Method and device for establishing physical model of fracture-developed rock

Abstract

The invention discloses a method and a device for establishing a physical model of fracture-developed rock. The method comprises the following steps: determining an elastic parameter, a density and a flexibility parameter of a porous rock matrix according to mineral components, volume contents and pore parameters in combination with the density and the elastic parameter of the mineral components; according to the truncation Gaussian function corresponding to the azimuth angle of each group of cracks and a Bond transformation matrix used for converting the local coordinate system of the cracks into an observation coordinate system, in combination with the flexibility parameter of the porous rock matrix, determining the flexibility parameter and the elastic parameter of the dry rock skeleton; based on the density of the porous rock matrix and the elastic parameters and fluid attributes of the dry rock skeleton, determining the elastic parameters and density of the fluid saturated rock; and determining the elastic wave velocity based on the elastic parameter and density of the fluid saturated rock. According to the method, multi-group fracture distribution description and rock physical modeling can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of geophysical oil and gas exploration, and in particular to a method and device for establishing a physical model of fracture-developed rocks. Background Art

[0002] Rock physics models bridge seismic data (elastic parameters) with reservoir characteristics (physical parameters). They primarily investigate the intrinsic relationship between seismic response characteristics and the properties of reservoir rocks and the fluids they contain. Characterizing elastic wave velocity is crucial in seismic exploration, encompassing all aspects of seismic data processing and inversion.

[0003] In unconventional oil and gas reservoirs, fractures are widely distributed. When directional fractures are embedded in an isotropic background matrix, the equivalent medium can be described as a transversely isotropic medium. In more complex cases, the background matrix may consist of thin interbeds embedded with a single vertical fracture cluster, requiring the equivalent medium to be described as an orthogonal medium. Even more complex, fractures are often not directional, but rather clustered in multiple groups. Effectively describing the distribution of multiple fracture clusters and predicting seismic wave propagation velocities is crucial as seismic exploration becomes increasingly sophisticated. Summary of the Invention

[0004] In order to rationally establish a physical model of rocks containing multiple groups of vertical fractures, effectively characterize rock physical characteristics and predict seismic wave velocity, the inventors have made the present invention. Through specific implementation methods, a method and device for establishing a physical model of fractured rocks are provided, which can solve the problems of describing the distribution of multiple groups of fractures and rock physical modeling under complex geological conditions.

[0005] In a first aspect, an embodiment of the present invention provides a method for establishing a physical model of fractured rock, comprising:

[0006] Based on the mineral components and their volume content and pore parameters in the rock attribute information, combined with the density and elastic parameters of each mineral component, the elastic parameters, density and flexibility parameters of the porous rock matrix are determined;

[0007] Determining, based on the azimuth angle of each group of cracks included in the crack parameters in the attribute information, a truncated Gaussian function corresponding to each azimuth angle and a Bond transformation matrix for converting a local coordinate system of the cracks to an observation coordinate system, and determining, in combination with the flexibility parameters of the porous rock matrix, flexibility parameters and elastic parameters of the dry rock skeleton;

[0008] Determining elastic parameters and density of fluid-saturated rock based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information;

[0009] The elastic wave velocity of the fluid-saturated rock is determined based on the elastic parameters and density of the fluid-saturated rock.

[0010] In a second aspect, an embodiment of the present invention provides a device for establishing a physical model of fractured rock, comprising:

[0011] The porous rock matrix parameter determination module is used to determine the elastic parameters, density and flexibility parameters of the porous rock matrix based on the mineral components and their volume content and pore parameters in the rock attribute information, combined with the density and elastic parameters of each mineral component;

[0012] a dry rock skeleton parameter determination module, configured to determine, based on the azimuth of each group of cracks included in the crack parameters in the attribute information, a truncated Gaussian function corresponding to each azimuth, and a Bond transformation matrix for converting the local coordinate system of the cracks to the observation coordinate system, and to determine the flexibility parameters and elastic parameters of the dry rock skeleton in combination with the flexibility parameters of the porous rock matrix;

[0013] a fluid-saturated rock parameter determination module, configured to determine the elastic parameters and density of the fluid-saturated rock based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information;

[0014] The fluid-saturated rock elastic wave velocity determination module is used to determine the elastic wave velocity of the fluid-saturated rock based on the elastic parameters and density of the fluid-saturated rock.

