Seismic imaging method and device for subsurface medium, electronic device and storage medium

Abstract

The application relates to the technical field of seismic exploration, in particular to a seismic imaging method and device for underground medium, electronic equipment and a storage medium. The method comprises the following steps: defining a Hamilton function of a tilted orthogonal anisotropic medium; determining a kinematic ray tracing system of the tilted orthogonal anisotropic medium and a dynamic ray tracing system of the tilted orthogonal anisotropic medium in a wavefront orthogonal coordinate system of the tilted orthogonal anisotropic medium based on the defined Hamilton function; solving the kinematic ray tracing system of the tilted orthogonal anisotropic medium and the dynamic ray tracing system of the tilted orthogonal anisotropic medium in the wavefront orthogonal coordinate system of the tilted orthogonal anisotropic medium based on a Runge-Kutta method to obtain three-dimensional ray tracing of the tilted orthogonal anisotropic medium and to acquire travel time field information of the tilted orthogonal anisotropic medium; and performing seismic Kirchhoff migration imaging based on the travel time field information. Through the scheme, high-precision travel time field information can be acquired, and the seismic imaging effect of the tilted orthogonal anisotropic medium is improved.

Description

Technical Field

[0001] This invention relates to the field of seismic exploration technology, and in particular to a seismic imaging method, apparatus, electronic device, and storage medium for underground media. Background Technology

[0002] Seismic ray tracing is the core of seismic Krichhoff and Beams migrations and plays a vital role in fields such as oil exploration. Its theoretical foundation lies in the high-frequency approximation of seismic wave propagation theory. Seismic ray tracing is applicable not only to arbitrarily undulating surface conditions but can also be flexibly applied to localized subsurface target areas. Compared to wave equation numerical simulation techniques, seismic ray tracing offers higher computational efficiency and allows for flexible control over specific details and different input / output seismic data types.

[0003] With the development of seismic exploration technology and in-depth research on the anisotropic propagation laws and mechanisms of seismic waves in subsurface media, introducing seismic anisotropic characteristics into seismic ray tracing technology is a necessary process to improve the accuracy of seismic processing and interpretation. Actual seismic data and laboratory measurements have fully verified the anisotropic characteristics of subsurface media, especially in unconventional oil and gas reservoirs such as shale. To simplify the study of seismic anisotropy and facilitate practical seismic applications, a pseudo-acoustic assumption is commonly adopted, assuming that the shear wave velocity in the direction parallel to the media's axis of symmetry is zero, thus avoiding the consideration of shear wave velocity factors. Initially, people only considered the different propagation velocities of seismic waves in directions parallel and perpendicular to the axis of symmetry, calling it a TI medium. When the axis of symmetry is perpendicular to the stratigraphic interface, it is called a transversely isotropic medium (VTI), where anisotropy is mainly caused by horizontal stratigraphic layers. When the axis of symmetry is parallel to the stratigraphic interface, it is called a vertically isotropic medium (HTI), where seismic anisotropy is mainly caused by vertically arranged fractures. When the axis of symmetry is inclined to the stratigraphic interface, it is called a tilted transversely isotropic medium (TTI). Under the pseudo-acoustic assumption, VTI and HTI media are generally characterized by three elastic parameters, while TTI media are characterized by three elastic parameters and two angles (dip and azimuth). With advancements in seismic acquisition technology and the gradual application of wide-azimuth acquisition data, it is necessary to consider not only the equivalent VTI caused by horizontal strata but also the equivalent HTI caused by vertically developed fractures. When considering fractured reservoirs and unconventional oil and gas reservoirs, both cases need to be considered comprehensively, and theoretically, orthogonal anisotropic media (ORT) should be used for description. When the strata are tilted and the fractures have a certain azimuth, arbitrary tilting orthogonal anisotropic media (TORT) are further required. It is worth noting that as the described medium becomes increasingly complex, under the pseudo-acoustic assumption, ORT media require six elastic parameters for characterization, while TORT media require three additional angular parameters (dip angle, azimuth angle, and polarization angle) on top of ORT. The media of actual fractured reservoirs and unconventional oil and gas reservoirs with great exploration and development potential are quite complex. If the orthogonal anisotropic media (ORT) ray tracing method is still used to achieve pre-stack depth migration in such subsurface reservoir media, it will lead to low imaging accuracy of seismic pre-stack depth migration. Summary of the Invention

[0004] In view of this, the present invention proposes a seismic imaging method, device, electronic device and storage medium for subsurface media. Through a stable and efficient ray tracing method for arbitrarily tilted orthogonal anisotropic media, the pre-stack depth migration of actual fractured reservoirs and unconventional oil and gas reservoirs is realized, resulting in higher imaging accuracy and better imaging effect of pre-stack depth migration.

