SV wave ray tracing method and device based on anisotropic medium and terminal

Abstract

The embodiment of the invention discloses an SV wave ray tracing method and device based on an anisotropic medium, and a terminal, and belongs to the field of seismic data processing. The method comprises the steps of determining a phase slowness expression of an SV wave in a VTI medium through a plurality of parameters of the VTI medium on the basis of a Cristoval frequency dispersion theory; performing Fourier transform and inverse Fourier transform on the phase slowness expression to obtain a wave equation of the SV wave; and determining the propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave. According to the technical scheme, the propagation path and travel time information of the SV wave in the VTI medium can be accurately determined, so that the propagation condition of the SV wave in the VTI medium can be accurately predicted, a more accurate theoretical basis is provided for seismic data processing, geophysical exploration and the like, and the precision and reliability in the aspects of seismic monitoring, resource exploration and the like can be improved.

Description

Technical Field

[0001] This application relates to the field of seismic data processing, and in particular to a method, apparatus and terminal for SV wave ray tracing based on anisotropic media. Background Technology

[0002] In the field of seismic data processing, ray tracing is a technique that simulates the propagation of seismic waves in subsurface media to obtain their propagation paths and times. Ray tracing provides theoretical support for seismic data acquisition and processing. Since subsurface media are generally anisotropic, ray tracing based on anisotropic media is more valuable for practical research. SV waves (vertically polarized shear waves) and P waves (p-waves) are both relatively common seismic waves, but compared to P waves, there is currently less research on ray tracing of SV waves. Therefore, how to accurately achieve SV wave ray tracing based on anisotropic media is a technical problem that needs to be solved. Summary of the Invention

[0003] This application provides a method, apparatus, and terminal for SV wave ray tracing based on anisotropic media, which can accurately determine the propagation path and travel time information of SV waves in VTI media. The technical solution is as follows:

[0004] On the one hand, a SV wave ray tracing method based on anisotropic media is provided, the method comprising:

[0005] Based on Christofer dispersion theory, the phase slowness expression of SV waves in VTI medium is determined by using multiple parameters of VTI medium. The parameters include vertical transverse wave velocity, vertical longitudinal wave velocity, and at least one anisotropic parameter of VTI medium. The phase slowness expression is used to represent the relationship between phase velocity and slowness during the propagation of SV waves in VTI medium.

[0006] The wave equation of the SV wave is obtained by performing Fourier transform and inverse Fourier transform on the phase slowness expression. The wave equation is used to describe the propagation of the SV wave in the VTI medium.

[0007] Based on the wave equation of the SV wave, the propagation path and travel time information of the SV wave in the VTI medium are determined. The travel time information includes the travel time of the SV wave at multiple propagation positions on the propagation path, and the travel time is the time taken for the SV wave to propagate from the source to the corresponding propagation position.

[0008] On the other hand, an SV wave ray tracing device based on anisotropic media is provided, the device comprising:

[0009] The first determining module is used to determine the phase slowness expression of the SV wave in the VTI medium based on Christofer dispersion theory and through multiple parameters of the VTI medium. The parameters include the vertical transverse wave velocity, the vertical longitudinal wave velocity, and at least one anisotropic parameter of the VTI medium. The phase slowness expression is used to represent the relationship between the phase velocity and slowness of the SV wave during its propagation in the VTI medium.

[0010] The transformation module is used to perform Fourier transform and inverse Fourier transform on the phase slowness expression to obtain the wave equation of the SV wave, which is used to describe the propagation of the SV wave in the VTI medium.

[0011] The second determining module is used to determine the propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave. The travel time information includes the travel time of the SV wave at multiple propagation positions on the propagation path, and the travel time is the time taken for the SV wave to propagate from the source to the corresponding propagation position.

[0012] In some embodiments, the first determining module is configured to solve the Christoffel equation based on multiple parameters of the VTI medium to obtain an intermediate expression, wherein the Christoffel equation describes the propagation characteristics of waves in anisotropic media; construct the dynamic correction velocity and equivalent anisotropic parameter of the SV wave based on the correlation between multiple parameters of the VTI medium, wherein the dynamic correction velocity and the equivalent anisotropic parameter are both related to the vertical transverse wave velocity, the vertical longitudinal wave velocity, and at least one anisotropic parameter; and substitute the dynamic correction velocity and the equivalent anisotropic parameter into the intermediate expression to obtain the phase slowness expression of the SV wave.

[0013] In some embodiments, the transformation module is configured to perform a Fourier transform on the phase slowness expression to obtain a first expression in the frequency domain; multiply both sides of the first expression by the wave field of the SV wave to obtain a second expression in the frequency domain, wherein the wave field is used to describe the distribution of the SV wave in three-dimensional space; and perform an inverse Fourier transform on the second expression to obtain the wave equation of the SV wave in the time domain.

[0014] In some embodiments, the second determining module is used to substitute the plane wave solution into the wave equation of the SV wave to obtain the equation of motion, wherein the plane wave solution is a solution form of the wave equation, and the equation of motion describes the travel time information of the SV wave; solve the equation of motion using the eigenvalue method to obtain a first set of ordinary differential equations, a second set of ordinary differential equations, and a third set of ordinary differential equations, wherein the first set of ordinary differential equations describes the relationship between the propagation position of the SV wave in the VTI medium and multiple parameters of the VTI medium, the second set of ordinary differential equations describes the relationship between the propagation direction of the SV wave in the VTI medium and the multiple parameters, and the third set of ordinary differential equations describes the relationship between the travel time of the SV wave and the multiple parameters; solve the first set of ordinary differential equations, the second set of ordinary differential equations, and the third set of ordinary differential equations to obtain the propagation path and travel time information of the SV wave in the VTI medium.

[0015] In some embodiments, the second determining module is configured to solve the second set of ordinary differential equations to obtain the slowness components of the SV wave on the x, y, and z axes; based on the slowness components of the SV wave on the x, y, and z axes, solve the first set of ordinary differential equations and the third set of ordinary differential equations respectively to obtain multiple propagation positions of the SV wave in the VTI medium and the travel time of the SV wave at each propagation position; determine the propagation path of the SV wave in the VTI medium based on the multiple propagation positions; and construct the travel time information based on the travel time of the SV wave at each propagation position.

