Method and device for velocity analysis by utilizing diffraction energy envelope of imaging domain
By using the velocity analysis method of the diffraction energy envelope in the imaging domain, and utilizing the focusing degree of diffraction energy for velocity analysis, the problem of poor diffraction wave imaging is solved, and a more accurate interpretation of the velocity of underground geological bodies is achieved.
Patent Information
- Application Number
- CN202411382515.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2026-03-31
AI Technical Summary
Traditional seismic data processing methods have failed to effectively enhance the energy of diffracted waves, resulting in poor diffracted wave imaging, which affects the accuracy of tectonic interpretation and the improvement of velocity models.
Velocity analysis is performed using the imaging domain diffraction energy envelope. By using the imaging gather envelope calculation method based on image cross-correlation, velocity analysis is performed using the focusing degree of diffraction energy, thus constructing an interactive velocity analysis approach.
It improves the accuracy of velocity interpretation of underground geological bodies, solves the problem that diffracted waves are more sensitive to velocity, and provides a more accurate velocity model.
Smart Images
Figure CN121763395A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seismic exploration data processing methods, specifically to a method and apparatus for velocity analysis using the energy envelope of imaging domain diffraction. Background Technology
[0002] Recorded seismic waves may be reflected or diffracted, depending on the geometry of the subsurface structure. Diffraction is an indicator of small-scale faults, cusps, and abrupt phase transitions. Generally, diffracted waves have lower energy than specularly reflected waves. However, conventional seismic data processing parameters are chosen to enhance the energy of specularly reflected waves, which may result in inadequate imaging of diffracted waves. Nevertheless, correctly imaging diffracted waves is crucial for improving fault discontinuities required for tectonic interpretation. Diffracted waves are more sensitive to velocity, making them an excellent choice for further refining initial velocity models based on specular reflection.
[0003] A major challenge in utilizing diffracted waves is their detection. Landa et al. proposed a method for detecting diffracted waves using co-migrating ordered gathers. In pre-stack residual migrations, Sava et al. also used focusing-and-defocusing techniques to update layer velocity models. Other researchers have explored methods for using diffracted waves to analyze and update velocity models. Khoshnava et al. conducted anisotropic diffraction approximations and found that ignoring anisotropy can lead to low-resolution, misplaced, or spurious diffracted images. The most common technique for analyzing reflection velocities in the image domain is Al-Yahya migration velocity analysis. Migration velocity analysis shows that the correct velocity will give images of the same shot point and receiver. If seismic traces imaged at the same point come from different observation systems, the accuracy of the migration velocity will be measured by the consistency (or “flatness”) of the co-imaging gathers. Sava et al. proposed a method for performing diffracted migration velocity analysis in the image domain.
[0004] Based on this technical background, the present invention studies a method and apparatus for velocity analysis using the diffraction energy envelope of the imaging domain. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a method and apparatus for velocity analysis using the diffraction energy envelope of the imaging domain. This method proposes an imaging gather envelope calculation method based on image cross-correlation, and performs velocity analysis according to the focusing degree of diffraction energy at different velocities. This provides technical support for the accurate velocity interpretation of underground geological bodies and solves the problem that conventional migration velocity analysis relies on reflected wave fields, while diffracted waves are more sensitive to velocity.
[0006] To achieve the above objectives, a first aspect of the present invention provides a method for velocity analysis using the diffraction energy envelope of the imaging domain, comprising:
[0007] Pre-stack migration velocity is obtained by performing migration imaging on seismic data volumes using batch displacement velocities;
[0008] The imaging envelope is calculated using the pre-stack offset velocity;
[0009] An interactive velocity analysis is performed on the results of the imaging envelope calculation to select a suitable pre-stack migration velocity.
[0010] A second aspect of the present invention provides a velocity analysis apparatus utilizing the diffraction energy envelope of the imaging domain, comprising:
[0011] The migration velocity acquisition module is used to perform migration imaging on seismic data volumes using batch displacement velocities to obtain pre-stack migration velocities.
[0012] An envelope calculation module is used to calculate the imaging envelope using the pre-stack offset velocity;
[0013] The velocity analysis module is used to perform interactive velocity analysis on the results of the imaging envelope calculation and select a suitable pre-stack migration velocity.
[0014] A third aspect of the present invention provides an electronic device, the electronic device comprising:
[0015] Memory, which stores executable instructions;
[0016] A processor that executes the executable instructions in the memory to implement the velocity analysis method using the imaging domain diffraction energy envelope as described in the first aspect.
[0017] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the velocity analysis method using the imaging domain diffraction energy envelope described in the first aspect.