[0005] To achieve the above objectives, one aspect of the present invention provides a seismic imaging method for subsurface media, specifically including the following steps:

[0006] Define the Hamiltonian function for an inclined orthotropic anisotropic medium;

[0007] Based on the Hamiltonian function of the inclined orthogonal anisotropic medium, a kinematic ray tracing system for the inclined orthogonal anisotropic medium and a dynamic ray tracing system for the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system are determined.

[0008] The kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system are solved based on the Runge-Kutta method to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium.

[0009] The travel time field information of the inclined orthogonal anisotropic medium is obtained based on the three-dimensional ray tracing.

[0010] Seismic Koschhof migration imaging is performed based on the travel time field information.

[0011] In some implementations, the Hamiltonian function for tilted orthotropic anisotropic media includes:

[0012] The Hamiltonian function for an inclined orthotropic anisotropic medium is defined as follows:

[0013]

[0014] in,

[0015] V p Let ε0 be the longitudinal wave velocity, ε1 and δ1 be the anisotropic medium parameters in the YZ plane of the rotating coordinate system, ε2 and δ2 be the anisotropic medium parameters in the XZ plane of the rotating coordinate system, and δ3 be the anisotropic medium parameters in the XY plane of the rotating coordinate system. This is the slowness vector in the rotating coordinate system;

[0016] Define the slowness vector in the rotating coordinate system as follows With the slowness vector in the Cartesian coordinate system Relationship,

[0017]

[0018] Where M is the coordinate transformation matrix, and θ, α and φ are the formation dip angle, azimuth angle and fracture polarization angle, respectively.

[0019] In some implementations, the kinematic ray tracing system for determining the kinematics of the inclined orthotropic anisotropic medium based on the Hamiltonian function of the inclined orthotropic medium includes:

[0020] Based on the Hamiltonian function and Cartesian coordinate function of the inclined orthogonal anisotropic medium, and the first derivative relationship between the slowness vector and time, the kinematic ray tracing system of the inclined orthogonal anisotropic medium is obtained.

[0021] In some implementations, determining the dynamic ray tracing system in the orthogonal coordinate system of the inclined orthogonal anisotropic medium based on the Hamiltonian function of the inclined orthogonal anisotropic medium includes:

[0022] The second-order partial derivative of the Hamiltonian function of the inclined orthogonal anisotropic medium is calculated, and the dynamic ray tracing system of the inclined orthogonal anisotropic medium is obtained by calculating the dynamic ray equations of the inclined orthogonal anisotropic medium based on the second-order Hamiltonian function of the inclined orthogonal anisotropic medium wavefront orthogonal coordinate system.

[0023] In some implementations, obtaining a three-dimensional ray trace of the inclined orthotropic anisotropic medium by solving the kinematics ray tracing system based on the Runge-Kutta method includes:

[0024] The spatial position of the emitted ray is obtained by solving the kinematic ray tracing system of the inclined orthogonal anisotropic medium using the Runge-Kutta method.

[0025] In some implementations, the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system is solved based on the Runge-Kutta method to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium, including:

[0026] The transformation matrix parameters of the ray are obtained by solving the dynamic ray tracing system in the orthogonal coordinate system of the wavefront of the inclined orthogonal anisotropic medium using the Runge-Kutta method.

[0027] In some implementations, obtaining travel time field information of the tilted orthotropic anisotropic medium based on the three-dimensional ray tracing includes:

[0028] Search for regular grid points at the spatial location and calculate the transformation matrix parameters of the regular grid points;

[0029] The transformation matrix parameters of the regular grid points are compared with the transformation matrix parameters of the spatial location, and the travel time of the regular grid points is determined based on the comparison results.

