Method and apparatus for quantitatively characterizing seismic response of fluid-saturated porous layered media

Abstract

The present invention discloses a method and apparatus for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. The method first obtains the physical properties of the fluid-saturated porous layered medium, which is composed of anisotropic strata. Based on the physical properties, the equivalent longitudinal wave modulus in the direction perpendicular to the stratum is obtained. Based on the equivalent longitudinal wave modulus, a frequency-dependent total stiffness coefficient matrix of the layered medium is obtained. Based on the frequency-dependent total stiffness coefficient matrix and the density of the layered medium, the dispersion and attenuation of the seismic wave are obtained and output according to a formula for calculating the complex velocity of anisotropic media. Compared with existing technologies, this method takes into account the influence of the intrinsic anisotropy of each stratum in the layered medium when calculating the velocity dispersion and attenuation response of the seismic wave, enabling the study of the frequency-dependent anisotropic characteristics of the seismic wave.

Description

Technical Field

[0001] The present invention relates to the field of geotechnical engineering technology, and in particular to a method, device, intelligent terminal and computer-readable storage medium for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. Background Art

[0002] Studying the dispersion and attenuation of seismic waves is of great significance for evaluating the properties of fluids in fluid-saturated porous media. When seismic waves pass through fluid-saturated porous media, the induced fluid flow is the main cause of the dispersion and attenuation of seismic waves.

[0003] Quantitatively characterizing the dispersion attenuation and frequency-dependent anisotropy of seismic waves caused by interlayer wave-induced fluid flow in layered media is crucial for the inversion and interpretation of physical properties of layered media. However, existing models fail to consider the influence of the intrinsic anisotropy of the strata within layered media and fail to investigate the frequency-dependent anisotropy of seismic waves when examining the dispersion attenuation of seismic waves perpendicular to the plane.

[0004] Therefore, the existing technology needs to be improved and enhanced. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method, device, intelligent terminal and computer-readable storage medium for quantitatively characterizing the seismic response of fluid-saturated porous layered media, aiming to solve the problem that the existing technology does not consider the influence of the intrinsic anisotropy of the strata in the layered media and fails to study the frequency-dependent anisotropy characteristics of the seismic waves when examining the dispersion attenuation of seismic waves on the vertical plane.

[0006] To achieve the above objectives, the present invention provides, in a first aspect, a method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, comprising:

[0007] Obtaining physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata;

[0008] Based on the physical parameters, an equivalent longitudinal wave modulus in a direction perpendicular to the plane is obtained;

[0009] Based on the equivalent longitudinal wave modulus, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained;

[0010] Based on the frequency-dependent full stiffness coefficient matrix and the density of the layered medium, and according to the anisotropic medium complex velocity calculation formula, the dispersion attenuation of the seismic wave is obtained and output.

[0011] Optionally, obtaining a frequency-dependent full stiffness coefficient matrix of the layered medium based on the equivalent longitudinal wave modulus includes:

[0012] Calculate the equivalent stiffness coefficient of layered media in high-frequency limit and low-frequency limit respectively;

[0013] extracting a relaxation function based on the equivalent longitudinal wave modulus;

[0014] Based on the equivalent stiffness coefficient and the relaxation function, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained.

[0015] Optionally, obtaining the equivalent longitudinal wave modulus in a direction perpendicular to the plane based on the physical property parameters includes:

[0016] According to the anisotropic constitutive model and boundary conditions of layered media, the strain distribution in the direction perpendicular to the layer is obtained;

[0017] Performing volume averaging on the strain distribution to obtain an average strain in a direction perpendicular to the plane;

[0018] According to the normal stress in the vertical plane direction and the average strain, the equivalent longitudinal wave modulus of the vertical plane is obtained, and the equivalent longitudinal wave modulus includes the equivalent longitudinal wave modulus of the vertical plane under the high frequency limit and the equivalent longitudinal wave modulus of the vertical plane under the low frequency limit.