[0018] The beneficial effects of this invention include:
[0019] (1) The present invention proposes a velocity analysis method using the imaging domain diffraction energy envelope, and proposes an imaging gather envelope calculation method based on image cross-correlation. The velocity analysis is performed according to the focusing degree of diffraction energy at different velocities, providing technical support for the accurate velocity interpretation of underground geological bodies. It solves the problem that conventional migration velocity analysis relies on the reflected wave field, and diffraction waves are more sensitive to velocity.
[0020] (2) The velocity analysis method proposed in this invention utilizes the diffraction energy envelope in the imaging domain. Based on the theory of focusing energy and image cross-correlation of the diffraction phase axis in the imaging domain, an imaging envelope calculation function based on image cross-correlation is proposed, and an interactive velocity analysis approach is constructed. Interactive velocity analysis can be performed according to the diffraction energy focusing program, providing technical support for interpreters.
[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description
[0022] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings.
[0023] Figure 1 This is a schematic flowchart of the velocity analysis method using the diffraction energy envelope of the imaging domain proposed in this invention.
[0024] Figure 2 This is a flowchart illustrating a specific implementation of the velocity analysis method using the diffraction energy envelope of the imaging domain proposed in this invention. Detailed Implementation
[0025] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.
[0026] This invention provides a method for velocity analysis using the diffraction energy envelope in the imaging domain, such as... Figure 1 As shown, it includes:
[0027] Pre-stack migration velocity is obtained by performing migration imaging on seismic data volumes using batch displacement velocities;
[0028] The imaging envelope is calculated using the pre-stack migration velocity.
[0029] Interactive velocity analysis was performed on the results of the imaging envelope calculation to select an appropriate pre-stack migration velocity.
[0030] This invention proposes an imaging gather envelope calculation method based on image cross-correlation, which performs velocity analysis based on the focusing degree of diffraction energy at different velocities, providing technical support for accurate velocity interpretation of underground geological bodies. This solves the problem that conventional migration velocity analysis relies on reflected wave fields, while diffracted waves are more sensitive to velocity.
[0031] According to the present invention, obtaining pre-stack migration velocity by performing migration imaging on seismic data volumes using batch displacement velocities includes:
[0032] Migration imaging of seismic data volumes using batch displacement velocities centered on relatively accurate initial velocities;
[0033] Pre-stack migration velocity is obtained by reflection tomography based on migration imaging.
[0034] According to the present invention, the calculation of the imaging envelope using pre-stack migration velocity includes:
[0035] Use the pre-stack offset velocity to examine the energy distribution and the position of individual diffractors;
[0036] The diffraction energy envelope of the imaging domain is calculated.
[0037] According to the present invention, interactive velocity analysis of the results of imaging envelope calculation includes:
[0038] Construct a 3D matrix, and assign each slice of the matrix to a profile offset at different pre-stack offset velocities;
[0039] Select the analysis window and calculate the sum of the envelopes on each imaging pathway along the depth direction.
[0040] According to the present invention, the size of the analysis window is equal to the dominant wavelength.
[0041] Preferably, the formula used to calculate the sum of the envelopes on each imaging pathway is:
[0042]
[0043] Where E(x) is the sum of the envelopes at position x, z0 and z1 are the depth constraints in the summation, r(x,z) is the offset channel, and r H (x,z) represents the Hilbert transform in the z-direction.
[0044] According to the present invention, within the analysis window, the optimal focusing assumption of the diffractor is conditional as follows:
[0045] Subsequent velocity perturbations only include the correct velocity model;
[0046] Static correction, multiple wave and surface wave suppression have been performed.
[0047] In this invention, based on the theory of focusing energy and image cross-correlation of diffraction phase axes in the imaging domain, an imaging envelope calculation function based on image cross-correlation is proposed, and an interactive velocity analysis approach is constructed. Interactive velocity analysis can be performed according to the diffraction energy focusing procedure, providing technical support for interpreters.
[0048] The present invention will be described in more detail below through embodiments.
[0049] Example 1:
[0050] like Figure 2 As shown, this embodiment proposes a velocity analysis method using the diffraction energy envelope in the imaging domain. Based on the theory of focusing energy of the diffraction phase axis in the imaging domain and image cross-correlation, an imaging envelope calculation function based on image cross-correlation is proposed, and an interactive velocity analysis approach is constructed. Finally, the method is verified by using numerical models of different complexities.
[0051] The specific steps of this method are as follows:
[0052] First, the data is migrated using a batch displacement velocity centered on a relatively accurate starting velocity, and pre-stack migration velocity based on reflection tomography is performed. Using Claerbout imaging conditions, the energy distribution and the position of individual diffractors are examined using the batch displacement velocity. A 10% decrease in velocity results in a downward concave image and a shallower migration position; while a 10% increase in velocity results in an upward concave image and a deeper migration position. For accurate velocities, diffractors are well focused at the correct position, and the energy is highest at the center of the window. In the absence of complex structures or significant lateral velocity variations, a good pre-stack migration velocity should be within a few percentage points of the correct velocity. Therefore, the method of this invention represents a potential improvement upon a relatively accurate velocity model.
