Seismic exploration processing method, device and equipment based on optimized viscous pure P wave

Abstract

The invention discloses a seismic exploration processing method, device and equipment based on optimized viscous pure P waves, and relates to the technical field of seismic exploration. According to the specific implementation scheme, the method comprises the steps of obtaining model parameters of a seismic exploration model, and determining the seismic exploration model according to the model parameters; according to the original pure P wave frequency dispersion relational expression, a three-dimensional VTI medium viscosity optimization pure P wave equation is determined; according to the three-dimensional VTI medium viscosity optimization pure P-wave equation and the seismic exploration model, seismic wave field simulation data are determined; and performing seismic exploration interpretation based on the seismic wave field simulation data to obtain an exploration result. According to the invention, the defect that the accuracy of the obtained exploration result is insufficient when seismic exploration interpretation is carried out on seismic wave field simulation data obtained based on an existing anisotropic pure P-wave equation in the prior art can be solved, and the accuracy of the seismic exploration result is improved.

Description

Technical Field

[0001] The present application relates to the field of seismic exploration technology, and in particular to a seismic exploration processing method, device and equipment based on optimized viscous pure P waves. Background Art

[0002] With the continuous deepening of exploration of fossil energy such as oil and natural gas, the exploration targets have developed from shallow conventional structural oil and gas reservoirs to medium-deep and ultra-deep concealed and fractured oil and gas reservoirs. Therefore, in the face of increasingly complex exploration targets, higher requirements are placed on the development of oil and gas exploration technology. Seismic exploration technology has the advantages of high resolution and deep penetration, so it is widely favored in oil and gas field exploration. Seismic forward modeling technology is the basis of seismic data processing in seismic exploration technology, which can effectively test the correctness of different processing methods and verify the rationality of interpretation results. Using different numerical methods to solve various types of seismic wave equations is one of the key contents of seismic forward modeling. In the numerical simulation of seismic wave fields in anisotropic media, compared with the direct use of the full elastic wave equation, the acoustic wave equation is simpler and easier to implement, and is widely used in model calculations and practical applications.

[0003] At present, the pure P-wave equation based on the decoupled P-SV wave dispersion relation in the anisotropic acoustic wave equation is obtained by separating the original coupled P-SV wave dispersion relation, which can effectively eliminate pseudo-shear wave interference and instability under different parameter conditions. When conducting seismic exploration, seismic simulation is performed through the anisotropic pure P-wave equation and the seismic exploration model to obtain seismic wave field simulation data, and seismic exploration interpretation is performed based on the seismic wave field simulation data to obtain exploration results.

[0004] However, when seismic exploration is interpreted based on the seismic wave field simulation data obtained based on the existing anisotropic pure P-wave equation, the exploration results obtained are not accurate enough. Summary of the invention

[0005] The embodiments of the present application provide a seismic exploration processing method, device and equipment based on optimized viscous pure P waves, thereby solving the problem of insufficient accuracy of exploration results obtained when performing seismic exploration interpretation based on seismic wave field simulation data obtained based on existing anisotropic pure P wave equations in the prior art, and improving the accuracy of seismic exploration results.

[0006] In a first aspect, an embodiment of the present application provides a seismic exploration processing method based on optimizing viscous pure P waves, comprising: The model parameters of the seismic exploration model are obtained, and the seismic exploration model is determined according to the model parameters; the three-dimensional VTI (Vertical Transverse Isotropic Medium) medium viscosity optimization pure P-wave equation is determined according to the original pure P-wave dispersion relation; the seismic wave field simulation data is determined according to the three-dimensional VTI medium viscosity optimization pure P-wave equation and the seismic exploration model; based on the seismic wave field simulation data, the seismic exploration interpretation is performed to obtain the exploration results; wherein, the three-dimensional VTI medium viscosity optimization pure P-wave equation is determined according to the original pure P-wave dispersion relation, including: determining a linear equation according to the original pure P-wave dispersion relation, the linear equation contains multiple polynomial coefficients; constructing an objective function according to the linear equation, solving the objective function, and determining multiple polynomial coefficients; determining an intermediate equation according to the linear equation and the original pure P-wave dispersion relation; and obtaining the three-dimensional VTI medium viscosity optimization pure P-wave equation according to the complex modulus expression and the intermediate equation.

[0007] Furthermore, the linear equation is shown in the following formula (1): (1) In formula (1), , represents the P-wave velocity along the symmetry axis, ε and δ are Thomsen anisotropy parameters, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients.

[0008] The intermediate equation is shown in formula (2): (2) In formula (2), ω Represents the angular frequency.

[0009] Furthermore, the objective function is shown in the following formula (3): (3) In formula (3), Represents the error value at both ends of the objective function, which is the preset value; , represents the P-wave velocity along the symmetry axis, ε and δ are Thomsen anisotropy parameters, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients.

[0010] Furthermore, based on the complex modulus expression and the intermediate equation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained, including: Based on the frequency-dependent complex velocity theory, the complex modulus expression is determined; the complex modulus expression is introduced into the intermediate equation, and the high-order terms related to the quality factor are ignored, and the three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained.

[0011] Furthermore, the viscosity-optimized pure P-wave equation for three-dimensional VTI media is shown in formula (4): (4) In formula (4), ω represents the angular frequency, represents the P-wave velocity along the symmetry axis, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients, Q represents the quality factor, represents the reference angular frequency, Is an imaginary unit.

