Evaluation method, device, electronic equipment and storage medium for earthquake observation system

Abstract

This invention relates to an evaluation method, apparatus, electronic device, and storage medium for a seismic observation system. The method involves acquiring a geological model of an exploration area; determining the maximum shot-receiver distance for each subsurface layer and, based on the maximum shot-receiver distance, determining the seismic observation system corresponding to each subsurface layer; identifying any subsurface layer as a target layer; obtaining the imaging area projected onto the surface of a target point on the target layer using a reverse ray tracing method, and determining the area of ​​the imaging area; determining the coverage frequency of the imaging area based on the seismic observation system corresponding to the target layer; and determining the coverage density of the imaging area based on the coverage frequency and the area of ​​the imaging area. This coverage density is used to evaluate the seismic observation system. Specifically, the method involves targeted statistical analysis of coverage density based on the maximum offset corresponding to different subsurface layers, using coverage density to determine the rationality of the observation system, thereby improving the evaluation rationality.

Description

Technical Field

[0001] This invention relates to the field of geophysical exploration technology, and in particular to an evaluation method, apparatus, electronic device, and storage medium for an earthquake observation system. Background Technology

[0002] Seismic data acquisition is the foundation of seismic exploration, and the accurate design of a seismic observation system is a key factor in the success of seismic data acquisition. Therefore, evaluating the quality of a seismic observation system is extremely important.

[0003] Coverage count is often used to evaluate observation systems. However, currently, the same maximum shot-receiver distance is used as the attribute for calculating coverage count for different subsurface layers. Since the coverage count is different for subsurface layers at different depths, the requirements for the observation system are also different. Therefore, the existing evaluation index is not effective and cannot guarantee the accuracy and precision of imaging. Summary of the Invention

[0004] The embodiments of the present invention provide an evaluation method, apparatus, electronic device and storage medium for an earthquake observation system, in order to solve the technical problem that existing evaluation indicators are not effective.

[0005] In a first aspect, embodiments of the present invention provide an evaluation method for a seismic observation system, comprising: acquiring a geological model of an exploration area, the geological model being used to display the surface and subsurface layers of different depths in the exploration area; determining the maximum shot-receiver distance corresponding to each subsurface layer, and determining a seismic observation system corresponding to each subsurface layer based on the maximum shot-receiver distance; determining any subsurface layer as a target layer, and for a target point on the target layer, obtaining an imaging area projected onto the surface by the target point using a reverse ray tracing method, and determining the area of ​​the imaging area; determining the coverage number of the imaging area based on the seismic observation system corresponding to the target layer; and determining the coverage density of the imaging area based on the coverage number and the area of ​​the imaging area, the coverage density being used to evaluate the seismic observation system.

[0006] As an embodiment of the present invention, obtaining the imaging area projected onto the ground surface by the reverse ray tracing method includes: determining the normal of the target layer at the target point, and determining the normal angle based on the first layer velocity and the second layer velocity, wherein the first layer velocity is the layer velocity corresponding to the target layer, and the second layer velocity is the layer velocity corresponding to the next layer of the target layer; determining the ray emitted from the target point toward the ground surface at the normal angle, and determining the area enclosed by the intersection of the ray and the ground surface as the imaging area.

[0007] As an embodiment of the present invention, determining the normal angle based on the first layer velocity and the second layer velocity includes: if the first layer velocity is less than the second layer velocity, then performing an arcsine calculation on the ratio of the first layer velocity and the second layer velocity to obtain the normal angle; if the first layer velocity is greater than the second layer velocity, then determining the normal angle as a preset angle.

[0008] As an embodiment of the present invention, the method further includes: generating a grid and projecting the grid onto the ground surface; after obtaining the imaging area of ​​the target point projected onto the ground surface according to the reverse ray tracing method, the method further includes: identifying the grids within the imaging area; determining the coverage number of the imaging area according to the seismic observation system corresponding to the target layer includes: obtaining the coverage number of each grid within the imaging area according to the seismic observation system of the target layer, and determining the sum of the coverage numbers of each grid as the coverage number of the imaging area.

[0009] As an embodiment of the present invention, the grid within the imaging region includes at least a first grid and a second grid, wherein the entire area of ​​the first grid is located within the imaging region, and a portion of the area of ​​the second grid is located within the imaging region; obtaining the coverage count of each grid within the imaging region based on the seismic observation system of the target layer includes: directly obtaining the coverage count of the first grid based on the seismic observation system of the target layer; and obtaining the coverage count of the second grid based on the proportion of the area occupied by the second grid inside and outside the imaging region.

[0010] As an embodiment of the present invention, the method further includes: projecting the grid onto each underground layer, wherein the target point is the center point of the target grid in the grid region corresponding to the target layer.