[0016] In some embodiments, the apparatus further includes:

[0017] The third determining module is used to determine multiple parameters of the VTI medium based on multiple formations of the layered model when the VTI medium is a layered model, wherein the multiple parameters change with the formation; and to determine multiple parameters of the VTI medium according to a preset rate of change when the VTI medium is a non-layered model, wherein the rate of change is used to indicate the change of the multiple parameters.

[0018] On the other hand, a terminal is provided, the terminal including a processor and a memory, the memory storing at least one computer program, the at least one computer program being loaded and executed by the processor to implement the SV wave ray tracing method based on anisotropic media as described above.

[0019] On the other hand, a computer-readable storage medium is provided, wherein at least one computer program is stored therein, the at least one computer program being loaded and executed by a processor to implement the SV wave ray tracing method based on anisotropic media as described above.

[0020] On the other hand, a computer program product is provided, including a computer program loaded and executed by a processor to implement the SV wave ray tracing method based on anisotropic media as described above.

[0021] This application provides a method for SV wave ray tracing based on anisotropic media. Based on Christoffel dispersion theory, it can accurately determine the phase slowness expression of SV waves according to multiple parameters of the VTI medium. Then, through mathematical transformations and equation solving, the propagation path and travel time of SV waves in the VTI medium are determined. This allows for more accurate prediction of the propagation of SV wave-type seismic waves in the VTI medium, providing a more accurate theoretical basis for seismic data processing and geophysical exploration, and contributing to improved accuracy and reliability in seismic monitoring and resource exploration. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of an implementation environment provided in an embodiment of this application;

[0024] Figure 2 This is a flowchart of an SV wave ray tracing method based on anisotropic media provided in an embodiment of this application;

[0025] Figure 3 This is a flowchart of another SV wave ray tracing method based on anisotropic media provided in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the propagation path of an SV wave provided in an embodiment of this application;

[0027] Figure 5 This is a schematic diagram of the travel time contour lines of an SV wave provided in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of a synthetic seismic record provided in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of the structure of an SV wave ray tracing device based on anisotropic media provided in an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the structure of a terminal provided in an embodiment of this application. Detailed Implementation

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

[0032] It is understood that the terms "first," "second," etc., used in this application may be used to describe various concepts herein, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of this application, a first system of ordinary differential equations may be referred to as a second system of ordinary differential equations, and similarly, a second system of ordinary differential equations may be referred to as a first system of ordinary differential equations.

[0033] It should be noted that all information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in this application have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, several parameters of the VTI media involved in this application were obtained with full authorization.

[0034] The implementation environment of the embodiments of this application is described below.

[0035] Figure 1 This is a schematic diagram of an implementation environment provided in an embodiment of this application. See also... Figure 1 The implementation environment includes a terminal 101 and a server 102. The terminal 101 can be connected to the server 102 via a wireless network or a wired network.

[0036] Optionally, terminal 101 can be at least one of a smartphone, desktop computer, laptop, or tablet computer. Terminal 101 has an application installed or running that can obtain the propagation path and travel time information of seismic waves in different underground media by simulating the propagation of seismic waves in various underground media. Therefore, technicians can use this application to perform ray tracing based on multiple media, such as ray tracing based on anisotropic media. This application is associated with server 102, which provides background services.

[0037] Optionally, server 102 can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms. In some embodiments, server 102 undertakes the main computing work, and terminal 101 undertakes the secondary computing work; or, server 102 undertakes the secondary computing work, and terminal 101 undertakes the main computing work; or, server 102 and terminal 101 collaborate on computing using a distributed computing architecture.

[0038] Terminal 101 can refer to one of a plurality of terminals; this embodiment uses terminal 101 as an example. Those skilled in the art will understand that the number of terminals can be more or less. For example, there may be several terminals, or dozens or hundreds of terminals, or even more. This application embodiment does not limit the number of terminals or the type of device.

[0039] Figure 2 This is a flowchart of an SV wave ray tracing method based on anisotropic media provided in an embodiment of this application. This embodiment is executed by a terminal as an example. See [link / reference]. Figure 2 The method includes:

[0040] 201. Based on Christofer's dispersion theory, the terminal determines the phase slowness expression of the SV wave in the VTI medium through multiple parameters of the VTI medium, including the vertical transverse wave velocity, the vertical longitudinal wave velocity, and at least one anisotropic parameter of the VTI medium.

[0041] In this application embodiment, Christofel's dispersion theory is used to describe the propagation characteristics and dispersion phenomenon of elastic waves in anisotropic media. Anisotropic media refers to media whose physical properties change with direction; that is, anisotropic media can exhibit different physical properties in different directions. Dispersion theory is used to describe how the wave propagation speed changes with frequency, i.e., the wave dispersion phenomenon.

[0042] Currently, the most widely studied anisotropic media are TI (Transverse Isotropy) media. TI media typically have an axis of symmetry; in directions perpendicular to the axis of symmetry, TI media exhibit isotropic properties, while in directions parallel to the axis of symmetry, they exhibit anisotropy. When the axis of symmetry of a TI medium is perpendicular to the ground, it is called a VTI medium.

[0043] The parameters of a VTI medium are used to describe its anisotropic properties. These parameters include the vertical shear wave velocity, the vertical longitudinal wave velocity, and at least one anisotropic parameter. The vertical shear wave velocity is the velocity of the shear wave in the direction perpendicular to the axis of symmetry of the VTI medium. The vertical longitudinal wave velocity is the velocity of the longitudinal wave in the direction perpendicular to the axis of symmetry of the VTI medium. The anisotropic parameter describes the degree of difference between the physical properties of the VTI medium in the direction parallel to the axis of symmetry and in the direction perpendicular to the axis of symmetry.

