Three-dimensional complex salt-containing cavern geological modeling and seismic wave field numerical simulation method and device

Abstract

The invention discloses a three-dimensional complex salt-containing cavern geological modeling and seismic wave field numerical simulation method and device, and relates to the technical field of seismic prospecting. The method uses a slice superposition technology and a smooth contour and combines a high-precision linear interpolation method to accurately approach and describe an irregular salt cavern shape; and establishing a salt cavern model (including a three-dimensional salt cavern longitudinal wave velocity model, a three-dimensional salt cavern transverse wave velocity model, a three-dimensional salt cavern density model, a three-dimensional salt cavern longitudinal wave absorption factor model and a three-dimensional salt cavern transverse wave absorption factor model) which better fits the real condition of the salt cavern. Embedding the finely constructed salt cavern model into a complex and real geological background model (a three-dimensional background stratum longitudinal wave velocity model, a three-dimensional background stratum transverse wave velocity model, a three-dimensional background stratum density model, a three-dimensional background stratum longitudinal wave absorption factor model and a three-dimensional background stratum transverse wave absorption factor model); therefore, more similar simulation of an actual underground geologic structure is realized.

Description

Technical Field

[0001] The present application relates to the field of seismic exploration technology, and in particular to a method and device for three-dimensional complex salt cave geological modeling and seismic wave field numerical simulation. Background Art

[0002] Numerical simulation of seismic wave fields is an indispensable foundation for seismic data processing and interpretation, and provides a theoretical basis for seismic data processing and interpretation. The establishment of geological models is the starting point of numerical simulation. At present, the technology of two-dimensional geological modeling is relatively mature, and there are a large number of powerful modeling software. However, there are many deficiencies in the establishment of three-dimensional models, and it is impossible to establish a three-dimensional model that is close to the actual geological body in the ideal. Summary of the invention

[0003] The purpose of this application is to provide a three-dimensional complex salt cavern geological modeling and seismic wave field numerical simulation method and device, which can more realistically simulate the actual underground geological structure of complex salt cavern geology.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a three-dimensional complex salt cave geological modeling method, comprising:

[0006] Obtaining geological parameters of salt cavern geology; the geological parameters include formation P-wave velocity, formation S-wave velocity, formation density, formation P-wave absorption factor, formation S-wave absorption factor of each formation and salt cavern P-wave velocity, salt cavern S-wave velocity, salt cavern density, salt cavern P-wave absorption factor, salt cavern S-wave absorption factor in the salt cavern;

[0007] A three-dimensional background stratum P-wave velocity model is established according to the stratum P-wave velocity of each stratum;

[0008] A three-dimensional salt cavern P-wave velocity model is established based on the salt cavern P-wave velocity, slice stacking technology and linear interpolation method.

[0009] The three-dimensional salt cavern P-wave velocity model is embedded in the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of salt cavern geology;

[0010] According to the complete P-wave velocity model of salt cavern geology, a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of salt cavern geology are established;

[0011] A three-dimensional complex salt cavern geological model is derived based on the complete P-wave velocity model, complete S-wave velocity model, complete density model, complete P-wave absorption factor model and complete S-wave absorption factor model of the salt cavern geology.

[0012] In a second aspect, the present application provides a method for numerically simulating a seismic wave field based on a three-dimensional complex salt cave geological model, the method comprising:

[0013] Calling a three-dimensional complex salt cave geological model; the three-dimensional complex salt cave geological model is constructed based on the three-dimensional complex salt cave geological modeling method;

[0014] Finite difference numerical simulation is performed on the three-dimensional complex salt cavern geological model to obtain seismic records and wave field snapshots; when performing finite difference numerical simulation, the three-dimensional complex salt cavern geological model after grid division is cut in the x-direction, y-direction, and z-direction to divide the entire three-dimensional model into multiple grid domains; each grid domain is executed by a processor to perform finite difference numerical simulation.

[0015] In a third aspect, the present application provides a three-dimensional complex salt cave geological modeling device, comprising:

[0016] A parameter acquisition module is used to acquire geological parameters of salt cavern geology; the geological parameters include the formation P-wave velocity, formation S-wave velocity, formation density, formation P-wave absorption factor, formation S-wave absorption factor of each formation and the salt cave P-wave velocity, salt cave S-wave velocity, salt cave density, salt cave P-wave absorption factor, and salt cave S-wave absorption factor in the salt cave;

[0017] A background stratum P-wave velocity model building module is used to build a three-dimensional background stratum P-wave velocity model according to the stratum P-wave velocity of each stratum;

[0018] A salt cavern P-wave velocity model building module, which is used to build a three-dimensional salt cavern P-wave velocity model based on the salt cavern P-wave velocity, slice stacking technology and linear interpolation method in the salt cavern;

[0019] A complete P-wave velocity model building module is used to embed the three-dimensional salt cavern P-wave velocity model into the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of salt cavern geology;

[0020] A parameter modification module is used to establish a complete shear wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology according to the complete P-wave velocity model of the salt cavern geology;

[0021] The complex salt cavern geological model construction module is used to obtain a three-dimensional complex salt cavern geological model based on a complete P-wave velocity model, a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology.

