A method and device for suppressing boundary offset noise based on offset distance statistics sorting

Abstract

The present disclosure relates to a boundary offset noise suppression method and device based on offset statistical sorting, including: performing offset data scanning on the acquired CMP gather, statistically obtaining each CMP number and its corresponding offset information, and forming a CMP gather offset information library; performing pre-stack migration processing on the CMP gather to obtain a migrated CRP gather; performing offset data scanning on the CRP gather, statistically obtaining each CRP number and its corresponding offset information, and forming a CRP gather offset information library; using the CRP gather offset information library to sort the CMP gather offset information library to obtain a CRP gather within the offset distribution range of the CMP gather. This is to solve the problem that due to the offset distribution range of the CMP gather at the boundary being smaller than the established offset output range of the CRP gather, there is a lack of offset data during offset integral summation, resulting in the phenomenon of "arc drawing" in the boundary offset after stacking. In the past, the spatial interpolation method used for "arc drawing" during migration was not conducive to amplitude preservation processing and was prone to data distortion.

Description

Technical Field

[0001] The present disclosure relates to the technical field of seismic data processing for oil exploration reflection waves, and particularly to a method and device for suppressing boundary migration noise based on offset statistical sorting. Background Art

[0002] In the prestack migration processing of seismic data, boundary noise (also called boundary migration "arc drawing") easily appears at the boundary of the migration profile. This boundary "arc drawing" problem has a certain impact on prestack migration imaging. The main reason for the boundary "arc drawing" of the migration profile is the change in the seismic observation system at the boundary. Prestack migration determines the migration and output range of the CRP gather according to the overall offset distribution of the CMP gather in the work area. Due to factors in seismic acquisition construction, the change in the observation system causes the offset distribution range of the CMP gather near the boundary to be much smaller than the established offset output range of the CRP gather. Although the offset of the CMP gather near the boundary is missing, the gather will still be output according to the given CRP offset range during migration. Since there is a lack of offset data during the boundary migration integral summation, the offset data of the CRP gather at the corresponding position after migration is distorted, resulting in the phenomenon of boundary migration "arc drawing" after stacking.

[0003] Currently, the solution to this migration "arc drawing" problem is data regularization, mainly using spatial interpolation of adjacent seismic trace data. However, the interpolation of adjacent seismic traces is not conducive to amplitude preservation processing. Especially when the adjacent seismic traces are far apart, the interpolated data is prone to distortion. Therefore, a method that can solve the migration "arc drawing" problem while ensuring fidelity is needed. Summary of the Invention

[0004] The present disclosure provides a method and device for suppressing boundary migration noise based on offset statistical sorting to solve the phenomenon of boundary migration "arc drawing" after stacking caused by the fact that the offset distribution range of the CMP gather at the boundary is smaller than the established offset output range of the CRP gather, resulting in a lack of offset data during the offset integral summation. The previous spatial interpolation method for migration "arc drawing" is not conducive to amplitude preservation processing and is prone to data distortion.

[0005] According to one aspect of the present disclosure, a method for suppressing boundary migration noise based on offset statistical sorting is provided, including:

[0006] Obtaining a CMP gather for prestack migration in the work area;

[0007] Scanning the offset data of the CMP gather, and statistically obtaining each CMP number and its corresponding offset information to form a CMP gather offset information library;

[0008] Performing prestack migration processing on the CMP gather to obtain a migrated CRP gather;

[0009] Perform offset data scanning on the CRP gather, count each CRP number and its corresponding offset information, and form a CRP gather offset information database;

[0010] Use the CRP gather offset information database to sort the CMP gather offset information database to obtain a CRP gather within the CMP gather offset distribution range;

[0011] Perform final stacking processing on the CRP gather within the CMP gather offset distribution range to obtain an offset result after boundary migration noise suppression.

[0012] Preferably, before performing offset data scanning on the CMP gather, it further includes:

[0013] Sort the CMP gather according to the offset size to obtain a sorted CMP gather.

[0014] Preferably, the offset information is the distribution range of the offset.

[0015] Preferably, the method of using the CRP gather offset information database to sort the CMP gather offset information database to obtain a CRP gather within the CMP gather offset range includes:

[0016] Compare and analyze the offset distribution ranges of the CMP gather offset information database and the CRP gather offset information database to form a CMP gather and CRP gather offset comparison list;

[0017] According to the offset distribution range in the CMP gather offset information database, sort the offset distribution range in the corresponding CRP gather offset information database to obtain a CRP gather within the CMP gather offset distribution range.

