Method, device, equipment, medium and program product for correcting a geological velocity model

Abstract

The application discloses a geological velocity model correction method and device, equipment, medium and program product, and relates to the near-surface modeling field. The method comprises the following steps: acquiring a point time difference, determining model coordinates of the known point in a first velocity model based on known point coordinates and model parameters of the first velocity model, assigning the point time difference to a velocity grid corresponding to the model coordinates, performing velocity correction processing on the first velocity model to obtain a second velocity model after correction, performing velocity interpolation processing on the second velocity model based on an inverse distance weighting method to obtain a third velocity model after correction, and performing velocity smoothing processing on the velocity grid in the third velocity model to obtain a corrected velocity model, wherein the corrected velocity model is used to represent a geological propagation velocity. The accuracy of the velocity in the velocity model is improved, the accuracy of the static correction amount calculated by using the corrected velocity model is also high, and the effect of migration imaging can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of near-surface modeling, and in particular to a method, apparatus, device, medium, and program product for correcting a geological velocity model. Background Art

[0002] Velocity is a key parameter reflecting subsurface structure and rock properties. The accuracy of near-surface velocity directly impacts the accuracy of static corrections to seismic data in the exploration area and, consequently, the resulting imaging. First-arrival tomographic inversion is currently the most common method for establishing near-surface velocity models. This method produces a time-equivalent velocity model, but the resulting velocity model is less accurate, resulting in lower precision static corrections used for calculations and poor imaging quality.

[0003] In related technologies, the first arrival residual method is usually used to improve the accuracy of the static correction value. However, the velocity model does not include the corresponding residual static correction value, so the accuracy of the velocity in the velocity model is still low, resulting in low accuracy of the static correction value calculated using only the velocity model. Summary of the Invention

[0004] The present invention provides a method, apparatus, device, medium, and program product for correcting a geological velocity model, which can improve the accuracy of shallow velocity in the velocity model. The static correction values ​​calculated using the model are highly accurate. The technical solution is as follows:

[0005] In one aspect, a method for correcting a geological velocity model is provided, the method comprising:

[0006] Obtaining point time differences, where the point time differences include an excitation point time difference and a receiving point time difference. The excitation point time difference refers to the time difference generated when the excitation point sends waves to the receiving point, and the receiving point time difference refers to the time difference generated when the receiving point receives waves. There is at least one excitation point and one receiving point.

[0007] determining, based on known point coordinates and model parameters of a first velocity model, model coordinates of the known point in the first velocity model, the known point including the excitation point and the receiving point, the known point coordinates including measured coordinates of the excitation point and the receiving point, the first velocity model being a three-dimensional model for predicting geological velocity, the first velocity model including a plurality of velocity grids, each of the velocity grids corresponding to a respective grid velocity;

[0008] Assigning the point time difference to the velocity grid corresponding to the model coordinates, performing velocity correction processing on the first velocity model to obtain a corrected second velocity model;

[0009] Based on the inverse distance weighted method, performing velocity interpolation processing on the second velocity model to obtain a corrected third velocity model, wherein the velocity interpolation processing is used to perform velocity correction on the velocity grid in the second velocity model;

[0010] Velocity smoothing is performed on the velocity grid in the third velocity model to obtain a modified velocity model, which is used to characterize geological propagation velocity.

[0011] In another aspect, a device for correcting a geological velocity model is provided, the device comprising:

[0012] An acquisition module is configured to acquire a point time difference, wherein the point time difference includes an excitation point time difference and a receiving point time difference. The excitation point time difference refers to a time difference generated when the excitation point sends a wave to the receiving point, and the receiving point time difference refers to a time difference generated when the receiving point receives a wave. There is at least one excitation point and at least one receiving point.

[0013] a determination module, configured to determine, based on the known point coordinates and model parameters of a first velocity model, the model coordinates of the known point in the first velocity model, wherein the known point includes the excitation point and the receiving point, the known point coordinates include the measured coordinates of the excitation point and the measured coordinates of the receiving point, and the first velocity model is a three-dimensional model for predicting geological velocity, and includes a plurality of velocity grids, each of the velocity grids corresponding to a respective grid velocity;

[0014] a correction module, which assigns the point time difference to the velocity grid corresponding to the model coordinates, performs velocity correction processing on the first velocity model, and obtains a corrected second velocity model;

[0015] an interpolation module, performing velocity interpolation processing on the second velocity model based on an inverse distance weighted method to obtain a corrected third velocity model, wherein the velocity interpolation processing is used to perform velocity correction on the velocity grid in the second velocity model;

[0016] The smoothing module performs velocity smoothing processing on the velocity grid in the third velocity model to obtain a modified velocity model, and the modified velocity model is used to characterize geological propagation velocity.

[0017] On the other hand, a computer device is provided, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the method for correcting a geological velocity model as described in any of the above embodiments of the present application.

[0018] On the other hand, a computer-readable storage medium is provided, wherein the storage medium stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by a processor to implement the method for correcting a geological velocity model as described in any of the above-mentioned embodiments of the present application.

[0019] In another aspect, a computer program product or computer program is provided. The computer program product or computer program includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method for correcting a geological velocity model described in any of the above embodiments.

[0020] The beneficial effects of the technical solutions provided in the embodiments of the present application include at least:

[0021] By obtaining the time difference between the excitation point and the receiving point, that is, the point time difference, and based on the actual measured coordinates of the excitation point and the receiving point, that is, the known point coordinates, the excitation point and the receiving point are mapped to the velocity model to obtain the model coordinates of the excitation point and the receiving point in the velocity model, the excitation point time difference and the receiving point time difference are assigned to the velocity grid of the corresponding position of the known point in the velocity model, the grid velocity of the known point is corrected, and the velocity difference processing is performed on the remaining velocity grid based on the inverse distance weighted method. Finally, the corrected velocity grid in the velocity model is smoothed to make the grid velocity in the velocity model continuous and natural, thereby improving the accuracy of the velocity in the velocity model. The static correction value calculated using the corrected velocity model is also more accurate, which can improve the effect of migration imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 is a schematic diagram of a two-dimensional cross section of a geological velocity model provided by an exemplary embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of an implementation environment provided by an exemplary embodiment of the present application;

[0025] Figure 3 is a flow chart of a method for correcting a geological velocity model provided by an exemplary embodiment of the present application;

[0026] Figure 4 is a flow chart of a method for correcting a known point velocity grid in a first velocity model based on point time difference provided by an exemplary embodiment of the present application;

[0027] Figure 5 is a flow chart of a method for performing velocity interpolation processing on a second velocity model based on an inverse distance weighted method provided by an exemplary embodiment of the present application;

[0028] Figure 6 This is a structural block diagram of a device for correcting a geological velocity model provided by an exemplary embodiment of the present application;

[0029] Figure 7 is a structural block diagram of a geological velocity model correction device provided by another exemplary embodiment of the present application;

[0030] Figure 8 It is a structural block diagram of a computer device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0032] In the field of seismic exploration, seismic data processing has moved from the time domain to the depth domain, and true surface depth migration has become a key process in industrial production. Time domain data processing requires high-precision static corrections, while true surface depth migration requires high-precision velocity models.

