Radial domain common offset common azimuth gather method, system, device and readable storage medium

Abstract

The application provides a method, system, device and readable storage medium for obtaining radial domain common offset common azimuth gather, the method sorts seismic data into CMP gathers, then respectively performs static correction, dynamic correction and cutting, and corrects to a fixed reference surface; taking the CMP point of the obtained CMP gather as a center, azimuth is distributed along the circumference at equal angles, and offset is distributed along the azimuth direction at equal intervals in the radial direction; respectively performing inverse dynamic correction and inverse static correction on the obtained radial domain CMP gather, and correcting to a CMP surface, collecting seismic traces with the same offset and azimuth in all gathers in the obtained gather, and composing a radial domain common offset common azimuth gather, the system respectively implements the above steps, and can obtain equal-interval azimuth and equal-interval offset arrangement, so that the observation system becomes very regular.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of seismic data processing, and particularly relates to a method, system and device for obtaining a radial domain common offset common azimuth gather and a readable storage medium. BACKGROUND

[0002] Compared with conventional seismic data, wide-azimuth and high-density seismic acquisition data have a wider and more uniform distribution range of azimuth and offset.

[0003] In recent years, the OVT (offset vector tile, also known as common offset common azimuth domain or offset vector tile) technology is widely used, which can effectively retain the azimuth information in the processing process, can solve the problem of azimuth anisotropy caused by wide-azimuth observation, is conducive to improving the accuracy of seismic imaging, and is conducive to carrying out fracture reservoir prediction.

[0004] However, the OVT technology still has some defects and shortcomings, mainly in that the offset and azimuth distribution of the OVT domain gather is irregular, and the offset and azimuth need to be combined manually after migration, which brings inconvenience to subsequent processing. SUMMARY

[0005] In view of the problems in the prior art, the application provides a method, system and device for obtaining a radial domain common offset common azimuth gather and a readable storage medium, which can obtain equidistant azimuth and equidistant offset arrangement, so that the observation system becomes very regular.

[0006] The application is achieved by the following technical solutions:

[0007] A method for obtaining a radial domain common offset common azimuth gather, comprising the following steps:

[0008] S1: sorting the seismic data into a CMP gather, then performing static correction, dynamic correction and cutting, and correcting to a fixed reference surface;

[0009] S2: taking the CMP point of the CMP gather obtained in S1 as the center, and arranging the azimuth along the circumference at equal angles and arranging the offset along the azimuth direction at equal intervals radially;

[0010] S3: The radial domain CMP gathers obtained in S2 are respectively deconvolved and de-static corrected, and corrected to the CMP surface, and the seismic traces with the same offset distance and azimuth angle in all the gathers obtained are collected to form the radial domain common offset common azimuth angle gathers.

[0011] Preferably, the number of the azimuth angles in S2 is equal to the quotient of 360 and the azimuth angle interval.

[0012] Further, the number of the offset distances in S2 is equal to the quotient of the maximum offset distance and the offset distance interval.

[0013] Preferably, the specific method of S2 is as follows:

[0014] The CMP gathers obtained in S1 are subjected to five-dimensional matching pursuit Fourier interpolation to obtain the interpolated radial domain CMP gathers.

[0015] A system for obtaining radial domain common offset common azimuth angle gathers comprises a seismic data preprocessing module, a seismic data reconstruction module and an obtaining module, wherein:

[0016] The seismic data preprocessing module is used for sorting the seismic data into CMP gathers, and then performing static correction, dynamic correction and cutting, and correcting to a fixed reference surface;

[0017] The seismic data reconstruction module is used for taking the CMP gathers output by the seismic data preprocessing module as input, and taking the following results as expected output:

[0018] The CMP points of the CMP gathers output by the seismic data preprocessing module are the centers of the circles, the azimuth angles are distributed along the circumference at equal angles, and the offset distances are radially distributed at equal intervals along the azimuth angle direction to obtain the reconstructed radial domain CMP gathers;

[0019] The obtaining module is used for respectively deconvolving and de-static correcting the reconstructed radial domain CMP gathers, correcting to the CMP surface, and collecting the seismic traces with the same offset distance and azimuth angle in all the obtained gathers to form the radial domain common offset common azimuth angle gathers.

[0020] Further, it further comprises a radial domain design module, and the seismic data reconstruction module takes the design scheme of the radial domain design module as expected output.

[0021] Further, the seismic data preprocessing module applies five-dimensional matching pursuit Fourier interpolation technology to reconstruct the CMP gathers output by the seismic data preprocessing module to obtain the reconstructed radial domain CMP gathers.

[0022] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method for obtaining radial domain common offset common azimuth gather according to any one of the above when executing the computer program.

[0023] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method for obtaining radial domain common offset common azimuth gather according to any one of the above.