[0044] Since Christoffel's dispersion theory can describe the propagation characteristics of waves in anisotropic media, such as the propagation direction and speed, the relationship between the propagation direction and speed of SV waves and the anisotropic characteristics of VTI media can be determined based on Christoffel's dispersion theory. Furthermore, since multiple parameters of the VTI medium can describe its anisotropic characteristics, expressions for the propagation direction and speed of SV waves in the VTI medium can be obtained using these parameters based on Christoffel's dispersion theory. Since SV waves (vertically polarized transverse waves) can also be called vertical shear waves, their vibration direction is perpendicular to the wave propagation direction and lies in the horizontal plane. Therefore, based on the vibration direction and propagation characteristics of SV waves, the phase slowness expression for SV waves can be solved from the above expressions. The phase slowness expression represents the relationship between the phase velocity and slowness during the propagation of SV waves in VTI media. Here, slowness is the reciprocal of phase velocity. Phase velocity refers to the propagation speed of the equiphase surface of the SV wave in the VTI medium.

[0045] 202. The terminal performs Fourier transform and inverse Fourier transform on the phase slowness expression to obtain the wave equation of the SV wave, which is used to describe the propagation of the SV wave in the VTI medium.

[0046] In this embodiment, the terminal first performs a Fourier transform on the phase slowness expression to obtain the frequency domain expression. Then, based on the wave field of the SV wave, the terminal transforms the frequency domain expression to the time domain using an inverse Fourier transform to obtain the wave equation of the SV wave. The wave field of the SV wave describes its distribution in three-dimensional space. The wave equation of the SV wave describes its propagation in the VTI medium, such as the relationship between any propagation position and travel time. Travel time refers to the time it takes for the SV wave to propagate from the source to its corresponding propagation position.

[0047] 203. The terminal determines the propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave.

[0048] In this embodiment, the terminal can determine multiple propagation positions of the SV wave and the travel time corresponding to each propagation position by solving the wave equation of the SV wave. Based on the multiple propagation positions of the SV wave, the propagation path of the SV wave in the VTI medium can be determined. Based on the travel time corresponding to the multiple propagation positions of the SV wave, the travel time information of the SV wave can be determined. In other words, the travel time information includes the travel time of the SV wave at multiple propagation positions along the propagation path.

[0049] This application provides a method for SV wave ray tracing based on anisotropic media. Based on Christoffel dispersion theory, it can accurately determine the phase slowness expression of SV waves according to multiple parameters of the VTI medium. Then, through mathematical transformations and equation solving, the propagation path and travel time of SV waves in the VTI medium are determined. This allows for more accurate prediction of the propagation of SV wave-type seismic waves in the VTI medium, providing a more accurate theoretical basis for seismic data processing and geophysical exploration, and contributing to improved accuracy and reliability in seismic monitoring and resource exploration.

[0050] The above Figure 2 The main flow of the SV wave ray tracing method based on anisotropic media provided in the embodiments of this application is illustrated. The following is a detailed description of the SV wave ray tracing scheme based on anisotropic media. Figure 3 This is a flowchart of another SV wave ray tracing method based on anisotropic media provided in this application embodiment. This method is executed by a terminal. See [link to relevant documentation]. Figure 3 The method includes:

[0051] 301. The terminal determines multiple parameters of the VIT medium, including the vertical transverse wave velocity, the vertical longitudinal wave velocity, and at least one anisotropic parameter of the VIT medium.

[0052] In this application embodiment, the VTI medium typically includes 5 parameters: V P0 V S0 , ε, δ, γ. Among them, V P0 V represents the vertical longitudinal wave velocity, which is the velocity of the longitudinal wave in the direction perpendicular to the axis of symmetry of the VTI medium. S0ε represents the vertical transverse wave velocity, which is the velocity of the transverse wave in the direction perpendicular to the axis of symmetry of the VTI medium. ε, δ, and γ are all anisotropy parameters. ε describes the anisotropy of the longitudinal wave in the VTI medium; ε represents the degree of difference between the velocity of the longitudinal wave in the direction perpendicular to the axis of symmetry and its velocity in the direction parallel to the axis of symmetry. The larger the absolute value of ε, the greater the difference in the velocity of the longitudinal wave in these directions, and the more significant the anisotropy of the longitudinal wave in the VTI medium. δ describes the anisotropy of the transverse wave in the VTI medium. The larger the absolute value of δ, the more significant the anisotropy of the transverse wave in the VTI medium. γ describes the anisotropy of the converted wave in the VTI medium.

[0053] In some embodiments, during ray tracing of SV waves based on VTI media, not all parameters of the VTI media are used, such as parameter γ. Therefore, the terminal only needs to determine the values ​​of the remaining four parameters, thereby eliminating some redundant parameters and reducing the computational load of ray tracing.

[0054] Optionally, the terminal can also perform parameter modeling based on the relationship between multiple parameters of the VTI medium to obtain fewer parameters, thereby further reducing the computational load. For example, the terminal can perform parameter modeling based on the following formulas (1) and (2).

[0055]

[0056] By using the relationship between the parameters shown in formulas (1) and (2) above, V can be constructed. nmo The two parameters are and ζ. Where V... nmo ζ represents the dynamic correction speed. ζ represents the equivalent anisotropy parameter. After completing the parameter modeling, the terminal can determine the values ​​of the dynamic correction speed and the equivalent anisotropy parameter based on the values ​​of multiple parameters of the VTI medium.

[0057] The following explains the values ​​of several parameters used by the terminal to determine the VTI media.

[0058] In some embodiments, the terminal can determine the variations of multiple parameters of the VTI medium based on its type. When the VTI medium is a layered model, the terminal determines multiple parameters of the VTI medium based on the multiple formations of the layered model. These multiple parameters vary with the formations. For example, the VTI medium may consist of two formations. Regarding the multiple parameters of the VTI medium, such as V... P0 V S0The terminal determines the values ​​corresponding to the upper and lower strata, ε and δ, respectively. When the VTI medium is a non-layered model, the terminal can determine multiple parameters of the VTI medium according to a preset rate of change. The rate of change indicates the variation of multiple parameters. The rates of change for different parameters can be the same or not entirely the same. The rate of change can be 0 or a preset value; this embodiment does not impose any limitations on this. For any parameter, when the rate of change is 0, the value of that parameter is a constant. By determining the values ​​of different parameters according to the type of VTI medium, the parameters of the VTI medium can more accurately reflect the anisotropic characteristics of the actual underground medium, improving the accuracy of ray tracing.

[0059] 302. Based on Christofer's dispersion theory, the terminal determines the phase slowness expression of the SV wave in the VTI medium through multiple parameters of the VTI medium.

