Geologic target-oriented VTI medium reverse time migration imaging method and device

Abstract

The invention provides a geological target-oriented VTI medium reverse time migration imaging method and device, and the method comprises the steps: inputting a velocity field and a dyeing region in an obtained underground velocity model, and building a real part velocity field and an imaginary part velocity field; transforming the VTI quasi-acoustic wave equation from a real number field to a complex number field; splitting the transformed VTI quasi-acoustic wave equation into a real part and an imaginary part, and discretizing a wave equation of the real part and a wave equation of the imaginary part respectively to obtain propagation and reflection results of simulated waves; and extracting imaginary part information of the complex field from the propagation and reflection results, and generating an imaginary part imaging result based on the imaginary part information. Therefore, the imaginary part imaging result is obtained, the imaging blind area of the traditional section is independently imaged, and the imaging precision of the under-salt structure is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas geophysics, and in particular to a VTI medium reverse time migration imaging method and device oriented to geological targets. Background Art

[0002] Seismic migration imaging is to return the reflected wave or diffraction wave energy in the seismic data to its original underground position to obtain a high-resolution underground structure image. In the past, the migration imaging technology was only used to determine the spatial position of the reflection (scattering) point. With the continuous development of migration technology, its waveform and amplitude characteristics have also become very important. These characteristics are very critical for analyzing lithological characteristics.

[0003] Among the current seismic data migration methods, the prestack reverse time migration method is the most accurate imaging method. As early as 1978, Hemon proposed in the literature the idea of ​​using the finite difference method to solve the wave equation to achieve reverse time migration. After 1983, reverse time migration technology was applied to the field of seismic exploration and made great progress. Baysal et al. proposed and described the reverse time migration algorithm, pointing out that the algorithm has high imaging accuracy in the case of steeply inclined structures with strong velocity contrast; in response to the problem that reverse time extrapolation based on the one-way wave equation leads to limitations in imaging dip angles, Whitmore proposed a reverse time migration method based on solving the two-way wave equation; in response to dip angle limitations, MMechan et al. proposed using the second-order finite difference method to solve the acoustic wave equation in the time and space domains.

[0004] However, the huge amount of computation and storage required by the algorithm at that time limited its wide application in actual production. At the same time, the reverse time migration method itself still has many problems. Summary of the invention

[0005] The present invention provides a VTI medium reverse time migration imaging method and device for geological targets, which are used to perform separate imaging of the imaging blind area of ​​the traditional profile, thereby improving the imaging accuracy of the subsalt structure.

[0006] In a first aspect, the present invention provides a VTI medium reverse time migration imaging method for geological targets, comprising:

[0007] Input the velocity field and the dyeing area into the acquired underground velocity model to establish the real velocity field and the imaginary velocity field;

[0008] Transform the VTI pseudo-acoustic wave equation from the real domain to the complex domain;

[0009] The transformed VTI pseudo-acoustic wave equation is split into a real part and an imaginary part, and the wave equation of the real part and the wave equation of the imaginary part are discretized respectively to obtain the propagation and reflection results of the simulated wave;

[0010] The imaginary part information of the complex domain is extracted from the propagation and reflection results, and an imaginary part imaging result is generated based on the imaginary part information.

[0011] Optionally, the velocity field and the dyed area are input into the acquired underground velocity model to establish the real velocity field and the imaginary velocity field, including:

[0012] Determining a dyeing area in the acquired underground velocity model, and associating the velocity field with the dyeing area to obtain corresponding association relationship information;

[0013] The real velocity field and the imaginary velocity field are established according to the association relationship information.

[0014] Optionally, the transformed VTI pseudo-acoustic wave equation is split into a real part and an imaginary part, and the wave equation of the real part and the wave equation of the imaginary part are discretized respectively to obtain propagation and reflection results of the simulated wave, including:

[0015] Splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part;

[0016] Discretize the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation respectively to obtain the discretized real part wave equation and imaginary part wave equation;

[0017] The discretized wave equation of the real velocity in the complex number domain and the wave equation of the imaginary velocity in the complex number domain are solved in the complex number domain to obtain the propagation and reflection results of the simulated wave.