[0011] As an embodiment of the present invention, after determining the coverage density of the imaging area based on the coverage number and the area of ​​the imaging area, the method further includes: adjusting the shot point and receiver point based on the coverage density to optimize the seismic observation system.

[0012] Secondly, embodiments of the present invention provide an evaluation device for a seismic observation system, comprising: a model acquisition module for acquiring a geological model of an exploration area, the geological model being used to display the surface and subsurface layers of different depths of the exploration area; a first determination module for determining the maximum shot-receiver distance corresponding to each subsurface layer, and determining a seismic observation system corresponding to each subsurface layer based on the maximum shot-receiver distance; a second determination module for determining any subsurface layer as a target layer, obtaining an imaging area projected onto the surface of a target point on the target layer using a reverse ray tracing method, and determining the area of ​​the imaging area; a third determination module for determining the coverage number of the imaging area based on the seismic observation system corresponding to the target layer; and a fourth determination module for determining the coverage density of the imaging area based on the coverage number and the area of ​​the imaging area, the coverage density being used to evaluate the seismic observation system.

[0013] Thirdly, embodiments of the present invention provide an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor is used to implement the steps of the evaluation method for the earthquake observation system described in any one of the first aspects when executing the program stored in the memory.

[0014] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of the evaluation method for the seismic observation system according to any one of the first aspects.

[0015] The seismic observation system evaluation method, apparatus, electronic device, and storage medium provided in the embodiments of the present invention acquire a geological model of the exploration area, which is used to display the surface and subsurface layers of different depths in the exploration area; determine the maximum shot-receiver distance corresponding to each subsurface layer, and determine the seismic observation system corresponding to each subsurface layer based on the maximum shot-receiver distance; determine any subsurface layer as the target layer, and for a target point on the target layer, obtain the imaging area projected onto the surface of the target point using the reverse ray tracing method, and determine the area of ​​the imaging area; determine the coverage number of the imaging area based on the seismic observation system corresponding to the target layer; determine the coverage density of the imaging area based on the coverage number and the area of ​​the imaging area, and the coverage density is used to evaluate the seismic observation system; that is, the embodiments of the present invention deploy corresponding seismic observation systems according to the maximum shot-receiver distance of different subsurface layers, obtain the coverage number of different subsurface layers, and simultaneously, for any point in the subsurface layer, find the imaging area on the surface that contributes to that point using the reverse ray tracing method, calculate the coverage density of the imaging area, and judge the rationality of the observation system by the coverage density, thereby improving the rationality of the evaluation, and enabling more effective deployment and optimization of the observation system based on this. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating an evaluation method for an earthquake observation system provided in an embodiment of the present invention;

[0019] Figure 2 A flowchart illustrating another method for evaluating an earthquake observation system provided in an embodiment of the present invention;

[0020] Figure 3 A flowchart illustrating another method for evaluating an earthquake observation system provided in an embodiment of the present invention;

[0021] Figure 4a This is a schematic diagram of an imaging area where a target point is projected onto the ground surface, provided by an embodiment of the present invention.

[0022] Figure 4b A map showing the number of times each grid on the earth's surface is provided as an embodiment of the present invention.

[0023] Figure 4c A schematic diagram of an imaging region grid provided in an embodiment of the present invention;

[0024] Figure 4d A coverage distribution map of an imaging region provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of an evaluation device for an earthquake observation system provided in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Seismic data acquisition is the foundation of seismic exploration, and the accurate design of a seismic observation system is a key factor in the success of seismic data acquisition. Therefore, evaluating the quality of a seismic observation system is extremely important.

[0029] Coverage count is commonly used to evaluate observation systems. However, current methods often employ the same maximum shot-receiver distance (MRD) for different subsurface layers. Since the coverage count varies at different depths, the requirements for the observation system also differ. Using only a single MRD may result in an observation system that fails to meet imaging needs at various layers. Furthermore, coverage count represents the number of reflections within a single surface area and cannot be correlated with attributes such as shot-receiver azimuth. Especially in key subsurface study areas or areas with severe obstruction, a regularly deployed observation system cannot identify areas that might influence the imaging, and optimization efforts cannot determine which areas can be densified with shot and receivable points. This hinders optimal system design. In conclusion, existing evaluation methods are ineffective and cannot guarantee the accuracy and precision of imaging.