[0033] Velocity models, also known as near-surface velocity models, are used to characterize geological propagation velocities. When constructing these models, high velocity accuracy is required for shallow depths. Even small velocity anomalies in shallow depths can severely distort larger structural features in deeper depths in depth migration profiles.

[0034] The most common method for establishing near-surface velocity models is to use first-arrival tomographic inversion. This method produces a time-equivalent velocity model, providing static corrections for early time-domain data processing and a more realistic near-surface velocity model for later true surface depth migration.

[0035] However, velocity models established using tomographic inversion methods often suffer from low velocity accuracy, resulting in low precision in the static corrections used for calculation, leading to poor imaging quality. To address this issue, the first-break residual method is often used to improve the accuracy of static corrections. This method has shown significant results in production applications, significantly improving the imaging quality of time-domain profiles. However, the process and results of improving static corrections using the first-break residual method are unrelated to the corresponding velocity model.

[0036] That is, the velocity model does not include the corresponding residual static correction. Therefore, after applying the first-arrival residual static correction, the seismic imaging quality is only improved in the time domain profile, while the seismic imaging quality in the depth domain data migration profile is still poor.

[0037] Simply processing the static correction value can improve its accuracy, but it does not solve the problem that the accuracy of the velocity model is still low. The accuracy of the static correction value calculated using the velocity model is also low, and the effect of subsequent migration imaging is poor.

[0038] In the embodiment of the present application, after the velocity model is established using the tomographic inversion method, the velocity in the velocity model can be corrected based on the point time difference by obtaining the time difference between the excitation point and the receiving point, that is, the point time difference, to obtain a corrected velocity model with higher accuracy. The static correction value calculated using the corrected velocity model is also more accurate, and the imaging quality in the depth domain migration profile is higher.

[0039] Indicative, such as Figure 1 As shown, a vertical section is made on any direction of the three-dimensional velocity model to obtain a two-dimensional velocity model 100. The horizontal axis of the two-dimensional velocity model 100 represents the ground distance, and the vertical axis represents the altitude, that is, the depth below the surface.

[0040] A plurality of velocity grids are created within the 2D velocity model 100 to represent the velocity at any location near the surface. Multiple excitation points and receiving points, also known as known points 130, exist on the surface line 110. Each known point 130 has a corresponding position coordinate in the 2D velocity model 100.

[0041] A speed threshold is preset in advance, and a height top 120 is formed in the two-dimensional speed model 100 based on the speed threshold. The high-speed top 120 is used to screen out speed grids that need to be corrected.

[0042] The velocity grid below the surface line 110 and above the highway top 120 needs to be corrected. The velocity grid at the known point 130 is the known point velocity grid 140, and the other velocity grids are blank velocity grids 150.

[0043] First, the known point time difference is obtained. The known point time difference includes the receiving point time difference and the excitation point time difference. The known point time difference is assigned to the known point velocity grid 140. Velocity correction is first performed on the known point velocity grid 140. For the blank velocity grid 150, velocity correction is performed using the inverse distance weighted method.

[0044] After all velocity grids meeting the correction conditions are corrected, the blank velocity grid 150 is smoothed to make the near-surface velocity in the two-dimensional velocity model 100 continuous, thereby obtaining a corrected velocity model with higher accuracy.

[0045] Next, the implementation environment involved in the embodiments of this application is described. For schematic illustration, please refer to Figure 3 The implementation environment involves a terminal 210 and a server 220 , and the terminal 210 and the server 220 are connected via a communication network 230 .

[0046] In some embodiments, terminal 210 is configured to transmit time difference data to server 220. In some embodiments, terminal 210 is installed with an application program having a velocity correction function (e.g., a function for predicting the topic of an information stream article including multimodal content). For example, terminal 210 is installed with an application program for correcting the velocity of a geological velocity model. For example, terminal 210 may be installed with a search engine program, a travel application, a life-assistance application, an instant messaging application, a video application, a game application, a news application, etc., although this embodiment of the present application is not limited thereto.

[0047] After receiving the time difference data, the server 220 performs speed correction by allocating the time difference data to the speed grid at the known point position in the speed model, and then uses the inverse distance weighted interpolation method to correct the speed of the speed grid at the unknown point position. The corrected speed grid at the unknown point position is smoothed to obtain the corrected speed model.

[0048] The velocity grid is used to represent the velocity at any point in the velocity model.

[0049] The above-mentioned terminal can be a mobile phone, tablet computer, desktop computer, portable notebook computer, smart TV, vehicle terminal, smart home device and other terminal devices in various forms, and the embodiments of the present application are not limited to this.

[0050] It is worth noting that the above-mentioned servers can be independent physical servers, or they can be server clusters or distributed systems composed of multiple physical servers. They can also be cloud servers that provide basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content delivery networks (CDN), as well as big data and artificial intelligence platforms.

[0051] Cloud technology refers to a hosting technology that unifies hardware, software, and network resources within a wide area network (WAN) or local area network (LAN) to enable data computing, storage, processing, and sharing. Cloud technology is a general term for network technology, information technology, integration technology, management platform technology, and application technology based on the cloud computing business model. It can form a resource pool that can be used on demand with flexibility and convenience. Cloud computing technology will become a crucial support. Backend services for technical network systems, such as video websites, image websites, and more portals, require extensive computing and storage resources. With the rapid development and application of the internet industry, every item will likely have its own unique identification mark and will need to be transmitted to backend systems for logical processing. Data of varying levels will be processed separately, and data from all industries will require a strong system backend, which can only be achieved through cloud computing.

[0052] In some embodiments, the above-mentioned server can also be implemented as a node in a blockchain system.

[0053] Combined with the above-mentioned noun introduction and implementation environment description, the computing resource prediction method provided in the embodiment of this application is described, please refer to Figure 3 , which shows a flow chart of a method for correcting a geological velocity model provided by an exemplary embodiment of the present application, and takes the method applied to a server as an example for explanation, such as Figure 3 As shown, the method includes:

[0054] Step 310: Obtain the time difference.

[0055] Among them, the point time difference includes the excitation point time difference and the receiving point time difference. The excitation point time difference refers to the time difference generated in the process of the excitation point sending waves to the receiving point, and the receiving point time difference refers to the time difference generated in the process of the receiving point receiving waves. The number of excitation points and receiving points is at least one.

[0056] In the field of seismic exploration, the excitation point is also called the shot point. Seismic waves are artificially excited at the location of the shot point. There is a certain distance between the receiving point and the excitation point, which is used to receive the waves from the excitation point.

[0057] If the number of seismic waves excited by an excitation point is at least one, then one excitation point corresponds to multiple receiving points, wherein the propagation distance and direction of the seismic wave can be arbitrary.

[0058] The method for obtaining the time difference includes the following steps:

[0059] (1) Get the first arrival pickup time.

[0060] The first arrival picking time refers to the time when the first arrival wave is picked up. Multiple waves are emitted from one excitation point, corresponding to multiple receiving points. The first arrival wave is the wave that is first received by the receiving point.

