A multiple wave intelligent suppression method

Abstract

The application discloses a multiple wave intelligent suppression method, comprising the following steps: S1, data preprocessing: using zero offset seismic velocity information to carry out dynamic correction processing on VSP seismic data, obtaining seismic data after dynamic correction processing, then cutting off the first arrival of the data, obtaining first preprocessing data; then selecting a time window, cutting off the data and carrying out corridor stacking on the first preprocessing data, obtaining second preprocessing data; S2, normalizing and inverting the second preprocessing data, obtaining suppression processing parameters; S3, using the suppression processing parameters to carry out suppression processing on the first preprocessing data, obtaining final suppression data. The application can greatly reduce the multiple wave noise component in the seismic data, and the seismic data without multiple waves has higher coincidence degree, which proves that the embodiment has good multiple wave suppression effect, improves the signal-to-noise ratio and fidelity of the data, has higher reliability, and is suitable for efficiently and intelligently suppressing multiple waves 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] Multiples are interference waves present in seismic waves. They arise when certain reflective interfaces with large reflection coefficients, either on the surface or underground, cause the primary reflected wave to bounce back underground. Therefore, to improve the signal-to-noise ratio and fidelity, multiples must be suppressed after acquiring 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, and calculates a deconvolution operator in the frequency and slowness domain to further deconvolve and suppress the multiple waves; 3. Doicin et al. proposed a specific micro-bend multiple wave attenuation method, which uses spatial matrix filtering in the fx domain to obtain the model of the multiple waves.

[0004] Most of the aforementioned wave suppression methods use surface seismic data to extract suppression parameters. However, the data obtained from this method is subject to uncertainty, which can lead to errors and affect the suppression effect. For some complex seismic data, multiple waves and noise may not be effectively suppressed. Furthermore, the effectiveness of multiple wave suppression methods using surface seismic data is also susceptible to underground geological conditions. For example, the complexity and heterogeneity of the underground medium, as well as the presence of geological structures such as interfaces and faults, can affect the suppression effect and accuracy of multiple wave suppression methods. Summary of the Invention

[0005] To address the above deficiencies in the prior art, the present invention aims to provide a method for intelligent multiple wave suppression, so as to achieve the purpose of efficient and intelligent multiple wave suppression and fidelity processing of seismic data.

[0006] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0007] A multiple wave intelligent suppression method comprises the following steps:

[0008] S1. Data preprocessing, obtaining first preprocessed data and second preprocessed data, including the following operations:

[0009] a. Select VSP seismic data and perform dynamic correction processing using zero-bias seismic velocity information to obtain seismic data after dynamic correction processing;

[0010] b. Perform first-arrival removal on the seismic data after the NMO processing to obtain VSP seismic data after first-arrival removal, recorded as the first preprocessed data;

[0011] c. Select an appropriate time window, perform data removal and corridor superposition on the first preprocessed data to obtain the second preprocessed data;

[0012] S2. Extraction of compression processing parameters, including the following operations,

[0013] d. normalizing the second preprocessed data obtained in step S1 to obtain normalized data;

[0014] e. performing inversion processing on the obtained normalized data to obtain the suppression processing parameters;

[0015] S3. Multiple Suppression

[0016] 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.

[0017] As a limitation of the present invention: the zero-bias velocity information 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;

[0018] The dynamic correction processing described in step S1a refers to the process of correcting the original one-way time profile to a two-way time profile.

[0019] 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;

[0020] The data excision in step S1 c refers to excision of data within 200ms from the well point position using the selected time window on the first pre-processed data;

[0021] The corridor superposition described in step S1 c refers to superimposing the resected data at the same time. After the data is superimposed, the same number of channels as the first pre-processed data are generated by duplication.

[0022] As another limitation of the present invention: the normalization processing described in step S2 d refers to extracting the maximum value in the data and dividing the second pre-processed data by the maximum value to obtain normalized data;

[0023] 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.

[0024] As another limitation of the present invention, the pressing process in step S3 includes two steps, specifically:

[0025] f. The first step is a multiplication operation. In step S1, the first preprocessed data is processed at different depths using the suppression processing parameters obtained in step S2 to obtain the first step of the suppression processing data;

[0026] 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.

[0027] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0028] The present invention performs multiple wave suppression processing on VSP seismic data. VSP, or Vertical Seismic Profile, is a seismic observation method. Vertical profile refers to the surface seismic profile. This method observes the seismic wave field in a well, placing seismic detectors at different depths in the well to record the seismic signals generated by the surface source. Therefore, VSP has a higher signal-to-noise ratio and resolution than conventional surface seismic methods and is widely used. In addition, the VSP method can simultaneously observe the downgoing and upgoing waves of multiple waves, which has a unique advantage in tracking the occurrence and propagation of multiple waves.

[0029] The present invention preprocesses VSP data to obtain first preprocessed data and second preprocessed data; 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 suppressed data obtained by this method are compared with simulated seismic data without multiple waves, and the two have a high degree of consistency, which proves that the present method has a good multiple wave suppression effect and improves the signal-to-noise ratio and fidelity of the seismic data.