[0022] In a fourth aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned three-dimensional complex salt cavern geological modeling method, or the above-mentioned seismic wave field numerical simulation method.

[0023] In a fifth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned three-dimensional complex salt cavern geological modeling method, or the above-mentioned seismic wave field numerical simulation method.

[0024] In a sixth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above-mentioned three-dimensional complex salt cave geological modeling method, or the above-mentioned seismic wave field numerical simulation method.

[0025] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0026] The present application provides a three-dimensional complex salt cave geological modeling, seismic wave field numerical simulation method and device, using slice superposition technology, contour smoothing and combining high-precision linear interpolation method to accurately approximate and depict irregular salt cave shapes, and establish a salt cave model that is more in line with the actual situation of the salt cave (including a three-dimensional salt cave P-wave velocity model, a three-dimensional salt cave S-wave velocity model, a three-dimensional salt cave density model, a three-dimensional salt cave P-wave absorption factor model and a three-dimensional salt cave S-wave absorption factor model). And the finely constructed salt cave model is embedded in a complex and real geological background model (three-dimensional background stratum P-wave velocity model, three-dimensional background stratum S-wave velocity model, three-dimensional background stratum density model, three-dimensional background stratum P-wave absorption factor model and three-dimensional background stratum S-wave absorption factor model), so as to achieve a more similar simulation of the actual underground geological structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is an application environment diagram of a three-dimensional complex salt cave geological modeling method in one embodiment of the present application;

[0029] Figure 2 A schematic diagram of a process flow of a three-dimensional complex salt cave geological modeling method provided in one embodiment of the present application;

[0030] Figure 3 A schematic diagram of a three-dimensional longitudinal wave velocity model (indexed by distance) provided in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of an xy section (index is a grid index) of a three-dimensional longitudinal wave velocity model provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of functional modules of a three-dimensional complex salt cave geological modeling device provided in one embodiment of the present application;

[0033] Figure 6 A schematic flow chart of a method for numerically simulating a seismic wave field based on a three-dimensional complex salt cavern geological model provided in one embodiment of the present application;

[0034] Figure 7 A schematic diagram of a mid-channel seismic recording of a horizontal surface receiving array provided in an embodiment of the present application;

[0035] Figure 8 A schematic diagram of receiving seismic records in a well provided in an embodiment of the present application;

[0036] Fig. 9 A schematic diagram of a wave field snapshot at a salt cavern location provided in an embodiment of the present application;

[0037] Fig.10 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0040] The three-dimensional complex salt cave geological modeling method provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal communicates with the server through the network. The data storage system can store the data that the server needs to process. The data storage system can be set up separately, integrated on the server, or placed on the cloud or other servers. The terminal can send the collected geological parameters of the salt cavern geology to the server. After the server receives the geological parameters of the salt cavern geology, the server establishes a three-dimensional background stratum P-wave velocity model according to the stratum P-wave velocity of each stratum; establishes a three-dimensional salt cavern P-wave velocity model according to the salt cavern P-wave velocity, slice superposition technology and linear interpolation method in the salt cavern; embeds the three-dimensional salt cavern P-wave velocity model into the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of the salt cavern geology; establishes a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology according to the complete P-wave velocity model of the salt cavern geology; and obtains a three-dimensional complex salt cavern geological model according to the complete P-wave velocity model, the complete S-wave velocity model, the complete density model, the complete P-wave absorption factor model and the complete S-wave absorption factor model of the salt cavern geology. The server can feedback the obtained three-dimensional complex salt cavern geological model to the terminal. In addition, in some embodiments, the three-dimensional complex salt cavern geological modeling method can also be implemented by a server or a terminal alone. For example, the terminal can directly perform three-dimensional complex salt cavern geological modeling on the geological parameters of the salt cavern geology, or the server can obtain the geological parameters of the salt cavern geology from the data storage system and perform three-dimensional complex salt cavern geological modeling.

[0041] The terminal may be, but is not limited to, various desktop computers, laptops, smart phones, tablet computers, IoT devices, and portable wearable devices. The server may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0042] In an exemplary embodiment, Figure 2 As shown, a three-dimensional complex salt cave geological modeling method is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or can be executed by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The server in the example is used to illustrate, including the following steps 101 to 106. Among them:

[0043] Step 101, obtaining geological parameters of salt cavern geology.