[0030] In some implementations, performing seismic Koschhof migration imaging based on the travel time field information includes:

[0031] Read the actual earthquake data, and input the actual earthquake data and the travel time field information into the Koschhof migration formula to perform seismic Koschhof migration imaging.

[0032] In another aspect of the present invention, a seismic imaging device for subsurface media is also provided, comprising:

[0033] A definition module is configured to define the Hamiltonian function for an inclined orthotropic anisotropic medium;

[0034] The first calculation module is configured to determine the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system in the wavefront orthogonal coordinate system of the inclined orthogonal anisotropic medium based on the Hamiltonian function of the inclined orthogonal anisotropic medium.

[0035] The second calculation module is configured to solve the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system based on the Runge-Kutta method, so as to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium.

[0036] The third calculation module is configured to acquire travel time field information of the inclined orthogonal anisotropic medium based on the three-dimensional ray tracing.

[0037] An imaging module configured to perform seismic Koschhof migration imaging based on the travel time field information.

[0038] In another aspect of the present invention, an electronic device is provided, comprising: at least one processor; and a memory storing a computer program executable on the processor, the computer program performing the steps of the method described above when executed by the processor.

[0039] In another aspect, the present invention provides a readable storage medium storing a computer program that, when executed by a processor, implements the above-described method steps.

[0040] The present invention has at least the following beneficial technical effects: on the one hand, it has a wide range of applications and can be adapted to various inclined fractured reservoir conditions; on the other hand, based on the defined Hamiltonian function of inclined orthotropic anisotropic media, the kinematic ray tracing system and the dynamic ray tracing system under the wavefront orthotropic coordinate system of inclined orthotropic anisotropic media obtained on this basis have high accuracy; furthermore, the calculated travel time field information has high accuracy and the seismic imaging effect is good. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0042] Figure 1 A flowchart of the seismic imaging method for subsurface media provided by the present invention;

[0043] Figure 2 This is a schematic diagram of the inclined orthogonal anisotropic medium layered model provided by the present invention;

[0044] Figures 3a to 3f These are schematic diagrams comparing the wave field snapshots from the forward modeling simulation of the wave equation at different times in the tilted orthogonal anisotropic medium provided by this invention with the travel time obtained by ray tracing.

[0045] Figure 4a , 4b 4c and 4c are the pre-stack depth migration results at different positions of the tilted orthotropic anisotropic medium layered model provided by the present invention;

[0046] Figure 5 A schematic diagram of an embodiment of the seismic imaging device for underground media provided by the present invention;

[0047] Figure 6 A schematic diagram of the structure of an embodiment of the electronic device provided by the present invention;

[0048] Figure 7 A schematic diagram of an embodiment of the readable storage medium provided by the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0050] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0051] Based on the above objectives, a first aspect of the present invention provides an embodiment of a seismic imaging method for subsurface media. For example... Figure 1 As shown, it includes the following steps:

[0052] S10. Define the Hamiltonian function for an inclined orthogonal anisotropic medium;

[0053] S20. Based on the Hamiltonian function of the inclined orthogonal anisotropic medium, determine the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system under the wavefront orthogonal coordinate system of the inclined orthogonal anisotropic medium;

[0054] S30. Solve the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system based on the Runge-Kutta method to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium.

[0055] S40. Based on the three-dimensional ray tracing, obtain the travel time field information of the inclined orthogonal anisotropic medium;

[0056] S50. Perform seismic Koschhof migration imaging based on the travel time field information.

[0057] This invention proposes a high-precision seismic ray tracing technique for arbitrarily tilted orthotropic media. Based on a precise definition of the Hamiltonian function for the tilted orthotropic media, a system of ray tracing equations is derived, providing quantitative expressions for the derivatives of coordinates and the phase velocity slowness vector with respect to time in Cartesian coordinates. Furthermore, by utilizing the second-order partial derivative of the Hamiltonian function for the tilted orthotropic media, an explicit expression for the second-order derivative of the ray coordinate system transformation matrix in the wavefront orthotropic coordinate system is obtained. The kinematic and dynamic ray tracing system in the pseudo-acoustic case of the arbitrarily tilted orthotropic media is solved using the Runge-Kutta method, enabling ray tracing of the emission point in three dimensions and obtaining travel time field information of the subsurface medium. Using this travel time field information, precise pre-stack depth imaging of arbitrarily tilted orthotropic media is ultimately achieved.