[0018] Optionally, the wave equation of the real part velocity in the complex domain is specifically:

[0019]

[0020] The wave equation of the imaginary velocity in the complex domain is specifically:

[0021]

[0022] in, u is the wave field, t is time, v is the phase velocity, subscripts i and r represent the imaginary and real parts of the variables, Δt is the time step, ε and δ are Thomsen parameters, n x and n z is a unit vector, is the gradient operator, is the Laplace operator.

[0023] In a second aspect, the present invention provides a VTI medium reverse time migration imaging device for geological targets, comprising:

[0024] Establishing a module for inputting a velocity field and a dyeing area in the acquired underground velocity model to establish a real velocity field and an imaginary velocity field;

[0025] A transformation module, used to transform the VTI pseudo-acoustic wave equation from the real domain to the complex domain;

[0026] A discretization module is used to split the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part, and discretize the wave equation of the real part and the wave equation of the imaginary part respectively to obtain the propagation and reflection results of the simulated wave;

[0027] The imaginary part imaging result generating module is used to extract the imaginary part information of the complex domain from the propagation and reflection results, and generate the imaginary part imaging result based on the imaginary part information.

[0028] Optionally, the establishing module includes:

[0029] An association submodule, used for determining a dyeing area in the acquired underground velocity model, and associating the velocity field with the dyeing area to obtain corresponding association relationship information;

[0030] The velocity field establishment submodule is used to establish the real velocity field and the imaginary velocity field according to the association relationship information.

[0031] Optionally, the discretization submodule includes:

[0032] A splitting unit, used for splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part;

[0033] A discretization unit is used to discretize the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation respectively to obtain the discretized real part wave equation and the imaginary part wave equation;

[0034] The simulated wave propagation and reflection result determination unit is used to solve the discretized wave equation of the real part velocity in the complex number domain and the wave equation of the imaginary part velocity in the complex number domain in the complex number domain to obtain the simulated wave propagation and reflection results.

[0035] Optionally, the wave equation of the real part velocity in the complex domain is specifically:

[0036]

[0037] The wave equation of the imaginary velocity in the complex domain is specifically:

[0038]

[0039] in, u is the wave field, t is time, v is the phase velocity, subscripts i and r represent the imaginary and real parts of the variables, Δt is the time step, ε and δ are Thomsen parameters, n x and n z is a unit vector, is the gradient operator, is the Laplace operator.

[0040] In a third aspect, the present application provides an electronic device, comprising a processor and a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the steps in the method provided in the first aspect are performed.

[0041] In a fourth aspect, the present application provides a storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps in the method provided in the first aspect are performed.

[0042] It can be seen from the above technical solutions that the present invention has the following advantages:

[0043] The present invention provides a VTI medium reverse time migration imaging method and device for geological targets, the method comprising: inputting a velocity field and a dyeing area in the acquired underground velocity model to establish a real velocity field and an imaginary velocity field; transforming the VTI pseudo-acoustic wave equation from the real domain to the complex domain; splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part, and discretizing the wave equation of the real part and the wave equation of the imaginary part respectively, to obtain the propagation and reflection results of the simulated wave; extracting the imaginary part information of the complex domain from the propagation and reflection results, and generating the imaginary imaging results based on the imaginary part information. By assigning the traditional real velocity to the real velocity of the complex domain, assigning the dyeing velocity to the imaginary velocity of the complex domain, and solving the discretized real and imaginary wave equations in the complex domain, the imaginary imaging results are obtained, so as to realize the separate imaging of the imaging blind area of ​​the traditional section, and improve the imaging accuracy of the subsalt structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0045] Figure 1 A flowchart of a first embodiment of a VTI medium reverse time migration imaging method for geological targets according to the present invention;