[0044] Reasonable geological parameters required for seismic wave simulation are set according to simulation requirements. Reasonable means that the parameter settings are in line with geological and physical principles. Specific geological parameters include: formation longitudinal wave velocity, formation transverse wave velocity, formation density, formation longitudinal wave absorption factor, formation transverse wave absorption factor of each stratum and salt cavern longitudinal wave velocity, salt cavern transverse wave velocity, salt cavern density, salt cavern longitudinal wave absorption factor, salt cavern transverse wave absorption factor in salt caverns.

[0045] Step 102: establishing a three-dimensional background formation P-wave velocity model according to the formation P-wave velocity of each formation.

[0046] Step 103, establishing a three-dimensional salt cavern longitudinal wave velocity model according to the salt cavern longitudinal wave velocity, slice stacking technology and linear interpolation method in the salt cavern.

[0047] Step 104, embed the three-dimensional salt cavern P-wave velocity model into the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of salt cavern geology. Figure 3 As shown in Figure 1, the complete three-dimensional longitudinal wave velocity model is established. Figure 4 As shown, an xy section of the three-dimensional P-wave velocity model is taken. The model simulates the situation where a complex stratum contains salt caverns. Compared with the 2D and 2.5D situations, such a three-dimensional P-wave velocity model is closer to the actual underground structure distribution.

[0048] The irregular three-dimensional salt cavern P-wave velocity model established in step 103 is embedded into the three-dimensional background stratum P-wave velocity model established in step 102 using an assignment method in MATLAB to obtain a complete P-wave velocity model. The assignment method is to replace a part of the three-dimensional matrix of the background stratum P-wave velocity model with the three-dimensional matrix of the salt cavern P-wave velocity model.

[0049] Step 105, establishing a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology according to the complete P-wave velocity model of the salt cavern geology.

[0050] Step 106, deriving a three-dimensional complex salt cavern geological model based on the complete P-wave velocity model, the complete S-wave velocity model, the complete density model, the complete P-wave absorption factor model and the complete S-wave absorption factor model of the salt cavern geology.

[0051] By implementing the above steps 101 to 106, the modeling method of the present application approximates the irregular shape of the salt cavern by combining slice accumulation, contour smoothing and trilinear interpolation method, and then embeds the irregular salt cavern into a more complex geological background model to achieve the purpose of simulating the actual underground geological structure.

[0052] In another exemplary embodiment of the present application, step 102, establishing a three-dimensional background formation P-wave velocity model according to the formation P-wave velocity of each formation, specifically includes:

[0053] (1) Use seismic velocity modeling software to establish an uneven two-dimensional layered P-wave velocity model containing faults based on the P-wave velocity of each stratum.

[0054] The professional seismic velocity modeling software Tesserial2D is used to establish an uneven two-dimensional layered P-wave velocity model containing faults and save it as a text document.

[0055] (2) The uneven two-dimensional layered P-wave velocity model containing faults is converted into a three-dimensional background stratum P-wave velocity model.

[0056] Use matlab code to convert the special format (txt format) data in the text document output by Tesseral2D in the previous step into a two-dimensional matrix in matlab. Use matlab to copy and flatten the above two-dimensional matrix into a three-dimensional matrix to obtain a three-dimensional background stratum P-wave velocity model.

[0057] In another exemplary embodiment of the present application, step 103, based on the salt cavern longitudinal wave velocity, slice stacking technology and linear interpolation method in the salt cavern, a three-dimensional salt cavern longitudinal wave velocity model is established, which specifically includes:

[0058] (1) Select slices with different geometric shapes according to the irregular shape of the salt cavern.

[0059] (2) According to the irregular shape of the salt cavern, slices of different geometric shapes are superimposed, and the salt cavern longitudinal wave velocity is used as an index to construct a preliminary salt cavern longitudinal wave velocity model.

[0060] The slice superposition technique is used, where the slices can be of various shapes, such as circles or polygons. These individual slices are combined through the written code to obtain the approximate shape of the salt cavern model.

[0061] Geological P-wave velocity modeling is to directly model the P-wave velocity as an index, so shape modeling is completed at the same time as velocity modeling. P-wave velocity modeling and shape modeling are completed simultaneously.

[0062] (3) The contour edge of the preliminary salt cavern longitudinal wave velocity model is smoothed to obtain a smoothed salt cavern longitudinal wave velocity model.

[0063] The contour edge of the salt cavern P-wave velocity model initially established above is highly uneven. A smoothing function is used to smooth the contour edge of the salt cavern P-wave velocity model, making the salt cavern closer to its true shape.