[0030] Cover density refers to the number of shot-receiver pairs per unit area, which is also the number of pre-stack migration imaging traces per unit area, and the coverage count per unit area. Cover density is related to the coverage count and the number of facets, and can reflect the overall strength of the observation system. Especially after associating facets, cover density is closely related to the adequacy of the shot-receiver offset distribution, effectively indicating the pre-stack migration imaging capability of the observation system. This is the essential difference from the concept of coverage count. Cover density is chosen as one of the parameters for evaluating the observation system. For key underground research locations, or locations with severe obstruction, a regularly deployed observation system cannot know where the influence will be on that location, and during optimization, it is also unknown in which areas the shot-receiver density can be increased, which is not conducive to the optimal design of the observation system.

[0031] To address the aforementioned technical problems, the technical concept of this invention is as follows: Based on the geological model, a targeted observation system is deployed according to the maximum shot-receiver distance obtained from the demonstration of each stratum, and the coverage number of different strata is obtained. At the same time, based on the principle of the reverse ray tracing method starting from the imaging point, the area on the surface that contributes to the imaging point is found, the coverage density in the area is calculated, and the seismic observation system is evaluated using the coverage density.

[0032] Cover density refers to the number of shot-receiver pairs per unit area, which is also the number of pre-stack migration imaging traces per unit area, and the number of coverages per unit area. Cover density is related to the number of coverages and the number of coverages, and can reflect the overall strength of the observation system. Especially after the correlation of coverages, the cover density is closely related to the adequacy of the shot-receiver offset distribution, effectively indicating the pre-stack migration imaging capability of the observation system. It can serve as an effective standard for judging whether the observation system is reasonable, and based on this, the observation system can be deployed and optimized more effectively.

[0033] Figure 1 This is a flowchart illustrating an evaluation method for an earthquake observation system provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the evaluation methods for this seismic observation system include:

[0034] Step S101: Obtain a geological model of the exploration area, which is used to show the surface and underground layers at different depths of the exploration area.

[0035] The execution entity in this embodiment is an evaluation device for a seismic observation system, or an electronic device equipped with an evaluation device for a seismic observation system. Specifically, based on existing geological data of the exploration area, a corresponding geological model can be constructed. The constructed geological model is typically a three-dimensional model, with lengths of length_x and length_y in the x and y directions (horizontal direction), respectively, and including the surface and subsurface layers of different depths in the z direction (vertical direction), denoted as h1, h2, ..., h. m, ...h n The lower layers h1, h2, ..., h m , ...h n The corresponding layer velocities are v1, v2, ..., v m ,…,v n h n The layer velocity v corresponding to the layer below the layer n+1 .

[0036] Step S102: Determine the maximum shot-receiver distance for each underground layer, and determine the seismic observation system for each underground layer based on the maximum shot-receiver distance.

[0037] Specifically, each subsurface layer corresponds to a different maximum shot-receiver distance, which can be determined based on single-shot records obtained using three-dimensional forward modeling technology. For example, different subsurface layers h1, h2, ..., h... m , ...h n The corresponding maximum shot-receiver offsets are offset_1, offset_2, ..., offset_m, ..., offset_n. Based on the already deployed shot and receiver locations, different maximum shot-receiver offsets are adopted for different subsurface layers to determine the range of influence of the shot points and the relationship between all shot-receiver pairs, thereby obtaining the seismic observation systems corresponding to different subsurface layers as geometry_1, geometry_2, ..., geometry_m, ..., geometry_n.

[0038] Step S103: Determine any underground layer as the target layer, and for the target point on the target layer, obtain the imaging area of ​​the target point projected onto the ground surface according to the reverse ray tracing method, and determine the area of ​​the imaging area.

[0039] Specifically, any underground layer in the geological model can be identified as the target layer. For any target point on the target layer, the effective imaging range, i.e. the imaging area, of the target point can be found by reverse ray tracing, and the area of ​​the imaging area can be determined.

[0040] In some embodiments, obtaining the imaging area projected onto the ground surface by the target point according to the reverse ray tracing method in step S103 includes: determining the normal of the target layer at the target point, and determining the normal angle according to the first layer velocity and the second layer velocity, wherein the first layer velocity is the layer velocity corresponding to the target layer, and the second layer velocity is the layer velocity corresponding to the next layer of the target layer; determining the ray emitted from the target point towards the ground surface with the normal angle, and determining the area enclosed by the intersection of the ray and the ground surface as the imaging area.

[0041] Specifically, a normal line is drawn through the target point in the target layer. Rays, at 5° intervals and at an angle θ to the normal line, are emitted towards the Earth's surface. These rays propagate upwards according to Snell's law and stop at the surface. The intersections of the rays with the surface are connected sequentially to form a closed region, which is the effective imaging area. The normal angle θ is determined based on the layer velocity of the target layer and the layer velocity of the layer below it.