[0060] In this embodiment, based on Christoffel dispersion theory, the terminal can determine the phase slowness expression of the SV wave in the VTI medium using multiple parameters of the VTI medium under high-frequency approximation assumptions. The high-frequency approximation assumption states that if the frequency of the SV wave is sufficiently high, its wavelength is very small relative to the size of the VTI medium, thus allowing the neglect of some wavelength-related complex effects, thereby reducing computational complexity and improving ray tracing efficiency. The phase slowness expression of the SV wave represents the relationship between the phase velocity and slowness during its propagation in the VTI medium.

[0061] In some embodiments, the terminal can obtain the phase slowness expression for SV waves by solving the Christoffel equation. The Christoffel equation describes the propagation characteristics of waves in anisotropic media. For anisotropic media, such as VTI media, the Christoffel equation can be used to determine the phase velocity and group velocity of different types of waves (such as P-waves, SV waves, etc.) in a specific propagation direction. By substituting multiple parameters of the VTI medium into the Christoffel equation and solving it, the terminal can obtain the intermediate expression shown in formula (3) below.

[0062]

[0063] The intermediate expression can also be referred to as the second-order phase velocity equation and the slowness expression for SV waves in anisotropy. In the intermediate expression, q is the phase velocity of the SV wave, and p is the slowness. The relationship between σ and γ0 and multiple parameters of the VTI medium is given in formula (1) above. The derivation of c is detailed in the following formulas (4)-(5).

[0064]

[0065] From the above formulas (4)-(5), it can be seen that, With vertical transverse wave velocity V S0 It is related to the slowness of the SV wave. c is related to the vertical P-wave velocity V. P0 Vertical transverse wave velocity V s0 And related to various anisotropic parameters ε and δ.

[0066] Then, the terminal obtains the dynamic correction velocity V of the SV wave from the parameter modeling. nmo Substituting the equivalent anisotropy parameter ζ into the above intermediate expression yields the simplified expression, which is the phase slowness expression for the SV wave. For example, under the second-order approximation condition, through V... nmo By simplifying the intermediate expression with ζ, we can obtain the phase slowness expression shown in the following formula (6). The second-order approximation condition means that in the process of series expansion of the expression, only the second-order terms are retained and the remaining higher-order terms are discarded.

[0067]

[0068] As can be seen from the phase slowness expression of the SV wave shown by formula (6), this expression can describe the relationship between the phase velocity, slowness, dynamic correction velocity of the SV wave and the equivalent anisotropy parameter of the VTI medium.

[0069] By solving the Christofel equation based on the parameters of the VTI medium, and simplifying the solved expression according to the dynamic correction velocity and equivalent anisotropy parameters, we can not only determine the phase slowness expression of the SV wave more quickly and accurately, but also reduce the parameters in the phase slowness expression, thereby reducing the amount of computation and improving computational efficiency.

[0070] 303. The terminal performs Fourier transform and inverse Fourier transform on the phase slowness expression to obtain the wave equation of the SV wave, which is used to describe the propagation of the SV wave in the VTI medium.

[0071] In this embodiment of the application, after the terminal obtains the phase slowness expression of the SV wave, it can perform time-frequency domain conversion through Fourier transform and inverse Fourier transform to obtain the wave equation of the SV wave in the time domain.

[0072] In some embodiments, the terminal first performs a Fourier transform on the phase sluggishness expression, transforming it from the time domain to the frequency domain to obtain a first expression in the frequency domain. Then, the terminal multiplies both sides of the first expression by the wave field of the SV wave to obtain a second expression in the frequency domain. The wave field of the SV wave is used to describe the distribution of the SV wave in three-dimensional space. For example, the wave field of the SV wave is F(x,y,z,t). Here, (x,y,z) are the three-dimensional coordinate positions of the SV wave, and t is the travel time. Then, the terminal performs an inverse Fourier transform on the second expression to obtain the wave equation of the SV wave in the time domain. Through Fourier transform and inverse Fourier transform, the phase sluggishness expression can be transformed into a wave equation relatively quickly and accurately, simplifying the process of determining the wave equation and improving the accuracy and efficiency of ray tracing. For example, the following formula (7) shows a wave equation of an SV wave.

[0073]

[0074] Where F is the wavefield of the SV wave, x, y, z are the spatial position parameters of the SV wave, and t is the travel time parameter of the SV wave. nmo Let ζ be the dynamic correction velocity, and ζ be the equivalent anisotropy parameter.

[0075] 304. The terminal determines the propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave.

[0076] In this embodiment, the terminal can determine multiple propagation positions of the SV wave and the travel time corresponding to each propagation position by solving the wave equation of the SV wave. Based on the multiple propagation positions of the SV wave, the terminal can determine the propagation path of the SV wave. Optionally, the propagation path of the SV wave is a line connecting the multiple propagation positions of the SV wave. The travel time information includes the travel time of the SV wave at the multiple propagation positions along the propagation path.

[0077] The process of solving the wave equation for the SV wave at the terminal is explained below through steps (1)-(3).

[0078] (1) The terminal substitutes the plane wave solution into the wave equation of the SV wave to obtain the equation of the process function. The plane wave solution is a form of the wave equation, that is, a specific wave function expression that satisfies the wave equation. The process function equation is used to describe the travel time information of the SV wave.

[0079] Optionally, the plane wave solution of the wave equation can be in the form of F(x,y,z,t)=A(x,y,z)f[t-τ(x,y,z)]. The equation obtained by the above plane wave solution is shown in the following formula (8).

[0080]

[0081] Where τ is the travel time. x, y, z are the spatial position parameters of the SV wave.

[0082] (2) The terminal solves the equations by means of the eigenvalue method and obtains the first set of ordinary differential equations, the second set of ordinary differential equations and the third set of ordinary differential equations.

[0083] The first set of ordinary differential equations describes the relationship between the propagation position of the SV wave in the VTI medium and multiple parameters of the VTI medium. In other words, the first set of ordinary differential equations is a set of equations describing the propagation position of the SV wave in the VTI medium. Optionally, the first set of ordinary differential equations includes three equations, which describe the position components of the SV wave in the x-axis, y-axis, and z-axis directions, respectively.

