Azimuth angle gather sampling and storing method with collection consistency
By calculating and interpolated azimuth angle and reflection angle, the problem of inconsistency between the azimuth angle domain data and the original collected data is solved, data distortion is reduced, storage costs are reduced, and more accurate superimposed imaging effects are achieved.
Patent Information
- Application Number
- CN202411626070.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-02-18
AI Technical Summary
In the prior art, the azimuth angle domain data is inconsistent with the original collected data, resulting in data distortion caused by regular angle sampling, affecting the superimposed imaging effect.
Given the number of angle samples in the close angle domain, calculate the reflection angle and azimuth angle corresponding to each sampling point, and calculate the true reflection angle and azimuth angle one by one during the imaging process, interpolate to the corresponding grid point, and accumulate the imaging value. To complete the storage of the azimuth angle channel set.
The data distortion caused by regular angle sampling is reduced, the horizontal sampling of the original seismic acquisition and observation system is maintained, the distortion of data of different offset distances caused by sampling interpolation is reduced, and the interpolation amount and data storage cost are reduced.
Smart Images
Figure CN119471816A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of seismic data sampling and storage, and more specifically, to a method for sampling and storing azimuth angle gathers with acquisition consistency. Background Art
[0002] Prestack seismic gathers are essential data for seismic acquisition, processing, interpretation, etc. Conventional pre-imaging seismic gathers include common shot gathers, common center point gathers, common offset gathers, etc. Post-imaging gathers mainly include offset domain common imaging point gathers, offset vector domain common imaging point gathers, angle domain common imaging point gathers, and azimuth angle domain common imaging point gathers. Different gathers are usually used for different applications. In recent years, with the widespread promotion and application of wide-azimuth acquisition, the extraction and application of azimuth angle domain gathers have been increasingly studied.
[0003] Conventional 3D seismic acquisition is to arrange shot points and receiver points on the surface according to certain rules. Shot points and receiver points are usually arranged according to orthogonal rules. For each shot data, it is equivalent to dividing the surrounding area according to regular grids and observing at each grid point. Projected to the underground azimuth angle domain, the reflection points and azimuth angle distribution corresponding to each imaging point are not equally spaced. If the azimuth angle gather is sampled according to uniform sampling, it is bound to cause small angle sampling to be too dense and large angle sampling to be too sparse, resulting in distortion of the azimuth angle gather. The stacked imaging of the azimuth angle gather is inconsistent with the original stacked imaging effect, which brings about artificial sampling errors. Summary of the invention
[0004] The purpose of the present invention is to overcome the shortcomings of the prior art that the azimuth angle domain data is inconsistent with the original collected data, and to provide an azimuth angle gather sampling and storage method with collection consistency, which can reduce data distortion caused by regular angle sampling.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:
[0006] A method for sampling and storing azimuth angle gathers with consistent acquisition is provided, comprising the following steps:
[0007] S1. According to the number of surface acquisition coverage, the number of angle sampling in the similar angle domain is given;
[0008] S2. According to the angle sampling number in the angle domain and the set sampling rules, the reflection angle and azimuth corresponding to each sampling point are calculated. Each grid corresponds to a reflection angle and an azimuth;
[0009] S3. During the imaging process, the azimuth and reflection angle corresponding to the imaging result are calculated for each imaging point one by one to obtain the real reflection angle and azimuth;
[0010] S4. According to the reflection angle and azimuth corresponding to each sampling point in step S2, the true reflection angle and azimuth calculated in step S3 are interpolated to the corresponding grid points;
[0011] S5. Accumulate the imaging values of all seismic traces to the corresponding grid points to complete the storage of the azimuth angle trace set.
[0012] The present invention proposes a method for sampling and storing azimuth angle gathers with consistent acquisition, which fully considers the characteristics of azimuth angle gathers and the characteristics of the actual seismic acquisition observation system, thereby reducing data distortion caused by regular angle sampling and reducing data storage costs. It can maintain the horizontal sampling of the original seismic acquisition observation system to the greatest extent, thereby reducing the distortion of data of different offset distances caused by sampling interpolation, reducing the interpolation amount, and reducing the data storage cost.
