Method and device for determining OBN acquisition maximum offset, electronic equipment and medium
By constructing a three-dimensional geological model and performing FWI inversion, the maximum offset of OBN acquisition was determined, which solved the problem of insufficient parameter optimization in existing technologies and improved the imaging accuracy of the acquired data and the accuracy of subsequent analysis.
Patent Information
- Application Number
- CN202411409810.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2026-04-10
AI Technical Summary
Existing technologies struggle to effectively optimize acquisition parameters when determining the maximum offset of OBN acquisition, resulting in insufficient accuracy in lithology identification and reservoir prediction.
By constructing a three-dimensional geological model of the target area, performing forward seismic illumination analysis, determining the maximum receiving distance of the target layer, and combining FWI inversion, calculating the migration aperture and initial maximum migration distance, and finally determining the final maximum migration distance.
This improved the imaging accuracy of OBN-acquired data, providing a foundation for subsequent lithological identification and reservoir prediction.
Smart Images
Figure CN121831877A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seismic exploration technology, and more specifically, to a method, apparatus, electronic device, and medium for determining the maximum offset distance of OBN acquisition. Background Technology
[0002] In recent years, ocean bottom node (OBN) exploration technology has been widely applied in oil and gas field exploration in various sea areas around the world, achieving good results. OBNs are less affected by sea conditions and the surrounding environment, receiving data with a higher signal-to-noise ratio, more comprehensive data, and without distortion. Furthermore, OBN seismic acquisition technology can simultaneously acquire P-wave and S-wave data, enabling wide-azimuth (all-around), ultra-high coverage, and ultra-large offset seismic data acquisition. The combined use of high-quality P-wave and S-wave data for lithology identification and reservoir prediction can significantly improve the accuracy of oil and gas reservoir identification. OBN technology represents the direction of development in marine seismic exploration technology; from a long-term development perspective, it is essential to master the acquisition design, construction, and processing technologies of OBNs.
[0003] Due to the unique working methods of OBN exploration, it is essential to conduct targeted research on acquisition technology design during the acquisition process. Maximum offset is one of the key parameters in the acquisition scheme, and its magnitude has a significant impact on target layer imaging. Generally, a velocity model of the exploration area is established, and forward modeling imaging analysis is used for targeted degradation analysis. However, this method has limitations in subsequent analyses such as lithology identification and reservoir prediction.
[0004] Currently, a method for determining the maximum offset distance for OBN acquisition still needs to be developed.
[0005] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention
[0006] This invention proposes a method, apparatus, electronic device, and medium for determining the maximum offset distance in OBN acquisition, which can solve the problem of determining the maximum offset distance parameter in the design of OBN acquisition schemes, optimize acquisition parameters, and improve the imaging accuracy of OBN acquisition data.
[0007] In a first aspect, embodiments of this disclosure provide a method for determining the maximum offset distance for OBN acquisition, including:
[0008] Construct a three-dimensional geological model of the target area;
[0009] Seismic wave forward illumination analysis was performed on the target layer to determine the maximum receiving distance of the target layer.
[0010] Calculate the offset aperture of the target layer to meet the requirements of offset imaging;
[0011] Based on the three-dimensional geological model, data forward modeling is performed to simulate a single shot, followed by FWI inversion to determine the initial maximum offset.
[0012] The final maximum offset distance is determined based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
[0013] As a specific implementation of this disclosure, the three-dimensional geological model is constructed based on the geological measurement data and interpretation results data of the target area.
[0014] As a specific implementation of this disclosure, performing seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer includes:
[0015] The shot point is placed underwater and used as the source point to simulate Gaussian ray irradiation of the target layer in the three-dimensional geological model. The analysis is performed based on the incident angle of 45 degrees. The maximum shot-receiver distance is determined according to the reflection position of the Gaussian ray irradiation of the target layer received on the seabed, which is the maximum receiving distance.
[0016] As a specific implementation of this disclosure, calculating the offset aperture of the target layer that meets the offset imaging requirements includes:
[0017] The distance required for diffraction to achieve the desired target layer structure is calculated based on the average velocity, reflection time, and tilt angle of the target layer. The offset aperture is then determined based on the diffraction distance at the maximum steep tilt angle.