[0084] The second set of ordinary differential equations describes the relationship between the propagation direction of the SV wave in the VTI medium and several parameters of the VTI medium. In other words, the second set of ordinary differential equations is a set of equations describing the propagation direction of the SV wave in the VTI medium. Optionally, the second set of ordinary differential equations also includes three equations, which describe the propagation direction components of the SV wave in the x-axis, y-axis, and z-axis directions, respectively.

[0085] The third set of ordinary differential equations describes the relationship between the travel time of the SV wave and multiple parameters of the VTI medium.

[0086] The following formulas (9)-(11) respectively show an exemplary first set of ordinary differential equations, a second set of ordinary differential equations, and a third set of ordinary differential equations.

[0087]

[0088] Where ds is the spatial step size. p x p y p z These represent the slowness components of the SV wave on the x, y, and z axes, respectively. for and The sum of ζ (x) ζ (y) ζ (z) ζ represents the rate of change of the equivalent anisotropy parameter ζ along the x, y, and z axes, respectively. T represents travel time. V bno(x) V nmo(y) V nmo(z) Divided into dynamic correction speed V nmo Rates of change along the x, y, and z axes.

[0089] Optionally, the rate of change of the equivalent anisotropy parameter and the dynamic correction velocity in different directions can be determined based on the rate of change of multiple parameters of the VTI medium. The rate of change of multiple parameters of the VTI medium is described in step 301 above and will not be repeated here.

[0090] (3) The terminal solves the first set of ordinary differential equations, the second set of ordinary differential equations and the third set of ordinary differential equations respectively to obtain the propagation path and travel time information of the SV wave in the VTI medium.

[0091] In some embodiments, the terminal can first solve the second set of ordinary differential equations based on the dynamic correction velocity and the equivalent anisotropy parameters to obtain the slowness components of the SV wave on the x, y, and z axes, that is, p. x p y p z Then, the terminal, based on p x p y p z Dynamic correction speed V nmo And the equivalent anisotropy parameter ζ, are used to solve the first and third sets of ordinary differential equations to obtain multiple propagation positions of the SV wave in the VTI medium and the travel time of the SV wave at each propagation position. Then, the terminal determines the propagation path of the SV wave in the VTI medium based on the multiple propagation positions; and constructs travel time information based on the travel time of the SV wave at each propagation position. Optionally, the propagation path of the SV wave in the VTI medium is a line connecting the multiple propagation positions.

[0092] By solving multiple sets of ordinary differential equations obtained from the equation of process function, and further solving these equations based on the dynamic correction velocity obtained from parameter modeling and the equivalent anisotropy parameters of the VTI medium, the propagation positions of SV waves in the VTI medium and the travel time at each propagation position can be determined relatively quickly and accurately. Furthermore, the terminal can determine the propagation path and travel time information of the SV wave, thereby simulating the propagation of the SV wave in the VTI medium more accurately, improving the accuracy and efficiency of SV wave ray tracing based on anisotropic media.

[0093] Figure 4 This is a schematic diagram of the propagation path of an SV wave provided in an embodiment of this application. Figure 4 As shown, the horizontal axis x represents the horizontal propagation distance of SV waves, in kilometers. The vertical axis z represents the formation depth, in kilometers. Figure 4 As shown in the three figures, the propagation paths of SV waves are not exactly the same in different VTI media.

[0094] like Figure 4 As shown in (a), the VTI medium is a constant velocity model. Vertical transverse wave velocity V S0The velocity is kept constant at 2000 m / s. The solid white line represents the propagation path of the SV wave when ε and δ are both 0. The dashed black line represents the propagation path of the SV wave when ε is 0.065 and δ is 0.059. The solid black line represents the propagation path of the SV wave when ε is 0.0195 and δ is -0.22.

[0095] like Figure 4 As shown in (b), the VTI medium is modeled using a velocity gradient. With increasing formation depth, the vertical shear wave velocity V... S0 The velocity is gradually increased from 1000 m / s to 2000 m / s. The solid white line represents the propagation path of the SV wave when both ε and δ are 0. The dashed black line represents the propagation path of the SV wave when ε is 0.065 and δ is 0.059. The solid black line represents the propagation path of the SV wave when ε is 0.0195 and δ is -0.22.

[0096] like Figure 4 As shown in (c), the VTI medium is a layered model. The vertical shear wave velocity Vt varies between different strata. S0 Different. The vertical shear wave velocity V in the upper strata. S0 The vertical shear wave velocity V in the lower strata is 1100 m / s. S0 The velocity is 2000 m / s. The solid white line represents the propagation path of the SV wave when both ε and δ are 0. The dashed black line represents the propagation path of the SV wave when ε is 0.065 and δ is 0.059.

[0097] Figure 5 This is a schematic diagram of the travel time contour lines of an SV wave provided in an embodiment of this application. The contour lines are drawn based on the propagation position of each SV wave at the same travel time during its propagation in a VTI medium. For example... Figure 5 As shown in (a), the VTI medium is a constant velocity model. Vertical transverse wave velocity V S0 Keep the speed at 2000 m / s. Figure 5 As shown in (b), the VTI medium is modeled using a velocity gradient. With increasing formation depth, the vertical shear wave velocity V... S0 The speed was gradually increased from 1000 m / s to 2000 m / s. Figure 5 In the two contour maps shown, line A represents the travel time contour of the SV wave when ε and δ are both 0; line B represents the travel time contour of the SV wave when ε is 0.065 and δ is 0.059; and line C represents the travel time contour of the SV wave when ε is 0.0195 and δ is -0.1. According to... Figure 5 As shown in the contour plot, the stronger the anisotropy of the VTI medium, the closer the SV wave travel time contours are to circles.

[0098] Figure 6 This is a schematic diagram of a synthetic seismic record provided in an embodiment of this application. Figure 6 As shown in the figure, within the wavy area, the marked area represents the wave field when performing ray tracing based on anisotropic media, while the unmarked area represents the wave field when performing ray tracing based on isotropic media. There is a significant difference between the wave fields when performing ray tracing based on anisotropic media and those based on isotropic media.