[0061] When artificially exciting seismic waves, there are multiple excitation points, and each excitation point corresponds to its own first arrival wave. A first arrival wave is associated with a pair of excitation points and receiving points.

[0062] (2) Obtain travel time.

[0063] Travel time refers to the time it takes for rays to reach the receiving point from the excitation point. When seismic waves propagate underground, factors such as geological structure affect the time it takes for them to reach the receiving point. The process of rays traveling from the excitation point to the receiving point is a straight line, and the travel time of rays from each excitation point to the receiving point is different.

[0064] (3) Based on the difference between the first arrival time and the travel time, the total time difference at the excitation point and the total time difference at the receiving point are obtained.

[0065] The total time difference at the excitation point is the sum of the time differences at the excitation points, and the total time difference at the receiving point is the sum of the time differences at the receiving points. The difference between the ray travel time between an excitation point and a receiving point and the first arrival wave pickup time corresponds to the total time difference between a single excitation point and a single receiving point. All total time differences are summed to obtain the cumulative total time difference between the excitation point and the receiving point.

[0066] Among them, the total time difference at the excitation point is half of the cumulative total time difference, and the total time difference at the receiving point is also half of the cumulative total time difference.

[0067] (4) Based on the number of excitation points, the total time difference of the excitation points is averaged to obtain the excitation point time difference.

[0068] The total time difference of the excitation point is evenly distributed to each excitation point to obtain the excitation point time difference. The excitation point time difference refers to the final time difference of the excitation point in the velocity model.

[0069] (5) Based on the number of receiving points, the total time difference of the receiving points is averaged to obtain the time difference of the receiving points.

[0070] The total time difference of the receiving points is evenly distributed to each receiving point to obtain the receiving point time difference. The receiving point time difference refers to the final time difference of the receiving point in the velocity model.

[0071] Optionally, the number of excitation points is m, and the number of receiving points is n. For a pair of excitation points and receiving points, the first arrival picking time is t0, and the ray travel time is t1.

[0072] Then, the total time difference Δt between a pair of excitation points and receiving points is obtained by the following formula 1:

[0073] Formula 1:

[0074] Δt=t0-t1

[0075] By decomposing the total time difference Δt, we can obtain the time difference Δtr of the receiving point and the time difference Δts of the excitation point in the current ray, which can be obtained by the following formula 2:

[0076] Formula 2:

[0077]

[0078] The average of the receiving point time difference Δtr is taken to obtain the receiving point time difference, which is also the final time difference of the receiving point in the velocity model, and is obtained by the following formula 3:

[0079] Formula 3:

[0080]

[0081] The excitation point time difference Δts is averaged to obtain the excitation point time difference, which is also the final time difference of the excitation point in the velocity model, and is obtained by the following formula 4:

[0082] Formula 4:

[0083]

[0084] It is worth noting that the number of excitation points and the number of receiving points can be arbitrary, and the number, propagation distance, and propagation direction of seismic waves excited by one excitation point can be arbitrary, which is not limited in this embodiment.

[0085] Step 320 : Determine the model coordinates of the known point in the first velocity model based on the coordinates of the known point and the model parameters of the first velocity model.

[0086] The known points include excitation points and receiving points. The known point coordinates include the measured coordinates of the excitation points and the measured coordinates of the receiving points. The first velocity model is a three-dimensional model for predicting geological velocity. The first velocity model includes multiple velocity grids, and each velocity grid corresponds to its own grid velocity.

[0087] The actual coordinates of the excitation point and the receiving point on the ground are manually measured. If the positions of the excitation point and the receiving point are known, then the excitation point and the receiving point are known points, and the coordinates of the known points are (x, y, z).

[0088] The first velocity model, also known as the near-surface velocity model, is a geological velocity model derived through tomographic inversion. The first velocity model is a three-dimensional model, expressed in X, Y, and Z axes. The first velocity model is obtained by intercepting the 3D model perpendicular to the ground and projecting it onto a two-dimensional plane.

[0089] The horizontal axis of the first velocity model is distance, which is used to represent the distance between the excitation point and the receiving point; the vertical axis is the measured elevation, that is, the altitude, which is used to represent the depth of each point in the velocity model. The closer to the ground surface, the higher the altitude, which represents a shallower depth.

[0090] The model parameters include the origin coordinates and the grid size of the first velocity model. The grid size is the three-dimensional size of the velocity grid.

[0091] The velocity grid is shaped like a cube in the three-dimensional model, and its three-dimensional grid size data is (dx, dy, dz), which respectively represent the length of the velocity grid in the X-axis direction, the Y-axis direction, and the Z-axis direction; the origin coordinates of the velocity model are (x0, y0, z0), where x0 and y0 are the starting positions of the velocity model in the horizontal direction, and z0 is the top of the model.

[0092] Determining the model coordinates of the known point in the first velocity model according to the known point coordinates and the model parameters of the first velocity model includes the following steps:

[0093] 1. Adjust the coordinates of the known point based on the interval difference between the coordinates of the known point and the origin coordinates of the first velocity model to obtain the transition coordinates of the known point;

[0094] 2. Based on the grid size, scale the transition coordinates to obtain the model coordinates of the known points.

[0095] Schematically, the model coordinates of the known points are obtained by the following formula 5:

[0096] Formula 5:

[0097]

[0098] Among them, (ix, iy, iz) represents the grid index of the known point in the velocity model, that is, the model coordinates of the known point.

[0099] In general, (ix, iy, iz) is the surface position of the known point in the first velocity model. Vertically from this position, the velocity grid is searched toward the depth of the first velocity model and the grid velocity is recorded. That is, the velocity grid is searched from the altitude value corresponding to the vertical coordinate of the velocity model from high to low.

[0100] The grid velocity of the velocity grid in the velocity model increases as the altitude decreases, that is, the closer to the surface, the smaller the velocity, and the farther away from the surface, the larger the velocity.

[0101] A velocity threshold Vmax is preset. If the grid velocity exceeds Vmax, the search and recording stops. The position of the current velocity grid is recorded from the known point on the surface. The number of grids is n. Based on the grid size of the velocity grid in the vertical direction (Z axis), the recorded grid velocity is stored in the array [vi]. The thickness of the array is n*dz.

[0102] It is worth noting that the grid size of the velocity grid can be arbitrary, and its three-dimensional values ​​and units can be arbitrary; the number of velocity grids in the first velocity model can be arbitrary; the model origin and model top in the first velocity model can be at any position, and their coordinates can be arbitrary; the direction when sectioning the three-dimensional first velocity model can be arbitrary; the preset velocity threshold Vmax can be arbitrary, and its value and unit can be arbitrary, and the embodiments of the present application do not limit this.

[0103] Step 330 : Allocate the point time difference to the velocity grid corresponding to the model coordinates, perform velocity correction processing on the first velocity model, and obtain a corrected second velocity model.

[0104] In step 320, the grid velocities that meet the velocity threshold requirements are recorded in array [vi], the velocity grids corresponding to these grid velocities are marked as known point velocity grids, and the grid velocities in the known point velocity grids are corrected using the point time difference.