[0046] Figure 2It is a flowchart of a second embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0047] Figure 3 It is a velocity parameter schematic diagram of a complex model of a third embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0048] Figure 4 It is a schematic diagram of anisotropic parameter ε of a complex model in Embodiment 3 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0049] Figure 5 A schematic diagram of anisotropic parameters of a complex model of a third embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0050] Figure 6 It is a schematic diagram of VTI reverse time migration results of a complex model in Embodiment 3 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0051] Figure 7 It is a schematic diagram of imaginary velocity parameters of a complex model in Embodiment 3 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0052] Figure 8 It is a schematic diagram of the dyed VTI reverse time migration result of a complex model in Example 3 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0053] Fig. 9 It is a velocity parameter schematic diagram of a complex model of a fourth embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0054] Fig.10 A schematic diagram of anisotropic parameter ε of a complex model in Embodiment 4 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0055] Fig.11 A schematic diagram of anisotropic parameters of a complex model of a fourth embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0056] Fig.12 It is a schematic diagram of VTI reverse time migration results of a complex model in Embodiment 4 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0057] Fig.13 It is a schematic diagram of imaginary velocity parameters of a complex model of a fourth embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0058] Fig.14 It is a schematic diagram of the dyed VTI reverse time migration result of a complex model in Example 4 of a VTI medium reverse time migration imaging method for geological targets of the present invention;

[0059] Fig.15 The structure diagram of an embodiment of a VTI medium reverse time migration imaging device for geological targets according to the present invention. DETAILED DESCRIPTION

[0060] The embodiment of the present invention provides a VTI medium reverse time migration imaging method and device for geological targets, which are used to perform separate imaging of the imaging blind area of ​​the traditional profile, thereby improving the imaging accuracy of the subsalt structure.

[0061] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] For example, see Figure 1 , Figure 1 The flowchart of the first embodiment of the VTI medium reverse time migration imaging method for geological targets of the present invention includes:

[0063] Step S101, inputting the velocity field and the dyeing area into the acquired underground velocity model, and establishing the real velocity field and the imaginary velocity field;

[0064] It should be noted that VTI media refers to media with vertical transverse anisotropy, also known as transverse anisotropic vertical layered media. In VTI media, the physical properties of the media (such as wave velocity and density) vary with depth in both the horizontal and vertical directions. This medium model is of great significance for explaining and understanding the propagation of seismic waves underground.

[0065] The underground velocity model is a description of the propagation velocity of waves in the underground medium. It can be obtained by seismic inversion methods, laboratory rock tests, etc. The underground velocity model is usually a three-dimensional function that describes the spatial variation of travel time and propagation velocity in the underground medium.

[0066] The dyed area usually has an uneven velocity distribution and produces attenuation, scattering and other effects on the propagation of seismic waves.

[0067] The velocity field is a field with velocity as an attribute in the earth model. It is derived from the subsurface velocity model and is usually represented on a discrete grid. The velocity field gives the velocity of the wave propagating at each grid point. It is used for seismic data processing and imaging, including methods such as reverse time migration.

[0068] The dyed area refers to the area in the underground medium where geological targets may exist. In the traditional VTI medium reverse time migration method, the dyed area refers to the area where geological targets (such as fractures, lithology changes, etc.) may exist, which usually has an uneven velocity distribution in the velocity field. The dyed area can be determined by means of seismic data analysis, geological interpretation, etc.

[0069] Step S102, transforming the VTI pseudo-acoustic wave equation from the real domain to the complex domain;

[0070] Step S103, splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part, and discretizing the wave equation of the real part and the wave equation of the imaginary part respectively, to obtain propagation and reflection results of the simulated wave;

[0071] Step S104, extracting the imaginary part information of the complex domain from the propagation and reflection results, and generating an imaginary part imaging result based on the imaginary part information.