[0042] In some embodiments, determining the normal angle based on the first layer velocity and the second layer velocity includes: if the first layer velocity is less than the second layer velocity, then performing an arcsine calculation on the ratio of the first layer velocity and the second layer velocity to obtain the normal angle; if the first layer velocity is greater than the second layer velocity, then determining the normal angle as a preset angle.

[0043] Specifically, one way to calculate the included normal angle θ is as shown in formula (1):

[0044]

[0045] Among them, v u v is the layer velocity of the target layer. d The layer velocity of the next layer below the target layer. When the layer velocity of the upper layer is less than that of the lower layer, the arcsine of the ratio of the upper layer velocity to the lower layer velocity is calculated to obtain the normal angle; when the layer velocity of the upper layer is greater than that of the lower layer, the normal angle is set to a preset angle, such as 60°.

[0046] Step S104: Determine the number of times the imaging area is covered according to the seismic observation system corresponding to the target layer.

[0047] For example, if the target layer is determined to be h m If the corresponding seismic observation system is geometry_m, the number of times the center position of the shot-receiver pair falls within the imaging area is determined by the number of times the imaging area is covered.

[0048] Step S105: Determine the coverage density of the imaging area based on the number of times the imaging area is covered and the area of ​​the imaging area. The coverage density is used to evaluate the seismic observation system.

[0049] Specifically, the coverage density of the imaging area is obtained by comparing the coverage count of the imaging area obtained in step S104 with the area of ​​the imaging area obtained in step S103. Coverage density serves as an effective standard for judging the rationality of a seismic observation system, and it can be used as a basis for more effective deployment and optimization of the observation system.

[0050] In some embodiments, after step S105, the method further includes: adjusting the shot point and receiver point according to the coverage density to optimize the seismic observation system.

[0051] Specifically, the seismic observation system consists of the locations of shot points and receivers, and the maximum shot-receiver distance determines the area of ​​influence of each shot point, which are then combined to form the overall system. After obtaining the coverage density, the number of shot-receiver points can be increased based on the coverage density to optimize the seismic observation system.

[0052] The seismic observation system evaluation method provided in this invention involves: acquiring a geological model of the exploration area, which describes the surface and at least one subsurface layer of the exploration area; determining the maximum shot-receiver distance for each subsurface layer and determining the seismic observation system corresponding to each subsurface layer based on the maximum shot-receiver distance; identifying any subsurface layer as a target layer; obtaining the imaging area projected onto the surface of the target point using a reverse ray tracing method for a target point on the target layer and determining the area of ​​the imaging area; determining the coverage number of the imaging area based on the seismic observation system corresponding to the target layer; and determining the coverage density of the imaging area based on the coverage number and the area of ​​the imaging area. The coverage density is used to evaluate the layout of the seismic observation system. In other words, this invention deploys corresponding seismic observation systems based on the maximum shot-receiver distance of different subsurface layers, obtaining the coverage number of different subsurface layers. Simultaneously, for any point in the subsurface layer, using the reverse ray tracing method, an imaging area contributing to that point is found on the surface, and the coverage density within that imaging area is calculated. The coverage density is used to determine whether the observation system is reasonable, improving the rationality of the evaluation and enabling more effective deployment and optimization of the observation system.

[0053] Based on the above embodiments, Figure 2 A flowchart illustrating another method for evaluating an earthquake observation system provided in an embodiment of the present invention is shown below. Figure 2 As shown, the evaluation methods for this seismic observation system include:

[0054] Step S201: Obtain a geological model of the exploration area, which is used to show the surface and underground layers at different depths of the exploration area.

[0055] Step S202: Determine the maximum shot-receiver distance for each underground layer, and determine the seismic observation system for each underground layer based on the maximum shot-receiver distance.

[0056] Step S203: Generate a grid and project the grid onto the ground surface.

[0057] Step S204: Determine any underground layer as the target layer, and for the target point on the target layer, obtain the imaging area of ​​the target point projected onto the ground surface according to the reverse ray tracing method, and determine the area of ​​the imaging area.

[0058] Step S205: Identify the grid within the imaging area.

[0059] Step S206: Obtain the coverage count of each grid within the imaging area based on the seismic observation system of the target layer, and determine the sum of the coverage counts of each grid as the coverage count of the imaging area.

[0060] Step S207: Determine the coverage density of the imaging region based on the number of times the imaging region is covered and the area of ​​the imaging region. The coverage density is used to evaluate the seismic observation system.

[0061] The implementation methods of steps S201, S202, S204 and S207 in the embodiments of the present invention are similar to the implementation methods of steps S101-S103 and S105 in the above embodiments, and will not be described again here.