[0012] Furthermore, based on the three-dimensional VTI medium viscosity optimization pure P-wave equation and seismic exploration model, the seismic wave field simulation data is determined, including: The pure P-wave equation is optimized according to the viscosity of three-dimensional VTI medium to determine the equation to be solved. Based on the equation to be solved and the seismic exploration model, the seismic wave field simulation data is obtained based on the high-order regular grid finite difference method and pseudo-spectral method.

[0013] Furthermore, the equation to be solved is shown in formula (5): (5) In formula (5), P represents the pressure wave field, is the time second-order partial derivative, is the first-order partial derivative in time, , and They represent the spatial partial derivatives in the xyz direction in three-dimensional space, represents the Fourier transform, represents the inverse Fourier transform, represents the wave number vector, represents the P-wave velocity along the symmetry axis, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients, Q represents the quality factor, Indicates the reference angular frequency.

[0014] In a second aspect, an embodiment of the present application provides a seismic exploration processing device based on optimized viscous pure P waves, comprising: The determination module is used to obtain the model parameters of the seismic exploration model, determine the seismic exploration model according to the model parameters; and determine the three-dimensional VTI medium viscosity optimized pure P wave equation according to the original pure P wave dispersion relationship.

[0015] The solution module is used to optimize the pure P-wave equation and seismic exploration model according to the viscosity of the three-dimensional VTI medium and determine the seismic wave field simulation data.

[0016] The processing module is used to interpret seismic exploration based on seismic wave field simulation data to obtain exploration results.

[0017] Among them, according to the original pure P-wave dispersion relation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is determined, including: according to the original pure P-wave dispersion relation, a linear equation is determined, the linear equation contains multiple polynomial coefficients; according to the linear equation, an objective function is constructed, the objective function is solved, and multiple polynomial coefficients are determined; according to the linear equation and the original pure P-wave dispersion relation, an intermediate equation is determined; according to the complex modulus expression and the intermediate equation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained.

[0018] In a third aspect, an embodiment of the present application provides a device, comprising: a processor; a memory for storing processor executable instructions; and a method for implementing the first aspect or any possible implementation of the first aspect when the processor executes the executable instructions.

[0019] In a fourth aspect, an embodiment of the present application provides a non-volatile computer-readable storage medium, which includes a device for storing a computer program or instruction. When the computer program or instruction is executed, the method of the first aspect or any possible implementation method of the first aspect is implemented.

[0020] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: The embodiment of the present application is based on the optimization concept and polynomial expansion strategy, combined with the original decoupled pure P-wave dispersion relationship, and introduces complex velocity, to obtain a three-dimensional VTI medium viscosity optimized pure P-wave equation that takes into account the medium absorption attenuation and anisotropy characteristics. By jointly applying the finite difference method and the pseudo-spectral method, combined with the seismic exploration model, a high-precision approximate numerical solution of the three-dimensional VTI medium viscosity optimized pure P-wave equation is achieved, seismic wave field simulation data is obtained, and seismic exploration interpretation is performed based on the seismic wave field simulation data to obtain exploration results. The accuracy of the seismic wave field simulation data obtained based on the pure P-wave equation is improved by fully considering the viscosity of the equation and solving the equation with high precision approximate numerical solution, thereby improving the accuracy of the seismic exploration results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic flow chart of a seismic exploration processing method based on optimized viscous pure P waves provided in an embodiment of the present application; FIG2(a) is an accurate calculation result obtained by determining the phase velocity value of the first VTI acoustic medium by an accurate calculation method, FIG2(b) is an absolute error between the calculation result obtained by determining the phase velocity value of the first VTI acoustic medium by a traditional Taylor expansion method and the accurate calculation result, and FIG2(c) is an absolute error between the calculation result obtained by determining the phase velocity value of the first VTI acoustic medium by the three-dimensional VTI medium viscosity optimized pure P-wave equation of the present application and the accurate calculation result; FIG3 (a) is an accurate calculation result obtained by determining the phase velocity value of the second VTI acoustic medium by an accurate calculation method, FIG3 (b) is an absolute error between the calculation result obtained by determining the phase velocity value of the second VTI acoustic medium by a traditional Taylor expansion method and the accurate calculation result, and FIG3 (c) is an absolute error between the calculation result obtained by determining the phase velocity value of the second VTI acoustic medium by the three-dimensional VTI medium viscosity optimized pure P-wave equation of the present application and the accurate calculation result; FIG4 (a) is a wave field slice of the XZ plane of the three-dimensional VTI uniform acoustic medium model determined by different pure P-wave equations, FIG4 (b) is a wave field slice of the XY plane of the three-dimensional VTI uniform acoustic medium model determined by different pure P-wave equations, and FIG4 (c) is a wave field slice of the YZ plane of the three-dimensional VTI uniform acoustic medium model determined by different pure P-wave equations; Figure 5 A single waveform curve extracted at a fixed point by different pure P-wave equations for a three-dimensional VTI uniform acoustic medium model provided in an embodiment of the present application; Figure 6 (a) shows the velocity parameter model of the three-dimensional Marmousi VTI attenuation medium model, and Figure 6 (b) shows the Thomsen anisotropy parameters of the three-dimensional Marmousi VTI attenuation medium model. ε Model, Figure 6 (c) shows the Thomsen anisotropy parameters of the three-dimensional Marmousi VTI attenuation medium model δ Model, Figure 6 (d) is the three-dimensional Marmousi VTI attenuation medium model Q Value model; FIG7 (a) is a wave field slice of the XZ plane of the three-dimensional VTI complex acoustic medium model determined by different pure P-wave equations, FIG7 (b) is a wave field slice of the XY plane of the three-dimensional VTI complex acoustic medium model determined by different pure P-wave equations, and FIG7 (c) is a wave field slice of the YZ plane of the three-dimensional VTI complex acoustic medium model determined by different pure P-wave equations; Figure 8 A single waveform curve extracted along a fixed X position in the XZ plane slice for a three-dimensional VTI complex acoustic medium model provided in an embodiment of the present application through different pure P-wave equations; Fig. 9 A schematic diagram of the composition of a seismic exploration processing device based on optimized viscous pure P waves provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are 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.