[0072] The embodiment of the present invention discloses a VTI medium reverse time migration imaging method for geological targets, which establishes real velocity field and imaginary velocity field by inputting velocity field and dyeing area in the acquired underground velocity model; transforms VTI pseudo-acoustic wave equation from real domain to complex domain; splits the transformed VTI pseudo-acoustic wave equation into real part and imaginary part, and discretizes the wave equation of the real part and the wave equation of the imaginary part respectively, to obtain propagation and reflection results of simulated waves; extracts the imaginary part information of the complex domain from the propagation and reflection results, and generates imaginary imaging results based on the imaginary part information. By assigning the traditional real velocity to the real velocity of the complex domain, assigning the dyeing velocity to the imaginary velocity of the complex domain, and solving the discretized real and imaginary wave equations in the complex domain, the imaginary imaging results are obtained, so as to realize the separate imaging of the imaging blind area of ​​the traditional section, and improve the imaging accuracy of the subsalt structure.

[0073] For example 2, please refer to Figure 2 , Figure 2 The flowchart of the second embodiment of the VTI medium reverse time migration imaging method for geological targets of the present invention includes:

[0074] Step S201, determining a dyeing area in the acquired underground velocity model, and associating the velocity field with the dyeing area to obtain corresponding association relationship information;

[0075] In the embodiment of the present invention, a dyeing area is determined in the acquired underground velocity model, and then the determined dyeing area is associated with the velocity field to introduce the influence of the dyeing velocity on the velocity field.

[0076] Usually, the dyeing velocity is regarded as the disturbance value of the velocity field, and the value in the dyeing area is different from that in the surrounding area. In this way, the influence of geological targets can be introduced into the velocity field to improve the imaging ability of geological targets.

[0077] Step S202, establishing the real velocity field and the imaginary velocity field according to the association relationship information;

[0078] In the embodiment of the present invention, the real velocity field is obtained by using the velocity model in the VTI medium reverse time migration method, which describes the phase velocity of the wave in the medium. The imaginary velocity field is obtained based on the correlation between the dyeing velocity determined in the dyeing area and the velocity field, which describes the attenuation and scattering effects of the wave in the medium.

[0079] Step S203, transforming the VTI pseudo-acoustic wave equation from the real domain to the complex domain;

[0080] In the embodiment of the present invention, the real wave equation in the conventional VTI medium reverse time migration method is converted into a complex wave equation to better describe the propagation of the wave, and the phase and amplitude information of the wave in the complex domain is considered, so that the diffraction and transmission effects of the wave can be described more accurately, which helps to improve the accuracy of imaging.

[0081] In the specific implementation, for VTI media, a scalar wave equation has been derived, that is, the VTI pseudo-acoustic wave equation can be expressed in the following way:

[0082]

[0083] Where u is the wave field, t is time, v is the phase velocity, ε and δ are Thomsen parameters, and n x and n z is a unit vector, is the gradient operator, is the Laplace operator.

[0084] For the above expression, in the embodiment of the present invention, the variables are expanded from real field to complex field, and the forms of u and v are respectively:

[0085] u=u r +iu i ;

[0086] v=v r +iv i ;

[0087] Here, the subscripts i and r represent the imaginary and real parts of the variable.

[0088] After expansion, the original scalar wave equation becomes:

[0089] in,

[0090]

[0091] First define:

[0092]

[0093] Then the expanded scalar wave equation, that is, the transformed VTI pseudo-acoustic wave equation, is rewritten as:

[0094]

[0095] Step S204, splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part;

[0096] In the embodiment of the present invention, the transformed VTI pseudo-acoustic wave equation in the complex domain is decomposed into a real part and an imaginary part, which respectively represent the wave propagation and the wave attenuation and scattering process, which helps to better describe the characteristics of different aspects in the medium and improve the imaging capability of geological targets.