[0064] (4) The smoothed salt cavern P-wave velocity model is interpolated using the trilinear interpolation method to obtain a three-dimensional salt cavern P-wave velocity model of the required size.

[0065] The role of trilinear interpolation is to adjust the size of the longitudinal wave velocity model as needed.

[0066] In another exemplary embodiment of the present application, a complete shear wave velocity model, a complete density model, a complete P-wave absorption factor model, and a complete shear wave absorption factor model are established in MATLAB with the help of the established complete P-wave velocity model. The specific implementation method is to use conditional statements and assignment statements to modify the P-wave velocity values ​​in the P-wave velocity model to other geological parameter values ​​established in step 101, and store the three-dimensional matrix representing the model as a binary file. Therefore, step 105, based on the complete P-wave velocity model of salt cavern geology, a complete shear wave velocity model, a complete density model, a complete P-wave absorption factor model, and a complete shear wave absorption factor model are established, specifically including:

[0067] (1) The formation P-wave velocity and salt cavern P-wave velocity in the complete P-wave velocity model are replaced by the formation S-wave velocity and salt cavern S-wave velocity, respectively, to obtain a complete S-wave velocity model of salt cavern geology.

[0068] (2) The formation P-wave velocity and the salt cavern P-wave velocity in the complete P-wave velocity model are replaced by the formation density and the salt cavern density, respectively, to obtain a complete density model of salt cavern geology.

[0069] (3) The formation P-wave velocity and the salt cavern P-wave velocity in the complete P-wave velocity model are replaced by the formation P-wave absorption factor and the salt cavern P-wave absorption factor, respectively, to obtain a complete P-wave absorption factor model of salt cavern geology.

[0070] (4) The formation P-wave velocity and salt cavern P-wave velocity in the complete P-wave velocity model are replaced by the formation S-wave absorption factor and the salt cavern S-wave absorption factor, respectively, to obtain a complete S-wave absorption factor model of salt cavern geology.

[0071] As another optional implementation, in step 105, a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of salt cavern geology are established, and the construction process of the complete P-wave velocity model can be adopted. Specifically:

[0072] (1) According to the formation shear wave velocity, formation density, formation compressional wave absorption factor and formation shear wave absorption factor of each formation, a three-dimensional background formation shear wave velocity model, a three-dimensional background formation density model, a three-dimensional background formation compressional wave absorption factor model and a three-dimensional background formation shear wave absorption factor model are established respectively.

[0073] (2) According to the salt cavern shear wave velocity, salt cavern density, salt cavern longitudinal wave absorption factor and salt cavern shear wave absorption factor in the salt cavern, the slice superposition technology and linear interpolation method were used to establish a three-dimensional salt cavern shear wave velocity model, a three-dimensional salt cavern density model, a three-dimensional salt cavern longitudinal wave absorption factor model and a three-dimensional salt cavern shear wave absorption factor model respectively.

[0074] Based on the above-mentioned smoothed salt cavern longitudinal wave velocity model, the salt cavern shear wave velocity, salt cavern density, salt cavern longitudinal wave absorption factor, and salt cavern shear wave absorption factor can be interpolated by linear interpolation method.

[0075] (3) The three-dimensional salt cavern shear wave velocity model is embedded in the three-dimensional background stratum shear wave velocity model to obtain a complete shear wave velocity model; the three-dimensional salt cavern density model is embedded in the three-dimensional background stratum density model to obtain a complete density model; the three-dimensional salt cavern P-wave absorption factor model is embedded in the three-dimensional background stratum P-wave absorption factor model to obtain a complete P-wave absorption factor model; the three-dimensional salt cavern S-wave absorption factor model is embedded in the three-dimensional background stratum S-wave absorption factor model to obtain a complete S-wave absorption factor model.

[0076] This application cleverly uses slice accumulation technology and combines a variety of high-precision interpolation methods to accurately approximate and depict irregular salt cavern shapes. Subsequently, this finely constructed salt cavern model is embedded in a complex and realistic geological background model to achieve a more similar simulation of the actual underground geological structure. And through finite difference numerical simulation, seismic wave numerical simulation is performed on this model to verify the application effect of this model in seismic exploration.

[0077] Based on the same inventive concept, the embodiment of the present application also provides a three-dimensional complex salt cave geological modeling device for implementing the three-dimensional complex salt cave geological modeling method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more three-dimensional complex salt cave geological modeling device embodiments provided below can refer to the limitations of the three-dimensional complex salt cave geological modeling method above, and will not be repeated here.