[0018] Preferably, it further includes: using the CRP gather offset information database to sort the CMP gather offset information database to obtain a CRP gather outside the CMP gather offset distribution range;

[0019] Perform quality control on the offset result after boundary migration noise suppression according to the CRP gather outside the CMP gather offset distribution range.

[0020] Preferably, the method of performing quality control on the offset result after boundary migration noise suppression according to the CRP gather outside the CMP gather offset distribution range includes:

[0021] Stack the CRP gather outside the CMP gather offset distribution range to form an invalid offset information stacking profile;

[0022] Judge whether there is an "arc drawing" phenomenon on the stacked section with the invalid offset information superimposed, and whether there is no valid information. If so, judge whether there is no "arc drawing" phenomenon on the migration result after boundary offset noise suppression. If so, the quality control passes.

[0023] According to one aspect of the present disclosure, a boundary offset noise suppression device based on offset statistics sorting is provided, including:

[0024] An acquisition unit for acquiring CMP gather for prestack migration in the work area;

[0025] A CMP gather information library generation unit for scanning offset data of the CMP gather, statistically obtaining each CMP number and its corresponding offset information, and forming a CMP gather offset information library;

[0026] A CRP gather generation unit for performing prestack migration processing on the CMP gather to obtain a migrated CRP gather;

[0027] A CRP gather information library generation unit for scanning offset data of the CRP gather, statistically obtaining each CRP number and its corresponding offset information, and forming a CRP gather offset information library;

[0028] A sorting unit for sorting the CMP gather offset information library by using the CRP gather offset information library to obtain a CRP gather within the CMP gather offset distribution range;

[0029] An offset result generation unit for performing final stacking processing on the CRP gather within the CMP gather offset distribution range to obtain an offset result after boundary offset noise suppression.

[0030] The present invention has at least the following beneficial effects:

[0031] The present disclosure proposes a boundary offset noise suppression method and device based on offset statistics sorting. By statistically obtaining the offset magnitude and distribution of the CMP gather before migration, mapping the statistical data to the migrated CRP gather, sorting the offset of the boundary CRP gather according to the mapping result, and removing seismic traces with distorted offset integral summation, the offset "arc drawing" noise is effectively removed on the premise of amplitude and fidelity preservation, improving the seismic section imaging quality. Description of the Drawings

[0032] The drawings here are incorporated into the specification and constitute a part of this specification. These drawings show embodiments consistent with the present disclosure and are used together with the specification to illustrate the technical solutions of the present disclosure.

[0033] Figure 1 A flowchart showing a boundary offset noise suppression method based on offset statistics sorting according to an embodiment of the present disclosure;

[0034] Figure 2 A comparison diagram before and after sorting the offset distribution range of the CRP gather according to an embodiment of the present disclosure;

[0035] Figure 3 A right-side profile without boundary offset noise suppression according to an embodiment of the present disclosure;

[0036] Figure 4 A stacked profile of the CRP gather after suppressing the right-side boundary offset noise based on offset statistics sorting according to an embodiment of the present disclosure;

[0037] Figure 5 A left-side profile without boundary offset noise suppression according to an embodiment of the present disclosure;

[0038] Figure 6 A stacked profile of the CRP gather after suppressing the left-side boundary offset noise based on offset statistics sorting according to an embodiment of the present disclosure. Detailed implementation manners

[0039] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0040] The term "exemplary" used herein means "serving as an example, embodiment, or illustration". Any embodiment described as "exemplary" herein does not have to be construed as superior to or better than other embodiments.

[0041] The term "and / or" herein merely describes an association relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality. For example, including at least one of A, B, and C may represent including any one or more elements selected from the set composed of A, B, and C.

[0042] In addition, to better illustrate the present disclosure, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present disclosure can be implemented without some specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art are not described in detail so as to highlight the gist of the present disclosure.

[0043] Figure 1 A flowchart showing a boundary offset noise suppression method based on offset statistics sorting according to an embodiment of the present disclosure; Figure 2 A comparison diagram before and after sorting the offset distribution range of the CRP gather according to an embodiment of the present disclosure; Figure 3 A right profile without boundary offset noise suppression according to an embodiment of the present disclosure; Figure 4 A CRP gather stacked profile after suppressing the right boundary offset noise based on offset statistics sorting according to an embodiment of the present disclosure; Figure 5 A left profile without boundary offset noise suppression according to an embodiment of the present disclosure; Figure 6 A CRP gather stacked profile after suppressing the left boundary offset noise based on offset statistics sorting according to an embodiment of the present disclosure. As Figures 1-6 As shown, a boundary offset noise suppression method based on offset statistics sorting includes: Step S01: Obtain a CMP gather for prestack migration in the work area; Step S02: Scan the offset data of the CMP gather, and count each CMP number and its corresponding offset information to form a CMP gather offset information library; Step S03: Perform prestack migration processing on the CMP gather to obtain a migrated CRP gather; Step S04: Scan the offset data of the CRP gather, and count each CRP number and its corresponding offset information to form a CRP gather offset information library; Step S05: Use the CRP gather offset information library to sort the CMP gather offset information library to obtain a CRP gather within the offset distribution range of the CMP gather; Step S06: Perform final stacking processing on the CRP gather within the offset distribution range of the CMP gather to obtain an offset result after suppressing the boundary offset noise.