[0097] In the specific implementation, the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation are respectively:

[0098]

[0099]

[0100] Step S205, discretizing the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation respectively to obtain the discretized real part wave equation and the imaginary part wave equation;

[0101] In the embodiment of the present invention, when the imaginary phase velocity is infinitely small, that is, v in the VTI pseudo-acoustic wave equation is i When the time is infinite, the real part of the VTI pseudo-acoustic wave equation tends to be equivalent to the scalar wave equation. For the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation, the time second-order explicit finite difference has the following expression:

[0102]

[0103]

[0104] Among them, t is time and Δt is the time step.

[0105] Step S206, solving the discretized wave equation of the real velocity in the complex domain and the wave equation of the imaginary velocity in the complex domain in the complex domain to obtain propagation and reflection results of simulated waves;

[0106] In an embodiment of the present invention, a numerical method is used to solve the discretized wave equation of the real velocity in the complex domain and the wave equation of the imaginary velocity in the complex domain, and the wave propagation and reflection process is simulated by sampling and calculating the wave field and velocity field at discrete grid points.

[0107] Step S207, extracting the imaginary part information of the complex domain from the propagation and reflection results, and generating an imaginary part imaging result based on the imaginary part information.

[0108] In the embodiment of the present invention, the imaging result expression is used in combination with the imaginary part information to obtain the imaginary part imaging result, wherein the imaging result expression is specifically:

[0109]

[0110] Among them, I(x,z) is the imaging result, u i (x,z,t) is the imaginary source field, R(x,z,t) is the receiver wave field, t min is the staining time point, t max The staining termination time point.

[0111] In a specific implementation, during the discretization process, the wave equation of the discretized complex domain real velocity and the wave equation of the complex domain imaginary velocity are iteratively calculated, the wave field state is updated, and the wave field state at the next moment is calculated. Finally, the imaginary imaging result is generated according to the calculated imaginary wave field information, thereby generating the imaginary imaging result.

[0112] The embodiment of the present invention discloses a VTI medium reverse time migration imaging method for geological targets, which establishes real velocity field and imaginary velocity field by inputting velocity field and dyeing area in the acquired underground velocity model; transforms VTI pseudo-acoustic wave equation from real domain to complex domain; splits the transformed VTI pseudo-acoustic wave equation into real part and imaginary part, and discretizes the wave equation of the real part and the wave equation of the imaginary part respectively, to obtain propagation and reflection results of simulated waves; extracts the imaginary part information of the complex domain from the propagation and reflection results, and generates imaginary imaging results based on the imaginary part information. By assigning the traditional real velocity to the real velocity of the complex domain, assigning the dyeing velocity to the imaginary velocity of the complex domain, and solving the discretized real and imaginary wave equations in the complex domain, the imaginary imaging results are obtained, so as to realize the separate imaging of the imaging blind area of ​​the traditional section, and improve the imaging accuracy of the subsalt structure.

[0113] For example 3, please refer to Figure 3 to Figure 6 , Figure 3 It is a velocity parameter schematic diagram of a complex model of a third embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention; Figure 4 It is a schematic diagram of anisotropic parameter ε of a complex model in Embodiment 3 of a VTI medium reverse time migration imaging method for geological targets of the present invention; Figure 5 A schematic diagram of anisotropic parameters of a complex model of a third embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention; Figure 6 FIG. 1 is a schematic diagram of the VTI reverse time migration result of a complex model of the third embodiment of the VTI medium reverse time migration imaging method for geological targets of the present invention; since there is a salt dome structure in the complex model, and the high-speed salt dome structure causes blurred imaging of the subsalt structure due to the shielding effect, the VTI medium reverse time migration imaging method for geological targets of the second embodiment of the present invention is applied to obtain Figure 7 Schematic diagram of the imaginary velocity parameters and Figure 8 Schematic diagram of the result of dyed VTI reverse time migration. It can be seen that after dyeing and imaging using the VTI medium reverse time migration imaging method for quality targets of the present invention, the subsalt imaging effect can be effectively enhanced.