[0015] In a third aspect, an embodiment of the present invention provides a computer storage medium storing computer executable instructions, which, when executed by a processor, implement the above-mentioned method for establishing a physical model of fractured rock.

[0016] In a fourth aspect, an embodiment of the present disclosure provides a server comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for establishing a physical model of fracture-developed rocks when executing the program.

[0017] The beneficial effects of the above technical solutions provided by the embodiments of the present invention include at least:

[0018] The method for establishing a physical model of fractured rocks provided by an embodiment of the present invention fully utilizes the mineral component parameters, pore parameters, fracture parameters and fluid properties in the rock attribute information, realizes the description of multiple groups of fracture distribution under complex geological conditions, and accurately constructs a rock physical model.

[0019] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 Schematic diagram of a method for establishing a physical model of fractured rock according to an embodiment of the present invention;

[0023] Figure 2 This is a flow chart of a method for establishing a physical model of fractured rock according to an embodiment of the present invention;

[0024] Figure 3 for Figure 2 Specific implementation flow chart of step S21;

[0025] Figure 4 for Figure 2 Specific implementation flow chart of step S24;

[0026] Figure 5 In the embodiment of the present invention, when the crack orientation distribution range is [-π / 2,π / 2], a truncated Gaussian function is used to describe the crack orientation distribution;

[0027] Figure 6 This figure shows the influence of the standard deviation of the orientation distribution of multiple groups of cracks on the elastic parameters when the background matrix is ​​isotropic in an embodiment of the present invention.

[0028] Figure 7 In the embodiment of the present invention, the influence of the azimuth distribution range and standard deviation of multiple groups of cracks on the monoclinic elastic parameters is shown;

[0029] Figure 8 In the embodiment of the present invention, when the background matrix is ​​isotropic, the longitudinal wave velocity prediction is performed when the standard deviation of the azimuth distribution of multiple groups of cracks changes;

[0030] Figure 9 In the embodiment of the present invention, when the background matrix is ​​isotropic, the shear wave velocity prediction is performed when the standard deviation of the azimuth distribution of multiple groups of cracks changes;

[0031] Figure 10Schematic diagram of the structure of the device for establishing a physical model of fractured rock in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0033] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention pertains. Although the present invention has only described preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

[0034] Example

[0035] The embodiment of the present invention provides a method for establishing a physical model of fractured rock. Figure 1 As shown, the specific implementation process refers to Figure 2 As shown, the following steps are included:

[0036] Step S21: Based on the mineral components and their volume content and pore parameters in the rock attribute information, the density and elastic parameters of each mineral component are combined with the elastic parameters, density and flexibility parameters of the porous rock matrix.

[0037] For specific implementation steps, see Figure 3 Shown, including:

[0038] Step S211: Determine the elastic parameters and density of the rock-mineral mixture based on the mineral components and their volume contents in the rock attribute information and the density and elastic parameters of each mineral component.

[0039] The rock mineral components include at least one, and the elastic parameters and density of the rock mineral mixture can be determined using one of the known models such as the VRH model and the Hashin-Shtrikman model.

[0040] Step S212: Determine the elastic parameters and density of the porous rock matrix based on the elastic parameters and density of the rock mineral mixture and the pore parameters in the attribute information.

[0041] The elastic parameters and density of the porous rock matrix can be determined using one of the known models such as the DEM model and the SCA model.

[0042] Step S213: Determine the flexibility parameters of the porous rock matrix based on its elastic parameters.

[0043] Step S22: Based on the azimuth angles of each group of cracks included in the crack parameters in the attribute information, determine the truncated Gaussian function corresponding to each azimuth angle and the Bond transformation matrix used to transform the local coordinate system of the cracks to the observation coordinate system. Combined with the flexibility parameters of the porous rock matrix, the flexibility parameters and elastic parameters of the dry rock skeleton are determined.

[0044] Under the assumption of long wavelength and non-interaction between cracks, the equivalent flexibility of rock can be expressed as:

[0045] S=S b +ΔS (1)

[0046] Where S is the flexibility parameter of the dry rock skeleton, S b is the flexibility parameter of the porous rock matrix, and ΔS is the change in flexibility caused by the vertical crack.