[0099] This application provides a method for SV wave ray tracing based on anisotropic media. Based on Christoffel dispersion theory, it can accurately determine the phase slowness expression of SV waves according to multiple parameters of the VTI medium. Then, through mathematical transformations and equation solving, the propagation path and travel time of SV waves in the VTI medium are determined. This allows for more accurate prediction of the propagation of SV wave-type seismic waves in the VTI medium, providing a more accurate theoretical basis for seismic data processing and geophysical exploration, and contributing to improved accuracy and reliability in seismic monitoring and resource exploration.

[0100] Figure 7 This is a schematic diagram of the structure of an SV wave ray tracing device based on anisotropic media provided in an embodiment of this application. See also... Figure 7 The device includes: a first determining module 701, a transforming module 702, a second determining module 703, and a third determining module 704.

[0101] The first determining module 701 is used to determine the phase slowness expression of SV waves in VTI medium based on Christofer dispersion theory and through multiple parameters of VTI medium. The parameters include vertical transverse wave velocity, vertical longitudinal wave velocity and at least one anisotropic parameter of VTI medium. The phase slowness expression is used to represent the relationship between phase velocity and slowness during the propagation of SV waves in VTI medium.

[0102] Transformation module 702 is used to perform Fourier transform and inverse Fourier transform on the phase slowness expression to obtain the wave equation of the SV wave, which is used to describe the propagation of the SV wave in the VTI medium.

[0103] The second determining module 703 is used to determine the propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave. The travel time information includes the travel time of the SV wave at multiple propagation positions on the propagation path. The travel time is the time taken for the SV wave to propagate from the source to the corresponding propagation position.

[0104] In some embodiments, the first determining module 701 is used to solve the Christoffel equation based on multiple parameters of the VTI medium to obtain an intermediate expression. The Christoffel equation is used to describe the propagation characteristics of waves in anisotropic media. Based on the correlation between multiple parameters of the VTI medium, the dynamic correction velocity and equivalent anisotropic parameter of the SV wave are constructed. The dynamic correction velocity and equivalent anisotropic parameter are both related to the vertical transverse wave velocity, the vertical longitudinal wave velocity, and at least one anisotropic parameter. Substituting the dynamic correction velocity and equivalent anisotropic parameter into the intermediate expression, the phase slowness expression of the SV wave is obtained.

[0105] In some embodiments, the transformation module 702 is used to perform a Fourier transform on the phase slowness expression to obtain a first expression in the frequency domain; multiply both sides of the first expression by the wave field of the SV wave to obtain a second expression in the frequency domain, wherein the wave field is used to describe the distribution of the SV wave in three-dimensional space; and perform an inverse Fourier transform on the second expression to obtain the wave equation of the SV wave in the time domain.

[0106] In some embodiments, the second determining module 703 is used to substitute the plane wave solution into the wave equation of the SV wave to obtain the equation of process function. The plane wave solution is a solution form of the wave equation, and the equation of process function is used to describe the travel time information of the SV wave. The equation of process function is solved by the eigenvalue method to obtain a first set of ordinary differential equations, a second set of ordinary differential equations, and a third set of ordinary differential equations. The first set of ordinary differential equations is used to describe the relationship between the propagation position of the SV wave in the VTI medium and multiple parameters of the VTI medium. The second set of ordinary differential equations is used to describe the relationship between the propagation direction of the SV wave in the VTI medium and multiple parameters. The third set of ordinary differential equations is used to describe the relationship between the travel time of the SV wave and multiple parameters. The propagation path and travel time information of the SV wave in the VTI medium are obtained by solving the first set of ordinary differential equations, the second set of ordinary differential equations, and the third set of ordinary differential equations.

[0107] In some embodiments, the second determining module 703 is used to solve the second set of ordinary differential equations to obtain the slowness components of the SV wave on the x, y, and z axes; based on the slowness components of the SV wave on the x, y, and z axes, to solve the first set of ordinary differential equations and the third set of ordinary differential equations respectively to obtain multiple propagation positions of the SV wave in the VTI medium and the travel time of the SV wave at each propagation position; to determine the propagation path of the SV wave in the VTI medium based on the multiple propagation positions; and to construct travel time information based on the travel time of the SV wave at each propagation position.

[0108] In some embodiments, the apparatus further includes:

[0109] The third determining module 704 is used to determine multiple parameters of the VTI medium based on multiple formations of the layered model when the VTI medium is a layered model. The multiple parameters change with the formation. When the VTI medium is a non-layered model, the multiple parameters of the VTI medium are determined according to a preset rate of change. The rate of change is used to indicate the changes of the multiple parameters.

[0110] This application provides an SV wave ray tracing device based on anisotropic media. Based on Christoffel dispersion theory, it can accurately determine the phase slowness expression of SV waves according to multiple parameters of the VTI medium. Then, through mathematical transformations and equation solving, it determines the propagation path and travel time of SV waves in the VTI medium. This allows for more accurate prediction of the propagation of SV wave-type seismic waves in the VTI medium, providing a more accurate theoretical basis for seismic data processing and geophysical exploration, and contributing to improved accuracy and reliability in seismic monitoring and resource exploration.

[0111] It should be noted that the SV wave ray tracing device based on anisotropic media provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the terminal can be divided into different functional modules to complete all or part of the functions described above. In addition, the SV wave ray tracing device based on anisotropic media provided in the above embodiments and the SV wave ray tracing method embodiments based on anisotropic media belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0112] This application also provides a terminal, which includes a processor and a memory. The memory stores at least one computer program, which is loaded and executed by the processor to implement the SV wave ray tracing method based on anisotropic media described in the above embodiments.

[0113] Figure 8 This is a schematic diagram of the structure of a terminal provided in an embodiment of this application.

[0114] Terminal 800 includes a processor 801 and a memory 802.

[0115] Processor 801 may include one or more processing cores, such as a quad-core processor, an octa-core processor, etc. Processor 801 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field Programmable Gate Array), and PLA (Programmable Logic Array). Processor 801 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 801 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, processor 801 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0116] 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 devices. In some embodiments, the non-transitory computer-readable storage media in memory 802 are used to store at least one computer program, which is used by processor 801 to implement the SV wave ray tracing method based on anisotropic media provided in the method embodiments of this application.