[0114] Example 4, please refer to Figures 9 to 12 , Fig. 9 It is a velocity parameter schematic diagram of a complex model of a fourth embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention; Fig.10 A schematic diagram of anisotropic parameter ε of a complex model in Embodiment 4 of a VTI medium reverse time migration imaging method for geological targets of the present invention; Fig.11 A schematic diagram of anisotropic parameters of a complex model of a fourth embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention; Fig.12 FIG. 1 is a schematic diagram of a VTI reverse time migration result of a complex model of a fourth embodiment of a VTI medium reverse time migration imaging method for geological targets of the present invention; since there is a salt dome structure in the complex model, and the high-speed salt dome structure causes blurred imaging of the subsalt structure due to the shielding effect, the VTI medium reverse time migration imaging method for geological targets of the second embodiment of the present invention is applied to obtain Fig.13 Schematic diagram of the imaginary velocity parameters and Fig.14 Schematic diagram of the result of dyed VTI reverse time migration. It can be seen that after dyeing and imaging using the VTI medium reverse time migration imaging method for quality targets of the present invention, the subsalt imaging effect can be effectively enhanced.

[0115] For example 5, please refer to Fig.15 , Fig.15The structural block diagram of an embodiment of a VTI medium reverse time migration imaging device for geological targets of the present invention includes:

[0116] Establishing module 501, for inputting velocity field and coloring area in the acquired underground velocity model, and establishing real velocity field and imaginary velocity field;

[0117] A transformation module 502, for transforming the VTI pseudo-acoustic wave equation from the real domain to the complex domain;

[0118] The discretization module 503 is used to split the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part, and discretize the wave equation of the real part and the wave equation of the imaginary part respectively to obtain the propagation and reflection results of the simulated wave;

[0119] The imaginary part imaging result generating module 504 is used to extract the imaginary part information in the complex domain from the propagation and reflection results, and generate the imaginary part imaging result based on the imaginary part information.

[0120] In an optional embodiment, the establishing module 501 includes:

[0121] An association submodule, used for determining a dyeing area in the acquired underground velocity model, and associating the velocity field with the dyeing area to obtain corresponding association relationship information;

[0122] The velocity field establishment submodule is used to establish the real velocity field and the imaginary velocity field according to the association relationship information.

[0123] In an optional embodiment, the discretization submodule includes:

[0124] A splitting unit, used for splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part;

[0125] A discretization unit is used to discretize the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation respectively to obtain the discretized real part wave equation and the imaginary part wave equation;

[0126] The simulated wave propagation and reflection result determination unit is used to solve the discretized wave equation of the real part velocity in the complex number domain and the wave equation of the imaginary part velocity in the complex number domain in the complex number domain to obtain the simulated wave propagation and reflection results.

[0127] In an optional embodiment, the wave equation of the real part velocity in the complex domain is specifically:

[0128]

[0129] The wave equation of the imaginary velocity in the complex domain is specifically:

[0130]

[0131] in, u is the wave field, t is time, v is the phase velocity, subscripts i and r represent the imaginary and real parts of the variables, Δt is the time step, ε and δ are Thomsen parameters, n x and n z is a unit vector, is the gradient operator, is the Laplace operator.

[0132] An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of a VTI medium reverse time migration imaging method for geological targets as described in any of the above embodiments.

[0133] An embodiment of the present invention further provides a computer storage medium having a computer program stored thereon, and when the computer program is executed by the processor, the steps of a VTI medium reverse time migration imaging method for geological targets as described in any of the above embodiments are implemented.

[0134] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0135] In the several embodiments provided in the present application, it should be understood that the methods, devices, electronic devices and storage media disclosed in the present invention can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0136] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0137] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0138] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a readable storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned readable storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0139] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A VTI medium reverse time migration imaging method for geological targets, characterized in that: include: Input the velocity field and the dyeing area into the acquired underground velocity model to establish the real velocity field and the imaginary velocity field; Transform the VTI pseudo-acoustic wave equation from the real domain to the complex domain; The transformed VTI pseudo-acoustic wave equation is split into a real part and an imaginary part, and the wave equation of the real part and the wave equation of the imaginary part are discretized respectively to obtain the propagation and reflection results of the simulated wave; The imaginary part information of the complex domain is extracted from the propagation and reflection results, and an imaginary part imaging result is generated based on the imaginary part information.