[0062] The difference from the above embodiments is that, in order to improve the speed of calculating coverage density, in this embodiment, a grid is generated and projected onto the ground surface; the grids within the imaging area are identified; the coverage count of each grid within the imaging area is obtained according to the seismic observation system of the target layer, and the sum of the coverage counts of each grid is determined as the coverage count of the imaging area; finally, the coverage density of the imaging area is determined according to the coverage count and the area of ​​the imaging area.

[0063] First, a single grid is pre-set to have a size of dx in the x-direction and dy in the y-direction. Based on the geological model, the lengths in the x and y directions are length_x and length_y, respectively, resulting in nx*ny grids, as shown in formulas (2) and (3).

[0064]

[0065]

[0066] Here, ceiling represents rounding up; projecting the grid vertically onto the Earth's surface yields nx*ny imaging grids.

[0067] Then, after determining the imaging area of ​​the target point using the reverse ray tracing method, the grid of the imaging area will be identified, such as identifying that there are An grids in imaging area A.

[0068] Then, based on the target layer h mThe corresponding seismic observation system, geometry_m, determines the coverage count of each grid cell within the imaging region by the number of times the center point of the shot-receiver pair falls within the imaging region. The sum of the coverage counts of all grid cells within the imaging region is then determined as the total coverage count of the imaging region. For example, if the coverage count of each of the An grid cells within imaging region A is fold_A1,…,fold_An, then the total coverage count of imaging region A is... Finally, the ratio of the number of times the imaging region is covered to the area of ​​the imaging region is determined as the coverage density of the imaging region.

[0069] In some embodiments, the target layer h m The corresponding seismic observation system geometry_m first obtains the coverage count of each grid on the surface as fold_1, fold_2, ..., fold_nxny based on the number of points at the center of the shot-receiver pair falling within each grid; then it directly filters out the coverage count of each grid within the imaging area.

[0070] In some embodiments, step S205 includes: identifying a first grid and a second grid within the imaging area, wherein the entire area of ​​the first grid is located within the imaging area, and a portion of the area of ​​the second grid is located within the imaging area; step S206, obtaining the coverage count of each grid within the imaging area based on the seismic observation system of the target layer, includes: directly obtaining the coverage count of the first grid based on the seismic observation system of the target layer; and obtaining the coverage count of the second grid based on the proportion of the area occupied by the second grid inside and outside the imaging area.

[0071] For example, there are An grids within imaging region A, including a first grid that is entirely within imaging region A and a second grid that is partially within imaging region A.

[0072] For the first grid Ak that is completely within the imaging region A, its coverage number can be directly determined, as shown in formula (4):

[0073] fold_Ak=fold_k (4)

[0074] For a second grid Aj that is partially within imaging region A, with an area of ​​Area_in within imaging region A and an area of ​​Area_out outside imaging region A, the coverage number fold_Aj of this grid is as shown in formula (5):

[0075]

[0076] Finally, the coverage density of the imaging area A is calculated as shown in formula (6), where the unit of coverage density is times per square meter (times / m²). 2or 10,000 times per square kilometer (10,000 times / km) 2 ).

[0077]

[0078] In some embodiments, the method further includes: projecting the grid onto each subsurface layer, wherein the target point is the center point of the target grid in the grid region corresponding to the target layer. Specifically, projecting the generated grid onto each subsurface layer can also yield nx*ny imaging grids, and when selecting the target point, the target layer h can be selected. m The center of one of the nx*ny grids is used as the starting point to project the imaging area onto the ground surface and calculate its coverage density, etc.

[0079] The evaluation method for an earthquake observation system provided in this embodiment of the invention generates a grid and projects the grid onto the Earth's surface; identifies the grids within the imaging area; obtains the coverage count of each grid within the imaging area based on the earthquake observation system of the target layer, and determines the sum of the coverage counts of each grid as the coverage count of the imaging area; finally, determines the coverage density of the imaging area based on the coverage count and the area of ​​the imaging area; that is, this embodiment of the invention achieves rapid calculation of coverage density through gridding.

[0080] Based on the above embodiments, Figure 3 This is a flowchart illustrating another method for evaluating an earthquake observation system provided in an embodiment of the present invention. Figure 4a This is a schematic diagram of an imaging area projected onto the ground surface according to an embodiment of the present invention. Figure 4b This invention provides a map showing the distribution of the number of times each grid on the land surface is covered. Figure 4c This is a schematic diagram of an imaging region grid provided in an embodiment of the present invention. Figure 4d This is a coverage distribution map of an imaging region provided in an embodiment of the present invention. To further understand the embodiments of the present invention, it is now combined with... Figure 3 , Figures 4a-4d The following example illustrates the calculation of the coverage density of the imaging area of ​​a target point on a target layer in a three-dimensional geological model of a certain exploration area.