[0018] As a specific implementation of this disclosure, the diffraction return distance at the maximum steep tilt angle is:
[0019]
[0020] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0021] As a specific implementation of this disclosure, determining the initial maximum offset includes:
[0022] Based on the simulated single-shot FWI inversion at different offsets, the FWI inversion results are compared, and the initial maximum offset is determined by comparing the accuracy of the inverted velocity model with the actual model.
[0023] Secondly, embodiments of this disclosure also provide an apparatus for determining the maximum offset distance of OBN acquisition, comprising:
[0024] The module builds a three-dimensional geological model of the target area;
[0025] The forward illumination analysis module performs seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer;
[0026] The calculation module calculates the offset aperture of the target layer that meets the requirements for offset imaging;
[0027] The FWI inversion module performs forward modeling of the data based on the three-dimensional geological model, simulates a single shot, and then performs FWI inversion to determine the initial maximum offset.
[0028] The output module determines the final maximum offset distance based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
[0029] As a specific implementation of this disclosure, the three-dimensional geological model is constructed based on the geological measurement data and interpretation results data of the target area.
[0030] As a specific implementation of this disclosure, performing seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer includes:
[0031] The shot point is placed underwater and used as the source point to simulate Gaussian ray irradiation of the target layer in the three-dimensional geological model. The analysis is performed based on the incident angle of 45 degrees. The maximum shot-receiver distance is determined according to the reflection position of the Gaussian ray irradiation of the target layer received on the seabed, which is the maximum receiving distance.
[0032] As a specific implementation of this disclosure, calculating the offset aperture of the target layer that meets the offset imaging requirements includes:
[0033] The distance required for diffraction to achieve the desired target layer structure is calculated based on the average velocity, reflection time, and tilt angle of the target layer. The offset aperture is then determined based on the diffraction distance at the maximum steep tilt angle.
[0034] As a specific implementation of this disclosure, the diffraction return distance at the maximum steep tilt angle is:
[0035]
[0036] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0037] As a specific implementation of this disclosure, determining the initial maximum offset includes:
[0038] Based on the simulated single-shot FWI inversion at different offsets, the FWI inversion results are compared, and the initial maximum offset is determined by comparing the accuracy of the inverted velocity model with the actual model.
[0039] Thirdly, embodiments of this disclosure also provide an electronic device, the electronic device comprising:
[0040] Memory, which stores executable instructions;
[0041] A processor that executes the executable instructions in the memory to implement the method for determining the maximum offset distance for OBN acquisition.
[0042] Fourthly, embodiments of this disclosure also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for determining the maximum offset distance for OBN acquisition.
[0043] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description
[0044] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.
[0045] Figure 1 A flowchart illustrating the steps of a method for determining the maximum offset distance for OBN acquisition according to an embodiment of the present invention is shown.
[0046] Figure 2 A schematic diagram of seismic wave forward illumination analysis of a target layer in a target area is shown according to an embodiment of the present invention.
[0047] Figure 3 A schematic diagram of a two-dimensional geological model in an actual geological model of a target area according to an embodiment of the present invention is shown.
[0048] Figure 4 A schematic diagram of the FWI inversion results of 6000m offset data according to an embodiment of the present invention is shown.
[0049] Figure 5 A schematic diagram of the FWI inversion results of 7000m offset data according to an embodiment of the present invention is shown.
[0050] Figure 6 A schematic diagram of the FWI inversion results of 8000m offset data according to an embodiment of the present invention is shown.
[0051] Figure 7 A block diagram of an apparatus for determining the maximum offset distance of OBN acquisition according to an embodiment of the present invention is shown.
[0052] Explanation of reference numerals in the attached figures:
[0053] 201. Construction Module; 202. Forward Illumination Analysis Module; 203. Calculation Module; 204. FWI Inversion Module; 205. Output Module. Detailed Implementation
[0054] 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.
[0055] To facilitate understanding of the solutions and effects of the embodiments of the present invention, six specific application examples are given below. Those skilled in the art should understand that these examples are merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.