[0078] In an exemplary embodiment, Figure 5 As shown, a three-dimensional complex salt cave geological modeling device is provided, comprising:

[0079] The parameter acquisition module M1 is used to obtain geological parameters of salt cavern geology; the geological parameters include the formation P-wave velocity, formation S-wave velocity, formation density, formation P-wave absorption factor, formation S-wave absorption factor of each stratum and the salt cave P-wave velocity, salt cave S-wave velocity, salt cave density, salt cave P-wave absorption factor, and salt cave S-wave absorption factor in the salt cave.

[0080] The background stratum P-wave velocity model building module M2 is used to build a three-dimensional background stratum P-wave velocity model according to the stratum P-wave velocity of each stratum.

[0081] The salt cavern P-wave velocity model building module M3 is used to establish a three-dimensional salt cavern P-wave velocity model according to the salt cavern P-wave velocity, slice stacking technology and linear interpolation method in the salt cavern.

[0082] The complete P-wave velocity model building module M4 is used to embed the three-dimensional salt cavern P-wave velocity model into the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of salt cavern geology.

[0083] The parameter modification module M5 is used to establish a complete shear wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology according to the complete P-wave velocity model of the salt cavern geology.

[0084] The complex salt cavern geological model construction module M6 is used to obtain a three-dimensional complex salt cavern geological model based on the complete P-wave velocity model, complete S-wave velocity model, complete density model, complete P-wave absorption factor model and complete S-wave absorption factor model of the salt cavern geology.

[0085] In another exemplary embodiment of the present application, relatively mature methods for numerical simulation of seismic wave fields include the finite difference method, the spectral element method, the finite element method, and the like. The finite difference method has the advantages of fast calculation speed and strong applicability to far and near wave fields and complex boundaries, and is therefore widely used in two-dimensional numerical simulation of seismic wave fields. With the continuous improvement of computer performance, the finite difference method has also been applied to three-dimensional numerical simulation of seismic wave fields. However, due to the huge amount of calculation required for three-dimensional numerical simulation itself, the computational efficiency for numerical simulation of larger models is still not considerable. In recent years, GPU parallelization and other methods are generally used to improve computational efficiency. For low-velocity bodies in complex models, the results of numerical simulations often have weak signals. Solving the problems of computational efficiency and signal reception is of great significance for the numerical simulation of seismic wave fields. In this regard, the present application proposes a method for numerical simulation of seismic wave fields based on a three-dimensional complex salt-bearing cavern geological model, comprising:

[0086] Step 201: calling a three-dimensional complex salt cavern geological model; the three-dimensional complex salt cavern geological model is constructed based on the aforementioned three-dimensional complex salt cavern geological modeling method.

[0087] Step 202: Perform finite difference numerical simulation on the three-dimensional complex salt cave geological model to obtain seismic records and wave field snapshots; when performing finite difference numerical simulation, the three-dimensional complex salt cave geological model after grid division is cut in the x direction, y direction, and z direction to divide the complete three-dimensional model into multiple grid domains; each grid domain is executed by a processor for finite difference numerical simulation. The three-dimensional model is still three-dimensional after the final division.

[0088] The following is a more complete and detailed process of numerical simulation of seismic wave fields in viscoelastic media, each step of which is implemented using a program compiled in C language. Figure 6 shown.

[0089] The first step is to read in the three-dimensional complex salt cave geological model.

[0090] The binary files of the five models generated by the above modeling method (complete P-wave velocity model of salt cave geology, complete S-wave velocity model, complete density model, complete P-wave absorption factor model and complete S-wave absorption factor model) are read in using C language code.

[0091] The second step is to generate the earthquake source and determine the earthquake source location.

[0092] When generating the source, the wavelet signal used in this application is the Ricker wavelet to write a source function, and other wavelets can also be used. The Ricker wavelet signal is:

[0093] r(τ)=(1-2τ 2 )exp(-τ 2 )

[0094]

[0095] Among them, r(τ) is the wavelet signal, t is the time, and f c is the center frequency, t d for a time delay.

[0096] The third step is to set up a receiving array to solve the signal reception problem mentioned above.

[0097] In order to obtain better numerical simulation results, a collaborative reception method between the well and the downhole is adopted. A planar detector array is set up on the surface, and detectors are arranged in the well to receive seismic wave transmission and reflection information from the side.

[0098] The fourth step is input parameter verification, which checks whether the source location generated in the second step and the detector location set in the third step match the model read in the sixth step.

[0099] Matching means that the location of the detector cannot exceed the model size.

[0100] Input parameters refer to the input of the aforementioned geological parameters. Verification is because the input parameters cannot violate the physical principles. For example, if the shear wave velocity of the three-dimensional complex salt cave geological model is 0, then the simulation will not be able to proceed, because viscoelastic waves cannot be simulated in pure fluids. If it does not conform to the physical principles, the numerical simulation process will go wrong.