[0058] Compared with existing orthogonal anisotropic medium imaging methods, the present invention has the following advantages: First, it has a wide range of applications and can be adapted to various inclined strata fractured reservoir conditions. Second, based on the defined Hamiltonian function of the inclined orthogonal anisotropic medium, the kinematic ray tracing system and the dynamic ray tracing system in the wavefront orthogonal coordinate system of the inclined orthogonal anisotropic medium obtained on this basis have high accuracy. Third, the calculated travel time field information has high accuracy and the seismic imaging effect is good.

[0059] In some implementations, the Hamiltonian function for tilted orthotropic anisotropic media includes:

[0060] The Hamiltonian function for an inclined orthotropic anisotropic medium is defined as follows:

[0061]

[0062] in,

[0063] V p Let ε0 be the longitudinal wave velocity, ε1 and δ1 be the anisotropic medium parameters in the YZ plane of the rotating coordinate system, ε2 and δ2 be the anisotropic medium parameters in the XZ plane of the rotating coordinate system, and δ3 be the anisotropic medium parameters in the XY plane of the rotating coordinate system. This is the slowness vector in the rotating coordinate system;

[0064] Define the slowness vector in the rotating coordinate system as follows With the slowness vector in the Cartesian coordinate system Relationship,

[0065]

[0066] Where M is the coordinate transformation matrix, and θ, α and φ are the formation dip angle, azimuth angle and fracture polarization angle, respectively.

[0067] In some implementations, the kinematic ray tracing system for determining the kinematics of the inclined orthotropic anisotropic medium based on the Hamiltonian function of the inclined orthotropic medium includes:

[0068] Based on the Hamiltonian function and Cartesian coordinate function of the inclined orthogonal anisotropic medium, and the first derivative relationship between the slowness vector and time, the kinematic ray tracing system of the inclined orthogonal anisotropic medium is obtained.

[0069] Specifically, the relationship between the Cartesian coordinate system coordinate functions and the first derivative of the slowness vector with time is as follows:

[0070]

[0071]

[0072] Based on the defined Hamiltonian function, the kinematic ray tracing system for inclined orthogonal anisotropic media can be obtained using Cartesian coordinate functions and the first derivative relationship between the slowness vector and time.

[0073]

[0074]

[0075]

[0076]

[0077] in,

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090] The kinematic ray tracing system for inclined orthogonal anisotropic media obtained by the present invention is more accurate than the existing kinematic ray tracing system for orthogonal anisotropic media.

[0091] In some implementations, determining the dynamic ray tracing system in the orthogonal coordinate system of the inclined orthogonal anisotropic medium based on the Hamiltonian function of the inclined orthogonal anisotropic medium includes:

[0092] The second-order partial derivative of the Hamiltonian function of the inclined orthogonal anisotropic medium is calculated, and the dynamic ray tracing system of the inclined orthogonal anisotropic medium is obtained by calculating the dynamic ray equations of the inclined orthogonal anisotropic medium based on the second-order Hamiltonian function of the inclined orthogonal anisotropic medium wavefront orthogonal coordinate system.

[0093] Specifically, the dynamic ray tracing system of an arbitrary tilted orthogonal anisotropic medium is obtained by using the defined Hamiltonian function to calculate the dynamic ray equations of the tilted orthogonal anisotropic medium wavefront orthogonal coordinate system.

[0094] The dynamic ray equations for inclined orthogonal anisotropic media are as follows:

[0095]

[0096]

[0097] in,

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] in, Let be the coordinate transformation matrix between the Cartesian coordinate system and the wavefront orthogonal coordinate system. The second-order partial derivative of the Hamiltonian function is as follows:

[0106]

[0107]

[0108]

[0109]

[0110]

[0111] in,

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127] The dynamic ray tracing system obtained by the present invention in the orthogonal coordinate system of the wavefront of the inclined orthogonal anisotropic medium is more accurate than the existing dynamic ray tracing system in the orthogonal coordinate system of the wavefront of the inclined orthogonal anisotropic medium.

[0128] In some implementations, obtaining a three-dimensional ray trace of the inclined orthotropic anisotropic medium by solving the kinematics ray tracing system based on the Runge-Kutta method includes:

[0129] The spatial position of the emitted ray is obtained by solving the kinematic ray tracing system of the inclined orthogonal anisotropic medium using the Runge-Kutta method.