[0056] Example 1
[0057] Figure 1 A flowchart illustrating the steps of a method for determining the maximum offset distance for OBN acquisition according to an embodiment of the present invention is shown.
[0058] like Figure 1 As shown, the method for determining the maximum offset distance for OBN acquisition includes:
[0059] Step 101: Construct a three-dimensional geological model of the target area;
[0060] Step 102: Perform seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer;
[0061] Step 103: Calculate the offset aperture of the target layer to meet the requirements of offset imaging;
[0062] Step 104: Perform forward modeling of data based on the three-dimensional geological model, simulate a single shot, and then perform FWI inversion to determine the initial maximum offset.
[0063] Step 105: Determine the final maximum offset distance based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
[0064] In one example, a three-dimensional geological model is constructed based on the measured geological data and interpretation results of the target area.
[0065] In one example, performing seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer includes:
[0066] The shot point is placed underwater as the source point to simulate Gaussian ray irradiation of the target layer in the three-dimensional geological model. The analysis is performed based on the incident angle of 45 degrees. The maximum shot-receiver distance is determined according to the reflection position of the Gaussian ray irradiation of the target layer received on the seabed, which is the maximum receiving distance.
[0067] In one example, calculating the offset aperture of the target layer to meet the requirements of offset imaging includes:
[0068] The distance required for diffraction to achieve the desired structure of the target layer is calculated based on the average velocity, reflection time, and dip angle of the target layer. The offset aperture is then determined based on the diffraction distance at the maximum steep dip angle.
[0069] In one example, the diffraction return distance at the maximum steep tilt angle is:
[0070]
[0071] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0072] In one example, determining the initial maximum offset includes:
[0073] Based on the simulated single shot, FWI inversion was performed at different offsets. The FWI inversion results were compared, and the initial maximum offset was determined by comparing the accuracy of the inverted velocity model with the actual model.
[0074] Specifically, based on the geological measurement data and interpretation results of the target area, including the depth domain interpretation profile data and depth domain stratigraphic data of previously collected data, a three-dimensional fine geological model of the target area is constructed.
[0075] Seismic wave forward illumination analysis was performed on the target layer to determine the maximum receiving distance. The shot point was placed underwater, serving as the source point to simulate Gaussian ray irradiation of the target layer in the 3D geological model, with an incident angle of 45 degrees. Since OBN acquisition involves the excitation point being underwater and the receiver point being on the seabed, a maximum shot-receiver distance was determined based on the reflection location of the Gaussian ray irradiation received from the target layer on the seabed.
[0076] Based on the target layer's structure and velocity parameters, calculate the required migration aperture for migration imaging. Calculate the diffraction return distance to meet the target layer's structural requirements based on the target layer's average velocity, reflection time, and tilt angle. Use the diffraction return distance at the steepest tilt angle as a reference to determine the design of the migration aperture. Empirically, it is recommended that the maximum migration distance to meet the migration aperture design be greater than twice the diffraction return distance at the steepest tilt angle.
[0077] The diffraction return distance at the maximum steep tilt angle is:
[0078]
[0079] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0080] Based on the 3D geological model, forward modeling was performed, using parameters with a relatively large offset to simulate a single shot. Wave equation forward modeling was also performed based on the 3D geological model. The forward modeling observation system was configured with the shot point located below the water surface and the receiver point located on the seabed. A large maximum shot-receiver distance was set, increasing the distance to add redundancy analysis while still meeting illumination analysis and migration aperture requirements.
[0081] Based on simulated single-shot FWI inversions at different offsets, the appropriate maximum offset is determined by comparing the FWI inversion results. Based on simulated data, velocity models are retrieved using different offsets for FWI inversion. OBN-acquired data has advantages such as long offsets and omnidirectional coverage, making it more suitable for FWI inversion requirements. Therefore, ensuring the integrity of the data required for FWI inversion is crucial in OBN acquisition. By comparing the FWI inversion results at different offsets, and based on the accuracy of the inverted velocity model, as well as comparing it with the actual model, the maximum offset value required for FWI inversion can be determined.