[0024] The following describes some of the techniques involved in the embodiments of the present application to facilitate understanding, and they should be considered as merely exemplary. Therefore, it should be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted in the following description.

[0025] Fossil energy such as oil and natural gas plays an important role in the country's economic construction and development. With the continuous deepening of oil and gas exploration, the exploration targets have developed from shallow conventional structural oil and gas reservoirs to medium-deep and ultra-deep concealed and fractured oil and gas reservoirs. Therefore, in the face of increasingly complex exploration targets, higher requirements are placed on the development of oil and gas exploration technology. Seismic exploration technology has the advantages of high resolution and deep penetration, so it is widely favored in oil and gas field exploration. However, traditional seismic exploration processing technology is mainly based on the assumption of elastic isotropy, so there is a problem of low accuracy in areas with complex exploration conditions. With the continuous improvement of basic theory and computer hardware, seismic processing technology that considers the anisotropy and viscosity characteristics of the medium has made great progress.

[0026] Seismic forward modeling technology is the basis of seismic data processing, which can effectively test the correctness of different processing methods and verify the rationality of interpretation results. Using different numerical methods to solve various types of seismic wave equations is one of the key contents of seismic forward modeling. In the numerical simulation of seismic wave fields in anisotropic media, compared with the direct use of the full elastic wave equation, the acoustic wave equation is simpler and easier to implement, and is widely used in model calculations and practical applications. However, the existing anisotropic acoustic wave equation is mainly derived from the pseudo-acoustic wave approximation theory, that is, it is directly simplified by setting the shear wave velocity in the original coupled P-SV wave dispersion relationship to 0. Therefore, when the medium parameters do not meet the pseudo-acoustic approximation theory, the existing anisotropic pseudo-acoustic wave equation is prone to cause inevitable pseudo-shear wave numerical interference and instability. In this context, the development of a pure P-wave equation based on the decoupled P-SV wave dispersion relationship has become the first choice. The pure P-wave equation is obtained by separating the original coupled P-SV wave dispersion relationship, which can effectively eliminate pseudo-shear wave interference and instability under different parameter conditions. To date, research on the pure P-wave equation still focuses on the balance between solution accuracy and efficiency, as well as the development and application of the pure P-wave equation.

[0027] In the numerical simulation of seismic wave fields, in addition to considering the anisotropic characteristics of the medium, viscosity is another factor that needs to be considered. In terms of describing the absorption and attenuation of the medium, the standard linear body theory, constant Q theory and complex velocity field theory are the three most commonly used theories. The standard linear body theory uses a series of linear body models to approximate the absorption attenuation and velocity dispersion of seismic waves within the seismic frequency band. The viscous wave equation constructed based on this theory is easy to implement, but its flexibility and approximate accuracy need to be improved. The fractional-order model based on the constant Q theory can effectively describe the absorption and attenuation effect of seismic waves within a certain frequency band, so it has received a lot of attention. However, although the constant Q viscous wave equation has high calculation accuracy, it is difficult to calculate because it involves fractional-order partial derivatives. Compared with the previous two theories, the viscous wave equation constructed based on complex velocity is clearer.

[0028] When conducting seismic exploration, seismic simulation is performed using the anisotropic pure P-wave equation and the seismic exploration model to obtain seismic wave field simulation data, and seismic exploration interpretation is performed based on the seismic wave field simulation data to obtain exploration results.

[0029] However, when seismic exploration is interpreted based on the seismic wave field simulation data obtained based on the existing anisotropic pure P-wave equation, the exploration results obtained are not accurate enough.

[0030] Against this background, the present disclosure provides a seismic exploration processing method based on optimizing viscous pure P waves, which can improve the accuracy of seismic exploration results.

[0031] The seismic exploration processing method based on optimized viscous pure P wave is exemplarily described below with reference to the accompanying drawings.

[0032] Figure 1 : is a flow chart of a seismic exploration processing method based on optimized viscous pure P waves provided in an embodiment of the present application. Figure 1 This is only an execution order shown in the embodiment of the present application, and does not represent the only execution order of the seismic exploration processing method based on optimized viscous pure P waves. In the case where the final result can be achieved, Figure 1 The steps shown can be performed in parallel or in reverse. Figure 1 As shown, the method may include: S101, obtaining model parameters of a seismic exploration model, and determining the seismic exploration model according to the model parameters.

[0033] For example, the model parameters of the seismic exploration model can be determined based on the actual geological exploration data of the area where oil and gas exploration is to be carried out. The parameter values ​​corresponding to the model parameters of the seismic exploration model are obtained by analyzing and calculating the actual geological exploration data. The seismic exploration model is set according to the model parameters to obtain an applicable seismic exploration model.