[0101] The fifth step is grid division.

[0102] Grid division specifically includes:

[0103] Sub-step 1: Discretize the read-in three-dimensional complex salt cave geological model into a grid with a grid size of NX×NY×NZ, where NX is the total number of grid points in the x direction, NY is the total number of grid points in the y direction, NZ is the total number of grid points in the z direction, the spatial step in the x direction is DX, the spatial step in the y direction is DY, and the spatial step in the z direction is DZ.

[0104] Sub-step 2: Divide the three-dimensional grid to improve computing efficiency. Specifically, cut the entire three-dimensional grid model in the x-direction, y-direction, and z-direction to make the entire model into nx×ny×nz grid domains, where nx is the number of processors in the x-direction, ny is the number of processors in the y-direction, and nz is the number of processors in the z-direction. The total number of processors occupied is nx×ny×nz. The size of nx, ny, and nz can be adjusted according to the performance of the computing device.

[0105] This step can speed up the calculation efficiency and solve the above-mentioned calculation efficiency problem. The parallel method in this application is MPI parallel, which can be understood as using CPU in MPI parallel and GPU parallel based on GPU (core component in graphics card, a processor designed for parallel computing).

[0106] The sixth step is to verify the algorithm stability, that is, to check the stability of the numerical simulation. If the grid and time step are not set properly, the numerical simulation process will be unstable and the calculation will not be able to continue. The following conditions are required to ensure the stability of the algorithm:

[0107]

[0108] Where dh is the spatial step length; dh is the maximum value of DX, DY, DZ in the fifth step; V s,min is the minimum shear wave velocity; f max is twice the center frequency; n is a parameter related to the finite difference order.

[0109]

[0110] Where DT is the time step; v p-maxis the maximum longitudinal wave velocity; h is a parameter related to the finite difference operator and type.

[0111] Only when DT and dh satisfy the above formula can the numerical simulation process proceed normally, otherwise it will directly cause the algorithm program to crash.

[0112] The seventh step is to set boundary conditions in the three-dimensional complex salt cavern geological model.

[0113] The ground surface is set as a free surface. When updating the stress component on the free surface, only the horizontal particle velocity is used. The sides and bottom of the model grid use absorbing boundaries. The absorbing boundary condition uses PML (Perfectly Matched Layers), that is, perfectly matched layers. Generally, setting the boundary thickness L to 20 grids can have a good absorption effect on seismic waves. If the absorbing boundary is not set, the seismic wave will produce strong reflections at the boundary, affecting the simulation effect. Among them, the specific form of the damping function involved in the absorbing boundary is:

[0114]

[0115] Where c is the damping function, V pml is the longitudinal wave velocity in the medium, α = 10 -4 , L is the thickness of the absorbing boundary layer.

[0116] The attenuation factor involved in the absorbing boundary is:

[0117]

[0118] Among them, dx(x), dy(y), and dz(z) are attenuation factors. The wave propagates to the boundary and needs to be absorbed, otherwise false reflection will be generated at the interface. Therefore, the signal is absorbed by the attenuation factors in three directions; x is the grid point position in the x direction; y is the grid point position in the y direction; z is the grid point position in the z direction; It is the adjustment coefficient used to adjust the strength of boundary absorption.

[0119] Step 8. After completing steps 1 to 7, high-order finite difference numerical simulation is performed.

[0120] Sub-step 1: The numerical simulation of this application is based on the stress-strain equation of viscoelastic media:

[0121] When i=j

[0122] When i≠j

[0123] Among them, r ij is a memory variable, with the following relationship:

[0124] When i≠j

[0125] When i=j

[0126] Momentum conservation equation:

[0127]

[0128] Among them, (i, j, k = x, y, z), σ ij is the ijth stress tensor, x ij is the coordinate in the ij direction, ν k , x k are the velocity and coordinate in the k direction, τ σ is the relaxation coefficient, ν i , x i , f i are the velocity, coordinates and external force in the i direction respectively; ρ is the density; τ p is twice the inverse of the longitudinal wave absorption factor; τ s It is twice the inverse of the shear wave absorption factor; M and μ are parameters used to limit the phase velocity of longitudinal and shear waves at the center frequency of the earthquake source.

[0129] Sub-step 2: Discretize the above equations and use a second-order central difference to approximate the time differential and a fourth-order staggered central difference to approximate the spatial differential. Introduce the fourth-order staggered difference:

[0130]

[0131] Where i is the grid point location, h is the grid spacing, and the difference and The approximate equation f(x) is and The derivative at . Here is a mathematical approximation solution method, which replaces the derivative in sub-step 1 with a difference. f(x) is the equation to be differentiated, and this difference method is used to solve the partial derivative of sub-step 1.