[0105] Among them, the known point velocity grid is divided into the excitation point velocity grid and the receiving point velocity grid.

[0106] The receiving point velocity grid refers to the velocity grid that records the grid velocity when searching from the receiving point position to the depth of the first velocity model (the direction of descending altitude) when there is a receiving point on the ground surface, that is, the velocity grid corresponding to the receiving point grid velocity in array [vi].

[0107] The excitation point velocity grid refers to the velocity grid that records the grid velocity when searching from the excitation point position to the depth of the first velocity model (in the direction of descending altitude) when there is an excitation point on the surface of the earth. It is also the velocity grid corresponding to the excitation point grid velocity in array [vi].

[0108] When the known point is a receiving point, the receiving point time difference tr obtained by Formula 3 is used to correct the receiving point velocity grid, that is, the receiving point time difference tr is distributed to the receiving point velocity grid according to a preset ratio.

[0109] When the known point is the excitation point, the excitation point time difference ts obtained by formula 4 is used to correct the excitation point velocity grid, that is, the excitation point time difference ts is distributed to the excitation point velocity grid according to a preset ratio.

[0110] After the velocity correction is performed on the known point velocity grid, the first velocity model becomes a second velocity model. In the second velocity model, except for the grid velocity of the known point velocity grid being different from that in the first velocity model, other model parameters are the same.

[0111] Step 340 : Based on the inverse distance weighted method, velocity interpolation processing is performed on the second velocity model to obtain a corrected third velocity model. The velocity interpolation processing is used to perform velocity correction on the velocity grid in the second velocity model.

[0112] On the ground surface line in the second velocity model, in addition to the known point positions of the existing excitation points or receiving points, there are other unknown point positions, and there are no excitation points or receiving points at the unknown point positions.

[0113] In step 330, the corresponding grid velocities of the known point velocity grids are searched downward for locations where receiving points or excitation points exist on the ground surface, recorded, and velocity corrections are performed on the known point velocity grids. Uncorrected velocity grids may exist. These velocity grids, also known as blank velocity grids, are traversed when searching from locations where no known points exist on the ground surface toward the depth of the second velocity model (in the direction of decreasing altitude).

[0114] Based on the inverse distance weighted method, speed difference processing is performed on the blank speed grids. This means randomly selecting a blank speed grid from the blank speed grids, calculating the distance between the current blank speed grid and other blank speed grids, and obtaining a weight based on the inverse of the distance. Based on the weight, speed correction is performed on the blank speed grid.

[0115] After velocity correction is performed on all blank velocity grids, the second velocity model becomes a third velocity model. In the third velocity model, except for the grid velocity of the blank velocity grid being different from that in the second velocity model, other model parameters are the same.

[0116] Step 350 : Perform velocity smoothing on the velocity grid in the third velocity model to obtain a modified velocity model. The modified velocity model is used to characterize geological propagation velocity.

[0117] The methods used to correct the velocity grids of known points and blank velocity grids are different. Therefore, in the corrected third velocity model, there are problems of non-smooth and discontinuous velocities between the velocity grids. It is necessary to perform velocity smoothing on the velocity grids in the third velocity model so that the grid velocities in the final corrected velocity model are continuous and smooth, and can accurately represent the geological velocity.

[0118] Among them, the known point velocity grid is corrected using point time difference, which has high accuracy and precision. When performing velocity smoothing, the grid velocity in the known point velocity grid must be kept unchanged.

[0119] When performing speed smoothing on a blank speed grid, the smoothing range of each blank speed grid must first be determined, and then the current blank speed grid is corrected based on the smoothing range of each blank speed grid. The smoothing range is obtained by the following formula 6:

[0120] Formula 6:

[0121]

[0122] Here, radius2 is the preset smoothing radius. Based on the smoothing radius and the grid size of the velocity grid (dx and dy), the search radius rx in the X-axis direction and the search radius ry in the Y-axis direction are calculated, that is, the number of velocity grids in different directions within the search range.

[0123] Optionally, when obtaining the smoothing range based on the search radii rx and ry, the smoothing range may be in any form, including but not limited to one of the following forms:

[0124] (1) With the current blank velocity grid as the center, search for a rectangular area with a radius rx and a radius ry as the length and width;

[0125] (2) With the current blank velocity grid as the center, the search radius rx and ry are the major and minor semi-axes of the elliptical area.

[0126] After determining the smoothing range of each blank velocity grid, the grid velocities corresponding to the blank velocity grids are smoothed one by one to obtain the smoothed velocity. The smoothed velocity is mainly obtained by the following formula 7:

[0127] Formula 7:

[0128]

[0129] Where arrV3 refers to the third velocity model, m refers to the number of blank velocity grids within the smoothing range that participate in the smoothing calculation, ix and iy refer to the grid indices of the current blank velocity grid, rx and ry refer to the smoothing radius, and jx and jy refer to the grid indices of the blank velocity grids within the smoothing range that participate in the smoothing calculation.

[0130] Formula 7 means that the smoothing range is determined based on the smoothing radius, with the target blank speed grid currently being smoothed as the center. The speeds corresponding to the remaining blank speed grids within the smoothing range are all added together, and the average value is taken as the smoothed speed. The smoothed speed is then used to replace the original grid speed of the target blank speed grid. The above steps are repeated until all blank speed grids have completed the speed smoothing process, and the third speed model becomes the final corrected speed model.

[0131] It is worth noting that the smoothing radius and the search radius can be arbitrary, the form of the smoothing range can be arbitrary, and the order of smoothing the blank velocity grids can be arbitrary, which is not limited in this embodiment.

[0132] In summary, the method provided in the present application obtains the time difference of the excitation point and the time difference of the receiving point, that is, the point time difference, and maps the excitation point and the receiving point to the velocity model based on the actual measured coordinates of the excitation point and the receiving point, that is, the known point coordinates, to obtain the model coordinates of the excitation point and the receiving point in the velocity model, and assigns the time difference of the excitation point and the receiving point to the velocity grid of the corresponding position of the known point in the velocity model, corrects the grid velocity of the known point, and performs velocity difference processing on the remaining velocity grid based on the inverse distance weighted method. Finally, the corrected velocity grid in the velocity model is smoothed to make the grid velocity in the velocity model continuous and natural, thereby improving the accuracy of the velocity in the velocity model. The static correction value calculated using the corrected velocity model is also more accurate, which can improve the effect of offset imaging.

[0133] The method provided in this embodiment obtains the excitation point time difference and the receiving point time difference based on the difference between the first arrival picking time and the ray travel time difference of the first arrival wave and the ray travel time between the excitation point and the receiving point. This method finds the direct cause of the low velocity accuracy in the velocity model and provides an accurate basis for correcting the velocity model. The excitation point time difference and the receiving point time difference are assigned to the corresponding point positions in the velocity model for velocity correction, making the corrected velocity model more accurate.