[0019] Optionally, the expression of the anisotropic constitutive model is:

[0020] p=M[ζ-α1(ε xx +ε yy )-α3ε zz ],

[0021] Among them, σ xx , σ yy and σ zz are the normal stresses in the x, y and z directions respectively; ε xx , ε yy and ε zz are the normal strains in the x, y and z directions respectively; p is the pore fluid pressure; ζ is the fluid volume increment; C ij is the stiffness coefficient of dry rock; α1 and α3 are Biot coefficients, and M is the Biot modulus.

[0022] Optionally, after obtaining the dispersion attenuation of the seismic wave, the method further includes:

[0023] According to the Thomsen anisotropy parameters, the frequency-dependent anisotropy characteristics are obtained to analyze the frequency-dependent anisotropy of seismic waves.

[0024] A second aspect of the present invention provides a device for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, wherein the device comprises:

[0025] A physical property parameter module is used to obtain physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata;

[0026] An equivalent longitudinal wave modulus module, used to obtain an equivalent longitudinal wave modulus in a vertical plane direction based on the physical property parameters;

[0027] A frequency-dependent full stiffness coefficient matrix module is used to obtain a frequency-dependent full stiffness coefficient matrix of a layered medium based on the equivalent longitudinal wave modulus;

[0028] The seismic wave result module is used to obtain and output the dispersion attenuation of the seismic wave based on the frequency-dependent full stiffness coefficient matrix and the density of the layered medium according to the anisotropic medium complex velocity calculation formula.

[0029] Optionally, the frequency-variable full stiffness coefficient matrix module includes:

[0030] The equivalent stiffness coefficient unit is used to calculate the equivalent stiffness coefficient of layered media in the high-frequency limit and the low-frequency limit respectively;

[0031] A relaxation function unit, configured to extract a relaxation function based on the equivalent longitudinal wave modulus;

[0032] The frequency-variable total stiffness coefficient matrix unit is used to obtain the frequency-variable total stiffness coefficient matrix of the layered medium based on the equivalent stiffness coefficient and the relaxation function.

[0033] Optionally, the equivalent longitudinal wave modulus module includes:

[0034] The strain distribution unit is used to obtain the strain distribution in the vertical layer direction according to the constitutive model and boundary conditions of the layered medium;

[0035] an average strain unit, used to perform volume averaging on the strain distribution to obtain an average strain in a direction perpendicular to the plane;

[0036] The equivalent longitudinal wave modulus unit is used to obtain the equivalent longitudinal wave modulus of the vertical plane based on the normal stress in the vertical plane direction and the average strain. The equivalent longitudinal wave modulus includes the equivalent longitudinal wave modulus of the vertical plane under the high-frequency limit and the equivalent longitudinal wave modulus of the vertical plane under the low-frequency limit.

[0037] A third aspect of the present invention provides an intelligent terminal, which includes a memory, a processor, and a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, which is stored in the memory and can be run on the processor. When the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is executed by the processor, any step of the method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is implemented.

[0038] A fourth aspect of the present invention provides a computer-readable storage medium, on which is stored a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. When the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is executed by a processor, the program implements any one of the steps of the method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium.

[0039] As can be seen from the above, the present invention calculates the equivalent longitudinal wave modulus and the frequency-dependent total stiffness coefficient matrix based on the physical properties of a layered medium composed of anisotropic strata. It then calculates the velocity dispersion and attenuation response of seismic waves based on the frequency-dependent total stiffness coefficient matrix and the density of the layered medium. Compared to existing technologies, this method takes into account the influence of the intrinsic anisotropy of each stratum in the layered medium when calculating the velocity dispersion and attenuation response of seismic waves, enabling the study of the frequency-dependent anisotropy characteristics of seismic waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 Schematic diagram of the effect of formation intrinsic anisotropy on seismic dispersion;

[0042] Figure 2 Schematic diagram of the effect of formation intrinsic anisotropy on seismic attenuation;

[0043] Figure 3 Schematic diagram of the effect of formation intrinsic anisotropy on velocity anisotropy;

[0044] Figure 4 Schematic diagram of the effect of formation intrinsic anisotropy on attenuation anisotropy;

[0045] Figure 5 1 is a flow chart of a method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium provided by an embodiment of the present invention;

[0046] Figure 6 is a schematic diagram of an equivalent voxel;