[0047] The expression for the flexibility change caused by a vertical crack with orthogonal characteristics in the local coordinate system of the crack is:

[0048]

[0049] Among them, Z N is the vertical flexibility, Z H and Z V They are horizontal and vertical tangential flexibility respectively.

[0050] In order to transform the local coordinate system of the crack to the observation coordinate system, the rotation matrix is ​​defined as:

[0051]

[0052] Based on the defined rotation matrix, the Bond transformation matrix expression is:

[0053]

[0054] Among them, β ij is the cosine function of the observation coordinate system (x1, x2, x3) and the local crack coordinate system (x′1, x′2, x′3), where the subscripts i and j represent the numbers 1, 2, or 3, respectively.

[0055] First, define the rotation matrix about the polar angle θ as:

[0056]

[0057] Let θ = -π / 2 and rotate (x′1, x′2, x′3) to (-x3, x2, x1), thus constructing a set of vertical cracks.

[0058]

[0059] ΔS' is the flexibility change matrix caused by the vertical crack in the observation coordinate system.

[0060] Secondly, rotate the crack along the x3 axis in azimuth and define the rotation matrix about the azimuth angle φ as:

[0061]

[0062] Substituting the azimuth rotation matrix into the Bond transformation matrix N yields the azimuth-related matrix N(φ):

[0063]

[0064] Where N(φ) is the Bond transformation matrix corresponding to the azimuth angle φ, which is used to transform the local coordinate system of the crack into the observation coordinate system.

[0065] The distribution description of multiple groups of cracks is assumed to satisfy the truncated Gaussian function distribution. The equivalent flexibility of the dry rock skeleton is defined as:

[0066]

[0067] Where F(φ) is the truncated Gaussian function, which is defined as:

[0068]

[0069] Where F(φ) is the truncated Gaussian function corresponding to the azimuth angle φ, a is the maximum value of the crack azimuth angle, b is the minimum value of the crack azimuth angle, and g(φ) is the Gaussian function corresponding to the azimuth angle φ, which is expressed as follows:

[0070]

[0071] Where φ0 is the main azimuth of the crack, σ is the standard deviation of the crack azimuth distribution, and G(﹒) is the cumulative distribution function (CDF) of the Gaussian function g(φ), which is expressed as follows:

[0072] G(x)=P(X≤x) (12)

[0073] The equivalent flexibility expression is abbreviated as:

[0074] S=S b + <NΔS'N T > F (13)

[0075] The subscript F represents the truncated Gaussian probability, and the main orientation (φ0) has the largest fracture flexibility weight. When φ = φ0, the orientation angle is strictly determined, and the above formula is simplified to a single group of fractures.

[0076] From the above introduction, it can be seen that according to the azimuth angle of each group of cracks contained in the crack parameters in the attribute information, the truncated Gaussian function F(φ) corresponding to each azimuth angle is determined by the above formula (10); according to the azimuth angle of each group of cracks contained in the crack parameters in the attribute information, the Bond transformation matrix N(φ) corresponding to each azimuth angle for converting the local coordinate system of the crack to the observation coordinate system is determined by the above formula (8); combined with the flexibility parameter of the porous rock matrix, the flexibility parameter S of the dry rock skeleton is determined by the above formula (9).

[0077] After determining the flexibility parameter S of the dry rock skeleton, the elastic parameters of the dry rock skeleton are obtained by inverse calculation. Furthermore, the elastic parameter matrix of the dry rock skeleton, that is, the equivalent elastic matrix after density normalization, is obtained, which can be expressed as:

[0078]

[0079] Among them, C e is the density-normalized equivalent elastic matrix of the dry rock skeleton, I is the 6×6 identity matrix, C b is the elastic parameter matrix of the porous rock matrix, ρ is the density of the porous rock matrix, [·] -1 Indicates inverse calculation.

[0080] Step S23: Based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information, the elastic parameters and density of the fluid-saturated rock are determined.

[0081] Specifically, the density of the porous rock matrix is ​​used as the density of the dry rock skeleton; based on the elastic parameters and density of the dry rock skeleton and the fluid properties in the property information, the elastic parameters and density of the fluid-saturated rock are determined.

[0082] Furthermore, the elastic parameters and density of fluid-saturated rocks can be determined according to the Brown-Korringa method.

[0083] Step S24: Determine the elastic wave velocity of the fluid-saturated rock based on the elastic parameters and density of the fluid-saturated rock.