[0130] In some implementations, the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system is solved based on the Runge-Kutta method to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium, including:

[0131] The transformation matrix parameters of the ray are obtained by solving the dynamic ray tracing system in the orthogonal coordinate system of the wavefront of the inclined orthogonal anisotropic medium using the Runge-Kutta method.

[0132] In some implementations, obtaining travel time field information of the tilted orthotropic anisotropic medium based on the three-dimensional ray tracing includes:

[0133] Search for regular grid points at the spatial location and calculate the transformation matrix parameters of the regular grid points;

[0134] The transformation matrix parameters of the regular grid points are compared with the transformation matrix parameters of the spatial location, and the travel time of the regular grid points is determined based on the comparison results.

[0135] In some implementations, performing seismic Koschhof migration imaging based on the travel time field information includes:

[0136] Read the actual earthquake data, and input the actual earthquake data and the travel time field information into the Koschhof migration formula to perform seismic Koschhof migration imaging.

[0137] In one specific embodiment, seismic imaging of inclined orthotropic anisotropic media is performed using the following scheme.

[0138] First, input parameters into the inclined orthotropic anisotropic layered medium model, a total of nine, namely V p0 The parameters ε1, δ1, ε2, δ2, δ3, θ, φ, and α can be obtained through well logging data or by seismic tomography and seismic full-waveform inversion methods. Additionally, information from the seismic observation system is needed to calculate the initial information of the ray. When these conditions are met, a ray tracing method for inclined orthogonal anisotropic media can be performed, specifically using wavefront construction methods. The specific steps are: first, determine the initial ray direction at the emission point location. Calculating the first-order time derivative of spatial coordinates using a kinematic ray tracing system for inclined orthotropic anisotropic media The spatial position of the emitted ray is calculated using the Runge-Kutta algorithm. The transformation matrix parameters of the ray are obtained using a ray tracing system for inclined orthogonal anisotropic media dynamics. and Then, the system searches for regular grid points near the spatial location and calculates their travel times. Based on the range of the seismic observation system and the distribution of shot points, it calculates the travel times of all subsurface inclined anisotropic media at all shot points and within the coverage area of ​​receiver points, forming the final travel time field information. On this basis, actual seismic data is read, and the travel time field information is input into the Kirchhoff migration formula to complete the migration of all data. Finally, the migration results for inclined orthotropic media are output, i.e., seismic migration imaging of subsurface arbitrarily inclined orthotropic media.

[0139] In one specific embodiment, the accuracy of the present invention is verified by the following method.

[0140] like Figure 2 The image shown is a schematic diagram of a layered model of an inclined orthogonal anisotropic medium. Figure 2 The values ​​for the layered inclined orthotropic anisotropic medium are given. The size of the layered three-dimensional model of the inclined orthotropic anisotropic medium is nx = 450, ny = 400, nz = 300, dx = dy = dz = 15m, and the shot point is located at the center of the ground (nx = 225, ny = 200, nz = 1). The dominant frequency used for the forward modeling of the wave equation is 25Hz. Figure 3 is a schematic diagram comparing the wave field snapshots from the forward modeling of the wave equation at different times in the inclined orthotropic anisotropic medium with the travel time obtained by ray tracing. Figure 3a and Figure 3b , Figure 3c and Figure 3d , Figure 3e and Figure 3fComparison results of seismic wavefield snapshots and ray-tracing travel times at times of 0.91s, 1.16s, and 1.46s, respectively; Figure 3a and Figure 3c and Figure 3e , Figure 3b and Figure 3d and Figure 3f The results are shown on slices of the 3D model XZ (y = 200) and YZ (x = 225), respectively. A comparison reveals that the wave field snapshot from the forward modeling of the wave equation in the tilted orthotropic anisotropic medium is consistent with the travel time obtained by ray tracing using this method. This demonstrates that the ray tracing results obtained by this invention for tilted orthotropic anisotropic media are correct, and the ray travel time is accurate, allowing for further pre-stack depth migration in tilted orthotropic anisotropic media.