[0044] The boundary offset noise suppression method based on offset statistics sorting provided by the embodiments of the present invention specifically includes the following steps:

[0045] Step S01: Obtain a CMP gather for prestack migration in the work area.

[0046] Step S02: Scan the offset data of the CMP gather, and count each CMP number and its corresponding offset information to form a CMP gather offset information library.

[0047] In the present disclosure, before scanning the offset data of the CMP gather, it further includes: Sorting the CMP gather according to the offset size to obtain a sorted CMP gather.

[0048] In the present disclosure, the offset information is the offset distribution range.

[0049] In the embodiments of the present disclosure, the CMP gather for prestack migration is sorted in ascending order according to the distribution range of the offset, and the sorted CMP gather is obtained to prepare for subsequent statistical work.

[0050] In the embodiments of the present disclosure, the sorted CMP gather is scanned for offset information to obtain the serial number and offset information of each CMP gather, including the offset size and the range respectively, forming a database of offset information for all CMP gathers.

[0051] Step S03: Perform prestack migration processing on the CMP gather to obtain the migrated CRP gather.

[0052] In the embodiments of the present disclosure, the sorted CMP gather is subjected to prestack time migration or prestack depth migration to obtain a CRP gather with a given output range of offset after migration.

[0053] Step S04: Scan the offset data of the CRP gather to count the offset information corresponding to each CRP number, forming a database of offset information for the CRP gather.

[0054] In the embodiments of the present disclosure, the migrated CRP gather is scanned for offset information to count the serial number and offset information of each CRP gather, including the offset size and the distribution range, forming a database of offset information for all CRP gathers.

[0055] Step S05: Use the database of offset information for the CRP gather to sort the database of offset information for the CMP gather to obtain the CRP gather within the offset distribution range of the CMP gather.

[0056] In the present disclosure, the method of using the database of offset information for the CRP gather to sort the database of offset information for the CMP gather to obtain the CRP gather within the offset distribution range of the CMP gather includes: comparing and analyzing the offset distribution ranges of the database of offset information for the CMP gather and the database of offset information for the CRP gather to form a comparison list of offsets for the CMP gather and the CRP gather; sorting the offset distribution ranges in the corresponding database of offset information for the CRP gather according to the offset distribution range in the database of offset information for the CMP gather to obtain the CRP gather within the offset distribution range of the CMP gather.

[0057] In the embodiments of the present disclosure, each offset distribution range in the database of offset information for the CMP gather is compared and analyzed with each offset distribution range in the corresponding database of offset information for the CRP gather to form a comparison list of offsets for the CMP gather and the CRP gather.

[0058] Using the CMP offset distribution range information to constrain the CRP offset at the boundary arc drawing, and sorting the CRP gather by offset range according to the principle that the offset distribution range of the CRP gather after offset is consistent with the offset distribution range of the CMP gather before offset, so as to obtain the sorted CRP gather; that is, selecting the overlapping part of the offset distribution range of each CRP gather and the offset distribution range of the corresponding CMP gather, so as to obtain the CRP gather within the offset range of the CMP gather. Among them, the CRP gather within the offset range of the CMP gather is considered as valid offset information, and the CRP gather outside the offset range of the CMP gather is considered as invalid offset information.

[0059] Figure 2 The comparison diagrams before and after sorting the offset distribution range of the CRP gather are shown. As Figure 2 shown, the CRP gather after sorting and optimization removes the seismic traces in the noise part of the invalid offset range, and the remaining offset distribution range of the CRP seismic traces is consistent with the offset distribution range of the CMP gather before offset at this point.

[0060] Step S06: Perform final stacking processing on the CRP gather within the offset range of the CMP gather to obtain the offset result after boundary offset noise suppression.

[0061] In the embodiment of the present disclosure, the CRP gather after sorting and optimization removes the seismic traces that cause "arc drawing" during offset. Stacking the CRP gather after sorting and optimization can effectively eliminate the "arc drawing" phenomenon at the boundary caused by the change of the acquisition system at the boundary.