[0084] See also Figure 4 As shown, the following steps may be included:

[0085] Step S241: Based on the elastic parameters of the fluid-saturated rock, determine the moduli corresponding to the longitudinal and shear wave velocities of the fluid-saturated rock.

[0086] Based on the elastic parameters of fluid-saturated rock, the moduli corresponding to the longitudinal and shear wave velocities of fluid-saturated rock are determined by the following equations (15)-(22):

[0087]

[0088] in,

[0089]

[0090]

[0091]

[0092] Γ ik =C ijkl n j n l (19)

[0093] tr(Γ)=Γ ii =Γ 11 +Γ 22 +Γ 33 (20)

[0094]

[0095]

[0096] In formulas (15)-(22), M is the modulus, X and Q are intermediate variables, i, j, k and l are the serial numbers of the coordinate axis directions in the observation coordinate system, tr(﹒) represents the trace, det(﹒) represents the determinant, tr[com(﹒)] represents the difference between the sum of the products of the matrix diagonal elements and the sum of the squares of the anti-diagonal elements, Γ ik is the product of the elastic parameter and the vertical vector, C ijkl is the elastic parameter of fluid-saturated rock, n j and n l are all unit vectors in corresponding directions.

[0097] Step S242: Determine the corresponding longitudinal and shear wave velocities of the fluid-saturated rock based on the density of the fluid-saturated rock and the moduli corresponding to the longitudinal and shear wave velocities.

[0098] According to the moduli corresponding to the density of fluid-saturated rock and the longitudinal and shear wave velocities, the P-wave velocity, S1-wave velocity, and S2-wave velocity of fluid-saturated rock are determined according to Equation (23).

[0099]

[0100] The method for establishing a physical model of fractured rocks provided by an embodiment of the present invention fully utilizes the mineral component parameters, pore parameters, fracture parameters and fluid properties in the rock attribute information, realizes the description of multiple groups of fracture distribution under complex geological conditions, and accurately constructs a rock physical model.

[0101] The equivalent medium constructed in this embodiment of the present invention can be extended to monoclinic media and can also degenerate into transversely isotropic and orthogonal media, generalizing the linear sliding model to more complex media. When the background matrix is ​​a transversely isotropic medium and the fracture azimuth is fixed at 0°, the medium degenerates into an orthogonal medium. When no fractures are present, the background matrix itself is a transversely isotropic medium.

[0102] See also Figure 5 As shown in the figure, when the crack orientation distribution range is [-π / 2,π / 2], the truncated Gaussian function is used to describe the crack orientation distribution. From black to white, the probability of crack distribution in this orientation changes from small to large, and the total probability is 1. When the background matrix is ​​isotropic, the influence of the orientation distribution standard deviation of multiple groups of cracks on the elastic parameters is shown in Figure 2. Figure 6 As shown in the figure, the crack distribution range is 2π and the main crack orientation is 0°. When the background matrix is ​​isotropic, the influence of the orientation distribution range and standard deviation of multiple groups of cracks on the monoclinic elastic parameters is shown in Figure 2. Figure 7 As shown, the lower limit of the crack orientation is 0, and the main crack orientation is 0°; see Figure 8 The figure shows the P-wave velocity prediction when the standard deviation of the orientation distribution of multiple groups of cracks changes under the condition that the background matrix is ​​isotropic. The crack distribution range is π and the main orientation of the crack is 0°. Figure 9 As shown, the shear wave velocity prediction when the standard deviation of the orientation distribution of multiple groups of cracks changes when the background matrix is ​​isotropic, the crack distribution range is π, and the main orientation of the crack is 0°.

[0103] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a physical model building device for fractured rock, the structure of which is as follows: Figure 10 As shown, including:

[0104] The porous rock matrix parameter determination module 101 is used to determine the elastic parameters, density and compliance parameters of the porous rock matrix based on the mineral components and their volume content and pore parameters in the rock attribute information, combined with the density and elastic parameters of each mineral component;

[0105] a dry rock skeleton parameter determination module 102 for determining, based on the azimuth of each group of fractures included in the fracture parameters in the attribute information, a truncated Gaussian function corresponding to each azimuth, and a Bond transformation matrix for converting the local fracture coordinate system to the observation coordinate system, and determining the flexibility parameters and elastic parameters of the dry rock skeleton in combination with the flexibility parameters of the porous rock matrix;

[0106] a fluid-saturated rock parameter determination module 103, configured to determine the elastic parameters and density of the fluid-saturated rock based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information;

[0107] The fluid-saturated rock elastic wave velocity determination module 104 is configured to determine the elastic wave velocity of the fluid-saturated rock based on the elastic parameters and density of the fluid-saturated rock.