[0132] The partial derivative in the time domain is approximately:

[0133]

[0134] Where i, j, k, n are the discretization of x, y, z, t, and x, y, z, t are spatial position and time.

[0135] The two formulas for partial derivatives in sub-step 2 are mathematically referred to as operators, which is a way to calculate partial derivatives. The partial derivatives in sub-step 1 are calculated by these two operators. Therefore, the operators in sub-step 2 are substituted into the equations in sub-step 1 to obtain the detailed finite difference equations.

[0136] Sub-step 3: Based on the finite difference equation, parallel numerical simulation is performed according to the grid domains divided as described above to obtain simulation data and generate seismic records and wave field snapshots of each grid domain.

[0137] Sub-step 4: Merge the wave field snapshots of each grid domain.

[0138] The present application provides a three-dimensional complex salt cave geological modeling and seismic wave field numerical simulation method. This method cleverly uses slice accumulation technology and combines a variety of high-precision interpolation methods to accurately approximate and depict irregular salt cave shapes. Subsequently, this finely constructed salt cave model is embedded in a complex and realistic geological background model to achieve a more similar simulation of the actual underground geological structure. In the reception of seismic data, an advanced method of joint acquisition on the well and underground is adopted. This method can significantly improve the quality of seismic data and ensure that more accurate and comprehensive underground information is obtained. In addition, some better methods are combined in some steps of the numerical simulation, such as improving computational efficiency through parallelism and using a more complete boundary absorption method. Figure 7 For Figure 3 The seismic records received on the surface after numerical simulation with the three-dimensional longitudinal wave velocity model, Figure 8 For Figure 3 The seismic records received in the well after numerical simulation with the three-dimensional longitudinal wave velocity model, and the joint reception method up and down the well makes the acquired information more complete and convenient for subsequent inversion. Fig. 9 For Figure 3 A snapshot of the wave field when the seismic wave propagates to the salt cavern when the three-dimensional longitudinal wave velocity model is used for numerical simulation. It can be seen that the seismic wave can propagate normally in this model.

[0139] The present application also provides an application scenario, which applies the above-mentioned three-dimensional complex salt cavern geological modeling method and seismic wave field numerical simulation method. Specifically: the three-dimensional complex salt cavern geological modeling method and seismic wave field numerical simulation method provided in this embodiment can be applied in the seismic wave field numerical simulation scenario. The scenario includes a parameter acquisition link, which is used to collect relevant geological parameters; a modeling link, which is used to construct a three-dimensional complex salt cavern geological model and a numerical simulation link, which is used to perform a seismic wave field numerical simulation method based on the three-dimensional complex salt cavern geological model; in this embodiment, the three-dimensional complex salt cavern geological modeling method belongs to the modeling link, and the seismic wave field numerical simulation method belongs to the numerical simulation link.

[0140] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.10 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store relevant data of the three-dimensional complex salt cave geological modeling method process and relevant data of the seismic wave field numerical simulation process. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a three-dimensional complex salt cave geological modeling method or a seismic wave field numerical simulation method based on a three-dimensional complex salt cave geological model is implemented.

[0141] Those skilled in the art will understand that Fig.10 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0142] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0143] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0144] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0145] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0146] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A three-dimensional complex salt cave geological modeling method, characterized in that: The three-dimensional complex salt cave geological modeling method comprises: Obtaining geological parameters of salt cavern geology; the geological parameters include formation P-wave velocity, formation S-wave velocity, formation density, formation P-wave absorption factor, formation S-wave absorption factor of each formation and salt cavern P-wave velocity, salt cavern S-wave velocity, salt cavern density, salt cavern P-wave absorption factor, salt cavern S-wave absorption factor in the salt cavern; A three-dimensional background stratum P-wave velocity model is established according to the stratum P-wave velocity of each stratum; A three-dimensional salt cavern P-wave velocity model is established based on the salt cavern P-wave velocity, slice stacking technology and linear interpolation method. The three-dimensional salt cavern P-wave velocity model is embedded in the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of salt cavern geology; According to the complete P-wave velocity model of salt cavern geology, a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of salt cavern geology are established; A three-dimensional complex salt cavern geological model is derived based on the complete P-wave velocity model, complete S-wave velocity model, complete density model, complete P-wave absorption factor model and complete S-wave absorption factor model of the salt cavern geology.

2. The three-dimensional complex salt cave geological modeling method according to claim 1 is characterized in that: A three-dimensional background stratum P-wave velocity model is established according to the stratum P-wave velocity of each stratum, specifically including: Seismic velocity modeling software is used to establish an uneven two-dimensional layered P-wave velocity model containing faults according to the P-wave velocity of each stratum; The uneven two-dimensional layered P-wave velocity model containing faults is converted into a three-dimensional background stratum P-wave velocity model.