[0024] Compared with the prior art, the present application has the following beneficial technical effects:

[0025] The method for obtaining common offset common azimuth data provided by the present application is based on the radial domain common offset common azimuth data regularization (abbreviated as Radial interpolation) technology to provide a basis for utilizing pre-stack azimuth information to the greatest extent. Firstly, the seismic data is preprocessed, that is, the CMP gathers are selected, then static correction, dynamic correction and cutting are performed, and the CMP points of the obtained CMP gathers are corrected to a fixed reference surface, then the CMP points of the obtained CMP gathers are taken as the centers, reasonable radial domain data positions are designed, the azimuth and offset of the seismic data are divided into equal parts, and are placed on the designed radial domain positions to obtain a new rearranged CMP gather, finally, the new CMP gather is subjected to inverse dynamic correction and inverse static correction to be corrected to the CMP surface, the seismic traces with the same offset and azimuth on all gathers are collected to form a new gather, and the radial domain common offset common azimuth gather is obtained. The radial domain common offset common azimuth data regularization technology is used to design the observation point positions in the radial domain, a very regular observation system with great difference from the field observation system but with regular offset and azimuth can be obtained through the five-dimensional data regularization technology, and the signal-to-noise ratio is greatly improved, which is the biggest difference from the traditional OVT. The very regular observation system is more advantageous to the processing algorithms which depend on regular offset sampling, such as the random multiple suppression algorithm. Meanwhile, due to the regularity and uniformity of the data, the near trace energy and the far trace energy are balanced, the attribute information of the data is well preserved, and the AVO or AVAZ inversion is easier to perform. In addition, the gather generated by the radial domain common offset common azimuth data regularization technology has unique common offset common azimuth coverage times and unique azimuth, which is more conducive to the execution of some modules based on single coverage data denoising, and can better suppress the acquisition footprints. With the deepening of the research and application of the technology, the technology will become a powerful supplement to the traditional OVT wide-azimuth seismic data processing technology, and better support the oil and gas exploration and development in complex areas.

[0026] The system for obtaining common offset and common azimuth data in the application can sort the seismic data into CMP gathers by the seismic data preprocessing module, and then perform static correction, dynamic correction and cutting, and correct to a fixed reference surface; the seismic data reconstruction module can take the CMP gathers output by the seismic data preprocessing module as input, take the CMP point of the expected output CMP gather as the center of a circle, take the azimuth along the circumference of the circle, take the offset along the azimuth direction, and obtain the radial domain CMP gather after reconstruction; finally, the last obtaining module can perform inverse dynamic correction and inverse static correction on the radial domain CMP gather after reconstruction, correct to the CMP surface, collect the seismic traces with the same offset and azimuth in all gathers, and then form the radial domain common offset and common azimuth gather. The observation system generated by the gather is very regular, which is very beneficial to the application of the subsequent regularized denoising module, and plays an obvious role in suppressing the acquisition footprint. Meanwhile, due to the equal and regular arrangement of the offset, the near trace and far trace information is relatively rich, the attribute information of the seismic data is well preserved, and the AVO or AVAZ inversion is easier to perform. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The flowchart of the method for obtaining the radial domain common offset and common azimuth gather in the application.

[0028] Figure 2a The schematic diagram of the conventional CMP gather arranged according to the offset.

[0029] Figure 2b The schematic diagram of the radial domain common offset and common azimuth gather obtained by the existing method.

[0030] Figure 2c The schematic diagram of the conventional CMP gather and the radial domain common offset and common azimuth gather data superimposed and arranged.

[0031] Figure 3a The schematic diagram of the conventional CMP gather.

[0032] Figure 3b The schematic diagram of the radial domain CMP gather after five-dimensional matching pursuit Fourier interpolation in the application.

[0033] Figure 3c The schematic diagram of the radial domain common offset and common azimuth gather in the application.

[0034] Figure 4a The schematic diagram of the conventional superposition.

[0035] Figure 4b The schematic diagram of the superposition after five-dimensional interpolation in the application.

[0036] Figure 5A structural schematic diagram of a radial domain common offset common azimuth gather system is obtained. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below in combination with the drawings in the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0038] The present application provides a method and system for obtaining a radial domain common offset common azimuth gather, which can obtain equidistant azimuths and equidistant offset arrangements, so that the observation system becomes very regular. The following is described in two aspects:

[0039] In a first aspect, the present application provides a method for obtaining a radial domain common offset common azimuth gather, as shown in the following steps: Figure 1

[0040] In step S101, the seismic data is sorted into CMP gathers, and then corrected to a fixed reference surface after static correction, dynamic correction and cutting.

[0041] In step S102, a reasonable radial domain division scheme is designed according to the actual CMP gathers in the gathers corrected to the fixed reference surface, and the best azimuth interval and offset interval are found. The specific idea is as follows:

[0042] The CMP points in the CMP gathers are taken as the centers, the azimuths are distributed along the circumference at equal angles, and the offsets are radially distributed at equal intervals along the azimuth direction.