[0034] It should be noted that obtaining the model parameters of the seismic exploration model and determining the seismic exploration model according to the model parameters are conventional technical means for those skilled in the art and will not be elaborated herein.

[0035] S102. Determine the three-dimensional VTI medium viscosity optimized pure P-wave equation according to the original pure P-wave dispersion relation.

[0036] Among them, according to the original pure P-wave dispersion relation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is determined, including: according to the original pure P-wave dispersion relation, a linear equation is determined, the linear equation contains multiple polynomial coefficients; according to the linear equation, an objective function is constructed, the objective function is solved, and multiple polynomial coefficients are determined; according to the linear equation and the original pure P-wave dispersion relation, an intermediate equation is determined; according to the complex modulus expression and the intermediate equation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained.

[0037] In the numerical simulation of seismic wave fields in anisotropic media, migration imaging and waveform inversion, a large number of theoretical experiments and practical tests have shown that the traditional pseudo-acoustic wave equation constructed based on acoustic assumptions is prone to cause pseudo-shear wave numerical interference and propagation instability. In order to solve this problem, scholars have developed various types of high-precision pure mode wave equations based on Christoffel of anisotropic media. Taking the commonly used three-dimensional VTI acoustic medium as an example, the accurate pure P-wave dispersion relationship can be expressed as shown in formula (6): (6) In formula (6), ω represents the angular frequency, , represents the P-wave velocity along the symmetry axis, ε and δ are Thomsen anisotropy parameters, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients.

[0038] In VTI acoustic media, the precise pure P-wave dispersion relation, namely, formula (6), contains a square root term, which is difficult to be directly calculated by conventional numerical solution methods. In order to facilitate subsequent calculations and applications, scholars have adopted different strategies to expand it. Taking the most commonly used Taylor series expansion method as an example, a first-order Taylor expansion formula (in the form of ) By approximately expanding the square root term in formula (6), we can obtain the simplified pure P-wave dispersion relation as shown in formula (7): (7) So far, the above formula has been widely used in anisotropic medium wave field simulation and imaging inversion. However, Taylor expansion is essentially a low-frequency approximation, which can only guarantee a high approximation accuracy in low-frequency or low-wave number regions. As the frequency or wave number increases, the approximation accuracy gradually decreases.

[0039] In order to further improve the simulation accuracy of the anisotropic wave field, this embodiment combines the optimization strategy with the polynomial expansion to process the original dispersion relation.

[0040] First, based on the idea of ​​polynomial expansion, part of formula (6) can be approximated as a linear equation, as shown in formula (1): (1) Formula (1) is a linear equation system that can minimize the errors at both ends to obtain the optimized polynomial coefficients , , , and .

[0041] Based on this, the objective function is constructed as shown in formula (3): (3) In formula (3), Represents the error value at both ends of the objective function, which can be set in advance.

[0042] By solving the above minimization problem through an optimization algorithm, that is, solving formula (3), the value of the optimized polynomial coefficient can be obtained.

[0043] According to formula (6), formula (1) and the polynomial coefficients obtained by solving formula (3), the intermediate formula shown in formula (2) can be obtained: (2) For three-dimensional VTI acoustic media, this embodiment constructs an improved pure P-wave equation, ie, an intermediate formula, by combining the optimization strategy with polynomial expansion in the above content.

[0044] In describing the absorption and attenuation effect of the medium on seismic wave propagation, the commonly used basic theories mainly include standard linear body theory, constant Q Theory and complex velocity theory. Compared with standard linear bodies, QThe theory describes the absorption attenuation effect more accurately, but the computational complexity and amount involved are greater; the complex velocity theory can significantly simplify the computational complexity and improve the computational efficiency while taking into account the accuracy. Therefore, on this basis, the three-dimensional VTI acoustic medium viscous pure P-wave equation based on complex velocity is further constructed.

[0045] Specifically, according to the complex modulus expression and the intermediate equation, a three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained, including: determining the complex modulus expression based on the frequency-dependent complex velocity theory; introducing the complex modulus expression into the intermediate equation, ignoring the high-order terms related to the quality factor, and obtaining the three-dimensional VTI medium viscosity optimized pure P-wave equation.

[0046] In order to simulate the propagation characteristics of seismic waves in attenuating media, based on the frequency-dependent complex velocity theory, the complex modulus expression can be shown as formula (8): (8) In formula (8), x represents the spatial coordinate; represents the reference angular frequency; is an imaginary unit; represents the quality factor parameter describing the attenuation properties of the medium, Q The smaller the value, the more serious the absorption attenuation of the medium. Q The larger the value, the smaller the absorption attenuation effect of the medium.

[0047] The significant advantage of formula (8) is that phase dispersion and amplitude attenuation are expressed independently of each other. Related to phase dispersion, It can reflect the amplitude attenuation.

[0048] Introduce formula (8) (i.e., the complex modulus expression) into formula (2) (i.e., the intermediate formula), ignoring the quality factor Q The relevant high-order terms can be simplified to obtain the formula shown in formula (9): (9) Formula (9) can be further decomposed into formula (4) as shown below, which is the pure P-wave equation for viscosity optimization of three-dimensional VTI media.

[0049] (4) In formula (4), ω represents the angular frequency, represents the P-wave velocity along the symmetry axis, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients, Q represents the quality factor, represents the reference angular frequency, Is an imaginary unit.