2. The VTI medium reverse time migration imaging method for geological targets according to claim 1, characterized in that: Input the velocity field and the dyed area into the acquired underground velocity model to establish the real velocity field and the imaginary velocity field, including: Determining a dyeing area in the acquired underground velocity model, and associating the velocity field with the dyeing area to obtain corresponding association relationship information; The real velocity field and the imaginary velocity field are established according to the association relationship information.

3. The VTI medium reverse time migration imaging method for geological targets according to claim 1, characterized in that: The transformed VTI pseudo-acoustic wave equation is split into a real part and an imaginary part, and the wave equation of the real part and the wave equation of the imaginary part are discretized respectively to obtain the propagation and reflection results of the simulated wave, including: Splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part; Discretize the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation respectively to obtain the discretized real part wave equation and imaginary part wave equation; The discretized wave equation of the real velocity in the complex number domain and the wave equation of the imaginary velocity in the complex number domain are solved in the complex number domain to obtain the propagation and reflection results of the simulated wave.

4. The VTI medium reverse time migration imaging method for geological targets according to claim 3, characterized in that: The wave equation of the real part velocity in the complex domain is specifically: The wave equation of the imaginary velocity in the complex domain is specifically: in, u is the wave field, t is time, v is the phase velocity, subscripts i and r represent the imaginary and real parts of the variables, Δt is the time step, ε and δ are Thomsen parameters, n x and n z is a unit vector, is the gradient operator, is the Laplace operator.

5. A VTI medium reverse time migration imaging device for geological targets, characterized in that: include: Establishing a module for inputting a velocity field and a dyeing area in the acquired underground velocity model to establish a real velocity field and an imaginary velocity field; A transformation module, used to transform the VTI pseudo-acoustic wave equation from the real domain to the complex domain; A discretization module is used to split the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part, and discretize the wave equation of the real part and the wave equation of the imaginary part respectively to obtain the propagation and reflection results of the simulated wave; The imaginary part imaging result generating module is used to extract the imaginary part information of the complex domain from the propagation and reflection results, and generate the imaginary part imaging result based on the imaginary part information.

6. The VTI medium reverse time migration imaging device for geological targets according to claim 5, characterized in that: The establishment module includes: An association submodule, used for determining a dyeing area in the acquired underground velocity model, and associating the velocity field with the dyeing area to obtain corresponding association relationship information; The velocity field establishment submodule is used to establish the real velocity field and the imaginary velocity field according to the association relationship information.

7. The VTI medium reverse time migration imaging device for geological targets according to claim 5, characterized in that: The discretization submodules include: A splitting unit, used for splitting the transformed VTI pseudo-acoustic wave equation into a real part and an imaginary part; A discretization unit is used to discretize the real part of the VTI pseudo-acoustic wave equation and the imaginary part of the VTI pseudo-acoustic wave equation respectively to obtain the discretized real part wave equation and the imaginary part wave equation; The simulated wave propagation and reflection result determination unit is used to solve the discretized wave equation of the real part velocity in the complex number domain and the wave equation of the imaginary part velocity in the complex number domain in the complex number domain to obtain the simulated wave propagation and reflection results.

8. The VTI medium reverse time migration imaging device for geological targets according to claim 3, characterized in that: The wave equation of the real part velocity in the complex domain is specifically: The wave equation of the imaginary velocity in the complex domain is specifically: in, u is the wave field, t is time, v is the phase velocity, subscripts i and r represent the imaginary and real parts of the variables, Δt is the time step, ε and δ are Thomsen parameters, n x and n z is a unit vector, is the gradient operator, is the Laplace operator.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the method according to any one of claims 1 to 4 is executed.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is performed.

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