[0043] Due to the symmetry of the signal, the seismic traces are only sorted into 0-180° data, and n azimuth data (n=180 / azimuth interval) are obtained. After the offsets are sorted at equal intervals, m offset data (m=maximum offset / offset interval) are obtained.

[0044] In the specific operation, according to the preset radial domain division scheme, five-dimensional matching pursuit Fourier interpolation is performed on each CMP gather in the gathers corrected to the fixed reference surface, to obtain the interpolated radial domain CMP gathers, and the seismic data is arranged in order along the radial domain positions designed in this step.

[0045] In step S103, the interpolated radial domain CMP gathers are respectively subjected to inverse dynamic correction and inverse static correction, to obtain the gathers corrected to the CMP surface. The seismic traces with the same offset and azimuth in all gathers corrected to the CMP surface are combined to form new gathers, to obtain the radial domain common offset common azimuth gathers.​

[0046] The method above designs reasonable radial domain data positions by taking the CMP point as the center, divides the azimuth and offset of the seismic data equally, and places them on the designed radial domain positions to obtain a new rearranged CMP gather. The new CMP gather is corrected to the CMP surface by reverse moveout correction and reverse static correction. The seismic traces with the same offset and azimuth on all gathers are collected to form a new gather to obtain the radial domain common offset and common azimuth gather. The observation system generated by the gather is very regular, which is very beneficial to the application of the subsequent regularized denoising module and plays an obvious role in suppressing the acquisition footprint. In addition, the offset is equally and regularly arranged, the near and far trace information is relatively rich, the attribute information of the seismic data is better preserved, and the AVO or AVAZ inversion is easier to perform. In addition, the radial domain data retains the prestack azimuth information more accurately, which is more beneficial to prestack inversion such as prestack fracture prediction.

[0047] In a second aspect, the present application is a system for obtaining a radial domain common offset and common azimuth gather, as shown in Figure 5 , which comprises:

[0048] A seismic data preprocessing module 11 is configured to sort the seismic data into a CMP gather, perform static correction, moveout correction, and cut-off on the CMP gather, and correct the CMP gather to a fixed reference surface.

[0049] A radial domain design module 12 is configured to design a reasonable radial domain division scheme according to the actual CMP gather, and find the best azimuth interval and offset interval. In this way, the CMP point in the CMP gather is taken as the center, the azimuth is equally distributed along the circumference, and the offset is equally spaced radially along the azimuth direction.

[0050] A seismic data reconstruction module 13 is configured to take the CMP gather output by the seismic data preprocessing module 11 as the input, take the design scheme of the radial domain design module 12 as the expected output, and apply a five-dimensional matching pursuit Fourier interpolation technology to reconstruct each CMP gather.

[0051] An acquisition module 14 is configured to correct the interpolated radial domain CMP gather to the CMP surface by reverse moveout correction and reverse static correction. The seismic traces with the same offset and azimuth on all gathers are collected to form a new gather to obtain the radial domain common offset and common azimuth gather.

[0052] The method for obtaining common offset common azimuth gathers in a radial domain of the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Specifically, it can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0053] Based on such understanding, the method of the present application can also be implemented by instructing relevant hardware through a computer program. The computer program can be stored in a computer readable storage medium. When the computer program is executed by a processor, the method described above can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer readable storage medium includes permanent and non-permanent, removable and non-removable media, and can be implemented by any method or technology. Information can be computer readable instructions, data structure, program modules or other data. The computer storage medium can be any available medium or data storage device that can be accessed by a computer, including but not limited to magnetic storage (such as floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor memory (such as ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid state disk (SSD), etc.).

[0054] The present application also provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method described above are implemented. The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), ready programmable gate arrays (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc.

[0055] Embodiment

[0056] The technical solutions of the method embodiment shown in the above are described in detail below by taking a specific embodiment. Figure 1

[0057] ​This embodiment utilizes actual seismic data, with a shot distance of 250 meters, a receiver distance of 200 meters, and 700 coverage passes (i.e., 25 × 28). The maximum shot-receiver distance is 8850 meters, and the aspect ratio is 0.71.

[0058] First, referring to Figure 2, we will explain the existing methods for obtaining common offset and common azimuth gathers. Figure 2a This is a schematic diagram of a standard CMP gather arranged by offset. Figure 2b This is a schematic diagram, or fan diagram, of a radial domain common offset and common azimuth gather obtained by existing methods. The fan root represents the origin of the gather, and each fan branch represents an azimuth angle. There are 18 fan branches in the range of 5-175 degrees, representing azimuth angle increments of 10 degrees each. Each fan branch has 44 colors, indicating 44 offsets, meaning 44 equally spaced offset increments of 200 meters each. This data is highly regular. Figure 2c This is a schematic diagram showing the overlay of conventional CMP gathers and radial domain co-offset co-azimuth gathers. Considering the symmetry and interchangeability of the signals, only the data arrangement from 5 to 175 degrees is displayed.