[0047] Figure 7 yes Figure 1 A schematic diagram of a specific flow chart of step S300 of the embodiment;

[0048] Figure 8 Schematic diagram of the structure of an apparatus for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium provided by an embodiment of the present invention;

[0049] Figure 9 This is a block diagram of the internal structure principle of a smart terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0051] It will be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0052] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0053] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0054] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0055] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0056] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0057] In the study of seismic rock physics methods, a rock physics theory that conforms to the physical properties of rocks is established based on the kinematic laws of seismic waves, thereby constructing the relationship between reservoir rock physical parameters and rock elastic parameters and seismic attribute parameters. This is of great significance for quantitatively analyzing the impact of changes in reservoir rock parameters on seismic attributes.

[0058] Developing high-precision numerical simulation technology for seismic wavefields in complex media has become a consensus in today's industry. Among them, the absorption and attenuation of seismic wave energy by the stratum and the azimuthal variation of elastic parameters (i.e., anisotropy) are important factors that cannot be ignored in high-precision wavefield simulation.

[0059] To quantitatively characterize the seismic response of layered media, it is necessary to establish a quantitative relationship between the physical properties of layered media and the seismic response. Quantitatively characterizing the dispersion attenuation and frequency-dependent anisotropy of seismic waves caused by interlayer wave-induced fluid flow in layered media is crucial for the inversion and interpretation of physical property parameters of layered media. However, existing models fail to consider the influence of the intrinsic anisotropy of the strata within layered media and fail to examine the frequency-dependent anisotropy of seismic waves when examining the dispersion attenuation of seismic waves perpendicular to the plane.

[0060] The present invention calculates the equivalent longitudinal wave modulus and frequency-dependent total stiffness coefficient matrix of vertical planes based on the physical properties of a layered medium composed of anisotropic strata and the anisotropic constitutive model of the layered medium. The velocity dispersion and attenuation response of seismic waves are then calculated based on the frequency-dependent total stiffness coefficient matrix and the density of the layered medium. This calculation of the velocity dispersion and attenuation response of seismic waves takes into account the influence of the intrinsic anisotropy of each stratum in the layered medium, enabling the study of the frequency-dependent anisotropic characteristics of seismic waves.

[0061] Exemplary Methods

[0062] This embodiment provides a method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, which is deployed on various smart terminals. This embodiment calculates the seismic wave dispersion attenuation and frequency-dependent anisotropy of a layered medium composed of an aquifer and a gas layer. In order to examine the influence of the intrinsic anisotropy of the formation, four cases are considered. The first case is that both the aquifer and the gas layer are anisotropic media; the second case is that the aquifer is an anisotropic medium and the gas layer is an isotropic medium; the third case is the opposite of the second case; and the fourth case is that both the aquifer and the gas layer are isotropic media. The dispersion attenuation of seismic waves is the largest in the direction perpendicular to the plane, so the dispersion attenuation in this direction is examined. Figure 1 and Figure 2 The figure shows the effect of stratum intrinsic anisotropy on seismic dispersion attenuation. It can be seen that there are obvious differences in the dispersion attenuation of seismic waves, so intrinsic anisotropy has a significant effect on the dispersion attenuation of seismic waves. Figure 1 It shows the effect of formation intrinsic anisotropy on seismic dispersion. Figure 2 The influence of formation intrinsic anisotropy on seismic attenuation is shown. Figure 3 and Figure 4 The effect of formation intrinsic anisotropy on seismic wave frequency anisotropy is shown. It can be seen that the influence of formation intrinsic anisotropy is significant. Figure 3 The effect of formation intrinsic anisotropy on velocity anisotropy is shown. Figure 4 The method of the present invention can quantitatively analyze the influence of stratum intrinsic anisotropy on seismic dispersion attenuation and seismic frequency variation anisotropy.

[0063] like Figure 5 As shown, this embodiment specifically includes the following steps:

[0064] Step S100: obtaining physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata;

[0065] Specifically, physical parameters include rock skeleton parameters (such as porosity, permeability, and modulus) and fluid data (such as fluid type and modulus). Anisotropy refers to the fact that medium properties vary with direction, which is reflected in seismic waves as the velocity of the seismic waves varies with direction.