[0082] By comprehensively analyzing the forward illumination results, the required offset aperture, and the FWI inversion results, the maximum offset distance suitable for the target area was finally selected.
[0083] This invention can determine the maximum offset distance of OBN acquisition in the target area, improve the imaging effect of OBN acquisition in the target area, and lay the foundation for subsequent analysis.
[0084] Example 2
[0085] The present invention also provides a device for determining the maximum offset distance of OBN acquisition, comprising:
[0086] The module builds a three-dimensional geological model of the target area;
[0087] The forward illumination analysis module performs seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer;
[0088] The calculation module calculates the offset aperture of the target layer to meet the requirements of offset imaging.
[0089] The FWI inversion module performs forward modeling of data based on a 3D geological model, simulates a single shot, and then performs FWI inversion to determine the initial maximum offset.
[0090] The output module determines the final maximum offset distance based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
[0091] In one example, a three-dimensional geological model is constructed based on the measured geological data and interpretation results of the target area.
[0092] In one example, performing seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer includes:
[0093] The shot point is placed underwater as the source point to simulate Gaussian ray irradiation of the target layer in the three-dimensional geological model. The analysis is performed based on the incident angle of 45 degrees. The maximum shot-receiver distance is determined according to the reflection position of the Gaussian ray irradiation of the target layer received on the seabed, which is the maximum receiving distance.
[0094] In one example, calculating the offset aperture of the target layer to meet the requirements of offset imaging includes:
[0095] The distance required for diffraction to achieve the desired structure of the target layer is calculated based on the average velocity, reflection time, and dip angle of the target layer. The offset aperture is then determined based on the diffraction distance at the maximum steep dip angle.
[0096] In one example, the diffraction return distance at the maximum steep tilt angle is:
[0097]
[0098] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0099] In one example, determining the initial maximum offset includes:
[0100] Based on the simulated single shot, FWI inversion was performed at different offsets. The FWI inversion results were compared, and the initial maximum offset was determined by comparing the accuracy of the inverted velocity model with the actual model.
[0101] Specifically, based on the geological measurement data and interpretation results of the target area, including the depth domain interpretation profile data and depth domain stratigraphic data of previously collected data, a three-dimensional fine geological model of the target area is constructed.
[0102] Seismic wave forward illumination analysis was performed on the target layer to determine the maximum receiving distance. The shot point was placed underwater, serving as the source point to simulate Gaussian ray irradiation of the target layer in the 3D geological model, with an incident angle of 45 degrees. Since OBN acquisition involves the excitation point being underwater and the receiver point being on the seabed, a maximum shot-receiver distance was determined based on the reflection location of the Gaussian ray irradiation received from the target layer on the seabed.
[0103] Based on the target layer's structure and velocity parameters, calculate the required migration aperture for migration imaging. Calculate the diffraction return distance to meet the target layer's structural requirements based on the target layer's average velocity, reflection time, and tilt angle. Use the diffraction return distance at the steepest tilt angle as a reference to determine the design of the migration aperture. Empirically, it is recommended that the maximum migration distance to meet the migration aperture design be greater than twice the diffraction return distance at the steepest tilt angle.
[0104] The diffraction return distance at the maximum steep tilt angle is:
[0105]
[0106] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0107] Based on the 3D geological model, forward modeling was performed, using parameters with a relatively large offset to simulate a single shot. Wave equation forward modeling was also performed based on the 3D geological model. The forward modeling observation system was configured with the shot point located below the water surface and the receiver point located on the seabed. A large maximum shot-receiver distance was set, increasing the distance to add redundancy analysis while still meeting illumination analysis and migration aperture requirements.
[0108] Based on simulated single-shot FWI inversions at different offsets, the appropriate maximum offset is determined by comparing the FWI inversion results. Based on simulated data, velocity models are retrieved using different offsets for FWI inversion. OBN-acquired data has advantages such as long offsets and omnidirectional coverage, making it more suitable for FWI inversion requirements. Therefore, ensuring the integrity of the data required for FWI inversion is crucial in OBN acquisition. By comparing the FWI inversion results at different offsets, and based on the accuracy of the inverted velocity model, as well as comparing it with the actual model, the maximum offset value required for FWI inversion can be determined.