3. The three-dimensional complex salt cave geological modeling method according to claim 1 is characterized in that: A three-dimensional salt cavern P-wave velocity model is established based on the salt cavern P-wave velocity, slice stacking technology and linear interpolation method, including: Select slices of different geometries according to the irregular shape of the salt cavern; According to the irregular shape of the salt cavern, slices of different geometric shapes are superimposed, and the salt cavern longitudinal wave velocity is used as an index to construct a preliminary salt cavern longitudinal wave velocity model. Smoothing the contour edge of the preliminary salt cavern P-wave velocity model to obtain a smoothed salt cavern P-wave velocity model; The smoothed salt cavern P-wave velocity model is interpolated using the trilinear interpolation method to obtain a three-dimensional salt cavern P-wave velocity model of the required size.

4. The three-dimensional complex salt cave geological modeling method according to claim 1 is characterized in that: According to the complete P-wave velocity model of salt cavern geology, a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of salt cavern geology are established, specifically including: Replacing the formation P-wave velocity and the salt cavern P-wave velocity in the complete P-wave velocity model with the formation S-wave velocity and the salt cavern S-wave velocity, respectively, to obtain a complete S-wave velocity model containing salt cavern geology; Replacing the formation P-wave velocity and the salt cavern P-wave velocity in the complete P-wave velocity model with the formation density and the salt cavern density, respectively, to obtain a complete density model of salt cavern geology; The formation P-wave velocity and the salt cavern P-wave velocity in the complete P-wave velocity model are replaced by the formation P-wave absorption factor and the salt cavern P-wave absorption factor, respectively, to obtain a complete P-wave absorption factor model of salt cavern geology; The formation P-wave velocity and the salt cavern P-wave velocity in the complete P-wave velocity model are replaced by the formation S-wave absorption factor and the salt cavern S-wave absorption factor, respectively, to obtain a complete S-wave absorption factor model of salt cavern geology.

5. A method for numerical simulation of seismic wave fields based on a three-dimensional complex salt cave geological model, characterized in that: The seismic wave field numerical simulation method comprises: Calling a three-dimensional complex salt cave geological model; the three-dimensional complex salt cave geological model is constructed based on the three-dimensional complex salt cave geological modeling method according to any one of claims 1 to 4; Finite difference numerical simulation is performed on the three-dimensional complex salt cavern geological model to obtain seismic records and wave field snapshots; when performing finite difference numerical simulation, the three-dimensional complex salt cavern geological model after grid division is cut in the x-direction, y-direction, and z-direction to divide the entire three-dimensional model into multiple grid domains; each grid domain is executed by a processor to perform finite difference numerical simulation.

6. A three-dimensional complex salt cave geological modeling device, characterized in that: The three-dimensional complex salt cave geological modeling device comprises: A parameter acquisition module is used to acquire geological parameters of salt cavern geology; the geological parameters include the formation P-wave velocity, formation S-wave velocity, formation density, formation P-wave absorption factor, formation S-wave absorption factor of each formation and the salt cave P-wave velocity, salt cave S-wave velocity, salt cave density, salt cave P-wave absorption factor, and salt cave S-wave absorption factor in the salt cave; A background stratum P-wave velocity model building module is used to build a three-dimensional background stratum P-wave velocity model according to the stratum P-wave velocity of each stratum; A salt cavern P-wave velocity model building module, which is used to build a three-dimensional salt cavern P-wave velocity model based on the salt cavern P-wave velocity, slice stacking technology and linear interpolation method in the salt cavern; A complete P-wave velocity model building module is used to embed the three-dimensional salt cavern P-wave velocity model into the three-dimensional background stratum P-wave velocity model to obtain a complete P-wave velocity model of salt cavern geology; A parameter modification module is used to establish a complete shear wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology according to the complete P-wave velocity model of the salt cavern geology; The complex salt cavern geological model construction module is used to obtain a three-dimensional complex salt cavern geological model based on a complete P-wave velocity model, a complete S-wave velocity model, a complete density model, a complete P-wave absorption factor model and a complete S-wave absorption factor model of the salt cavern geology.

7. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the three-dimensional complex salt cave geological modeling method described in any one of claims 1 to 4, or the seismic wave field numerical simulation method described in claim 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the three-dimensional complex salt cave geological modeling method described in any one of claims 1 to 4 or the seismic wave field numerical simulation method described in claim 5 is implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the three-dimensional complex salt cave geological modeling method described in any one of claims 1 to 4 or the seismic wave field numerical simulation method described in claim 5 is implemented.

Images