[0050] It can be understood that formula (9) and formula (4) are two different expressions of the viscosity-optimized pure P-wave equation for three-dimensional VTI media.

[0051] It can be seen from formula (4) that the phase dispersion and amplitude attenuation properties reflected by the three-dimensional VTI medium viscosity optimized pure P-wave equation constructed in this embodiment are decoupled from each other. The first term on the right side of the equal sign in formula (4) corresponds to the original pure P-wave equation, the second term on the right side of the equal sign corresponds to the phase dispersion property, and the third term on the right side of the equal sign corresponds to the amplitude attenuation property.

[0052] S103. Determine seismic wave field simulation data based on the three-dimensional VTI medium viscosity optimization pure P-wave equation and the seismic exploration model.

[0053] Specifically, according to the three-dimensional VTI medium viscosity optimization pure P wave equation and seismic exploration model, the seismic wave field simulation data is determined, including: The pure P-wave equation is optimized according to the viscosity of three-dimensional VTI medium to determine the equation to be solved. Based on the equation to be solved and the seismic exploration model, the seismic wave field simulation data is obtained based on the high-order regular grid finite difference method and pseudo-spectral method.

[0054] Formula (4) is the three-dimensional VTI medium viscosity optimization pure P-wave equation provided in this embodiment. The numerical solution result can be obtained by numerically solving the equation. The numerical solution result can be processed by the seismic exploration model to obtain the seismic wave field simulation data.

[0055] For the left side of the equation (4), The term, when converted to the time domain, is the second-order time partial derivative, and the central difference method with second-order accuracy can be used to achieve an approximate solution. For the wave number term on the right side of the equation, the high-order regular grid finite difference method and pseudo-spectral method can be combined to solve it.

[0056] According to the above solution method, formula (4) can be transformed into the equation to be solved as shown in formula (5): (5) In formula (5), P represents the pressure wave field, is the time second-order partial derivative, is the first-order partial derivative in time, , and They represent the spatial partial derivatives in the xyz direction in three-dimensional space, represents the Fourier transform, represents the inverse Fourier transform, represents the wave number vector, represents the P-wave velocity along the symmetry axis, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients, Q represents the quality factor, Indicates the reference angular frequency.

[0057] Among them, in formula (5) , , , , , , , , , , and All of them can be solved by pseudo-spectral method.

[0058] Below The solution is shown in formula (10): (10) In formula (10), Item and The terms can all be efficiently solved using the pseudospectral method. Similarly, the other wavenumber mixing terms in formula (5) can all be calculated using a process similar to that shown in formula (10), which will not be repeated here.

[0059] S104. Based on the seismic wave field simulation data, perform seismic exploration interpretation to obtain exploration results.

[0060] After obtaining the seismic wave field simulation data, visualization can be performed: the seismic wave field simulation data can be visualized to more intuitively observe the propagation process and characteristics of seismic waves. Visualization methods can include drawing seismic wave propagation snapshots, wave field animations, seismic record profiles, etc. For example, by drawing wave field snapshots at different times, the propagation path and wavefront morphology of seismic waves in anisotropic media can be observed; making wave field animations can dynamically display the propagation process of seismic waves and help study and understand the propagation mechanism of seismic waves.

[0061] By analyzing the visualized seismic wave field simulation data, the propagation characteristics of seismic waves, such as wave velocity, amplitude, phase, frequency, etc., can be extracted. By analyzing these characteristics, we can understand the impact of anisotropic media on seismic waves, such as wave velocity anisotropy, amplitude attenuation, phase change, etc. in anisotropic media. At the same time, by analyzing the propagation characteristics of seismic waves, we can infer the structure and properties of underground media, providing a basis for seismic exploration and geological interpretation.

[0062] Seismic wave field simulation data is applied to seismic exploration interpretation to help identify underground geological structures and oil and gas reservoirs and other targets to obtain exploration results. For example, by comparing seismic wave field simulation data with actual seismic exploration data, the anisotropic characteristics of underground media, stratigraphic structure, and distribution of oil and gas reservoirs can be inferred. At the same time, seismic wave field simulation data can also be used to guide the collection and processing of seismic exploration data, thereby improving the efficiency and accuracy of seismic exploration.

[0063] For those skilled in the art, obtaining exploration results by interpreting seismic exploration based on seismic wave field simulation data is a conventional technical means, and the specific implementation method of obtaining exploration results by interpreting seismic exploration based on seismic wave field simulation data will not be described in detail here.

[0064] The embodiment of the present application is based on the optimization concept and polynomial expansion strategy, combined with the original decoupled pure P-wave dispersion relationship, and introduces complex velocity, to obtain a three-dimensional VTI medium viscosity optimized pure P-wave equation that takes into account the medium absorption attenuation and anisotropy characteristics. By jointly applying the finite difference method and the pseudo-spectral method, combined with the seismic exploration model, a high-precision approximate numerical solution of the three-dimensional VTI medium viscosity optimized pure P-wave equation is achieved, seismic wave field simulation data is obtained, and seismic exploration interpretation is performed based on the seismic wave field simulation data to obtain exploration results. The accuracy of the seismic wave field simulation data obtained based on the pure P-wave equation is improved by fully considering the viscosity of the equation and solving the equation with high precision approximate numerical solution, thereby improving the accuracy of the seismic exploration results.

[0065] The advantages of this application are illustrated below with a practical example.