[0109] By comprehensively analyzing the forward illumination results, the required offset aperture, and the FWI inversion results, the maximum offset distance suitable for the target area was finally selected.
[0110] This invention can determine the maximum offset distance of OBN acquisition in the target area, improve the imaging effect of OBN acquisition in the target area, and lay the foundation for subsequent analysis.
[0111] Example 3
[0112] OBN seismic acquisition is required for a certain target area, necessitating the design of an observation system tailored to the geological characteristics and target layer of that area. In the design of this observation system, the optimal selection of key acquisition parameters is crucial. Among these, the optimal selection of the maximum offset is a critical parameter, directly impacting the imaging quality of the acquired data and subsequent inversion modeling.
[0113] A three-dimensional geological model is constructed based on the depth domain interpretation results and stratigraphic data collected in the target area in the past. In the process of constructing the geological model, it is necessary to match the actual situation as much as possible, including structural features, the depth and velocity of each stratigraphic level, so that the subsequent analysis is more in line with the actual situation.
[0114] Figure 2 A schematic diagram of seismic wave forward illumination analysis of a target layer in a target area is shown according to an embodiment of the present invention.
[0115] Excitation sources are positioned on a horizontal plane above areas with complex geological structures in the model to simulate Gaussian ray irradiation of the deepest target layer. This aims to better reflect the specificity of the maximum offset parameter in structurally complex regions, ensuring imaging quality in such areas. To ensure the accuracy of parameter selection, simulated Gaussian ray irradiation is conducted in different regions. Finally, the results from each observation point are statistically analyzed, and a suitable maximum offset parameter value is selected based on comprehensive consideration. Because the target layer region may contain multiple strata, and the structural variations may be diverse, it is necessary to irradiate different strata during simulated Gaussian ray irradiation to ensure that the selected maximum offset parameter value is most effective. It is generally considered that an incident angle of 40° or higher is required for AVO analysis and elastic impedance inversion of the target layer. Figure 1 In this embodiment, the target layer is irradiated with rays emitted from and received at the sea surface at an incident angle of 45 degrees. The offset distance is calculated based on the distance reflected from the sea surface to the receiving position of the seabed geophone, and the result is 6900m.
[0116] The maximum offset parameter value is selected based on the target layer's requirements for the offset aperture. Pre-stack migration's data requirements should be guaranteed during data acquisition, especially the maximum offset and maximum longitudinal offset, which are decisive factors for improving the quality of mid-deep data. If these two parameters are chosen too small, simply increasing the offset aperture during post-processing will not achieve the desired migration effect. During processing, pre-stack migration comprehensively determines the optimal offset aperture based on the target layer's regional velocity and the steepest dip angle. Therefore, in this embodiment, the target layer's average velocity (3825.21 m / s), reflection time (2974 ms), and maximum dip angle (30°) are used. 0 The calculated diffraction return distance is 3281m. To meet the requirements of the offset aperture, the maximum offset distance should be selected to be more than twice this value, that is, more than 3281x2=6562m.
[0117] Based on the established three-dimensional geological model, wave equation simulation of a single shot is performed. Before the simulation, a simulated observation method needs to be established. In this embodiment, the observation method uses a shot point located 5m below the water surface and a receiver point located on the seabed, simulating actual field acquisition methods as closely as possible. A relatively large value of 9000m is selected for the maximum shot-receiver distance. This is essentially adding a certain distance while still meeting the requirements for illumination analysis and offset aperture, with the aim of increasing redundancy analysis and ensuring that the selected maximum offset distance meets the requirements of subsequent analyses.
[0118] By simulating single-shot FWI velocity model inversion, and comparing the accuracy of velocity models obtained from FWI inversion using single-shot data at different offsets, the maximum required shot-receiver distance was studied. FWI inversion, as a high-precision quantitative seismic imaging method, has achieved excellent results in oil and gas exploration in complex areas. However, to truly realize the value of FWI inversion, the integrity of the seismic data must be guaranteed. In this embodiment, different offsets (5000m, 6000m, 7000m, 8000m, 9000m) of forward modeling data from the target area were used as input data for FWI inversion. The inversion results of different offsets were compared. When the improvement in inversion accuracy is not significant after increasing the offset value, the offset value can be considered to satisfy the integrity requirements of the FWI inversion data; larger offset values are considered unnecessary.