[0134] The method provided in this embodiment achieves the task of mapping the excitation points and receiving points from the field to the velocity model by obtaining the actual measured coordinates of the excitation points and receiving points and, based on the model parameters and grid size data of the velocity model, obtaining the grid indexes of the excitation points and receiving points in the velocity model, and providing the accurate positions of the points requiring velocity correction in the velocity model.

[0135] In some embodiments, the known point velocity grid in the first velocity model is corrected based on the point time difference to obtain a corrected second velocity model, which can be achieved by the following steps: Figure 4 As shown, Figure 4 is a flow chart of the method for correcting the velocity grid of known points.

[0136] Step 410 , taking the inverse of the grid speed to obtain the grid slowness, and summing the grid slowness to obtain the total slowness.

[0137] The grid slowness s is obtained by taking the inverse of the known point grid velocity v recorded in the array [vi], which is obtained by the following formula 8:

[0138] Formula 8:

[0139]

[0140] Obtain the known point grid slowness corresponding to each known point grid velocity in the data [vi] to obtain the array [si], sum all the known point grid slownesses to obtain the total slowness sumS, which is obtained by the following formula 9:

[0141] Formula 9:

[0142]

[0143] Step 420 : Based on the proportion of the grid slowness in the total slowness, the point time difference is proportionally distributed to the velocity grid corresponding to the model coordinate.

[0144] The model coordinates refer to the position coordinates of the known point in the first velocity model or the grid index of the known point in the first velocity model. The known point can be an excitation point or a receiving point. When the known point is an excitation point, the excitation point time difference ts is assigned to the excitation point velocity grid; when the known point is a receiving point, the receiving point time difference tr is assigned to the receiving point velocity grid.

[0145] The time difference assigned to each velocity grid is dt, where the allocation ratio is obtained by the following formula:

[0146] Formula 10:

[0147]

[0148] Wherein, t is the time difference between the excitation point ts or the receiving point tr, which is determined by the type of known point.

[0149] Step 430: Obtain a change in the grid slowness based on the ratio of the grid slowness to the grid size.

[0150] For each known point velocity grid, calculate the change in its grid slowness, which is obtained by the following formula 11:

[0151] Formula 11:

[0152]

[0153] Where dsi is the grid slowness change, dt is the time difference assigned to each known point grid, and dz is the grid size. After storing all the grid slowness changes dsi calculated by the above formula 11, the grid slowness change storage array arrS is obtained.

[0154] Step 440 : Take the inverse of the sum of the grid slowness and the grid slowness change to obtain the corrected speed of the speed grid corresponding to the model coordinates.

[0155] For each known point velocity grid, there is a corresponding grid slowness and grid slowness change. The corrected speed vi is calculated using the following formula:

[0156] Formula 12:

[0157]

[0158] Step 450: Replace the grid velocity with the corrected velocity to obtain a corrected second velocity model.

[0159] In the first velocity model, each velocity grid has its initial velocity, and the known point velocity grid also has its initial known point velocity. After correcting them based on the point time difference, the corrected velocity obtained is more accurate. After replacing the initial velocity with the corrected velocity, a second velocity model with simple correction is obtained.

[0160] In the second velocity model, the grid velocity of the known point velocity grid is corrected, and in a subsequent process of further correcting the second velocity model, the grid velocity of the known point velocity grid remains unchanged.

[0161] In summary, the method provided in the present application obtains the time difference of the excitation point and the time difference of the receiving point, that is, the point time difference, and maps the excitation point and the receiving point to the velocity model based on the actual measured coordinates of the excitation point and the receiving point, that is, the known point coordinates, to obtain the model coordinates of the excitation point and the receiving point in the velocity model, and assigns the time difference of the excitation point and the receiving point to the velocity grid of the corresponding position of the known point in the velocity model, corrects the grid velocity of the known point, and performs velocity difference processing on the remaining velocity grid based on the inverse distance weighted method. Finally, the corrected velocity grid in the velocity model is smoothed to make the grid velocity in the velocity model continuous and natural, thereby improving the accuracy of the velocity in the velocity model. The static correction value calculated using the corrected velocity model is also more accurate, which can improve the effect of offset imaging.

[0162] The method provided in this embodiment converts the point time difference into grid slowness and distributes the grid slowness proportionally to each known point velocity grid to obtain a corrected known point grid velocity. This improves the accuracy of the velocity model and enables the velocity grid at the known point position in the corrected second velocity model to maintain its velocity accuracy.

[0163] In some embodiments, after correcting the grid velocity of the known point velocity grid, the remaining blank velocity grids are also corrected. Based on the inverse distance weighted method, the second velocity model is subjected to velocity interpolation processing to obtain a corrected third velocity model, such as Figure 5 As shown, the method steps for interpolating the second velocity model are as follows.

[0164] Step 510: Obtain the search range of the velocity grid.

[0165] The interpolation processing of the second velocity model refers to interpolating all velocity grids that meet the velocity threshold Vmax except the known point velocity grids, that is, interpolating the blank velocity grids whose grid velocities are less than the velocity threshold Vmax.

[0166] Select any blank speed grid as the current blank speed grid and get the search range of the current blank speed grid.

[0167] The search range contains multiple blank velocity grids that have not been processed with velocity correction.

[0168] First, the search radius is calculated based on the preset interpolation radius. Specifically, it is obtained by the following formula 13:

[0169] Formula 13:

[0170]

[0171] Where dx and dy are the grid sizes of the velocity grid, rx and ry are the search radii, and radius is the interpolation radius.

[0172] Optionally, when obtaining the search range based on the search radius rx and ry, the search range may be in any form, including but not limited to one of the following forms:

[0173] (1) With the current blank velocity grid as the center, search for a rectangular area with a radius rx and a radius ry as the length and width;

[0174] (2) With the current blank velocity grid as the center, the search radius rx and ry are the major and minor semi-axes of the elliptical area.

[0175] It is worth noting that the search radius rx and ry can be arbitrary, and the value and unit of the search radius can be arbitrary; the interpolation radius can be arbitrary, and the value and unit of the interpolation radius can be arbitrary, and this embodiment does not limit this.

[0176] Step 520 : Based on the coordinates and grid size of the velocity grid in the second velocity model, obtain the sum of squares of distances between the velocity grid and any blank velocity grid within the search range.

[0177] For any current blank velocity grid, after obtaining its search range, the sum of squared distances is calculated based on the velocity grids existing within the search range.

[0178] Optionally, in addition to the current blank velocity grid, the search range also includes blank velocity grids A, B, and C.

[0179] Optionally, the grid index of blank velocity grid A in the second velocity model cross-section is (jx1, jy1), the grid index of blank velocity grid B in the second velocity model cross-section is (jx2, jy2), and the grid index of blank velocity grid C in the second velocity model cross-section is (jx3, jy3).

[0180] The formula for calculating the sum of squared distances is as follows, Formula XIV:

[0181] Formula XIV:

[0182] d = (jx - ix) * (jx - ix) * dx * dx + (jy - iy) * (jy - iy) * dy * dy

[0183] Where d is the sum of squared distances, ix and iy are the grid indices of the current blank velocity grid, dx and dy are the grid sizes of the second velocity model, and jx and jy are the grid indices of other velocity grids in the search range except the current blank velocity grid.