[0013] Preferably, in step S3, the reflection angle γ is calculated using the following formula:
[0014]
[0015] Where P s represents the ray parameter of the wave field from the shot point to the imaging point, P R Represents the ray parameters from the wave field at the detection point to the imaging point.
[0016] Preferably, in step S3, the azimuth angle is calculated using the following formula:
[0017]
[0018] Where P M represents the center point ray parameter, and y represents the true north direction.
[0019] Preferably, the azimuth and reflection angles of the azimuth angle gather are stored in a manner consistent with the surface acquisition system.
[0020] Preferably, the tangent values of the two angles are equally spaced according to the following formula to maintain the consistency of angle sampling and surface offset sampling;
[0021]
[0022] In the formula, h x represents the surface offset, z represents the depth of the imaging point; Δh x is the assumed offset spacing; h y Indicates the offset in the y direction.
[0023] Preferably, the set sampling rules include: collecting a consistent angle projection map based on the surface, taking the center of the concentric circles of the projection azimuth angle as the origin, drawing an equidistant spiral line in the projection map, and performing equal arc sampling on the equidistant spiral line.
[0024] Preferably, the equidistant helix is obtained in the following manner:
[0025] The equidistant spiral satisfies the following in the polar coordinate system:
[0026]
[0027] Among them, r is the radius of the polar coordinate system, and tanγ is the distance that each circle of the equidistant spiral increases. According to the arc length property of the equidistant spiral, its arc length s satisfies:
[0028]
[0029] Wherein, α and β represent the azimuth and reflection angle respectively.
[0030] The arc lengths of the equidistant spirals are taken to be equal, so as to calculate and determine the azimuth and reflection angle corresponding to each grid point.
[0031] The present invention also provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-described method when executing the computer program.
[0032] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.
[0033] Compared with the prior art, the present invention has the following beneficial effects:
[0034] The present invention provides a method for sampling and storing azimuth angle gathers with consistent acquisition, which fully considers the characteristics of azimuth angle gathers and the characteristics of actual seismic acquisition observation systems, thereby reducing data distortion caused by regular angle sampling, and maintaining the horizontal sampling of the original seismic acquisition observation system to the greatest extent, thereby reducing the distortion of data of different offset distances caused by sampling interpolation, reducing the interpolation amount, and reducing the data storage cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 Schematic diagram of the flow chart of the sampling and storage method for azimuth angle gathers with consistent acquisition.
[0036] Figure 2 Schematic diagram of the relationship between underground azimuth angle gathers and surface shot check points.
[0037] Figure 3This is the correspondence between the surface offset and the underground reflection angle in the case of horizontal layers.
[0038] Figure 4 Collect consistent angle projection diagrams for the surface.
[0039] Figure 5 A schematic diagram showing the acquisition of consistent azimuth angle sampling according to the method of the present invention.
[0040] Figure 6 This is a schematic diagram showing conventional azimuth angle gather sampling. DETAILED DESCRIPTION
[0041] The present invention is further described below in conjunction with specific implementation methods. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams, not actual drawings, and cannot be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.
[0042] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0043] Embodiment 1
[0044] This embodiment is a first embodiment of a method for sampling and storing azimuth angle gathers with acquisition consistency, comprising the following steps:
[0045] S1. According to the number of surface acquisition coverage, the number of angle sampling in the similar angle domain is given;
[0046] S2. According to the angle sampling number in the angle domain and the set sampling rules, the reflection angle and azimuth corresponding to each sampling point are calculated. Each grid corresponds to a reflection angle and an azimuth;
[0047] S3. During the imaging process, the azimuth and reflection angle corresponding to the imaging result are calculated for each imaging point one by one to obtain the real reflection angle and azimuth;
[0048] S4. According to the reflection angle and azimuth corresponding to each sampling point in step S2, the true reflection angle and azimuth calculated in step S3 are interpolated to the corresponding grid points;
[0049] S5. Accumulate the imaging values of all seismic traces to the corresponding grid points to complete the storage of the azimuth angle trace set.