[0062] In the present disclosure, it further includes: sorting the CMP gather offset information library by using the CRP gather offset information library to obtain the CRP gather outside the offset range of the CMP gather; and performing quality control on the offset result after boundary offset noise suppression according to the CRP gather outside the offset range of the CMP gather.

[0063] In the present disclosure, the method for performing quality control on the offset result after boundary offset noise suppression according to the CRP gather outside the offset range of the CMP gather includes: stacking the CRP gather outside the offset range of the CMP gather to form an invalid offset information stacking profile; judging whether there is an "arc drawing" phenomenon and whether there is no valid information on the invalid offset information stacking profile. If so, then judge whether there is no "arc drawing" phenomenon on the offset result after boundary offset noise suppression. If so, the quality control passes.

[0064] In the embodiments of the present disclosure, the obtained migration result after boundary migration noise suppression is analyzed for effectiveness. After the invalid offset information is superimposed, an arc-shaped migration phenomenon will appear in the section. After removing the CRP gather with invalid offsets and superimposing, the arc-shaped migration phenomenon is eliminated, thereby completing the selection of effective CRP channels.

[0065] In step S05, when sorting the offset distribution range in the corresponding CRP gather offset information library according to the offset distribution range in the CMP gather offset information library, in addition to obtaining the CRP gather within the offset distribution range of the CMP gather, the CRP gather outside the offset distribution range of the CMP gather can also be obtained. The obtained CRP gather within the offset distribution range of the CMP gather and the CRP gather outside the offset distribution range of the CMP gather are respectively superimposed to obtain the effective offset information superimposed section, that is, the migration result after boundary migration noise suppression, and the invalid offset information superimposed section.

[0066] If there is still valid information on the invalid offset information superimposed section, or there is still arc-shaped noise on the effective offset superimposed section, the quality control fails. Steps S05 to S06 can be repeated to re-optimize the range of invalid offsets to effectively remove the arc-shaped migration noise.

[0067] Figure 3 The right section without boundary migration noise suppression is shown, as Figure 3 shown, a serious arc-shaped phenomenon appears at the boundary; Figure 4 The CRP gather superimposed section after boundary migration noise suppression on the right side based on offset statistical sorting is shown, as Figure 4 shown, the problem of arc-shaped migration on the right boundary is significantly eliminated; Figure 5 The left section without boundary migration noise suppression is shown, as Figure 5 shown, a relatively serious arc-shaped phenomenon also appears at the boundary; Figure 6 The CRP gather superimposed section after boundary migration noise suppression on the left side based on offset statistical sorting is shown, as Figure 6 shown, the problem of arc-shaped migration on the left boundary is also effectively eliminated.

[0068] It can be understood that the above-mentioned method embodiments mentioned in the present disclosure can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present disclosure will not elaborate further.

[0069] The execution entity of a boundary offset noise suppression method based on offset statistical sorting can be an image processing device. For example, the boundary offset noise suppression method based on offset statistical sorting can be executed by a terminal device, a server, or other processing devices. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the boundary offset noise suppression method based on offset statistical sorting can be implemented by a processor invoking computer-readable instructions stored in a memory.

[0070] Those skilled in the art can understand that in the above method of the specific implementation manner, the writing order of each step does not mean a strict execution order and constitutes any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.

[0071] The present disclosure also provides a boundary offset noise suppression device based on offset statistical sorting, including: an acquisition unit, configured to acquire a CMP gather for pre-stack migration in a work area; a CMP gather information library generation unit, configured to perform offset data scanning on the CMP gather, count each CMP number and its corresponding offset information, and form a CMP gather offset information library; a CRP gather generation unit, configured to perform pre-stack migration processing on the CMP gather to obtain a migrated CRP gather; a CRP gather information library generation unit, configured to perform offset data scanning on the CRP gather, count each CRP number and its corresponding offset information, and form a CRP gather offset information library; a sorting unit, configured to use the CRP gather offset information library to sort the CMP gather offset information library to obtain a CRP gather within the CMP gather offset range; an offset result generation unit, configured to perform final stacking processing on the CRP gather within the CMP gather offset range to obtain an offset result after boundary offset noise suppression.