[0059] Figure 3a This demonstrates a standard CMP gather. Figure 3b (The image has been rotated vertically for better visibility, but is still described using the original horizontal view.) This illustrates the radial domain CMP gather after five-dimensional matching pursuit Fourier interpolation according to the present invention. Figure 3c (The image has been rotated vertically for better visibility, but is still described using the original horizontal view.) This illustrates the radial domain common offset and common azimuth gather of this invention. Figure 3b The lines arranged periodically up and down on the Tao collection Figure 3c On the trace gather, the straight lines gradually descending from left to right represent the azimuth angle, and the remaining lines represent the offset distance. After five-dimensional matching tracking and Fourier interpolation, the trace gather is first divided into 44 groups with equal intervals according to the offset distance, and then divided into 18 groups with equal intervals according to the azimuth angle. The same offset distance data from 0 to 360 degrees are then grouped together to obtain... Figure 3b This data is more than Figure 3a The signal-to-noise ratio of the conventional CMP gather has been significantly improved. By arranging the data from each fan branch together, a radial domain common offset and common azimuth gather is obtained, such as... Figure 3c .

[0060] Figure 4a (The image has been rotated vertically to make it generally clear, but it is still described using the original horizontal view.) This shows a schematic diagram of a conventional overlay. Figure 4bThe figure shows the schematic diagram of the post-stacking of the five-dimensional interpolation in the radial domain. It can be seen that the post-stacking of the five-dimensional matching pursuit Fourier interpolation has better continuity in the same direction axis, higher signal-to-noise ratio, and better preservation of the characteristics of the fault and other small-scale geological bodies. Moreover, the data is more regular, the near-trace and far-trace data energy is stronger, and the vertical resolution of the radial domain data is higher than that of the original data.

[0061] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application is described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for acquiring common-offset common-azimuth gathers in a radial domain, characterized by, It comprises the following steps: S1: sorting seismic data into CMP gathers, then respectively performing static correction, dynamic correction and cutting, and correcting to a fixed reference surface; S2: taking the CMP point of the CMP gather obtained in S1 as the center, azimuths are distributed equiangularly along the circumference, and offsets are distributed equidistantly along the azimuth direction; S3: respectively performing inverse dynamic correction and inverse static correction on the radial domain CMP gather obtained in S2, and correcting to the CMP surface, collecting seismic traces with the same offset and azimuth on all gathers in the obtained gather, and forming a radial domain common offset common azimuth gather.

2. The method of claim 1, wherein, The number of the azimuths in S2 is equal to the quotient of 360 and the azimuth interval.

3. The method of claim 2, wherein, The number of the offsets in S2 is equal to the quotient of the maximum offset and the offset interval.

4. The method of claim 1, wherein, The specific method of S2 is: Performing five-dimensional matching pursuit Fourier interpolation on the CMP gather obtained in S1 to obtain the interpolated radial domain CMP gather.

5. An acquisition radial domain common offset common azimuth gather system, characterized by, It comprises a seismic data preprocessing module, a seismic data reconstruction module and an acquisition module, wherein: The seismic data preprocessing module is used for sorting seismic data into CMP gathers, then respectively performing static correction, dynamic correction and cutting, and correcting to a fixed reference surface; The seismic data reconstruction module is used for taking the CMP gather output by the seismic data preprocessing module as input, and taking the following results as expected output: The CMP point of the CMP gather output by the seismic data preprocessing module is taken as the center, azimuths are distributed equiangularly along the circumference, and offsets are distributed equidistantly along the azimuth direction, to obtain the reconstructed radial domain CMP gather; The acquisition module is used for respectively performing inverse dynamic correction and inverse static correction on the reconstructed radial domain CMP gather, and correcting to the CMP surface, collecting seismic traces with the same offset and azimuth on all gathers in the obtained gather, and forming a radial domain common offset common azimuth gather.

6. The acquiring radial domain common-midpoint common-azimuth gather system of claim 5, wherein, It further comprises a radial domain design module, and the seismic data reconstruction module takes the design scheme of the radial domain design module as expected output.

7. The acquiring radial domain common-midpoint common-azimuth gather system of claim 5, wherein, The seismic data preprocessing module applies five-dimensional matching pursuit Fourier interpolation technology to reconstruct the CMP gather output by the seismic data preprocessing module, to obtain the reconstructed radial domain CMP gather.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the method for acquiring a radial domain common offset common azimuth gather according to any one of claims 1-4.

9. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 8. The computer program is executed by the processor to realize the method for acquiring a radial domain common offset common azimuth gather according to any one of claims 1-4.

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