to subtract the first step of the compression processing data in f to obtain the final compression result data.

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