[0066] Forward modeling of seismic wavefield response characteristics can be categorized as physical forward modeling and numerical forward modeling. Physical forward modeling can realistically represent seismic wave characteristics, but due to its high cost and poor repeatability, it is less widely used. Numerical forward modeling, on the other hand, is more widely used. In this example, numerical forward modeling was used, and the physical property parameters were simulated values for a fluid-saturated porous layered medium; however, commonly used methods in the field can also be used to obtain measured values for fluid-saturated porous layered media.

[0067] Seismic wave dispersion and attenuation are affected by many factors, such as the seismic wave incident angle, rock skeleton, and fluid physical parameters. The physical parameters used in this embodiment include: the thickness of the upper and lower layers of the layered medium is the same, both 0.05m, and they are saturated with formation water and gas respectively. The anisotropic formation elastic parameters are as follows: C 11 =47.31GPa,C 12 =7.83GPa,C 13 =5.29GPa,C 33 =33.89GPa,C 44 =17.15GPa,C 66=19.74GPa. To study the effect of intrinsic anisotropy, the dispersion and attenuation of seismic waves under different combinations of anisotropic and isotropic formations are investigated, where the elastic properties of the isotropic formation skeleton are the average of the elastic properties of the anisotropic formation skeleton, i.e., C 11 =42.39GPa,C 12 =6.36 GPa. Furthermore, the bulk modulus of the skeleton particles is 38 GPa, the density is 2.65 g / cm³, the skeleton permeability is 1 mD, and the porosity is 6.7%. The bulk modulus of the upper formation water is 2.5 GPa, the viscosity is 0.001 Pa*s, and the density is 1 g / cm³; the bulk modulus of the lower gas is 0.0096 GPa, the viscosity is 0.000015 Pa*s, and the density is negligible. The seismic wave incident angle is 0 degrees, that is, vertical incidence.

[0068] Step S200: obtaining an equivalent longitudinal wave modulus in a direction perpendicular to the plane based on the physical property parameters;

[0069] Specifically, when earthquake waves Figure 6 When propagating in the vertical plane shown, the equivalent longitudinal wave modulus in the vertical plane direction can be calculated. Biot's theory laid the foundation for studying the scattering and attenuation of seismic waves caused by fluid flow. By deriving the acoustic wave equation in fluid-saturated porous media, Biot established the relationship between dispersion, attenuation, and medium parameters, and predicted the existence of slow P waves in porous media. However, he did not consider the jetting effect of porous fluid at high frequencies, and therefore his predictions of high-frequency velocities and attenuation in fluid-saturated media were not very accurate.

[0070] In this embodiment, the anisotropic constitutive model satisfied by each layer in the layered medium is expressed as follows:

[0071] p=M[ζ-α1(ε xx +ε yy )-α3ε zz ].

[0072] Among them, σ xx , σ yy and σ zz are the normal stresses in the x, y and z directions respectively; ε xx , ε yy and ε zz are the normal strains in the x, y and z directions respectively; p is the pore fluid pressure; ζ is the fluid volume increment; C ij is the stiffness coefficient of dry rock; α i and M are the Biot coefficient and Biot modulus respectively.

[0073]

[0074] Where φ is the porosity of each layer, K f With K s are the bulk moduli of the fluid in each layer and the rock skeleton particles, respectively.

[0075] The 3D seismic model is composed of a stack of volume units (abbreviated as voxels). First, an equivalent voxel is selected according to the existing voxel selection method, and then a normal stress σ is applied to the upper and lower interfaces of the equivalent voxel. zz =-τ0e iωt , where τ is the modified relaxation time and ω is the frequency vector. At the same time, the four sides of the equivalent element are fixed, that is, ε xx =ε yy = 0. At this time, the upper and lower interfaces of the equivalent element are impermeable, and the fluid velocity and fluid pressure at the formation interface inside the equivalent element are continuous, so the following boundary conditions are met:

[0076]

[0077] Among them, κ z and η are the vertical permeability of the stratum in the layered medium and the viscosity of the saturated formation fluid, respectively. The subscripts 1 and 2 represent layer 1 and layer 2, respectively.