[0050] The present invention proposes an azimuth angle gather storage method for maintaining acquisition consistency, which can maintain the horizontal sampling of the original seismic acquisition observation system to the greatest extent, thereby reducing the distortion of data with different offset distances caused by sampling interpolation, reducing the interpolation amount, and reducing the data storage cost.
[0051] The so-called seismic migration azimuth angle domain common imaging point gather is the image output by migration imaging that can reflect different azimuths and different reflection angles at underground imaging points. Usually, the underground reflection angle γ satisfies:
[0052]
[0053] Azimuth satisfy:
[0054]
[0055] In formulas (1) and (2), P S represents the ray parameter of the wave field from the shot point to the imaging point, P R P represents the ray parameter of the wave field propagating from the detection point to the imaging point. M represents the ray parameter of the center point, and y usually represents the true north direction. Through equations (1) and (2), as long as the ray parameters of the wave field propagating from the shot point and the receiver point to the imaging point can be calculated, the corresponding wave field can be projected into the angle domain to realize the output of the azimuth angle domain gather.
[0056] In step S3, the azimuth angle and the reflection angle in the imaging process are calculated according to the above formulas (1) and (2), respectively.
[0057] Formulas (1) and (2) give the relationship between the ray parameters and the azimuth angle projection at the imaging point, but cannot intuitively give the angle sampling interval and sampling range. Figure 2 The relationship between the common imaging point gathers in the underground azimuth angle domain and the distribution of surface shot check points. Here, only the projection relationship between the surface shot spacing and the underground angle is shown for one shot check pair. Figure 3 This is a reflection path diagram of three shot detection pairs observed in a two-dimensional underground horizontal layered medium. This diagram can intuitively show the corresponding relationship between the coordinate position of the shot detection point and the reflection angle at the underground imaging point. Obviously, the reflection angle satisfies:
[0058]
[0059] In the formula, h x represents the surface offset, and z represents the depth of the imaging point. In conventional acquisition, the surface offsets are usually arranged regularly at certain intervals.
[0060] Assume that the offset distance is Δh x , then the angular intervals between different seismic traces satisfy the following relationship:
[0061]
[0062] That is, for a given imaging point, the interval of the reflection angle tangent satisfies uniform sampling. Similarly, in the three-dimensional case, the reflection angle and azimuth angle satisfy:
[0063]
[0064] In the formula, h y Indicates the offset in the y direction. That is, when the surface offset is uniformly sampled, the interval between the reflection angle and the tangent of the azimuth angle satisfies uniform sampling.
[0065] Since trigonometric functions are nonlinear transcendental functions, formulas (4) and (5) define the nonlinear projection relationship between the surface offset interval and the underground azimuth angle interval. In the case of uniform sampling of the surface offset, the underground reflection angle and azimuth are modulated by the tangent function. If the underground angle interval is uniformly sampled, the small angle sampling will be too dense and the large angle sampling will be too sparse. In other words, in the case of uniform angle sampling, a large amount of redundant data will be interpolated from the small angle data, while a large angle will lose a large amount of data, resulting in artificial sampling loss. On the one hand, this will cause the angle domain stacking profile to be inconsistent with the original stacking profile, affecting the angle domain imaging results; on the other hand, in order to ensure sufficient large angle sampling rate, the number of angle sampling points will inevitably be increased, resulting in angle sampling waste and affecting the storage of angle domain imaging gathers.