[0108] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0109] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned method for establishing a physical model of fractured rock is implemented.

[0110] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a server, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for establishing a physical model of fractured rock is implemented.

[0111] Unless otherwise specifically stated, terms such as process, calculate, compute, determine, display, and the like may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, that manipulate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within the memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0112] It should be understood that the specific order or hierarchy of steps in the disclosed processes is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0113] In the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that embodiments of the claimed subject matter require more features than are recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of any individual disclosed embodiment. The appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0114] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein may be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described around their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. A skilled person may implement the described functions in an adaptable manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of this disclosure.

[0115] The steps of the methods or algorithms described in conjunction with the embodiments herein may be directly embodied as hardware, software modules executed by a processor, or a combination thereof. The software module may be located in a RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and storage medium may also be present in a user terminal as discrete components.

[0116] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or external to the processor. In the latter case, it is communicatively coupled to the processor via various means, which are well known in the art.

[0117] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above embodiments, but one of ordinary skill in the art will recognize that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to encompass all such changes, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent the term "comprising" is used in the specification or claims, the term is intended to be encompassed in a manner similar to the term "including," as explained in terms of "including," used as a transitional word in the claims. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or."

Claims

1. A method for establishing a physical model of fractured rock, characterized in that: include: Based on the mineral components and their volume content and pore parameters in the rock attribute information, combined with the density and elastic parameters of each mineral component, the elastic parameters, density and flexibility parameters of the porous rock matrix are determined; Determining, based on the azimuth angle of each group of cracks included in the crack parameters in the attribute information, a truncated Gaussian function corresponding to each azimuth angle and a Bond transformation matrix for converting a local coordinate system of the cracks to an observation coordinate system, and determining, in combination with the flexibility parameters of the porous rock matrix, flexibility parameters and elastic parameters of the dry rock skeleton; Determining elastic parameters and density of fluid-saturated rock based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information; The elastic wave velocity of the fluid-saturated rock is determined based on the elastic parameters and density of the fluid-saturated rock.

2. The method according to claim 1, characterized in that The determining, based on the azimuth of each group of cracks included in the crack parameters in the attribute information, a truncated Gaussian function corresponding to each azimuth, includes: According to the azimuth angle of each group of cracks included in the crack parameters in the attribute information, the truncated Gaussian function corresponding to each azimuth angle is determined as follows: In formula (1), F(φ) is the truncated Gaussian function corresponding to the azimuth angle φ; g(φ) is the Gaussian function corresponding to the azimuth angle φ, φ0 is the main azimuth of the crack, σ is the standard deviation of the crack azimuth distribution; G(·) is the cumulative distribution function of the Gaussian function, a is the maximum value of the crack azimuth, and b is the minimum value of the crack azimuth.

3. The method according to claim 2, characterized in that According to the azimuth angle of each group of cracks included in the crack parameters in the attribute information, a Bond transformation matrix corresponding to each azimuth angle and used to transform the local coordinate system of the cracks into the observation coordinate system is determined, including: According to the azimuth angle of each group of cracks included in the crack parameters in the attribute information, the Bond transformation matrix corresponding to each azimuth angle for converting the local coordinate system of the crack to the observation coordinate system is determined as follows: In formula (2), N(φ) is the Bond transformation matrix corresponding to the azimuth angle φ.

4. The method according to claim 3, characterized in that The determining of the flexibility parameter and elastic parameter of the dry rock skeleton in combination with the flexibility parameter of the porous rock matrix includes: Combined with the flexibility parameter of the porous rock matrix, the flexibility parameter of the dry rock skeleton is determined using the following formula (3): In formula (3), S is the flexibility parameter of the dry rock skeleton, S b is the flexibility parameter of the porous rock matrix, ΔS' is the flexibility change matrix caused by the vertical crack in the observation coordinate system; Based on the flexibility parameters of the dry rock skeleton, its elastic parameters are determined by inverse calculation.