[0078] According to the above anisotropic constitutive model and boundary conditions, the strain distribution in the vertical plane direction is obtained. The specific expression is:

[0079]

[0080] in, is the positive strain ε zz The amplitude, C 33_1 with C 33_2 are the longitudinal wave moduli of dry rock in the vertical direction of layer 1 and layer 2, α 31 With α 32 The Biot coefficients are α3 for the 1st and 2nd layers respectively.

[0081]

[0082] in, and are the longitudinal wave moduli of saturated rocks in the vertical plane direction of layer 1 and layer 2, M1 and M2 are the Biot moduli of layer 1 and layer 2, a and b are the half thickness of layer 1 and layer 2, respectively.

[0083] The average strain in the vertical direction is obtained by volume averaging the strain distribution. The specific expression is:

[0084]

[0085] According to the definition of equivalent modulus, the equivalent longitudinal wave modulus on the vertical plane can be obtained from the normal stress and average strain applied to the upper and lower interfaces of the equivalent element. The specific expression is:

[0086]

[0087] in, is the equivalent longitudinal wave modulus in the vertical plane direction (ω→∞) in the high frequency limit, L=a+b.

[0088] In the low-frequency limit (ω→0), the above expression of the equivalent longitudinal wave modulus is simplified to obtain the equivalent longitudinal wave modulus in the vertical plane direction in the low-frequency limit (ω→0). The specific expression is:

[0089]

[0090] Step S300: obtaining a frequency-dependent full stiffness coefficient matrix of the layered medium based on the equivalent longitudinal wave modulus;

[0091] Specifically, in this embodiment, Figure 7 As shown, the specific steps include:

[0092] Step S310: Calculating the equivalent stiffness coefficient of the layered medium at the high frequency limit and the low frequency limit respectively;

[0093] Specifically, the anisotropic Gassmann equation and the Backus averaging method are used to obtain (Equivalent stiffness coefficient of layered media in the high-frequency limit) and (Equivalent stiffness coefficient of layered media in the low-frequency limit).

[0094] Step S320: extracting a relaxation function based on the equivalent longitudinal wave modulus;

[0095] Specifically, the expression of the relaxation function of the elastic coefficient is as follows:

[0096]

[0097] in, The morphological parameters, which are relaxation functions with τ, can be extracted from the longitudinal wave modulus at the vertical level. The specific expression is as follows:

[0098]

[0099] Step S330: Based on the equivalent stiffness coefficient and the relaxation function, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained.

[0100] Specifically, taking advantage of the fact that the stiffness coefficients of layered media have the same relaxation function, the branching function can be used to solve the full stiffness coefficient of the layered media. The specific expression is as follows:

[0101]

[0102] in, and are the equivalent stiffness coefficients of the layered medium in the high-frequency and low-frequency limits, respectively, and f(ω) is the relaxation function for calculating the elastic coefficient.

[0103] After calculating all the total stiffness coefficients, the frequency-dependent total stiffness coefficient matrix is obtained.

[0104] In this embodiment, the equivalent stiffness coefficients of the frequency-dependent total stiffness coefficient matrix in the low-frequency limit and the high-frequency limit are obtained by combining the Backus average with the Gassmann equation, and then the relaxation function is extracted by the vertical longitudinal wave modulus; finally, the total stiffness coefficient matrix of the layered medium at any frequency (i.e., the frequency-dependent total stiffness coefficient matrix of the layered medium) is obtained by combining the equivalent stiffness coefficient and the relaxation function.

[0105] Step S400: Based on the frequency-dependent full stiffness coefficient matrix and the density of the layered medium, and according to the anisotropic medium complex velocity calculation formula, the dispersion attenuation of the seismic wave is obtained and output.

[0106] Specifically, after obtaining the frequency-dependent full stiffness coefficient matrix and the density of the layered medium, the complex velocity of the layered medium is calculated according to the complex velocity calculation formula of the anisotropic medium, and the dispersion attenuation of the seismic wave is obtained from the complex velocity.