[0066] For the three-dimensional VTI acoustic medium model, the traditional Taylor expansion relationship, i.e., formula (2), and the three-dimensional VTI medium viscosity optimized pure P-wave equation of this embodiment, i.e., formula (4), are applied to calculate the phase velocity values ​​respectively, and the calculation results are compared with the precise calculation results obtained by the precise calculation method to illustrate the accuracy advantage of the method of the present application.

[0067] Model parameter setting: The first VTI acoustic medium is a weakly anisotropic medium, and the model parameters are , , ; The second VTI acoustic medium is a strongly anisotropic medium, and the model parameters are , , .

[0068] Figure 2 (a) is the precise calculation result obtained by determining the phase velocity value of the first VTI acoustic medium through the precise calculation method, Figure 2 (b) is the absolute error between the calculation result obtained by determining the phase velocity value of the first VTI acoustic medium through the traditional Taylor expansion method and the precise calculation result, and Figure 2 (c) is the absolute error between the calculation result obtained by determining the phase velocity value of the first VTI acoustic medium through the three-dimensional VTI medium viscosity optimized pure P-wave equation of the present application and the precise calculation result.

[0069] Figure 3 (a) is the precise calculation result obtained by determining the phase velocity value of the second VTI acoustic medium through the precise calculation method, Figure 3 (b) is the absolute error between the calculation result obtained by determining the phase velocity value of the second VTI acoustic medium through the traditional Taylor expansion method and the precise calculation result, and Figure 3 (c) is the absolute error between the calculation result obtained by determining the phase velocity value of the second VTI acoustic medium through the three-dimensional VTI medium viscosity optimized pure P-wave equation of the present application and the precise calculation result.

[0070] Referring to Figures 2(a), 2(b), 2(c) and 3(a), 3(b), 3(c), it can be seen that compared with the exact solution, the calculation results of the traditional Taylor expansion method have large errors, especially in the medium with strong anisotropy. In contrast, the three-dimensional VTI medium viscosity optimized pure P-wave equation constructed by the optimized polynomial expansion strategy in this application can evenly divide the numerical error along different phase angles and azimuth angles, and achieve higher approximate accuracy in the entire calculation area.

[0071] The advantages of the present application are further illustrated with another practical example.

[0072] For the three-dimensional VTI uniform acoustic medium model, the calculation results are obtained and compared through the original pure P-wave equation, the viscous pure P-wave equation considering only phase distortion, the viscous pure P-wave equation considering only amplitude attenuation, and the viscous pure P-wave equation considering both phase distortion and amplitude attenuation (that is, the three-dimensional VTI medium viscous optimized pure P-wave equation of the present application).

[0073] The three-dimensional VTI uniform acoustic medium model is set as follows: The size of the three-dimensional model is 2000m×2000m×2000m, and the spacing between the cube discrete grid units is 10m. The source is a Ricker wavelet, which is placed in the center of the model to generate vibration. The parameters of the VTI acoustic medium model are: , , , .

[0074] Figure 4 (a) is a wave field slice of the XZ plane of the three-dimensional VTI uniform acoustic medium model determined by different pure P-wave equations, Figure 4 (b) is a wave field slice of the XY plane of the three-dimensional VTI uniform acoustic medium model determined by different pure P-wave equations, and Figure 4 (c) is a wave field slice of the YZ plane of the three-dimensional VTI uniform acoustic medium model determined by different pure P-wave equations; wherein, in Figures 4 (a), 4 (b) and 4 (c), the upper left area is a wave field snapshot corresponding to the original pure P-wave equation, the upper right area is a wave field snapshot corresponding to the viscous pure P-wave equation that only considers phase distortion, the lower left area is a wave field snapshot corresponding to the viscous pure P-wave equation that only considers amplitude attenuation, and the upper right area is a wave field snapshot corresponding to the viscous pure P-wave equation that simultaneously considers phase distortion and amplitude attenuation.

[0075] Figure 5 Single-channel waveform curves extracted at fixed points by different pure P-wave equations for the three-dimensional VTI uniform acoustic medium model provided in the embodiment of the present application. Among them, the red solid line is the single-channel waveform curve corresponding to the original pure P-wave equation, the green dotted line is the single-channel waveform curve corresponding to the viscous pure P-wave equation that only considers phase distortion, the blue solid line is the single-channel waveform curve corresponding to the viscous pure P-wave equation that only considers amplitude attenuation, and the purple dotted line is the single-channel waveform curve corresponding to the viscous pure P-wave equation that considers both phase distortion and amplitude attenuation.

[0076] Refer to Figures 4(a), 4(b), 4(c) and Figure 5 It can be seen that in the three-dimensional VTI uniform model (i.e., the three-dimensional VTI uniform acoustic medium model), compared with the original pure P-wave equation, the viscous pure P-wave equation that only considers phase distortion can only lead to time shift in phase, and the viscous pure P-wave equation that only considers amplitude distortion can only cause amplitude attenuation. The viscous pure P-wave equation that considers both phase distortion and amplitude attenuation can simultaneously reflect the amplitude attenuation and phase distortion of seismic waves, and effectively characterize the absorption attenuation effect.

[0077] The advantages of the present application are further illustrated with another practical example.

[0078] For the three-dimensional VTI complex acoustic medium model, the calculation results are obtained and compared using the original pure P-wave equation and the viscous pure P-wave equation that simultaneously considers phase distortion and amplitude attenuation (i.e., the three-dimensional VTI medium viscous optimized pure P-wave equation of the present application).