[0184] Schematically, calculate the sum of squared distances d1 from the current blank velocity grid to blank velocity grid A. Substitute into Formula XIV to get d1 = (jx1 - ix) * (jx1 - ix) * dx * dx + (jy1 - iy) * (jy1 - iy) * dy * dy.

[0185] It should be noted that the number of velocity grids in the search range can be arbitrary, including but not limited to the three velocity grids in the above example. Each velocity grid can be distinguished by different markings, including but not limited to English characters, Arabic numerals, Chinese characters, etc.; the grid index of each velocity grid in the two-dimensional second velocity model can be arbitrary, and the numerical value and unit of the grid index can be arbitrary. This embodiment does not limit this.

[0186] Step 530: Obtain the weighting value based on the reciprocal of the sum of squared distances, and sum the weighting values to obtain the weighted sum of the velocity grids.

[0187] Where the weighting value refers to the weight of each velocity grid to the current velocity grid within the search range of the current blank velocity grid. The weighting value is used for subsequent calculation of the average slowness value and is obtained by the following Formula XV:

[0188] Formula XV:

[0189]

[0190] Where d is the sum of the squares of the distances between the current blank velocity grid and any velocity grid within the search range, and Wjx,jy is the weight from any velocity grid within the search range to the current blank velocity grid, i.e., the weighted value.

[0191] Summing the weighted values ​​means summing the weighted values ​​of all speed grids to the current blank speed grid within the search range of the current blank speed grid, which is obtained by the following formula 16:

[0192] Formula 16:

[0193]

[0194] Where sumW is the weighted sum.

[0195] Step 540 : Obtain an average slowness value of the velocity grid based on the ratio relationship among the weighted value, the weighted sum, and the grid slowness change.

[0196] Schematically, obtaining the average slowness value of the velocity grid is achieved by the following steps.

[0197] (1) Multiplying the grid slowness change dsi of the velocity grid and the weighted value Wjx,jy to obtain the first product;

[0198] The grid slowness change dsi is calculated by formula 11.

[0199] (2) Sum the first products of all grids within the search range to obtain the sum of the first products;

[0200] (3) After taking the inverse of the weighted sum, multiply it with the first product sum to obtain the average slowness value.

[0201] The above steps (1) to (3) are obtained by the following formula 17.

[0202] Formula 17:

[0203]

[0204] Wherein, avgSiz is the average slowness value, sumW is the weighted sum, Wjx,jy is the weighted value, and arrSjx,jy,jz refers to the grid slowness change storage array arrS obtained after storing all grid slowness changes calculated by the above formula 11.

[0205] Step 550 : Correcting the grid velocity of the blank velocity grid based on the average slowness value to obtain a corrected third velocity model.

[0206] Schematically, after obtaining the average slowness value of each blank velocity grid, the blank velocity grid is corrected by the following steps.

[0207] (1) Obtaining the initial grid velocity of the blank velocity grid, taking the inverse of the initial grid velocity, and adding it to the average slowness value to obtain the first correction parameter;

[0208] (2) taking the inverse of the first correction parameter to obtain the first correction speed of the blank speed grid;

[0209] (3) The initial grid velocity is replaced by the first corrected velocity to obtain the corrected third velocity model.

[0210] The above steps (1) to (3) are obtained by the following formula 18:

[0211] Formula 18:

[0212]

[0213] Where v* is the corrected velocity obtained after velocity correction of the blank velocity grid, avgSiz is the average slowness value, and v is the initial grid velocity of the blank velocity grid.

[0214] In summary, the method provided in the present application obtains the time difference of the excitation point and the time difference of the receiving point, that is, the point time difference, and maps the excitation point and the receiving point to the velocity model based on the actual measured coordinates of the excitation point and the receiving point, that is, the known point coordinates, to obtain the model coordinates of the excitation point and the receiving point in the velocity model, and assigns the time difference of the excitation point and the receiving point to the velocity grid of the corresponding position of the known point in the velocity model, corrects the grid velocity of the known point, and performs velocity difference processing on the remaining velocity grid based on the inverse distance weighted method. Finally, the corrected velocity grid in the velocity model is smoothed to make the grid velocity in the velocity model continuous and natural, thereby improving the accuracy of the velocity in the velocity model. The static correction value calculated using the corrected velocity model is also more accurate, which can improve the effect of offset imaging.

[0215] The method provided in this embodiment corrects the known point velocity grids and then corrects the remaining blank velocity grids. The second velocity model is interpolated using the inverse distance weighted method. The inverse of the sum of the squares of the distances between each velocity grid within the search range and the current blank velocity grid is used as a weighted value to further determine the grid slowness change required to correct the blank velocity grid. This ensures that the grid velocities corresponding to all velocity grids in the second velocity model that meet the velocity threshold are corrected, thereby improving the precision and accuracy of the velocity model.

[0216] The method provided in this embodiment processes the ratio relationship between the grid slowness change and the weighted value, and then takes the inverse as the average slowness value, so as to obtain an accurate transition intermediate value. Based on the transition intermediate value, the velocity of the blank velocity grid is corrected, thereby improving the precision and accuracy of the velocity model.

[0217] The method provided in this embodiment obtains the initial velocity of a blank velocity grid, takes its reciprocal, and then performs a basic process of adding the reciprocal to the average slowness value and taking the reciprocal again to obtain a corrected grid velocity that can replace the initial velocity. This allows the grid velocities of all blank velocity grids other than the known point velocity grid to be corrected, thereby improving the precision and accuracy of the velocity model.

[0218] Figure 6 This is a structural block diagram of a correction device for a geological velocity model provided by an exemplary embodiment of the present application. Figure 6 As shown, the device includes the following parts.

[0219] An acquisition module 610 is configured to acquire a point time difference, where the point time difference includes an excitation point time difference and a receiving point time difference. The excitation point time difference refers to a time difference generated when the excitation point transmits a wave to the receiving point, and the receiving point time difference refers to a time difference generated when the receiving point receives a wave. There is at least one excitation point and at least one receiving point.

[0220] a determination module 620 configured to determine the model coordinates of the known point in the first velocity model based on the known point coordinates and model parameters of the first velocity model, wherein the known point includes the excitation point and the receiving point, and the known point coordinates include the measured coordinates of the excitation point and the measured coordinates of the receiving point. The first velocity model is a three-dimensional model for predicting geological velocity, and includes a plurality of velocity grids, each of which corresponds to a respective grid velocity.

[0221] a correction module 630, configured to assign the point time difference to the velocity grid corresponding to the model coordinates, perform velocity correction processing on the first velocity model, and obtain a corrected second velocity model;

[0222] an interpolation module 640 configured to perform velocity interpolation processing on the second velocity model based on an inverse distance weighted method to obtain a corrected third velocity model, wherein the velocity interpolation processing is used to perform velocity correction on the velocity grid in the second velocity model;

[0223] The smoothing module 650 is configured to perform velocity smoothing on the velocity grid in the third velocity model to obtain a modified velocity model, wherein the modified velocity model is used to characterize geological propagation velocity.

