A method and apparatus for land surface multiple suppression

Abstract

The application discloses a land surface multiple wave suppression method and device, and belongs to the technical field of oil exploration. The application uses the data of the shot point and the receiver point static correction amount as the SRME input data, uses the total static correction amount of the shot point and the receiver point to carry out internal interpolation processing time difference correction, and thus carries out the relief surface multiple wave prediction. The land surface multiple wave suppression method and device provided by the application uses the static correction amount of the shot point and the receiver point, places the shot point and the receiver point on the real surface, restores the real travel time of the seismic wave, uses the total static correction amount of the shot point and the receiver point for internal regularization of the SRME, improves the precision of the surface multiple wave prediction model, and thus achieves the purpose of better suppressing the surface multiple wave, and is suitable for the relief surface multiple wave suppression.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum exploration and relates to a surface multiple wave suppression method, in particular to a land surface multiple wave suppression method and device. Background Art

[0002] Surface multiples are not only present in marine seismic data but are also widely developed in terrestrial seismic data. They severely degrade seismic data quality and are a major challenge in seismic data processing. Currently, SRME technology is commonly used to suppress surface multiples.

[0003] SRME technology uses seismic data to predict surface-related multiples through two-dimensional convolution in the spatiotemporal domain. These predicted multiples are then subtracted through adaptive subtraction to achieve surface-related multiple suppression. SRME was first applied to ocean streamer data. It assumes that the shot and receiver points are in the same horizontal plane. Therefore, during internal regularization, the time difference between the target and borrowed seismic traces is primarily the moving average time difference caused by offset differences, which can be corrected by velocity calculation. However, due to surface fluctuations or near-surface velocity variations in terrestrial seismic data, this condition cannot be met. The current solution is to first apply the data to a smooth CMP reference surface before predicting surface multiples. This approach overcomes the aforementioned issues, but the application of high-frequency statics disrupts the true traveltime relationship, resulting in significant errors between the predicted surface multiples and the reflection times of the surface multiples in the data. This time difference is difficult to fully resolve through subsequent adaptive subtraction, affecting the effectiveness of surface multiple suppression. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for suppressing land surface multiple waves, so as to solve the problems of low prediction accuracy and poor suppression effect of land surface multiple waves in seismic data.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A land surface multiple suppression method uses the static correction data of shot points and receiver points as SRME input data, and uses the total static correction data of shot points and receiver points to perform internal interpolation processing and time difference correction, thereby predicting surface multiple waves.

[0007] As a limitation, the following steps are included:

[0008] S1. After the seismic data has been processed with static correction and noise suppression, the static correction values ​​are used to form a gather.

[0009] S2. The total static correction values ​​of the shot points and the receiver points are combined, interpolated and encrypted, and together with the coordinates of the shot points and the receiver points, form a total static correction value library of the shot points and the receiver points;

[0010] S3. Input the gathers and total statics database, use SRME to predict surface multiples, and form a surface multiple model.

[0011] The total static correction database is used for internal regularized time difference correction;

[0012] S4. After the seismic data is processed by static correction and noise suppression, the surface multiple wave model is adaptively subtracted after static correction to obtain the seismic data with suppressed surface multiple waves.

[0013] As a further limitation, the static correction includes a reference plane static correction and a surface consistency residual static correction; and the static correction amount includes a reference plane static correction amount and a surface consistency residual static correction amount.

[0014] As a further limitation, the total static correction is the accumulation of the reference static correction and the surface consistency residual static correction.

[0015] The present invention also provides a land surface multiple wave suppression device, comprising:

[0016] Seismic data processing module, used to convert seismic data after static correction and noise suppression processing into static correction values ​​to form gathers;

[0017] The total static correction value library acquisition module is used to merge, interpolate and encrypt the total static correction values ​​of the shot point and the receiver point, and form the total static correction value library of the shot point and the receiver point together with the coordinates of the shot point and the receiver point;

[0018] The surface multiple wave model acquisition module is used to input the gathers and total static correction database, use SRME to predict the surface multiple waves, and form a surface multiple wave model;

[0019] The surface multiple wave suppression module is used to adaptively subtract the statically corrected seismic data from the surface multiple wave model to obtain seismic data with suppressed surface multiple waves.