[0079] The three-dimensional VTI uniform acoustic medium model is modified to obtain the three-dimensional VTI complex acoustic medium model (i.e., the three-dimensional Marmousi VTI attenuation medium model) as shown in Figures 6 (a) to 6 (d). Figure 6 (a) is the velocity parameter model of the three-dimensional Marmousi VTI attenuation medium model, and Figure 6 (b) is the Thomsen anisotropy parameter of the three-dimensional Marmousi VTI attenuation medium model. ε Model, Figure 6 (c) shows the Thomsen anisotropy parameters of the three-dimensional Marmousi VTI attenuation medium model δ Model, Figure 6 (d) is the three-dimensional Marmousi VTI attenuation medium model Q The three-dimensional VTI complex acoustic medium model has a size of 2700m×2700m×2700m and a grid spacing of 15m. The source is a Ricker wavelet with a main frequency of 20Hz, which is placed in the shallow layer of the model to generate vibration.

[0080] Figure 7 (a) is a wave field slice of the XZ plane of the three-dimensional VTI complex acoustic medium model determined by different pure P-wave equations, Figure 7 (b) is a wave field slice of the XY plane of the three-dimensional VTI complex acoustic medium model determined by different pure P-wave equations, and Figure 7 (c) is a wave field slice of the YZ plane of the three-dimensional VTI complex acoustic medium model determined by different pure P-wave equations; among them, in Figure 7 (a), Figure 7 (b) and Figure 7 (c), the left half area is the wave field snapshot corresponding to the original pure P-wave equation, and the right half area is the wave field snapshot corresponding to the viscous pure P-wave equation that simultaneously considers phase distortion and amplitude attenuation.

[0081] Figure 8 The single-channel waveform curve extracted from the three-dimensional VTI complex acoustic medium model by different pure P-wave equations in the XZ plane slice along the fixed X position provided in the embodiment of the present application. Among them, the red solid line is the single-channel waveform curve corresponding to the original pure P-wave equation, and the blue dotted line is the single-channel waveform curve corresponding to the viscous pure P-wave equation that simultaneously considers phase distortion and amplitude attenuation.

[0082] Refer to Figures 7(a), 7(b), 7(c) and Figure 8 It can be seen that in the complex model (i.e., the three-dimensional VTI complex acoustic medium model), compared with the original pure P-wave simulation results, the viscous pure P-wave equation that simultaneously considers phase distortion and amplitude attenuation can effectively reflect the influence of the attenuating anisotropic medium on the travel time and amplitude of seismic waves, and better describe the characteristics of the kinematics and dynamics of seismic waves in the absorbing attenuating anisotropic medium.

[0083] In summary, through the three-dimensional VTI medium viscosity optimized pure P-wave equation and the corresponding solution method of the present application, an effective numerical solution result of the seismic wave field can be obtained.

[0084] Although the present application provides method operation steps such as embodiments or flow charts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in this embodiment is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in the order of the method shown in this embodiment or the accompanying drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0085] like Fig. 9 As shown, the embodiment of the present application also provides a seismic exploration processing device based on optimized viscous pure P wave. The device includes: a determination module 901, a solution module 902 and a processing module 903.

[0086] The determination module 901 is used to obtain the model parameters of the seismic exploration model, determine the seismic exploration model according to the model parameters, and determine the three-dimensional VTI medium viscosity optimized pure P wave equation according to the original pure P wave dispersion relationship.

[0087] The solution module 902 is used to determine the seismic wave field simulation data according to the three-dimensional VTI medium viscosity optimization pure P wave equation and the seismic exploration model.

[0088] The processing module 903 is used to perform seismic exploration interpretation based on the seismic wave field simulation data to obtain exploration results.

[0089] Among them, according to the original pure P-wave dispersion relation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is determined, including: according to the original pure P-wave dispersion relation, a linear equation is determined, the linear equation contains multiple polynomial coefficients; according to the linear equation, an objective function is constructed, the objective function is solved, and multiple polynomial coefficients are determined; according to the linear equation and the original pure P-wave dispersion relation, an intermediate equation is determined; according to the complex modulus expression and the intermediate equation, the three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained.

[0090] The beneficial effects and specific implementation methods of the device embodiment can be referred to the aforementioned method embodiment, and will not be described in detail here.

[0091] Some modules in the apparatus described in the present application can be described in the general context of computer executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0092] The devices or modules described in the above application embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described in various modules according to their functions. When implementing the embodiments of the present application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, the module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0093] The methods, devices or modules described in this application can be implemented in the form of computer-readable program codes. The controller can be implemented in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program codes (such as software or firmware) that can be executed by the (micro)processor, logic gates, switches, application-specific integrated circuits (English: Application Specific Integrated Circuit; Abbreviation: ASIC), programmable logic controllers and embedded microcontrollers. Examples of controllers include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in the form of pure computer-readable program codes, the controller can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included in it for implementing various functions can also be regarded as structures within the hardware component. Or even, the means for realizing various functions may be regarded as both a software module for realizing the method and a structure within a hardware component.

[0094] An embodiment of the present application further provides a device, comprising: a processor; a memory for storing processor executable instructions; when the processor executes the executable instructions, the method described in the embodiment of the present application is implemented.

[0095] The embodiments of the present application also provide a non-volatile computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed, the method described in the embodiments of the present application is implemented.