[0107] Furthermore, after obtaining the dispersion attenuation of seismic waves, anisotropy parameters can be further calculated based on the Thomsen anisotropy parameters to obtain frequency-dependent anisotropy characteristics and analyze the frequency-dependent anisotropy of seismic waves. The method of the present invention for quantitatively characterizing the seismic response of fluid-saturated porous layered media is a method for calculating the dispersion attenuation of seismic waves in layered media that takes into account the influence of the intrinsic anisotropy of the formation. Furthermore, this method can calculate the dispersion attenuation of seismic waves in any direction, thereby enabling the study of the frequency-dependent anisotropy characteristics of seismic waves.

[0108] In summary, this embodiment takes into account the influence of fluid on seismic wave velocity and anisotropy, establishes the relationship between physical parameters and seismic wave properties based on the geometric characteristics and dynamic characteristics of the seismic wave field, the attenuation and dispersion of seismic waves, the shear wave splitting of seismic waves in anisotropic media, and other properties, and calculates actual seismic data through seismic forward modeling, which has a significant impact on the actual exploration and development of oil and gas.

[0109] Exemplary devices

[0110] like Figure 8As shown, corresponding to the above-mentioned method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, an embodiment of the present invention further provides a device for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. The device for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium includes:

[0111] Physical property parameter module 600, for obtaining physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata;

[0112] An equivalent longitudinal wave modulus module 610 is configured to obtain an equivalent longitudinal wave modulus in a vertical plane direction based on the physical property parameters;

[0113] A frequency-dependent full stiffness coefficient matrix module 620 is used to obtain a frequency-dependent full stiffness coefficient matrix of the layered medium based on the equivalent longitudinal wave modulus;

[0114] The seismic wave result module 630 is used to obtain and output the dispersion attenuation of the seismic wave based on the full stiffness coefficient matrix and the density of the layered medium according to the anisotropic medium complex velocity calculation formula.

[0115] Optional, frequency-dependent full stiffness coefficient matrix module includes:

[0116] The equivalent stiffness coefficient unit is used to calculate the equivalent stiffness coefficient of layered media in the high-frequency limit and the low-frequency limit respectively;

[0117] A relaxation function unit, configured to extract a relaxation function based on the equivalent longitudinal wave modulus;

[0118] The frequency-variable total stiffness coefficient matrix unit is used to obtain the frequency-variable total stiffness coefficient matrix of the layered medium based on the equivalent stiffness coefficient and the relaxation function.

[0119] Optional, equivalent longitudinal wave modulus module, including:

[0120] The strain distribution unit is used to obtain the strain distribution in the vertical layer direction according to the constitutive model and boundary conditions of the layered medium;

[0121] an average strain unit, used to perform volume averaging on the strain distribution to obtain an average strain in a direction perpendicular to the plane;

[0122] The equivalent longitudinal wave modulus unit is used to obtain the equivalent longitudinal wave modulus of the vertical plane based on the normal stress in the vertical plane direction and the average strain. The equivalent longitudinal wave modulus includes the equivalent longitudinal wave modulus of the vertical plane under the high-frequency limit and the equivalent longitudinal wave modulus of the vertical plane under the low-frequency limit.

[0123] Specifically, in this embodiment, the specific functions of each module of the above-mentioned device for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium can refer to the corresponding description in the above-mentioned method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, and will not be repeated here.

[0124] Based on the above embodiment, the present invention also provides an intelligent terminal, whose principle block diagram can be shown as follows: Figure 9 As shown. The above-mentioned intelligent terminal includes a processor, a memory, a network interface and a display screen connected through a system bus. Among them, the processor of the intelligent terminal is used to provide computing and control capabilities. The memory of the intelligent terminal includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. The internal memory provides an environment for the operation of the operating system and the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium in the non-volatile storage medium. The network interface of the intelligent terminal is used to communicate with an external terminal through a network connection. When the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is executed by the processor, the steps of any one of the above-mentioned methods for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium are implemented. The display screen of the intelligent terminal can be a liquid crystal display screen or an electronic ink display screen.