[0030] In summary, the present invention can reduce the noise in seismic data and achieve a higher degree of consistency with seismic data without multiple waves, proving 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 use in seismic data processing for efficient and intelligent multiple wave suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 This is the seismic data after the simulated VSP dynamic correction processing in the embodiment of the present invention;

[0033] Figure 2 is the first pre-processed data in an embodiment of the present invention;

[0034] Figure 3 is the second pre-processed data in the embodiment of the present invention;

[0035] Figure 4 The first step of data compression processing in the embodiment of the present invention;

[0036] Figure 5 The second step data is compressed and processed in the embodiment of the present invention;

[0037] Figure 6 This is simulation data without multiple waves in the embodiment of the present invention. DETAILED DESCRIPTION

[0038] The preferred embodiment of the present invention is described below with reference to the accompanying drawings. It should be understood that the multiple wave intelligent suppression method described herein 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.

[0039] Embodiment A multiple wave intelligent suppression method

[0040] This embodiment is a method for intelligent multiple suppression, including three steps: data preprocessing, suppression parameter extraction, and multiple suppression. This method realizes efficient and intelligent multiple suppression, and provides a new technical means for seismic data fidelity processing. This embodiment will be further described in detail below with reference to the accompanying drawings. It should be noted that: Figures 1 to 6 The horizontal coordinates are all depths, in meters; the vertical coordinates are all time, in milliseconds.

[0041] The specific method of this embodiment is:

[0042] S1. Data Preprocessing

[0043] 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;

[0044] a. Using the zero-bias seismic velocity information, the selected VSP seismic data is subjected to dynamic correction to obtain the seismic data after dynamic correction. Figure 1 ;

[0045] Among them, zero-bias seismic velocity information refers to parameters such as first arrival and well-source distance picked up from the original data, which are calculated based on the existing Geoeast software;

[0046] Dynamic correction processing is a conventional processing step in VSP processing, which refers to the process of correcting the original one-way time profile to a two-way time profile.

[0047] In particular, the selected VSP seismic data may be single-component data or one component of three-component data; and may be data before amplitude or frequency compensation or data after corresponding compensation.

[0048] b. Perform first-arrival removal on the seismic data after the dynamic correction obtained in operation a to obtain the VSP seismic data after first-arrival removal, which is recorded as the first preprocessed data. Figure 2 ;

[0049] c. Select an appropriate time window, perform data removal and corridor superposition on the first pre-processed data obtained in operation b, and obtain the second pre-processed data. Figure 3 ;

[0050] 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;

[0051] 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.

[0052] Corridor superposition refers to the simultaneous superposition of the above-mentioned excised data. Different from conventional corridor superposition, after the data is superimposed, this embodiment duplicates and generates the same number of channels as the first pre-processed data.

[0053] S2. Extraction of compression processing parameters

[0054] Performing mathematical calculations on the second pre-processed data in step S1 to obtain compression processing parameters specifically includes the following operations:

[0055] d. normalizing the second preprocessed data, specifically: extracting the maximum value in the data and dividing the second preprocessed data by the maximum value to obtain normalized data;

[0056] 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.

[0057] S3. Multiple wave intelligent suppression

[0058] The first pre-processed data in step S1 is subjected to compression processing using the compression processing parameters obtained in step S2 to obtain final intelligent compression result data, which specifically includes the following operations:

[0059] f. The first step of the suppression process is a multiplication operation: In step S1, the first preprocessed data is processed at different depths using the suppression processing parameters obtained in step S2 to obtain the first step of the suppression process data, see Figure 4;

[0060] g. The second step of the suppression process is a subtraction operation. The first pre-processed data is subtracted from the first step of the suppression process in operation f to obtain the first step of the suppression process data, which is the final intelligent suppression result data. See Figure 5 .

[0061] Figure 6 The data obtained by direct simulation does not contain multiple waves, which 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.

[0062] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection 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 perform dynamic correction processing using zero-bias seismic velocity information to obtain seismic data after dynamic correction processing; b. Perform first-arrival removal on the seismic data after NMO processing to obtain VSP seismic data after first-arrival removal, recorded as the first preprocessed data; c. Select an appropriate time window, perform data removal and corridor superposition on the first preprocessed data to 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 the suppression processing parameters; S3. Multiple Suppression Using the compression processing parameters obtained in S2, the first pre-processed data in S1 is compressed to obtain final compression result data; 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 at different depths using the suppression processing parameters obtained in step S2 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.

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 S1a 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 excision in step S1 c refers to excision of 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 resected data at the same time. After the data is superimposed, the same number of channels as the first pre-processed data are generated by duplication.

4. The multiple wave intelligent suppression method according to claim 1, characterized in that: The normalization processing described in step S2d refers to extracting the maximum value in the data and dividing the second pre-processed data by the maximum value to obtain normalized 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.

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