[0141] In one specific embodiment, based on verifying the accuracy of the travel time in the inclined orthotropic anisotropic medium, pre-stack depth migration is performed on the travel time field information. The specific process is as follows:

[0142] Given a three-dimensional model, specifically a layered model of an inclined orthotropic anisotropic medium, the parameters are as follows: V p0 =2000ms, ε1=0.7, δ1=0.2, ε2=0.12, δ2=0.05, δ3=0.1, α=45, φ=45, θ=45, given the size of the 3D model: nx=ny=1001, nz=801, dx=dy=dz=10m, pulse data of the Ricker wavelet is set every 0.5 seconds between 1-8 seconds, the dominant frequency is 30Hz, the shot point is located at the center of the ground, the receiver point is located on the ground, and the spatial interval is 40m. The result of the 3D model after pre-stack depth migration is shown in Figure 4. Figure 4a , 4b Figures 4 and 4c show the migration results of the Xline, Crossline, and Z=2000m slices calculated by the pre-stack depth migration method for inclined orthotropic media, respectively, and are compared with the analytical wavefront curves at different times. As can be seen from Figure 4, the proposed method has a wide range of applications and is accurate, representing a high-precision seismic imaging method for complex inclined anisotropic media.

[0143] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 5 As shown, embodiments of the present invention also provide a seismic imaging device for subsurface media, comprising:

[0144] Definition module 110, configured to define Hamiltonian functions for inclined orthotropic anisotropic media;

[0145] The first calculation module 120 is configured to determine the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system in the wavefront orthogonal coordinate system of the inclined orthogonal anisotropic medium based on the Hamiltonian function of the inclined orthogonal anisotropic medium.

[0146] The second calculation module 130 is configured to solve the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system based on the Runge-Kutta method, so as to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium.

[0147] The third calculation module 140 is configured to acquire travel time field information of the inclined orthogonal anisotropic medium based on the three-dimensional ray tracing.

[0148] Imaging module 150, configured to perform seismic Koschhof migration imaging based on the travel time field information.

[0149] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 6 As shown, an embodiment of the present invention also provides an electronic device 30, which includes a processor 310 and a memory 320. The memory 320 stores a computer program 321 that can run on the processor. When the processor 310 executes the program, it performs the steps of the method described above.

[0150] The memory, as a non-volatile readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the seismic imaging method for subsurface media described in this application embodiment. The processor executes various functional applications and data processing of the device by running the non-volatile software programs, instructions, and modules stored in the memory, thereby implementing the seismic imaging method for subsurface media described in the above method embodiment.

[0151] The memory may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the device, etc. Furthermore, the memory may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the local module via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0152] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 7 As shown, an embodiment of the present invention also provides a readable storage medium 40, which stores a computer program 410 that, when executed by a processor, performs the methods described above.

[0153] Finally, it should be noted that those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium for the program can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. The above computer program embodiments can achieve the same or similar effects as any of the corresponding foregoing method embodiments.

[0154] Those skilled in the art will also understand that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the functionality of various illustrative components, blocks, modules, circuits, and steps has been generally described. Whether this functionality is implemented as software or as hardware depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art can implement the functionality in various ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the embodiments disclosed herein.

[0155] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. The sequence numbers of the disclosed embodiments of this invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0156] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0157] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A seismic imaging method for subsurface media, characterized in that, include: The Hamiltonian function of an inclined orthotropic anisotropic medium is defined as follows: in, , , , , , , , For the longitudinal wave velocity, , Here are the parameters of the anisotropic medium in the YZ plane in the rotating coordinate system. , Here are the parameters of the anisotropic medium in the XZ plane in the rotating coordinate system. Let XY be the parameters of the anisotropic medium in the rotating coordinate system. This is the slowness vector in the rotating coordinate system; Define the slowness vector in the rotating coordinate system as follows With the slowness vector in the Cartesian coordinate system Relationship, in, This is the coordinate transformation matrix. , and These are the formation dip angle, azimuth angle, and fracture polarization angle, respectively. Based on the Hamiltonian function of the inclined orthogonal anisotropic medium, a kinematic ray tracing system for the inclined orthogonal anisotropic medium and a dynamic ray tracing system for the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system are determined. The kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system are solved based on the Runge-Kutta method to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium. The travel time field information of the inclined orthogonal anisotropic medium is obtained based on the three-dimensional ray tracing. Seismic Koschhof migration imaging is performed based on the travel time field information.