5. The method according to claim 1, wherein The determining of the elastic wave velocity of the fluid-saturated rock based on the elastic parameters and density of the fluid-saturated rock comprises: Determining moduli corresponding to longitudinal and shear wave velocities of the fluid-saturated rock based on elastic parameters of the fluid-saturated rock; The corresponding longitudinal and shear wave velocities of the fluid-saturated rock are determined based on the density of the fluid-saturated rock and the moduli corresponding to the longitudinal and shear wave velocities.

6. The method according to claim 5, characterized in that The determining of the moduli corresponding to the longitudinal and shear wave velocities of the fluid-saturated rock based on the elastic parameters of the fluid-saturated rock includes: Based on the elastic parameters of the fluid-saturated rock, the moduli corresponding to the longitudinal and shear wave velocities of the fluid-saturated rock are determined by the following equations (4)-(11): in, C ik =C ijkl n j n l (8) tr(Γ)=Γ ii =C 11 +C 22 +C 33 (9) In formulas (4)-(11), M is the modulus, X and Q are intermediate variables, i, j, k and l are the serial numbers of the coordinate axis directions in the observation coordinate system, φ is the azimuth, tr(﹒) represents the trace, det(﹒) represents the determinant, tr[com(﹒)] represents the difference between the sum of the products of the matrix diagonal elements and the sum of the squares of the anti-diagonal elements, Γ ik is the product of the elastic parameter and the vertical vector, C ijkl is the elastic parameter of the fluid-saturated rock, n j and n l are all unit vectors in corresponding directions.

7. The method according to claim 5, characterized in that Determining corresponding longitudinal and shear wave velocities of the fluid-saturated rock based on the density of the fluid-saturated rock and the moduli corresponding to the longitudinal and shear wave velocities includes: The P wave velocity, S1 wave velocity and S2 wave velocity of the fluid-saturated rock are determined based on the density of the fluid-saturated rock and the moduli corresponding to the longitudinal and shear wave velocities.

8. The method according to claim 1, characterized in that The mineral components and their volume content and pore parameters in the rock attribute information, combined with the density and elastic parameters of each mineral component, the elastic parameters, density and flexibility parameters of the porous rock matrix, include: Determine the elastic parameters and density of the rock-mineral mixture based on the mineral components and their volume content in the rock attribute information and the density and elastic parameters of each mineral component; Determining the elastic parameters and density of the porous rock matrix based on the elastic parameters and density of the rock mineral mixture and the porosity parameters in the attribute information; The flexibility parameters of the porous rock matrix are determined based on the elastic parameters of the porous rock matrix.

9. The method according to claim 1, characterized in that The determining of the elastic parameters and density of the fluid-saturated rock based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information, includes: Taking the density of the porous rock matrix as the density of the dry rock skeleton; Based on the elastic parameters and density of the dry rock skeleton and the fluid properties in the property information, the elastic parameters and density of the fluid-saturated rock are determined.

10. A device for establishing a physical model of fractured rock, characterized in that: The device comprises: The porous rock matrix parameter determination module is used to determine the elastic parameters, density and flexibility parameters of the porous rock matrix based on the mineral components and their volume content and pore parameters in the rock attribute information, combined with the density and elastic parameters of each mineral component; a dry rock skeleton parameter determination module, configured to determine, based on the azimuth of each group of cracks included in the crack parameters in the attribute information, a truncated Gaussian function corresponding to each azimuth, and a Bond transformation matrix for converting the local coordinate system of the cracks to the observation coordinate system, and to determine the flexibility parameters and elastic parameters of the dry rock skeleton in combination with the flexibility parameters of the porous rock matrix; a fluid-saturated rock parameter determination module, configured to determine the elastic parameters and density of the fluid-saturated rock based on the density of the porous rock matrix and the elastic parameters of the dry rock skeleton, and the fluid properties in the property information; The fluid-saturated rock elastic wave velocity determination module is used to determine the elastic wave velocity of the fluid-saturated rock based on the elastic parameters and density of the fluid-saturated rock.

11. A computer storage medium, characterized in that The computer storage medium stores computer executable instructions, which, when executed by a processor, implement the method for establishing a physical model of fractured rock according to any one of claims 1 to 9.

12. A server, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for establishing a physical model of fractured rock according to any one of claims 1 to 9 is implemented.

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