[0081] Step S301: Obtain a geological model of the exploration area, which is used to show the surface and underground layers at different depths of the exploration area.

[0082] Specifically, a three-dimensional geological model of the exploration area (for reference) Figure 4aThe lengths in the x and y directions are 560m and 265m respectively. The surface is called surface, and the underground layers are h1 and h2, with corresponding layer velocities of 1000m / s and 2000m / s respectively, and the layer velocity of the layer below h2 is 3000m / s.

[0083] Step S302: Determine the maximum shot-receiver distance for each underground layer, and determine the seismic observation system for each underground layer based on the maximum shot-receiver distance.

[0084] Specifically, the maximum shot-receiver offsets corresponding to the underground layers h1 and h2 are obtained as offset1 and offset2, respectively, based on the already deployed shot and receiver positions. For the h1 layer, the maximum shot-receiver offset offset1 is used to obtain the corresponding observation system geometry_1, and for the h2 layer, the maximum shot-receiver offset offset2 is used to obtain the corresponding observation system geometry_2.

[0085] Step S303: Generate a grid and project the grid onto the surface and each underground layer.

[0086] Specifically, the size of a single grid is determined to be 20m in the x-direction and 20m in the y-direction. Based on the lengths of the geological model in the x and y directions, nx*ny grids are obtained, as follows:

[0087]

[0088]

[0089] Projecting the grid vertically onto the Earth's surface yields 28*14=392 imaging grids, and 392 imaging grids can also be obtained on h1 and h2.

[0090] Step S304: Determine any underground layer as the target layer, and determine the number of times each grid on the surface is covered according to the seismic observation system corresponding to the target layer.

[0091] Specifically, if h2 is determined to be the target layer, then based on the observation system geometry_2 already deployed on layer h2, the coverage number of each imaging grid on the surface can be obtained as 0,…,50,100,…,200, such as… Figure 4b As shown.

[0092] Step S305: For the target point on the target layer, determine the normal of the target layer at the target point, and determine the angle between the normals based on the velocity of the first layer and the velocity of the second layer.

[0093] Specifically, select one of the 392 grids on the target layer h2, take the center of the grid as the starting point, draw the normal line through the center point, and determine the included angle θ of the normal, as follows:

[0094]

[0095] Step S306: Determine the ray emitted from the target point towards the ground surface at the normal angle, and determine the area enclosed by the intersection of the ray and the ground surface as the imaging area, and determine the area of ​​the imaging area.

[0096] refer to Figure 4a As shown, rays at an angle θ to the normal, spaced 5° apart, are emitted towards the Earth's surface. According to Snell's law, these rays propagate upwards and stop at the surface. Connecting the points where the rays intersect the surface sequentially forms a closed region, which is the effective imaging area. The imaging area can be referenced... Figure 4b Region A, enclosed by circular lines, has an area of ​​40380 m². 2 .

[0097] Step S307: Identify the first grid and the second grid within the imaging area, wherein the entire area of ​​the first grid is located within the imaging area, and a portion of the second grid is located within the imaging area.

[0098] Specifically, the imaging grid within imaging region A consists of 42 grids, including the first grid that is completely within imaging region A, such as... Figure 4c Ak in the text also includes part of the second grid within region A, such as... Figure 4c Aj in the middle.

[0099] Step S308: Obtain the coverage count of the first grid directly from the seismic observation system of the target layer, obtain the coverage count of the second grid according to the proportion of the area occupied by the second grid inside and outside the imaging area, and determine the sum of the coverage counts of each grid as the coverage count of the imaging area.

[0100] Specifically, the coverage number of the imaging grid within imaging region A is fold_A1,…,fold_A42. For the imaging grid Ak completely within region A, the coverage number is...

[0101] fold -Ak =fold k =150

[0102] For a portion of the imaging grid Aj within region A, the coverage number is fold_Aj, and the area within region A is 100m². 2 The area outside region A is 300m² 2 Then the number of times this grid is covered.

[0103]

[0104] Similarly, the coverage count of all imaging grids within imaging region A is obtained, as shown in the following figure. Figure 4d As shown.

[0105] Step S309: Determine the coverage density of the imaging region based on the number of times the imaging region is covered and the area of ​​the imaging region. The coverage density is used to evaluate the seismic observation system.

[0106] Specifically, the coverage density of imaging region A is as follows:

[0107]

[0108] Similarly, the coverage density within the effective imaging range of any point in any layer of the geological model can be analyzed.