[0053] Secondly, a 3D matrix is constructed, with each slice corresponding to a profile offset at a different velocity; then, using a window of interest to the interpreter, the sum of the envelopes along the depth direction for each imaging pathway is calculated:
[0054]
[0055] Where E(x) is the average intensity (sum of the envelope) at position x, z0 and z1 are the depth constraints considered in the summation, r(x,z) is the offset channel, and r H (x,z) is its Hilbert transform in the z-direction; it depends on the envelope because it eliminates the sensitivity to frequency and phase in imaging; it is also used to highlight the region of interest in the explosion reflection model.
[0056] In this embodiment, within the analysis window, the optimal focusing assumption of the diffractor is valid under the following conditions: (1) the subsequent velocity perturbation includes only the correct velocity model, and (2) overstatic correction, multiple wave and surface wave suppression have been performed to eliminate imaging artifacts.
[0057] This embodiment proposes an imaging gather envelope calculation method based on image cross-correlation. It performs velocity analysis based on the focusing degree of diffraction energy at different velocities, providing technical support for accurate velocity interpretation of underground geological bodies. This solves the problem that conventional migration velocity analysis relies on reflected wave fields, while diffracted waves are more sensitive to velocity.
[0058] Example 2:
[0059] This embodiment provides a method for velocity analysis using the diffraction energy envelope of the imaging domain, such as... Figure 1 As shown, it includes:
[0060] Pre-stack migration velocity is obtained by performing migration imaging on seismic data volumes using batch displacement velocities;
[0061] The imaging envelope is calculated using the pre-stack migration velocity.
[0062] Interactive velocity analysis was performed on the results of the imaging envelope calculation to select an appropriate pre-stack migration velocity;
[0063] In this embodiment, obtaining the pre-stack migration velocity by performing migration imaging on the seismic data volume using batch displacement velocities includes:
[0064] Migration imaging of seismic data volumes using batch displacement velocities centered on relatively accurate initial velocities;
[0065] Pre-stack migration velocity was obtained by reflection tomography based on migration imaging;
[0066] In this embodiment, the calculation of the imaging envelope using the pre-stack migration velocity includes:
[0067] Use the pre-stack offset velocity to examine the energy distribution and the position of individual diffractors;
[0068] Calculate the diffraction energy envelope in the imaging domain;
[0069] In this embodiment, interactive velocity analysis of the imaging envelope calculation results includes:
[0070] Construct a 3D matrix, and assign each slice of the matrix to a profile offset at different pre-stack offset velocities;
[0071] Select the analysis window and calculate the sum of the envelopes on each imaging pathway along the depth direction;
[0072] In this embodiment, the size of the analysis window is equal to the dominant wavelength;
[0073] In this embodiment, the formula used to calculate the sum of the envelopes on each imaging channel is:
[0074]
[0075] Where E(x) is the sum of the envelopes at position x, z0 and z1 are the depth constraints in the summation, r(x,z) is the offset channel, and r H (x,z) represents the Hilbert transform in the z-direction;
[0076] In this embodiment, within the analysis window, the optimal focusing assumption of the diffractor is conditional as follows:
[0077] Subsequent velocity perturbations only include the correct velocity model;
[0078] Static correction, multiple wave and surface wave suppression have been performed.
[0079] Example 3:
[0080] This embodiment provides a velocity analysis device using the diffraction energy envelope of the imaging domain, including:
[0081] The migration velocity acquisition module is used to perform migration imaging on seismic data volumes using batch displacement velocities to obtain pre-stack migration velocities.
[0082] The envelope calculation module is used to calculate the imaging envelope using the pre-stack migration velocity.
[0083] The velocity analysis module is used to perform interactive velocity analysis on the results of the imaging envelope calculation and select an appropriate pre-stack migration velocity.