[0020] Due to the adoption of the above technical solution, the present invention has the following technical advancements compared with the prior art:

[0021] The present invention provides a land surface multiple wave suppression method and device. By using the static correction values ​​of shot points and receiver points, the shot points and receiver points are placed on the actual ground surface to restore the actual travel time of the seismic waves. The total static correction values ​​of the shot points and receiver points are interpolated and encrypted, and applied to the internal regularization of the SRME, thereby improving the accuracy of the surface multiple wave prediction model, thereby achieving the purpose of better suppressing surface multiple waves. The method and device are suitable for suppressing surface multiple waves on undulating surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a flow chart in the embodiment, wherein: Figure 1 a is the flowchart of the current land surface multiple wave suppression scheme. Figure 1 b is a flowchart of the technical solution of the present invention;

[0023] Figure 2 This is a diagram showing the forward simulation data preprocessing results in the embodiment, where: Figure 2 a is the input forward simulation data, Figure 2 b is the data after static correction and noise suppression processing, Figure 2 c is the data of static correction for reaction;

[0024] Figure 3 is the total static correction curve in the embodiment, where: Figure 3 a is the total static correction curve of the shot point, Figure 3 b is the total static correction curve of the detection point, Figure 3 c is the total static correction curve after interpolation and encryption;

[0025] Figure 4 is the surface multiple wave model predicted by SRME in the embodiment;

[0026] Figure 5 The static correction processing result of the surface multiple wave model in the embodiment is applied;

[0027] Figure 6 This is the result of suppressing surface multiple waves in the embodiment;

[0028] Figure 7 This is a comparison of the surface multiple wave models predicted by the two schemes in the embodiment, where: Figure 7 a and Figure 7 b are the input data of the current land surface multiple wave suppression scheme and the predicted surface multiple wave model, Figure 7 c and Figure 7 d are the input data and the predicted surface multiple wave model of the technical solution of the present invention respectively. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below by way of specific examples. It should be understood that the described examples are only used to illustrate the present invention and are not intended to limit the present invention.

[0030] Embodiment A method and device for suppressing multiple waves on land surface

[0031] This embodiment provides a land surface multiple wave suppression method, which is tested by applying forward modeling data of undulating surface. The flow chart is as follows: Figure 1 b, and is consistent with the current land surface multiple wave suppression scheme (flow chart as shown in Figure 1 a) were compared with Figure 1It can be seen that the technical solution of the present invention has a significant difference in the processing method flow compared with the prior art. The specific operating steps of the technical solution of the present invention are as follows:

[0032] S1. The forward modeling data of the undulating surface (such as Figure 2 (a) Perform datum static correction, surface consistency residual static correction and noise suppression iterative processing, focusing on suppressing the first arrival wave interference. The data processing results are shown in Figure 2 As shown in b;

[0033] S2. Use the reference static correction amount of the shot point and the residual static correction amount of the surface consistency to restore the shot point to the surface. Use the reference static correction amount of the receiver point and the residual static correction amount of the surface consistency to restore the receiver point to the surface to form a gather. The data processing result is as follows: Figure 2 As shown in c;

[0034] S3. The reference static correction amount and the residual static correction amount of the surface consistency of the shot point are accumulated together to form the total static correction amount of the shot point, and the reference static correction amount and the residual static correction amount of the surface consistency of the receiver point are accumulated together to form the total static correction amount of the receiver point;

[0035] S4. Combine the total static correction values ​​of the shot points and receiver points, interpolate and encrypt them, and use the grid as a plane with the size of the processing bin (the total static correction curve is as follows Figure 3 As shown in the figure), the coordinates of the shot and receiver points are put into the database to form the total static correction database of the shot and receiver points.