[0117] In some embodiments, the terminal 800 may also optionally include: a peripheral device interface 803 and at least one peripheral device. The processor 801, memory 802, and peripheral device interface 803 can be connected via a bus or signal line. Each peripheral device can be connected to the peripheral device interface 803 via a bus, signal line, or circuit board. Optionally, the peripheral device includes at least one of: a radio frequency circuit 804, a display screen 805, a camera assembly 806, an audio circuit 807, and a power supply 808.

[0118] Peripheral device interface 803 can be used to connect at least one I / O (Input / Output) related peripheral device to processor 801 and memory 802. In some embodiments, processor 801, memory 802 and peripheral device interface 803 are integrated on the same chip or circuit board; in some other embodiments, any one or two of processor 801, memory 802 and peripheral device interface 803 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0119] The radio frequency (RF) circuit 804 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 804 communicates with communication networks and other communication devices via electromagnetic signals. The RF circuit 804 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals back into electrical signals. Optionally, the RF circuit 804 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The RF circuit 804 can communicate with other devices through at least one wireless communication protocol. This wireless communication protocol includes, but is not limited to: metropolitan area networks (MANs), various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks (WLANs), and / or WiFi (Wireless Fidelity) networks. In some embodiments, the RF circuit 804 may also include circuitry related to NFC (Near Field Communication), which is not limited in this application.

[0120] Display screen 805 is used to display a UI (User Interface). This UI may include graphics, text, icons, videos, and any combination thereof. When display screen 805 is a touch display screen, it also has the ability to collect touch signals on or above its surface. These touch signals can be input as control signals to processor 801 for processing. In this case, display screen 805 can also be used to provide virtual buttons and / or a virtual keyboard, also known as soft buttons and / or a soft keyboard. In some embodiments, there may be one display screen 805, disposed on the front panel of terminal 800; in other embodiments, there may be at least two display screens, disposed on different surfaces of terminal 800 or in a folded design; in other embodiments, display screen 805 may be a flexible display screen, disposed on a curved or folded surface of terminal 800. Furthermore, display screen 805 may be configured as a non-rectangular irregular shape, i.e., a non-rectangular screen. Display screen 805 may be made of materials such as LCD (Liquid Crystal Display) or OLED (Organic Light-Emitting Diode).

[0121] The camera assembly 806 is used to acquire images or videos. Optionally, the camera assembly 806 includes a front-facing camera and a rear-facing camera. The front-facing camera is disposed on the front panel of the terminal 800, and the rear-facing camera is disposed on the back of the terminal 800. In some embodiments, there are at least two rear-facing cameras, which are any one of a main camera, a depth-sensing camera, a wide-angle camera, and a telephoto camera, to achieve background blurring by fusion of the main camera and the depth-sensing camera, panoramic shooting by fusion of the main camera and the wide-angle camera, VR (Virtual Reality) shooting, or other fusion shooting functions. In some embodiments, the camera assembly 806 may also include a flash. The flash may be a single-color temperature flash or a dual-color temperature flash. A dual-color temperature flash refers to a combination of a warm light flash and a cool light flash, which can be used for light compensation at different color temperatures.

[0122] The audio circuit 807 may include a microphone and a speaker. The microphone is used to collect sound waves from the user and the environment, converting the sound waves into electrical signals that are input to the processor 801 for processing, or input to the radio frequency circuit 804 to achieve voice communication. For stereo sound acquisition or noise reduction purposes, multiple microphones may be used, each located at a different part of the terminal 800. The microphone may also be an array microphone or an omnidirectional microphone. The speaker is used to convert the electrical signals from the processor 801 or the radio frequency circuit 804 into sound waves. The speaker may be a conventional diaphragm speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can convert electrical signals not only into audible sound waves but also into inaudible sound waves for purposes such as distance measurement. In some embodiments, the audio circuit 807 may also include a headphone jack.

[0123] Power supply 808 is used to supply power to the various components in terminal 800. Power supply 808 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When power supply 808 includes a rechargeable battery, the rechargeable battery can support wired charging or wireless charging. The rechargeable battery can also be used to support fast charging technology.

[0124] In some embodiments, the terminal 800 further includes one or more sensors 809. The one or more sensors 809 include, but are not limited to, an accelerometer 180, a gyroscope 811, a pressure sensor 812, an optical sensor 813, and a proximity sensor 814.

[0125] Accelerometer 180 can detect the magnitude of acceleration along the three coordinate axes of a coordinate system established by terminal 800. For example, accelerometer 180 can be used to detect the components of gravitational acceleration along the three coordinate axes. Processor 801 can control display screen 805 to display the user interface in either a landscape or portrait view based on the gravitational acceleration signal acquired by accelerometer 180. Accelerometer 180 can also be used for games or for acquiring user motion data.

[0126] The gyroscope sensor 811 can detect the orientation and rotation angle of the terminal 800. The gyroscope sensor 811 can work in conjunction with the accelerometer sensor 180 to collect the user's 3D movements on the terminal 800. Based on the data collected by the gyroscope sensor 811, the processor 801 can perform the following functions: motion sensing (e.g., changing the UI based on the user's tilt), image stabilization during shooting, game control, and inertial navigation.

[0127] The pressure sensor 812 can be disposed on the side bezel of the terminal 800 and / or the lower layer of the display screen 805. When the pressure sensor 812 is disposed on the side bezel of the terminal 800, it can detect the user's grip signal on the terminal 800, and the processor 801 can perform left / right hand recognition or quick operation based on the grip signal collected by the pressure sensor 812. When the pressure sensor 812 is disposed on the lower layer of the display screen 805, the processor 801 can control the operable controls on the UI interface based on the user's pressure operation on the display screen 805. The operable controls include at least one of button controls, scroll bar controls, icon controls, and menu controls.

[0128] An optical sensor 813 is used to collect ambient light intensity. In one embodiment, the processor 801 can control the display brightness of the display screen 805 based on the ambient light intensity collected by the optical sensor 813. Optionally, when the ambient light intensity is high, the display brightness of the display screen 805 is increased; when the ambient light intensity is low, the display brightness of the display screen 805 is decreased. In another embodiment, the processor 801 can also dynamically adjust the shooting parameters of the camera assembly 806 based on the ambient light intensity collected by the optical sensor 813.