[0119] Figure 3 A schematic diagram of a two-dimensional geological model in an actual geological model of a target area according to an embodiment of the present invention is shown.
[0120] Figure 4 A schematic diagram of the FWI inversion results of 6000m offset data according to an embodiment of the present invention is shown.
[0121] Figure 5 A schematic diagram of the FWI inversion results of 7000m offset data according to an embodiment of the present invention is shown.
[0122] Figure 6 A schematic diagram of the FWI inversion results of 8000m offset data according to an embodiment of the present invention is shown.
[0123] Figure 3 It is one of the two-dimensional geological models in the actual geological model of the target area in this embodiment. Figure 4 The results are from the inversion of data at a 6000m offset, which show that the shallow layers have obtained relatively good inversion model results. Figure 5 The results of the inversion of data at a 7000m offset show that the accuracy of deep velocity inversion has been further improved. Figure 6 The inversion results are from 8000m offset data, and it can be seen that the improvement in inversion accuracy is not significant. Therefore, based on the accuracy comparison of FWI inversion, it is considered that the maximum shot-receiver distance for this target area should be above 7000m.
[0124] Based on a comprehensive analysis of the results of forward illumination, the required offset aperture, and the FWI inversion, a maximum offset distance of 7000m or more was ultimately selected as suitable for OBN acquisition in this target area.
[0125] This invention establishes a three-dimensional geological model of the target area, performs forward seismic illumination analysis on the target layer, and determines the maximum receiving distance of the target layer. Then, based on the velocity and structural characteristics of the target layer, it calculates the maximum offset distance corresponding to the migration aperture required for migration imaging. Next, it uses the geological model of the target area for forward modeling, performs FWI inversion using different offset data from the forward modeling, and compares the FWI inversion accuracy to determine the required maximum offset value. Finally, it comprehensively analyzes the forward illumination results, the required migration aperture results, and the maximum offset value determined by the FWI inversion results to determine the maximum offset parameter value for OBN acquisition in the target area. This method considers the maximum shot-receiver distance required by subsequent AVO analysis, migration imaging, and FWI inversion during the OBN acquisition scheme design, ensuring high data requirements for OBN acquisition.
[0126] Example 4
[0127] Figure 7 A block diagram of an apparatus for determining the maximum offset distance of OBN acquisition according to an embodiment of the present invention is shown.
[0128] like Figure 7 As shown, the device for determining the maximum offset distance of OBN acquisition includes:
[0129] Module 201 is used to construct a three-dimensional geological model of the target area.
[0130] The forward illumination analysis module 202 performs forward illumination analysis of seismic waves on the target layer to determine the maximum receiving distance of the target layer;
[0131] Calculation module 203 calculates the offset aperture of the target layer that meets the requirements of offset imaging;
[0132] FWI inversion module 204 performs forward modeling of data based on the three-dimensional geological model, simulates a single shot, and then performs FWI inversion to determine the initial maximum offset.
[0133] The output module 205 determines the final maximum offset distance based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
[0134] In one example, a three-dimensional geological model is constructed based on the measured geological data and interpretation results of the target area.
[0135] In one example, performing seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer includes:
[0136] The shot point is placed underwater as the source point to simulate Gaussian ray irradiation of the target layer in the three-dimensional geological model. The analysis is performed based on the incident angle of 45 degrees. The maximum shot-receiver distance is determined according to the reflection position of the Gaussian ray irradiation of the target layer received on the seabed, which is the maximum receiving distance.
[0137] In one example, calculating the offset aperture of the target layer to meet the requirements of offset imaging includes:
[0138] The distance required for diffraction to achieve the desired structure of the target layer is calculated based on the average velocity, reflection time, and dip angle of the target layer. The offset aperture is then determined based on the diffraction distance at the maximum steep dip angle.