[0072] In some embodiments, the functions or modules included in the device provided in the embodiments of the present disclosure can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0073] The present disclosure mainly aims at the problem that the boundary of the observation system changes, resulting in uneven or missing offset distribution of the boundary CMP gather, and offset noise appears at the boundary of the pre-stack migrated profile, that is, the boundary migration "arc drawing" problem. The offset range of the post-migrated CRP is constrained by the offset range of the pre-migrated CMP gather. According to the principle that the offset range of the pre-stack migrated CRP gather is consistent with the offset range of the pre-migrated CMP gather, the effective CRP seismic traces are sorted out. Starting from the formation mechanism of the boundary migration "arc drawing", the statistical sorting method is used to remove the invalid seismic traces that cause the migration "arc drawing", effectively and amplitude-preserving suppressing the migration "arc drawing" noise, effectively eliminating the boundary migration noise, significantly improving the imaging effect of the boundary position of the pre-stack migrated profile, and improving the pre-stack migration imaging quality. In addition, the present disclosure also avoids the risk of data distortion caused by the regularized spatial interpolation of seismic data, making the obtained results more amplitude-preserving and fidelity-preserving.

[0074] The embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments.

Claims

1. A method for suppressing boundary migration noise based on offset statistics sorting, characterized in that, it includes: Obtain the CMP gather for pre-stack migration in the work area; Perform offset data scanning on the CMP gather, count the offset information corresponding to each CMP number, and form a CMP gather offset information library; Perform pre-stack migration processing on the CMP gather to obtain the migrated CRP gather; Perform offset data scanning on the CRP gather, count the offset information corresponding to each CRP number, and form a CRP gather offset information library; Use the CRP gather offset information library to sort the CMP gather offset information library to obtain the CRP gather within the offset distribution range of the CMP gather. The method includes: Compare and analyze the offset distribution ranges of the CMP gather offset information library and the CRP gather offset information library to form a comparison list of the offsets of the CMP gather and the CRP gather; According to the offset distribution range in the CMP gather offset information library, sort the offset distribution range in the corresponding CRP gather offset information library to obtain the CRP gather within the offset distribution range of the CMP gather; Perform final stacking processing on the CRP gather within the offset distribution range of the CMP gather to obtain the migration result after suppressing boundary migration noise.

2. The method for suppressing boundary migration noise based on offset statistics sorting according to claim 1, characterized in that, Before performing offset data scanning on the CMP gather, it further includes: Sort the CMP gather according to the offset size to obtain the sorted CMP gather.

3. The method for suppressing boundary migration noise based on offset statistics sorting according to claim 1, characterized in that: The offset information is the distribution range of the offset.

4. The method for suppressing boundary migration noise based on offset statistics sorting according to claim 1, characterized in that, it further includes: Use the CRP gather offset information library to sort the CMP gather offset information library to obtain the CRP gather outside the offset distribution range of the CMP gather; According to the CRP gather outside the offset distribution range of the CMP gather, perform quality control on the migration result after suppressing boundary migration noise.

5. The method for suppressing boundary migration noise based on offset statistics sorting according to claim 4, characterized in that, The method for performing quality control on the migration result after suppressing boundary migration noise according to the CRP gather outside the offset distribution range of the CMP gather includes: Stack the CRP gather outside the offset distribution range of the CMP gather to form an invalid offset information stacking profile; Judge whether there is an "arc drawing" phenomenon and whether there is no valid information on the invalid offset information stacking profile. If so, judge whether there is no "arc drawing" phenomenon on the migration result after suppressing boundary migration noise. If so, the quality control passes.

6. A device for suppressing boundary migration noise based on offset statistics sorting, characterized in that, it includes: An acquisition unit for acquiring CMP gathers for pre-stack migration in a work area; A CMP gather information library generation unit for performing offset data scanning on the CMP gathers, counting each CMP number and its corresponding offset information, and forming a CMP gather offset information library; A CRP gather generation unit for performing pre-stack migration processing on the CMP gathers to obtain migrated CRP gathers; A CRP gather information library generation unit for performing offset data scanning on the CRP gathers, counting each CRP number and its corresponding offset information, and forming a CRP gather offset information library; A sorting unit for sorting the CMP gather offset information library by using the CRP gather offset information library to obtain CRP gathers within the offset distribution range of the CMP gathers. The method includes: comparing and analyzing the offset distribution ranges of the CMP gather offset information library and the CRP gather offset information library to form a comparison list of the offsets of the CMP gathers and the CRP gathers; sorting the offset distribution range within the CRP gather offset information library corresponding to the offset distribution range in the CMP gather offset information library to obtain CRP gathers within the offset distribution range of the CMP gathers; An offset result generation unit for performing final stacking processing on the CRP gathers within the offset distribution range of the CMP gathers to obtain an offset result after boundary offset noise suppression.

Images