[0125] Those skilled in the art will understand that Figure 9 The principle block diagram shown in the figure is only a block diagram of a partial structure related to the solution of the present invention and does not constitute a limitation on the smart terminal to which the solution of the present invention is applied. The specific smart terminal may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0126] In one embodiment, a smart terminal is provided. The smart terminal includes a memory, a processor, and a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, stored in the memory and executable on the processor. When executed by the processor, the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium performs the following operating instructions:

[0127] Obtaining physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata;

[0128] Based on the physical parameters, an equivalent longitudinal wave modulus in a direction perpendicular to the plane is obtained;

[0129] Based on the equivalent longitudinal wave modulus, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained;

[0130] Based on the frequency-dependent full stiffness coefficient matrix and the density of the layered medium, and according to the anisotropic medium complex velocity calculation formula, the dispersion attenuation of the seismic wave is obtained and output.

[0131] Optionally, obtaining a frequency-dependent full stiffness coefficient matrix of the layered medium based on the equivalent longitudinal wave modulus includes:

[0132] Calculate the equivalent stiffness coefficient of layered media in high-frequency limit and low-frequency limit respectively;

[0133] extracting a relaxation function based on the equivalent longitudinal wave modulus;

[0134] Based on the equivalent stiffness coefficient and the relaxation function, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained.

[0135] Optionally, obtaining the equivalent longitudinal wave modulus in a direction perpendicular to the plane based on the physical property parameters includes:

[0136] According to the anisotropic constitutive model and boundary conditions of layered media, the strain distribution in the direction perpendicular to the layer is obtained;

[0137] Performing volume averaging on the strain distribution to obtain an average strain in a direction perpendicular to the plane;

[0138] According to the normal stress in the vertical plane direction and the average strain, the equivalent longitudinal wave modulus of the vertical plane is obtained, and the equivalent longitudinal wave modulus includes the equivalent longitudinal wave modulus of the vertical plane under the high frequency limit and the equivalent longitudinal wave modulus of the vertical plane under the low frequency limit.

[0139] Optionally, the expression of the anisotropic constitutive model is:

[0140] p=M[ζ-α1(ε xx +ε yy )-α3ε zz ],

[0141] Among them, σ xx , σ yy and σ zz are the normal stresses in the x, y and z directions respectively; ε xx , ε yy and ε zz are the normal strains in the x, y and z directions respectively; p is the pore fluid pressure; ζ is the fluid volume increment; C ij is the stiffness coefficient of dry rock; α1 and α3 are Biot coefficients, and M is the Biot modulus.

[0142] Optionally, after obtaining the dispersion attenuation of the seismic wave, the method further includes:

[0143] According to the Thomsen anisotropy parameters, the frequency-dependent anisotropy characteristics are obtained to analyze the frequency-dependent anisotropy of seismic waves.

[0144] An embodiment of the present invention also provides a computer-readable storage medium, on which is stored a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. When the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is executed by a processor, the steps of any one of the methods for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium provided in the embodiments of the present invention are implemented.

[0145] It should be understood that the sequence numbers of the steps in the above embodiments do not imply a specific order of execution; the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0146] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the above-mentioned device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0147] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0148] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0149] In the embodiments provided by the present invention, it should be understood that the disclosed apparatus / terminal device and method can be implemented in other ways. For example, the apparatus / terminal device embodiments described above are merely illustrative. For example, the division of the modules or units described above is merely a logical functional division. In actual implementation, other division methods may be used. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented.

[0150] If the above-mentioned integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The above-mentioned computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the above-mentioned computer program includes computer program code, and the above-mentioned computer program code can be in source code form, object code form, executable file or some intermediate form. The above-mentioned computer-readable medium may include: any entity or device capable of carrying the above-mentioned computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the above-mentioned computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction.