[0109] In summary, based on the geological model, this embodiment of the invention finds the range that can affect the imaging of a certain point underground (such as layer velocity) by reverse ray tracing, i.e., the effective imaging range, based on the characteristics of different maximum offset distances of underground strata. At the same time, it targets the coverage density within the statistical range to purposefully determine whether the layout of the observation system is reasonable and the areas that need optimization, thereby realizing the layout and optimization of the observation system.

[0110] Figure 5 This is a schematic diagram of the structure of an evaluation device for an earthquake observation system provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the device 500 includes:

[0111] The model acquisition module 501 is used to acquire a geological model of the exploration area, which displays the surface and subsurface layers at different depths of the exploration area; the first determination module 502 is used to determine the maximum shot-receiver distance corresponding to each subsurface layer, and determine the seismic observation system corresponding to each subsurface layer based on the maximum shot-receiver distance; the second determination module 503 is used to determine any subsurface layer as the target layer, and for a target point on the target layer, obtain the imaging area projected onto the surface of the target point using the reverse ray tracing method, and determine the area of ​​the imaging area; the third determination module 504 is used to determine the coverage number of the imaging area based on the seismic observation system corresponding to the target layer; the fourth determination module 505 is used to determine the coverage density of the imaging area based on the coverage number and the area of ​​the imaging area, and the coverage density is used to evaluate the seismic observation system.

[0112] As an embodiment of the present invention, the second determining module 503 is specifically used for: determining the normal of the target layer at the target point, and determining the normal angle according to the first layer velocity and the second layer velocity, wherein the first layer velocity is the layer velocity corresponding to the target layer, and the second layer velocity is the layer velocity corresponding to the next layer of the target layer; determining the ray emitted from the target point towards the ground surface with the normal angle, and determining the area enclosed by the intersection of the ray and the ground surface as the imaging area.

[0113] As an embodiment of the present invention, the second determining module 503 is specifically used for: if the speed of the first layer is less than the speed of the second layer, then performing an arcsine calculation on the ratio of the speed of the first layer and the speed of the second layer to obtain the normal angle; if the speed of the first layer is greater than the speed of the second layer, then determining the normal angle as a preset angle.

[0114] As an embodiment of the present invention, the device further includes a grid generation module 506, which is used to generate a grid and project the grid onto the ground surface; the second determining module 503 is further used to: identify the grids in the imaging area; the third determining module 504 is specifically used to: obtain the coverage number of each grid in the imaging area according to the seismic observation system of the target layer, and determine the sum of the coverage numbers of each grid as the coverage number of the imaging area.

[0115] As an embodiment of the present invention, the second determining module 503 is specifically used to: identify a first grid and a second grid within the imaging area, wherein the entire area of ​​the first grid is located within the imaging area, and a portion of the area of ​​the second grid is located within the imaging area; the third determining module 504 is specifically used to: directly obtain the coverage number of the first grid according to the seismic observation system of the target layer; and obtain the coverage number of the second grid according to the proportion of the area occupied by the second grid inside and outside the imaging area.

[0116] As an embodiment of the present invention, the grid generation module 506 is further configured to: project the grid onto each underground layer, wherein the target point is the center point of the target grid in the grid region corresponding to the target layer.

[0117] As an embodiment of the present invention, the fourth determining module 505 is further configured to: adjust the shot point and receiver point according to the coverage density to optimize the seismic observation system.

[0118] The evaluation device for the earthquake observation system provided in this embodiment of the invention has a similar implementation principle and technical effect to the above embodiments, and will not be described again here.

[0119] like Figure 6As shown, this embodiment of the invention provides an electronic device, including a processor 601, a communication interface 602, a memory 603, and a communication bus 604, wherein the processor 601, the communication interface 602, and the memory 603 communicate with each other via the communication bus 604.

[0120] Memory 603 is used to store computer programs;

[0121] In one embodiment of the present invention, when the processor 601 executes the program stored in the memory 603, it implements the steps of the evaluation method for the earthquake observation system provided in any of the foregoing method embodiments.

[0122] The electronic device provided in this embodiment of the invention has a similar implementation principle and technical effect to the above embodiments, and will not be described again here.

[0123] The aforementioned memory 603 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Memory 603 has storage space for program code used to perform any of the method steps described above. For example, the storage space for program code may include individual program codes for implementing the various steps in the methods described above. This program code can be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, optical discs (CDs), memory cards, or floppy disks. Such computer program products are typically portable or fixed storage units. The storage unit may have storage segments or storage spaces arranged similarly to memory 603 in the aforementioned electronic device. The program code may be compressed, for example, in a suitable form. Typically, the storage unit includes programs for performing the method steps according to embodiments of the invention, i.e., code that can be read by a processor such as 601, which, when run by the electronic device, causes the electronic device to perform the various steps in the methods described above.