2. The method according to claim 1, characterized in that, The kinematic ray tracing system for determining the kinematics of the inclined orthotropic anisotropic medium based on the Hamiltonian function of the inclined orthotropic medium includes: Based on the Hamiltonian function and Cartesian coordinate function of the inclined orthogonal anisotropic medium, and the first derivative relationship between the slowness vector and time, the kinematic ray tracing system of the inclined orthogonal anisotropic medium is obtained.

3. The method according to claim 1, characterized in that, The dynamic ray tracing system in the orthogonal coordinate system of the inclined orthogonal anisotropic medium, determined based on the Hamiltonian function of the inclined orthogonal anisotropic medium, includes: The second-order partial derivative of the Hamiltonian function of the inclined orthogonal anisotropic medium is calculated, and the dynamic ray tracing system of the inclined orthogonal anisotropic medium is obtained by calculating the dynamic ray equations of the inclined orthogonal anisotropic medium based on the second-order Hamiltonian function of the inclined orthogonal anisotropic medium wavefront orthogonal coordinate system.

4. The method according to claim 1, characterized in that, The three-dimensional ray tracing of the inclined orthogonal anisotropic medium obtained by solving the kinematics ray tracing system based on the Runge-Kutta method includes: The spatial position of the emitted ray is obtained by solving the kinematic ray tracing system of the inclined orthogonal anisotropic medium using the Runge-Kutta method.

5. The method according to claim 4, characterized in that, The dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system is solved based on the Runge-Kutta method, and the three-dimensional ray tracing of the inclined orthogonal anisotropic medium is obtained as follows: The transformation matrix parameters of the ray are obtained by solving the dynamic ray tracing system in the orthogonal coordinate system of the wavefront of the inclined orthogonal anisotropic medium using the Runge-Kutta method.

6. The method according to claim 5, characterized in that, The travel time field information of the inclined orthogonal anisotropic medium obtained based on the three-dimensional ray tracing includes: Search for regular grid points at the spatial location and calculate the transformation matrix parameters of the regular grid points; The transformation matrix parameters of the regular grid points are compared with the transformation matrix parameters of the spatial location, and the travel time of the regular grid points is determined based on the comparison results.

7. The method according to claim 1, characterized in that, Seismic Koschhof migration imaging based on the aforementioned travel time field information includes: Read the actual earthquake data, and input the actual earthquake data and the travel time field information into the Koschhof migration formula to perform seismic Koschhof migration imaging.

8. A seismic imaging device for subsurface media, characterized in that, include: The definition module is configured to define the Hamiltonian function of an inclined orthotropic anisotropic medium, wherein the Hamiltonian function of the inclined orthotropic anisotropic medium is: in, , , , , , , , For the longitudinal wave velocity, , Here are the parameters of the anisotropic medium in the YZ plane in the rotating coordinate system. , Here are the parameters of the anisotropic medium in the XZ plane in the rotating coordinate system. Let XY be the parameters of the anisotropic medium in the rotating coordinate system. This is the slowness vector in the rotating coordinate system; Define the slowness vector in the rotating coordinate system as follows With the slowness vector in the Cartesian coordinate system Relationship, in, This is the coordinate transformation matrix. , and These are the formation dip angle, azimuth angle, and fracture polarization angle, respectively. The first calculation module is configured to determine the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system in the wavefront orthogonal coordinate system of the inclined orthogonal anisotropic medium based on the Hamiltonian function of the inclined orthogonal anisotropic medium. The second calculation module is configured to solve the kinematic ray tracing system of the inclined orthogonal anisotropic medium and the dynamic ray tracing system of the inclined orthogonal anisotropic medium in the wavefront orthogonal coordinate system based on the Runge-Kutta method, so as to obtain the three-dimensional ray tracing of the inclined orthogonal anisotropic medium. The third calculation module is configured to acquire travel time field information of the inclined orthogonal anisotropic medium based on the three-dimensional ray tracing. An imaging module configured to perform seismic Koschhof migration imaging based on the travel time field information.

9. An electronic device, comprising: At least one processor; as well as A memory storing a computer program executable on the processor, characterized in that the processor executes the program by performing the steps of the method as described in any one of claims 1 to 7.

10. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it performs the steps of the method as described in any one of claims 1 to 7.

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