[0084] In this embodiment, obtaining the pre-stack migration velocity by performing migration imaging on the seismic data volume using batch displacement velocities includes:
[0085] Migration imaging of seismic data volumes using batch displacement velocities centered on relatively accurate initial velocities;
[0086] Pre-stack migration velocity was obtained by reflection tomography based on migration imaging;
[0087] In this embodiment, the calculation of the imaging envelope using the pre-stack migration velocity includes:
[0088] Use the pre-stack offset velocity to examine the energy distribution and the position of individual diffractors;
[0089] Calculate the diffraction energy envelope in the imaging domain;
[0090] In this embodiment, interactive velocity analysis of the imaging envelope calculation results includes:
[0091] Construct a 3D matrix, and assign each slice of the matrix to a profile offset at different pre-stack offset velocities;
[0092] Select the analysis window and calculate the sum of the envelopes on each imaging pathway along the depth direction;
[0093] In this embodiment, the size of the analysis window is equal to the dominant wavelength;
[0094] In this embodiment, the formula used to calculate the sum of the envelopes on each imaging channel is:
[0095]
[0096] Where E(x) is the sum of the envelopes at position x, z0 and z1 are the depth constraints in the summation, r(x,z) is the offset channel, and r H (x,z) represents the Hilbert transform in the z-direction;
[0097] In this embodiment, within the analysis window, the optimal focusing assumption of the diffractor is conditional as follows:
[0098] Subsequent velocity perturbations only include the correct velocity model;
[0099] Static correction, multiple wave and surface wave suppression have been performed.
[0100] Example 4:
[0101] This invention provides an electronic device including a memory and a processor, comprising:
[0102] Memory, which stores executable instructions;
[0103] The processor executes executable instructions in memory to implement a velocity analysis method that utilizes the diffraction energy envelope of the imaging domain.
[0104] This memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.
[0105] The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the invention, the processor is used to execute computer-readable instructions stored in the memory.
[0106] Those skilled in the art should understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this invention.
[0107] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.
[0108] Example 5:
[0109] This invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a velocity analysis method using the diffraction energy envelope of the imaging domain.
[0110] A computer-readable storage medium according to embodiments of the present invention stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present invention are performed.
[0111] The aforementioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).
[0112] The embodiments of this invention propose a velocity analysis method using the imaging domain diffraction energy envelope, and propose an imaging gather envelope calculation method based on image cross-correlation. The method performs velocity analysis according to the focusing degree of diffraction energy at different velocities, providing technical support for the accurate velocity interpretation of underground geological bodies. It solves the problem that conventional migration velocity analysis relies on the reflected wave field, while diffraction waves are more sensitive to velocity.
[0113] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.
Claims
1. A method for velocity analysis using the diffraction energy envelope of the imaging domain, characterized in that, include: Pre-stack migration velocity is obtained by performing migration imaging on seismic data volumes using batch displacement velocities; The imaging envelope is calculated using the pre-stack offset velocity; An interactive velocity analysis is performed on the results of the imaging envelope calculation to select a suitable pre-stack migration velocity.
2. The method according to claim 1, characterized in that, Pre-stack migration velocities obtained by migrating seismic data volumes using batch displacement velocities include: Migration imaging of seismic data volumes using batch displacement velocities centered on relatively accurate initial velocities; Pre-stack migration velocity is obtained by reflection tomography based on the migration imaging.
3. The method according to claim 2, characterized in that, Calculating the imaging envelope using the pre-stack migration velocity includes: The energy distribution and the position of individual diffractors are examined using the pre-stack offset velocity. The diffraction energy envelope of the imaging domain is calculated.
4. The method according to claim 1, characterized in that, Interactive velocity analysis of the results of the imaging envelope calculation includes: Construct a 3D matrix, and assign each slice of the matrix to a profile offset at different pre-stack offset velocities; Select the analysis window and calculate the sum of the envelopes on each imaging pathway along the depth direction.
5. The method according to claim 4, characterized in that, The size of the analysis window is equal to the dominant wavelength.
6. The method according to claim 4, characterized in that, The formula used to calculate the sum of the envelopes on each imaging pathway is: Where E(x) is the sum of the envelopes at position x, z0 and z1 are the depth constraints in the summation, r(x,z) is the offset channel, and r H (x,z) represents the Hilbert transform in the z-direction.
7. The method according to claim 4, characterized in that, Within the analysis window, the optimal focusing assumption for the diffractor is conditional as follows: Subsequent velocity perturbations only include the correct velocity model; Static correction, multiple wave and surface wave suppression have been performed.
8. A velocity analysis device utilizing the diffraction energy envelope of an imaging domain, characterized in that, include: The migration velocity acquisition module is used to perform migration imaging on seismic data volumes using batch displacement velocities to obtain pre-stack migration velocities. An envelope calculation module is used to calculate the imaging envelope using the pre-stack offset velocity; The velocity analysis module is used to perform interactive velocity analysis on the results of the imaging envelope calculation and select a suitable pre-stack migration velocity.
9. An electronic device, characterized in that, The electronic device includes: Memory, which stores executable instructions; A processor that executes the executable instructions in the memory to implement the velocity analysis method using the imaging domain diffraction energy envelope according to any one of claims 1-7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the velocity analysis method using the imaging domain diffraction energy envelope as described in any one of claims 1-7.