[0124] Embodiments of the present invention also provide a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the evaluation method for the seismic observation system as described above.

[0125] The computer-readable storage medium may be included in the device / apparatus described in the above embodiments; or it may exist independently and not assembled into the device / apparatus. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of the present invention.

[0126] According to embodiments of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0127] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0128] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for evaluating an earthquake observation system, characterized in that, include: Obtain a geological model of the exploration area, which is used to show the surface and underground strata at different depths of the exploration area; Determine the maximum shot-receiver distance for each underground layer, and determine the seismic observation system for each underground layer based on the maximum shot-receiver distance; Any underground layer is identified as the target layer. For a target point on the target layer, the imaging area projected onto the ground surface by the target point is obtained using the reverse ray tracing method, and the area of ​​the imaging area is determined. The number of times the imaging area is covered is determined based on the seismic observation system corresponding to the target layer; The coverage density of the imaging region is determined based on the number of times the imaging region is covered and the area of ​​the imaging region. The coverage density is used to evaluate the seismic observation system. The step of obtaining the imaging area of ​​the target point projected onto the ground surface using the reverse ray tracing method includes: Determine the normal of the target layer at the target point, and determine the angle between the normals based on the first layer velocity and the second layer velocity. The first layer velocity is the layer velocity corresponding to the target layer, and the second layer velocity is the layer velocity corresponding to the next layer after the target layer. The ray emitted from the target point at the normal angle toward the ground surface is determined, and the area enclosed by the intersection of the ray and the ground surface is determined as the imaging area.

2. The method according to claim 1, characterized in that, The determination of the normal angle based on the first layer velocity and the second layer velocity includes: If the velocity of the first layer is less than the velocity of the second layer, then the arcsine of the ratio of the velocity of the first layer to the velocity of the second layer is calculated to obtain the normal angle. If the velocity of the first layer is greater than the velocity of the second layer, then the included normal angle is determined to be a preset angle.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Generate a grid and project the grid onto the earth's surface; After obtaining the imaging area of ​​the target point projected onto the ground surface using the reverse ray tracing method, the method further includes: Identify the grid within the imaging area; Determining the coverage number of the imaging area based on the seismic observation system corresponding to the target layer includes: The coverage count of each grid within the imaging area is obtained based on the seismic observation system of the target layer, and the sum of the coverage counts of each grid is determined as the coverage count of the imaging area.

4. The method according to claim 3, characterized in that, The identification of the grid within the imaging area includes: Identify a first grid and a second grid within the imaging region, wherein the entire area of ​​the first grid is located within the imaging region, and a portion of the area of ​​the second grid is located within the imaging region; The step of obtaining the coverage number of each grid within the imaging area based on the seismic observation system of the target layer includes: The coverage count of the first grid is obtained directly from the seismic observation system of the target layer; The number of times the second grid is covered is determined based on the proportion of the area occupied by the second grid inside and outside the imaging area.

5. The method according to claim 3, characterized in that, The method further includes: The grid is projected onto each underground layer, wherein the target point is the center point of the target grid in the grid region corresponding to the target layer.

6. The method according to claim 1 or 2, characterized in that, After determining the coverage density of the imaging region based on the coverage frequency and area of ​​the imaging region, the method further includes: The shot point and receiver point are adjusted according to the coverage density to optimize the seismic observation system.

7. An evaluation device for an earthquake observation system, characterized in that, include: The model acquisition module is used to acquire a geological model of the exploration area, which is used to display the surface and underground layers at different depths of the exploration area. The first determining module is used to determine the maximum shot-receiver distance for each underground layer, and to determine the seismic observation system for each underground layer based on the maximum shot-receiver distance. The second determining module is used to determine any underground layer as the target layer, and for a target point on the target layer, to obtain the imaging area of ​​the target point projected onto the ground surface according to the reverse ray tracing method, and to determine the area of ​​the imaging area. The third determining module is used to determine the number of times the imaging area is covered based on the seismic observation system corresponding to the target layer; The fourth determining module is used to determine the coverage density of the imaging area based on the number of times the imaging area is covered and the area of ​​the imaging area, wherein the coverage density is used to evaluate the seismic observation system; The second determining module is specifically used for: Determine the normal of the target layer at the target point, and determine the angle between the normals based on the first layer velocity and the second layer velocity, where the first layer velocity is the layer velocity corresponding to the target layer, and the second layer velocity is the layer velocity corresponding to the next layer after the target layer. The ray emitted from the target point at the normal angle toward the ground surface is determined, and the area enclosed by the intersection of the ray and the ground surface is determined as the imaging area.

8. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the evaluation method for the seismic observation system according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the evaluation method for the seismic observation system as described in any one of claims 1-6.

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