[0036] S5. Input the gathers formed in step S2, call the total static correction library formed in step S4, and use SRME to predict surface multiple waves. The total static correction library is used for internal regularized moveout correction to form a surface multiple wave model, such as Figure 4 As shown;

[0037] S6. Apply the base surface static corrections of the shot points, receiver points and surface consistency residual static corrections to the surface multiple wave model formed in step S5 to the CMP reference surface, such as Figure 5 As shown;

[0038] S7. The seismic data processed in step S1 and the surface multiple wave model processed in step S6 are sorted into shot gather data and adaptively subtracted to obtain seismic data with suppressed surface multiple waves, such as Figure 6 shown.

[0039] According to the current land surface multiple wave suppression scheme (flow chart as shown in the figure Figure 1 a) and the technical solution of the present invention (flow chart as shown in Figure 1 b) respectively process the forward modeling data of the undulating surface, and the processing results are as follows Figure 7As shown, the figure shows the common offset section;

[0040] Depend on Figure 7 By comparison, it can be seen that the surface multiple wave model predicted by the technical solution of the present invention is consistent with the multiple wave time in the forward simulation data and the morphology is basically the same; while the surface multiple wave model predicted by the current land surface multiple wave suppression solution is very different from the forward simulation data in locations with large surface undulations.

[0041] This embodiment also provides a land surface multiple wave suppression device, comprising:

[0042] A seismic data processing module is used to apply static correction values ​​to seismic data that have undergone static correction and noise suppression processing to form a gather;

[0043] The total static correction value library acquisition module is used to merge, interpolate and encrypt the total static correction values ​​of the shot point and the receiver point, and form the total static correction value library together with the coordinates of the shot point and the receiver point;

[0044] The surface multiple wave model acquisition module is used to input the gathers and total static correction database, use SRME to predict the surface multiple waves, and form a surface multiple wave model;

[0045] The surface multiple wave suppression module is used to adaptively subtract the statically corrected seismic data from the surface multiple wave model to obtain seismic data with suppressed surface multiple waves.

Claims

1. A land surface multiple wave suppression method, characterized in that: The following steps are involved: S1. After the seismic data has been processed with static correction and noise suppression, the static correction values ​​are used to form a gather. The static correction includes reference plane static correction and surface consistency residual static correction; the static correction amount includes reference plane static correction amount and surface consistency residual static correction amount; S2. The total static correction values ​​of the shot points and the receiver points are combined, interpolated and encrypted, and together with the coordinates of the shot points and the receiver points, form a total static correction value library of the shot points and the receiver points; The total static correction is the sum of the reference static correction and the surface consistency residual static correction; The total static correction database is used for internal regularized time difference correction; S3. Input the gathers and total statics database, use SRME to predict surface multiples, and form a surface multiple model. S4. After the seismic data is processed by static correction and noise suppression, the surface multiple wave model is adaptively subtracted after static correction to obtain the seismic data with suppressed surface multiple waves.

2. A land surface multiple wave suppression device, used to implement the land surface multiple wave suppression method according to claim 1, characterized in that: include: Seismic data processing module, used to convert seismic data after static correction and noise suppression processing into static correction values ​​to form gathers; The total static correction value library acquisition module is used to merge, interpolate and encrypt the total static correction values ​​of the shot point and the receiver point, and form the total static correction value library of the shot point and the receiver point together with the coordinates of the shot point and the receiver point; The surface multiple wave model acquisition module is used to input the gathers and total static correction database, use SRME to predict the surface multiple waves, and form a surface multiple wave model; The surface multiple wave suppression module is used to adaptively subtract the statically corrected seismic data from the surface multiple wave model to obtain seismic data with suppressed surface multiple waves.

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