[0066] The projection relationship of formula (5) suggests that when storing the azimuth and reflection angle of the azimuth angle gather, they can be segmented in a manner consistent with the surface acquisition system, that is, according to formula (5), the tangent values of the two angles are segmented at equal intervals, so that the consistency of angle sampling and surface offset sampling can be basically maintained.
[0067] Figure 4 As shown in the figure, the dotted line is the offset distance regular sampling, and the azimuth angle of the projection is shown by the light-colored concentric circles in the figure. In order to further maintain the consistency of the angle domain sampling and the surface offset distance sampling, in step S2, the following rules are adopted: Figure 4As shown, equal arc length sampling is performed on the black thick line. The sampling result is equivalent to that the circumference of the arc increases as you go outward, and the more samples are taken, which further improves the consistency between the angle domain sampling and the surface sampling and reduces the error caused by sampling differences.
[0068] The present embodiment provides a method for sampling and storing azimuth angle gathers with consistent acquisition, which fully considers the characteristics of azimuth angle gathers and the characteristics of the actual seismic acquisition observation system, thereby reducing data distortion caused by regular angle sampling and maintaining the horizontal sampling of the original seismic acquisition observation system to the greatest extent, thereby reducing the distortion of data at different offset distances caused by sampling interpolation, reducing the interpolation amount, and reducing the data storage cost.
[0069] Embodiment 2
[0070] This embodiment is a second embodiment of a method for sampling and storing azimuth angle gathers with acquisition consistency. The other steps are the same as those of the first embodiment. The difference is that, in this embodiment, the sampling rules set in step S2 include: Figure 4 As shown, according to the consistent angle projection map collected on the surface, with the center of the concentric circles of the projected azimuth angle as the origin, equidistant spiral lines are drawn in the projection map, and equal arc sampling is performed on the equidistant spiral lines; the sampling result is equivalent to the outer circle, the larger the circumference of the arc, the more samples are taken, further improving the consistency of angle domain sampling and surface sampling, and reducing the error caused by sampling differences.
[0071] Specifically, the equidistant spiral is obtained as follows:
[0072] The equidistant spiral satisfies in the polar coordinate system
[0073]
[0074] Among them, r is the radius of the polar coordinate system, and tanγ is the distance that each circle of the equidistant spiral increases. According to the arc length property of the equidistant spiral, its arc length s satisfies
[0075]
[0076] Here, α and β represent the azimuth and reflection angle, respectively. Given two azimuth angles according to formula (7), the arc length of each equidistant spiral can be calculated. By making the arc lengths of the equidistant spirals equal, the azimuth and reflection angle corresponding to each grid point can be determined.
[0077] The sampling rules provided in this embodiment result in sampling that is equivalent to the fact that the circumference of the equidistant spiral increases as the outer circle is moved, the more samples are taken, the fewer samples are taken for small reflection angles, and the more samples are taken for large reflection angles, thereby further improving the consistency between the angle domain sampling and the surface sampling and reducing the errors caused by sampling differences.
[0078] Embodiment 3
[0079] This embodiment is a third embodiment of a method for sampling and storing azimuth angle gathers with acquisition consistency. The azimuth angle gathers are sampled and stored in the manner given in the first and second embodiments. Figure 5 The figure shows the underground azimuth angle gather output by the present invention. The broken line above the header is the azimuth, with an angle range of 0-360°, and the gradually rising curve is the reflection angle, with an angle range of 0-50°. It can be seen that the small reflection angle samples are less and the large reflection angle samples are more, which is highly consistent with the conventional acquisition. Figure 6 This is a conventionally sampled azimuth angle gather. This gather has too many small-angle samples and insufficient large-angle samples, which will increase the storage cost and cause differences between angle domain imaging and conventional imaging effects.
[0080] Embodiment 4
[0081] This embodiment is the fourth embodiment of a method for sampling and storing azimuth angle gathers with acquisition consistency. In this embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the steps of the methods described in embodiments one to three are implemented.