[0224] In an optional embodiment, the acquisition module 610 is also used to obtain the first arrival picking time, the first arrival picking time refers to the picking time of the first arrival wave, the first arrival wave refers to the wave received earliest by the receiving point, wherein one excitation point emits multiple waves, corresponding to multiple receiving points; obtain the travel time, the travel time refers to the time it takes for the ray to reach the receiving point from the excitation point; based on the difference between the first arrival time and the travel time, the total time difference of the excitation point and the total time difference of the receiving point are obtained, the total time difference of the excitation point is the sum of the time differences of the excitation points, and the total time difference of the receiving point is the sum of the time differences of the receiving points; based on the number of the excitation points, the total time difference of the excitation points is averaged to obtain the excitation point time difference; based on the number of the receiving points, the total time difference of the receiving points is averaged to obtain the receiving point time difference.

[0225] In an optional embodiment, the model parameters include the origin coordinates and grid size of the first velocity model, and the grid size is the three-dimensional size of the velocity grid;

[0226] The determination module 620 is further configured to adjust the known point coordinates based on an interval difference between the known point coordinates and the origin coordinates of the first velocity model to obtain transition coordinates of the known point; and scale the transition coordinates proportionally based on the grid size to obtain the model coordinates.

[0227] In an optional embodiment, the correction module 630, such as Figure 7 As shown, it also includes:

[0228] The reciprocal summing unit 631 is configured to take the reciprocal of the grid speed to obtain a grid slowness, and sum the grid slowness to obtain a slowness sum;

[0229] an allocating unit 632 for allocating the point time difference to the velocity grid corresponding to the model coordinate in proportion based on the proportion of the grid slowness in the total slowness;

[0230] a calculation unit 633 configured to obtain a grid slowness change based on a ratio of the grid slowness to the grid size;

[0231] The calculation unit 633 is further configured to obtain the reciprocal of the sum of the grid slowness and the grid slowness change to obtain a corrected speed of the speed grid corresponding to the model coordinates;

[0232] The replacing unit 634 is configured to replace the grid velocity with the corrected velocity to obtain a corrected second velocity model.

[0233] In an optional embodiment, the interpolation module 640 further includes:

[0234] An acquiring unit 641 is configured to acquire a search range of the velocity grid, wherein the search range includes a plurality of blank velocity grids that have not been subjected to velocity correction processing;

[0235] A calculation unit 642 is configured to obtain a sum of squares of distances between the velocity grid and any blank velocity grid within the search range based on the coordinates of the velocity grid in the second velocity model and the grid size;

[0236] a summing unit 643 configured to obtain a weighted value based on the inverse of the sum of squares of the distances, and sum the weighted values ​​to obtain a weighted sum of the velocity grid;

[0237] The calculation unit 642 is further configured to obtain an average slowness value of the velocity grid based on a ratio relationship among the weighted value, the weighted sum, and the grid slowness change;

[0238] The correction unit 644 is configured to correct the grid velocity of the blank velocity grid based on the average slowness value to obtain the corrected third velocity model.

[0239] In an optional embodiment, the calculation unit 642 is further used to multiply the grid slowness change of the speed grid and the weighted value to obtain a first product; sum the first products of all grids within the search range to obtain a first product sum; take the inverse of the weighted sum, and multiply it with the first product sum to obtain the average slowness value.

[0240] In an optional embodiment, the correction unit 644 is further used to obtain the initial grid velocity of the blank velocity grid, take the inverse of the initial grid velocity, and add it to the average slowness value to obtain a first correction parameter; take the inverse of the first correction parameter to obtain a first corrected velocity of the blank velocity grid; and replace the initial grid velocity with the first corrected velocity to obtain the corrected third velocity model.

[0241] In summary, the device provided in this embodiment obtains the time difference of the excitation point and the time difference of the receiving point, that is, the point time difference, and maps the excitation point and the receiving point to the velocity model based on the actual measured coordinates of the excitation point and the receiving point, that is, the known point coordinates, to obtain the model coordinates of the excitation point and the receiving point in the velocity model, and assigns the time difference of the excitation point and the receiving point to the velocity grid of the corresponding position of the known point in the velocity model, corrects the grid velocity of the known point, performs velocity difference processing on the remaining velocity grid based on the inverse distance weighted method, and finally smoothes the corrected velocity grid in the velocity model to make the grid velocity in the velocity model continuous and natural, thereby improving the accuracy of the velocity in the velocity model. The static correction value calculated using the corrected velocity model is also more accurate, which can improve the effect of offset imaging.

[0242] It should be noted that the geological velocity model correction device provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0243] Figure 8 The following is a block diagram of a computer device 800 according to an exemplary embodiment of the present application. The computer device 800 may be a smartphone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III), an MP4 player (Moving Picture Experts Group Audio Layer IV), a laptop computer, or a desktop computer. The computer device 800 may also be referred to as a user device, a portable terminal, a laptop terminal, a desktop terminal, or other similar names.

[0244] Typically, the computer device 800 includes a processor 801 and a memory 802 .

[0245] The processor 801 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 801 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). The processor 801 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 801 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 801 may also include an AI processor, which is used to process computing operations related to machine learning.

[0246] Memory 802 may include one or more computer-readable storage media, which may be non-transitory. Memory 802 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in memory 802 is used to store at least one instruction, which is executed by processor 801 to implement the geological velocity model correction method provided in the method embodiments of this application.

[0247] In some embodiments, the computer device 800 further includes other components, which can be understood by those skilled in the art. Figure 8 The structure shown in the figure does not constitute a limitation on the terminal 800, and the terminal 800 may include more or fewer components than shown in the figure, or combine certain components, or adopt a different component arrangement.

[0248] Optionally, the computer-readable storage medium may include: a read-only memory (ROM), a random access memory (RAM), a solid-state drive (SSD), or an optical disk. Among them, the random access memory may include a resistance random access memory (ReRAM) and a dynamic random access memory (DRAM). The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0249] The embodiment of the present application further provides a computer device, which can be implemented as follows: Figure 3 The terminal or server shown. The computer device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, code set, or instruction set, and the at least one instruction, at least one program, code set, or instruction set is loaded and executed by the processor to implement the geological velocity model correction method provided by each of the above method embodiments.

[0250] An embodiment of the present application also provides a computer-readable storage medium, on which is stored at least one instruction, at least one program, code set, or instruction set, which is loaded and executed by a processor to implement the geological velocity model correction method provided in the above-mentioned method embodiments.

[0251] Embodiments of the present application also provide a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method for correcting a geological velocity model described in any of the above embodiments.

[0252] Optionally, the computer-readable storage medium may include: a read-only memory (ROM), a random access memory (RAM), a solid-state drive (SSD), or an optical disk. Among them, the random access memory may include a resistance random access memory (ReRAM) and a dynamic random access memory (DRAM). The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0253] Those skilled in the art will understand that all or part of the steps of implementing the above embodiments can be completed by software, or by a program to instruct the relevant software to complete the steps. The program can be stored in a computer-readable storage medium, and the above-mentioned storage medium can be a read-only memory, a disk or an optical disk, etc.