[0129] The proximity sensor 814, also known as a distance sensor, is installed on the front panel of the terminal 800. The proximity sensor 814 is used to detect the distance between the user and the front of the terminal 800. In one embodiment, when the proximity sensor 814 detects that the distance between the user and the front of the terminal 800 is gradually decreasing, the processor 801 controls the display screen 805 to switch from a screen-on state to a screen-off state; when the proximity sensor 814 detects that the distance between the user and the front of the terminal 800 is gradually increasing, the processor 801 controls the display screen 805 to switch from a screen-off state to a screen-on state.

[0130] Those skilled in the art will understand that Figure 8 The structure shown does not constitute a limitation on terminal 800 and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0131] This application also provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to implement the SV wave ray tracing method based on anisotropic media described in the above embodiments.

[0132] This application also provides a computer program product, including a computer program loaded and executed by a processor to implement the SV wave ray tracing method based on anisotropic media as described in the above embodiments.

[0133] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0134] The above are merely optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application should be included within the protection scope of the present application.

Claims

1. A method of SV wave ray tracing based on anisotropic media, characterized by, The method comprises: determining a phase-slowness expression of an SV wave in a VTI medium based on a Christoffel dispersion theory and through a plurality of parameters of the VTI medium, the parameters comprising a vertical transverse wave velocity, a vertical longitudinal wave velocity, and at least one anisotropy parameter of the VTI medium, the phase-slowness expression being used to represent a relationship between a phase velocity and a slowness of the SV wave during propagation of the SV wave in the VTI medium; performing Fourier transform and inverse Fourier transform on the phase-slowness expression to obtain a wave equation of the SV wave, the wave equation being used to describe a propagation of the SV wave in the VTI medium; determining a propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave, the travel time information comprising travel times of the SV wave at a plurality of propagation positions on the propagation path, the travel time being a time consumed by the SV wave from a source to a corresponding propagation position.

2. The method of claim 1, wherein, The determining a phase-slowness expression of an SV wave in a VTI medium based on a Christoffel dispersion theory and through a plurality of parameters of the VTI medium comprises: solving a Christoffel equation based on the plurality of parameters of the VTI medium to obtain an intermediate expression, the Christoffel equation being used to describe a propagation characteristic of a wave in an anisotropic medium; constructing a moveout velocity and an equivalent anisotropy parameter of the SV wave based on a correlation relationship between the plurality of parameters of the VTI medium, the moveout velocity and the equivalent anisotropy parameter both being related to the vertical transverse wave velocity, the vertical longitudinal wave velocity, and the at least one anisotropy parameter; substituting the moveout velocity and the equivalent anisotropy parameter into the intermediate expression to obtain the phase-slowness expression of the SV wave.

3. The method of claim 1, wherein, The performing Fourier transform and inverse Fourier transform on the phase-slowness expression to obtain a wave equation of the SV wave comprises: performing Fourier transform on the phase-slowness expression to obtain a first expression in a frequency domain; multiplying both sides of the first expression by a wave field of the SV wave to obtain a second expression in the frequency domain, the wave field being used to describe a distribution of the SV wave in a three-dimensional space; performing inverse Fourier transform on the second expression to obtain the wave equation of the SV wave in a time domain.

4. The method of claim 1, wherein, The determining a propagation path and travel time information of the SV wave in the VTI medium based on the wave equation of the SV wave comprises: substituting a plane wave solution into the wave equation of the SV wave to obtain an eikonal equation, the plane wave solution being a form of a solution of the wave equation, the eikonal equation being used to describe the travel time information of the SV wave; Solving the first ordinary differential equation set, the second ordinary differential equation set and the third ordinary differential equation set, propagation path and travel time information of the SV wave in the VTI medium are obtained. The solving the first ordinary differential equation set, the second ordinary differential equation set and the third ordinary differential equation set, propagation path and travel time information of the SV wave in the VTI medium comprises:

5. The method of claim 4, wherein, Solving the second ordinary differential equation set, the slowness components of the SV wave on x, y and z axes are obtained; Based on the slowness components of the SV wave on x, y and z axes, the first ordinary differential equation set and the third ordinary differential equation set are solved respectively, a plurality of propagation positions of the SV wave in the VTI medium and travel time of the SV wave at each propagation position are obtained; Based on the plurality of propagation positions, the propagation path of the SV wave in the VTI medium is determined; Based on the travel time of the SV wave at each propagation position, the travel time information is constructed. The method further comprises:

6. The method of claim 1, wherein, In the case that the VTI medium is a layered model, based on a plurality of strata of the layered model, a plurality of parameters of the VTI medium are determined, the plurality of parameters change with the change of strata; In the case that the VTI medium is a non-layered model, according to a preset change rate, a plurality of parameters of the VTI medium are determined, the change rate is used to indicate the change of the plurality of parameters. The device comprises:

7. An apparatus for SV wave ray tracing based on anisotropic media, characterized by, A first determining module is configured to determine, based on the Christoffel dispersion theory, a phase slowness expression of an SV wave in a VTI medium through a plurality of parameters of the VTI medium, the parameters comprising a vertical transverse wave velocity, a vertical longitudinal wave velocity and at least one anisotropy parameter of the VTI medium, the phase slowness expression being used to represent a relationship between phase velocity and slowness of the SV wave during propagation of the SV wave in the VTI medium; A transforming module is configured to perform Fourier transform and inverse Fourier transform on the phase slowness expression, to obtain a wave equation of the SV wave, the wave equation being used to describe propagation of the SV wave in the VTI medium; A second determining module is configured to determine, based on the wave equation of the SV wave, propagation path and travel time information of the SV wave in the VTI medium, the travel time information comprising travel time of the SV wave at a plurality of propagation positions on the propagation path, the travel time being time consumed by the SV wave from a source to the corresponding propagation position. ​ 8. A terminal, characterized by comprising: The terminal comprises a processor and a memory, and the memory stores at least one computer program, which is loaded and executed by the processor to implement the SV wave ray tracing method based on an anisotropic medium as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores at least one computer program, which is loaded and executed by the processor to implement the SV wave ray tracing method based on an anisotropic medium as claimed in any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that, The computer program is loaded and executed by the processor to implement the SV wave ray tracing method based on an anisotropic medium as claimed in any one of claims 1 to 6.

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