[0151] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, characterized in that: include: Obtaining physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata; Based on the physical parameters, an equivalent longitudinal wave modulus in a direction perpendicular to the plane is obtained; Based on the equivalent longitudinal wave modulus, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained; Based on the frequency-dependent full stiffness coefficient matrix and the density of the layered medium, and according to the complex velocity calculation formula of the anisotropic medium, the dispersion attenuation of the seismic wave is obtained and output; The method of obtaining a frequency-dependent full stiffness coefficient matrix of the layered medium based on the equivalent longitudinal wave modulus includes: Calculate the equivalent stiffness coefficient of layered media in high-frequency limit and low-frequency limit respectively; extracting a relaxation function based on the equivalent longitudinal wave modulus; Based on the equivalent stiffness coefficient and the relaxation function, a frequency-dependent full stiffness coefficient matrix of the layered medium is obtained; The obtaining of the equivalent longitudinal wave modulus in the vertical plane direction based on the physical property parameters includes: According to the anisotropic constitutive model and boundary conditions of layered media, the strain distribution in the direction perpendicular to the layer is obtained; Performing volume averaging on the strain distribution to obtain an average strain in a direction perpendicular to the plane; According to the normal stress in the vertical plane direction and the average strain, the equivalent longitudinal wave modulus of the vertical plane is obtained, and the equivalent longitudinal wave modulus includes the equivalent longitudinal wave modulus of the vertical plane under the high frequency limit and the equivalent longitudinal wave modulus of the vertical plane under the low frequency limit.

2. The method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium according to claim 1, wherein: The expression of the anisotropic constitutive model is: p=M[ζ-α1(ε xx +e yy )-a3e zz ] Among them, σ xx , σ yy and σ zz are the normal stresses in the x, y and z directions respectively; ε xx , ε yy and ε zz are the normal strains in the x, y and z directions respectively; p is the pore fluid pressure; ζ is the fluid volume increment; Cij is the stiffness coefficient of dry rock; α1 and α3 are Biot coefficients, and M is the Biot modulus.

3. The method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium according to claim 1, wherein: After obtaining the dispersion attenuation of the seismic wave, the method further includes: According to the Thomsen anisotropy parameters, the frequency-dependent anisotropy characteristics are obtained to analyze the frequency-dependent anisotropy of seismic waves.

4. An apparatus for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, characterized in that: The device comprises: A physical property parameter module is used to obtain physical property parameters of a fluid-saturated porous layered medium, wherein the layered medium is composed of anisotropic strata; An equivalent longitudinal wave modulus module, used to obtain an equivalent longitudinal wave modulus in a vertical plane direction based on the physical property parameters; A frequency-dependent full stiffness coefficient matrix module is used to obtain a frequency-dependent full stiffness coefficient matrix of a layered medium based on the equivalent longitudinal wave modulus; A seismic wave result module is used to obtain and output the dispersion attenuation of seismic waves based on the frequency-dependent full stiffness coefficient matrix and the density of the layered medium according to the anisotropic medium complex velocity calculation formula; The frequency-variable full stiffness coefficient matrix module includes: The equivalent stiffness coefficient unit is used to calculate the equivalent stiffness coefficient of layered media in the high-frequency limit and the low-frequency limit respectively; A relaxation function unit, configured to extract a relaxation function based on the equivalent longitudinal wave modulus; A frequency-variable total stiffness coefficient matrix unit is used to obtain a frequency-variable total stiffness coefficient matrix of the layered medium based on the equivalent stiffness coefficient and the relaxation function; The equivalent longitudinal wave modulus module includes: The strain distribution unit is used to obtain the strain distribution in the vertical layer direction according to the constitutive model and boundary conditions of the layered medium; an average strain unit, used to perform volume averaging on the strain distribution to obtain an average strain in a direction perpendicular to the plane; The equivalent longitudinal wave modulus unit is used to obtain the equivalent longitudinal wave modulus of the vertical plane based on the normal stress in the vertical plane direction and the average strain. The equivalent longitudinal wave modulus includes the equivalent longitudinal wave modulus of the vertical plane under the high-frequency limit and the equivalent longitudinal wave modulus of the vertical plane under the low-frequency limit.

5. Intelligent terminal, characterized in that: The intelligent terminal includes a memory, a processor, and a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium, which is stored in the memory and can be run on the processor. When the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is executed by the processor, the steps of the method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium as described in any one of claims 1 to 3 are implemented.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium. When the program for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium is executed by a processor, the steps of the method for quantitatively characterizing the seismic response of a fluid-saturated porous layered medium as described in any one of claims 1 to 3 are implemented.

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