[0139] In one example, the diffraction return distance at the maximum steep tilt angle is:
[0140]
[0141] Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
[0142] In one example, determining the initial maximum offset includes:
[0143] Based on the simulated single shot, FWI inversion was performed at different offsets. The FWI inversion results were compared, and the initial maximum offset was determined by comparing the accuracy of the inverted velocity model with the actual model.
[0144] Example 5
[0145] This embodiment provides an electronic device, which includes: a memory storing executable instructions; and a processor that executes the executable instructions in the memory to implement the above-described method for determining the maximum offset distance of OBN acquisition.
[0146] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.
[0147] 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.
[0148] 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 this disclosure, the processor is used to execute computer-readable instructions stored in the memory.
[0149] Those skilled in the art will 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 disclosure.
[0150] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.
[0151] Example 6
[0152] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for determining the maximum offset distance for OBN acquisition.
[0153] A computer-readable storage medium according to embodiments of the present disclosure 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 disclosure are performed.
[0154] 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).
[0155] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.
[0156] 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 determining the maximum offset distance for OBN acquisition, characterized in that, include: Construct a three-dimensional geological model of the target area; Seismic wave forward illumination analysis was performed on the target layer to determine the maximum receiving distance of the target layer. Calculate the offset aperture of the target layer to meet the requirements of offset imaging; Based on the three-dimensional geological model, data forward modeling is performed to simulate a single shot, followed by FWI inversion to determine the initial maximum offset. The final maximum offset distance is determined based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
2. The method for determining the maximum offset distance for OBN acquisition according to claim 1, wherein, The three-dimensional geological model is constructed based on the geological measurement data and interpretation results of the target area.
3. The method for determining the maximum offset distance for OBN acquisition according to claim 1, wherein, Seismic wave forward illumination analysis was performed on the target layer to determine the maximum receiving distance of the target layer, including: The shot point is placed underwater and used as the source point to simulate Gaussian ray irradiation of the target layer in the three-dimensional geological model. The analysis is performed based on the incident angle of 45 degrees. The maximum shot-receiver distance is determined according to the reflection position of the Gaussian ray irradiation of the target layer received on the seabed, which is the maximum receiving distance.
4. The method for determining the maximum offset distance for OBN acquisition according to claim 1, wherein, Calculating the offset aperture of the target layer to meet the requirements of offset imaging includes: The distance required for diffraction to achieve the desired target layer structure is calculated based on the average velocity, reflection time, and tilt angle of the target layer. The offset aperture is then determined based on the diffraction distance at the maximum steep tilt angle.
5. The method for determining the maximum offset distance for OBN acquisition according to claim 4, wherein, The diffraction return distance at the maximum steep tilt angle is: Where dx is the diffraction return distance of the target layer, v is the average velocity of the target layer, t is the reflection time of the target layer, and θ is the distance from the target layer. max This is the steepest dip angle of the strata.
6. The method for determining the maximum offset distance for OBN acquisition according to claim 1, wherein, Determining the initial maximum offset includes: Based on the simulated single-shot FWI inversion at different offsets, the FWI inversion results are compared, and the initial maximum offset is determined by comparing the accuracy of the inverted velocity model with the actual model.
7. A device for determining the maximum offset distance of OBN acquisition, characterized in that, include: The module builds a three-dimensional geological model of the target area; The forward illumination analysis module performs seismic wave forward illumination analysis on the target layer to determine the maximum receiving distance of the target layer; The calculation module calculates the offset aperture of the target layer that meets the requirements for offset imaging; The FWI inversion module performs forward modeling of the data based on the three-dimensional geological model, simulates a single shot, and then performs FWI inversion to determine the initial maximum offset. The output module determines the final maximum offset distance based on the maximum receiving distance, the offset aperture, and the initial maximum offset distance.
8. The apparatus for determining the maximum offset distance of OBN acquisition according to claim 7, wherein, The three-dimensional geological model is constructed based on the geological measurement data and interpretation results of the target area.
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 method for determining the maximum offset distance for OBN acquisition as described in any one of claims 1-6.
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 method for determining the maximum offset distance for OBN acquisition as described in any one of claims 1-6.