[0096] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist independently, or two or more modules may be integrated into one module.

[0097] The above storage media include but are not limited to random access memory (RAM), read-only memory (ROM), cache, hard disk drive (HDD) or memory card. The memory can be used to store computer program instructions.

[0098] It can be seen from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the technical solution of the present application can be essentially or partly reflected in the prior art in the form of a software product, or it can be reflected in the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0099] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0100] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A seismic exploration processing method based on optimized viscous pure P waves, characterized in that: include: Acquiring model parameters of a seismic exploration model, and determining the seismic exploration model according to the model parameters; According to the original pure P-wave dispersion relation, the viscosity optimized pure P-wave equation of three-dimensional VTI medium is determined; Determining seismic wave field simulation data according to the three-dimensional VTI medium viscosity optimized pure P wave equation and the seismic exploration model; Based on the seismic wave field simulation data, seismic exploration interpretation is performed to obtain exploration results; Among them, determining the three-dimensional VTI medium viscosity optimization pure P-wave equation based on the original pure P-wave dispersion relationship includes: determining a linear equation based on the original pure P-wave dispersion relationship, the linear equation containing multiple polynomial coefficients; constructing an objective function based on the linear equation, solving the objective function, and determining the multiple polynomial coefficients; determining an intermediate equation based on the linear equation and the original pure P-wave dispersion relationship; and obtaining the three-dimensional VTI medium viscosity optimization pure P-wave equation based on the complex modulus expression and the intermediate equation.

2. The method according to claim 1, characterized in that The linear equation is shown in the following formula (1): （1） In formula (1), , represents the P-wave velocity along the symmetry axis, ε and δ are Thomsen anisotropy parameters, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients; The intermediate equation is shown in the following formula (2): （2） In formula (2), ω Represents the angular frequency.

3. The method according to claim 1, characterized in that The objective function is shown in the following formula (3): （3） In formula (3), represents the error value at both ends of the objective function, which is a preset value; , represents the P-wave velocity along the symmetry axis, ε and δ are Thomsen anisotropy parameters, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients.

4. The method according to claim 1, characterized in that: The three-dimensional VTI medium viscosity optimized pure P-wave equation is obtained according to the complex modulus expression and the intermediate equation, including: Based on the frequency-dependent complex velocity theory, the complex modulus expression is determined; The complex modulus expression is introduced into the intermediate equation, and the high-order terms related to the quality factor are ignored, so as to obtain the three-dimensional VTI medium viscosity optimized pure P-wave equation.

5. The method according to claim 1, characterized in that The three-dimensional VTI medium viscosity optimized pure P-wave equation is shown in formula (4): （4） In formula (4), ω represents the angular frequency, represents the P-wave velocity along the symmetry axis, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients, Q represents the quality factor, represents the reference angular frequency, Is an imaginary unit.

6. The method according to claim 5, characterized in that Determining seismic wave field simulation data according to the three-dimensional VTI medium viscosity optimized pure P wave equation and the seismic exploration model includes: Determining an equation to be solved according to the three-dimensional VTI medium viscosity optimized pure P-wave equation; According to the equation to be solved and the seismic exploration model, based on a high-order regular grid finite difference method and a pseudo-spectral method, the seismic wave field simulation data is obtained.

7. The method according to claim 6, characterized in that The equation to be solved is shown in formula (5): （5） In formula (5), P represents the pressure wave field, is the time second-order partial derivative, is the first-order partial derivative in time, , and They represent the spatial partial derivatives in the xyz direction in three-dimensional space, represents the Fourier transform, represents the inverse Fourier transform, represents the wave number vector, represents the P-wave velocity along the symmetry axis, , and They represent the spatial wave numbers in the xyz directions in three-dimensional space, , , , and are the polynomial coefficients, Q represents the quality factor, Indicates the reference angular frequency.

8. A seismic exploration processing device based on optimized viscous pure P waves, characterized in that: include: A determination module, used to obtain model parameters of a seismic exploration model, and determine the seismic exploration model according to the model parameters; According to the original pure P-wave dispersion relation, the viscosity optimized pure P-wave equation of three-dimensional VTI medium is determined; A solution module, used for determining seismic wave field simulation data according to the three-dimensional VTI medium viscosity optimization pure P wave equation and the seismic exploration model; A processing module, used for performing seismic exploration interpretation based on the seismic wave field simulation data to obtain exploration results; Among them, determining the three-dimensional VTI medium viscosity optimization pure P-wave equation based on the original pure P-wave dispersion relationship includes: determining a linear equation based on the original pure P-wave dispersion relationship, the linear equation containing multiple polynomial coefficients; constructing an objective function based on the linear equation, solving the objective function, and determining the multiple polynomial coefficients; determining an intermediate equation based on the linear equation and the original pure P-wave dispersion relationship; and obtaining the three-dimensional VTI medium viscosity optimization pure P-wave equation based on the complex modulus expression and the intermediate equation.

9. A device for performing a seismic exploration processing method based on optimized viscous pure P waves, characterized in that: include: processor; a memory for storing processor-executable instructions; When the processor executes the executable instructions, the method according to any one of claims 1 to 7 is implemented.

10. A non-volatile computer-readable storage medium, characterized in that: The device comprises a computer program or an instruction for storing the computer program or the instruction, which, when executed, enables the method according to any one of claims 1 to 7 to be implemented.

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