[0082] Embodiment 5
[0083] This embodiment is the fifth embodiment of a method for sampling and storing azimuth angle gathers with acquisition consistency. In this embodiment, a computer-readable storage medium is provided, on which a computer program is stored, characterized in that when the computer program is executed by a processor, the steps of the method described in embodiments one to three are implemented.
[0084] In summary, the sampling and storage method of azimuth angle gathers with acquisition consistency of the present invention fully considers the characteristics of azimuth angle gathers and the characteristics of the actual seismic acquisition observation system, thereby reducing data distortion caused by regular angle sampling, and can maintain the horizontal sampling of the original seismic acquisition observation system to the greatest extent, thereby reducing the distortion of data of different offset distances caused by sampling interpolation, reducing the interpolation amount, and reducing the data storage cost.
[0085] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0086] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.
Claims
1. A method for sampling and storing azimuth angle gathers with consistent acquisition, characterized in that: The following steps are involved: S1. According to the number of surface acquisition coverage, the number of angle sampling in the similar angle domain is given; S2. According to the angle domain angle sampling number and the set sampling rules, the reflection angle and azimuth corresponding to each sampling point are calculated, and each grid corresponds to a reflection angle and an azimuth; S3. During the imaging process, the azimuth and reflection angle corresponding to the imaging result are calculated for each imaging point one by one to obtain the real reflection angle and azimuth; S4. According to the reflection angle and azimuth corresponding to each sampling point in step S2, the true reflection angle and azimuth calculated in step S3 are interpolated to the corresponding grid points; S5. Accumulate the imaging values of all seismic traces to the corresponding grid points to complete the storage of the azimuth angle trace set.
2. The azimuth angle gather sampling and storage method for collecting consistent data according to claim 1, characterized in that: In step S3, the reflection angle γ is calculated using the following formula: Where P s represents the ray parameter of the wave field from the shot point to the imaging point, P R Represents the ray parameters from the wave field at the detection point to the imaging point.
3. The azimuth angle gather sampling and storage method for collecting consistent data according to claim 2, characterized in that: In step S3, the azimuth angle is calculated using the following formula: Where P M represents the center point ray parameter, and y represents the true north direction.
4. The method for sampling and storing azimuth angle gathers with acquisition consistency according to claim 1, characterized in that: When storing the azimuth and reflection angles of the azimuth gather, they are segmented in a manner consistent with the surface acquisition system.
5. The method for sampling and storing azimuth angle gathers with acquisition consistency according to claim 4, characterized in that: According to the following formula, the tangent values of the two angles are equally divided to maintain the consistency of angle sampling and surface offset sampling; In the formula, h x represents the surface offset, z represents the depth of the imaging point; Δh x is the assumed offset spacing; h y Indicates the offset in the y direction.
6. The method for sampling and storing azimuth angle gathers with acquisition consistency according to any one of claims 1 to 5, characterized in that: The set sampling rules include: collecting consistent angle projection images based on the surface, taking the center of the concentric circles of the projection azimuth angle as the origin, drawing equidistant spiral lines in the projection image, and performing equal arc length sampling on the equidistant spiral lines.
7. The method for sampling and storing azimuth angle gathers with acquisition consistency according to claim 6, characterized in that: The equidistant spiral is obtained as follows: The equidistant spiral satisfies the following in polar coordinates: Among them, r is the radius of the polar coordinate system, and tanγ is the distance that each circle of the equidistant spiral increases. According to the arc length property of the equidistant spiral, its arc length s satisfies: Wherein, α and β represent the azimuth and reflection angle respectively.
8. The method for sampling and storing azimuth angle gathers with acquisition consistency according to claim 7, characterized in that: In step S2, the arc lengths of the equidistant spirals are taken to be equal, so as to calculate and determine the azimuth angle and reflection angle corresponding to each grid point.
9. A computer device comprising a memory and a processor, characterized in that: The memory stores a computer program, and the processor implements the steps of the method described in any one of claims 1 to 8 when executing the computer program.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.