[0254] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for correcting a geological velocity model, characterized in that: The method comprises: Obtaining point time differences, where the point time differences include an excitation point time difference and a receiving point time difference. The excitation point time difference refers to the time difference generated when the excitation point sends waves to the receiving point, and the receiving point time difference refers to the time difference generated when the receiving point receives waves. There is at least one excitation point and one receiving point. determining, based on known point coordinates and model parameters of a first velocity model, model coordinates of the known point in the first velocity model, the known point including the excitation point and the receiving point, the known point coordinates including measured coordinates of the excitation point and the receiving point, the first velocity model being a three-dimensional model for predicting geological velocity, the first velocity model including a plurality of velocity grids, each of the velocity grids corresponding to a respective grid velocity; Taking the inverse of the grid speed to obtain a grid slowness, and summing the grid slownesses to obtain a slowness sum; Based on the proportion of the grid slowness in the total slowness, the point time difference is proportionally distributed to the velocity grid corresponding to the model coordinate; Obtaining a grid slowness change based on a ratio of the grid slowness to a grid size, wherein the grid size is a three-dimensional size of the velocity grid; Taking the reciprocal of the sum of the grid slowness and the grid slowness change to obtain a corrected speed of the speed grid corresponding to the model coordinates; Replacing the grid velocity with the corrected velocity to obtain a corrected second velocity model; performing velocity interpolation processing on the second velocity model based on an inverse distance weighted method to obtain a corrected third velocity model, wherein the velocity interpolation processing is used to perform velocity correction on the velocity grid in the second velocity model; Velocity smoothing is performed on the velocity grid in the third velocity model to obtain a modified velocity model, which is used to characterize geological propagation velocity.

2. The method according to claim 1, characterized in that The acquisition point time difference includes: Obtaining a first arrival picking time, where the first arrival picking time refers to the picking time of a first arrival wave, and the first arrival wave refers to the wave first received by the receiving point. One excitation point emits multiple waves, corresponding to multiple receiving points; Acquire travel time, where the travel time refers to the time it takes for the ray to travel from the excitation point to the receiving point; Based on the difference between the first arrival time and the travel time, the total time difference of the excitation point and the total time difference of the receiving point are obtained, wherein the total time difference of the excitation point is the sum of the time differences of the excitation points, and the total time difference of the receiving point is the sum of the time differences of the receiving points; Based on the number of the excitation points, averaging the total time differences of the excitation points to obtain the excitation point time differences; Based on the number of the receiving points, the total time differences of the receiving points are averaged to obtain the time differences of the receiving points.

3. The method according to claim 1, characterized in that The model parameters include the origin coordinates of the first velocity model; The determining, based on the known point coordinates and the model parameters of the first velocity model, the model coordinates of the known point in the first velocity model includes: Adjusting the coordinates of the known point based on an interval difference between the coordinates of the known point and the coordinates of the origin of the first velocity model to obtain transition coordinates of the known point; The transition coordinates are scaled based on the grid size to obtain the model coordinates.

4. The method according to any one of claims 1 to 3, characterized in that: The method of performing velocity interpolation processing on the second velocity model based on the inverse distance weighted method to obtain a revised third velocity model includes: Acquire a search range of the velocity grid, wherein the search range includes a plurality of blank velocity grids that have not been subjected to velocity correction processing; Obtaining, based on the coordinates of the velocity grid in the second velocity model and the grid size, a sum of squares of distances between the velocity grid and any blank velocity grid within the search range; Obtaining a weighted value based on the inverse of the sum of squares of the distances, and summing the weighted values ​​to obtain a weighted sum of the velocity grid; Obtaining an average slowness value of the velocity grid based on a ratio relationship among the weighted value, the weighted sum, and the grid slowness change; The grid velocity of the blank velocity grid is corrected based on the average slowness value to obtain the corrected third velocity model.

5. The method according to claim 4, characterized in that The obtaining of the average slowness value of the speed grid based on the ratio relationship among the weighted value, the weighted sum, and the grid slowness change includes: multiplying the grid slowness change of the velocity grid and the weighted value to obtain a first product; Summing the first products of all grids within the search range to obtain a first product sum; The reciprocal of the weighted sum is taken and then multiplied by the first product sum to obtain the average slowness value.

6. The method according to claim 4, characterized in that The step of correcting the grid velocity of the blank velocity grid based on the average slowness value to obtain the corrected third velocity model includes: obtaining an initial grid velocity of the blank velocity grid, taking the inverse of the initial grid velocity, and adding the inverse to the average slowness value to obtain a first correction parameter; Taking the inverse of the first correction parameter to obtain a first correction speed of the blank speed grid; The initial grid velocity is replaced by the first corrected velocity to obtain the corrected third velocity model.

7. A correction device for a geological velocity model, characterized in that: The device comprises: An acquisition module is configured to acquire a point time difference, wherein the point time difference includes an excitation point time difference and a receiving point time difference. The excitation point time difference refers to a time difference generated when the excitation point sends a wave to the receiving point, and the receiving point time difference refers to a time difference generated when the receiving point receives a wave. There is at least one excitation point and at least one receiving point. a determination module, configured to determine, based on the known point coordinates and model parameters of a first velocity model, the model coordinates of the known point in the first velocity model, wherein the known point includes the excitation point and the receiving point, the known point coordinates include the measured coordinates of the excitation point and the measured coordinates of the receiving point, and the first velocity model is a three-dimensional model for predicting geological velocity, and includes a plurality of velocity grids, each of the velocity grids corresponding to a respective grid velocity; A correction module is configured to take the inverse of the grid speed to obtain a grid slowness, and sum the grid slownesses to obtain a slowness sum; proportionally distribute the point time difference to the velocity grid corresponding to the model coordinate based on the proportion of the grid slowness in the slowness sum; obtain a grid slowness change based on a ratio of the grid slowness to a grid size, where the grid size is a three-dimensional size of the velocity grid; take the inverse of the sum of the grid slowness and the grid slowness change to obtain a corrected velocity of the velocity grid corresponding to the model coordinate; and replace the grid velocity with the corrected velocity to obtain a corrected second velocity model; an interpolation module, performing velocity interpolation processing on the second velocity model based on an inverse distance weighted method to obtain a corrected third velocity model, wherein the velocity interpolation processing is used to perform velocity correction on the velocity grid in the second velocity model; The smoothing module performs velocity smoothing processing on the velocity grid in the third velocity model to obtain a modified velocity model, and the modified velocity model is used to characterize geological propagation velocity.

8. A computer device, characterized in that: The computer device includes a processor and a memory, wherein the memory stores at least one program, and the at least one program is loaded and executed by the processor to implement the method for correcting the geological velocity model according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The storage medium stores at least one program, which is loaded and executed by the processor to implement the method for correcting the geological velocity model according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises a computer program, which, when executed by a processor, implements the method for correcting a geological velocity model according to any one of claims 1 to 6.

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