Method and device for building three-dimensional geomechanical model to predict crustal stress and medium

Abstract

The invention provides a method and equipment for building a three-dimensional geomechanical model to predict crustal stress and a medium. The method for building the three-dimensional geomechanical model to predict the crustal stress comprises the steps that a three-dimensional finite element grid is built for a surrounding rock stratum based on a three-dimensional geomechanical model of a reservoir; calculating a geomechanical parameter curve based on the one-dimensional geomechanical data of the reservoir; establishing a three-dimensional geomechanical model for the surrounding rock stratum based on the calculated geomechanical parameters; and predicting crustal stress based on the three-dimensional geomechanical model. According to the method, the geomechanical parameter logging data of the whole well section are predicted, the geomechanical parameter three-dimensional models of the overlying strata and the underlying strata are further constructed in combination with the inversion result, the geomechanical parameter models are adjusted and optimized, and the precision of the geomechanical models is improved.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas geophysical exploration, and relates to a method and system for improving the accuracy of predicting geostress with a three-dimensional geomechanical model, and specifically to a method, device, electronic equipment and storage medium for establishing a three-dimensional geomechanical model to predict geostress. Background Art

[0002] The 3D geomechanical model is a complex system that involves multiple aspects such as strata, structure, rock mechanics, and seismic activity. The model contains the 3D forms and characteristics of various geological bodies and geological phenomena, such as stratum distribution, fault structure, joint structure, fold structure, magmatic activity, metamorphism, etc. The 3D geomechanical model is an important tool for studying geology and seismology. It can help us better understand the nature of geological phenomena and seismic activity, and provide more accurate information for geological exploration and resource development.

[0003] The three-dimensional geomechanical model can reveal the lateral and vertical variation patterns of geomechanical parameters and original field stresses, and describe in detail the spatial heterogeneity of geomechanical parameters and original field stresses. It is widely used in mining, tunnel excavation or certain oil exploration processes.

[0004] To describe the spatial variability of the geomechanical properties of three-dimensional rock mass, the traditional methods used are: Rock Mass Rating, Q system method, Geological Strength Index method. These classification systems are based on the parameter composition obtained during the field measurement process and are suitable for uniform and continuous rock mass. With the introduction of numerical methods, such as the Finite Element Method and the Finite Difference Method, they have become the main methods for people to solve the construction of geotechnical engineering models. The biggest advantage of the finite element method is that it is good at dealing with nonlinear, heterogeneous and complex boundary problems. At present, the commonly used simulator in reservoir geostress simulation is the Geomechanics module in Petrel. In the simulator, a mathematical model for geostress calculation that meets the reservoir conditions (i.e., the control equation) is selected, and the initial and boundary conditions are given. The mathematical model is solved by computer to obtain a three-dimensional geomechanical model, and then the three-dimensional geomechanical model is verified by a one-dimensional geomechanical model.

[0005] In the process of unconventional oil and gas exploration and development, the study of reservoir geostress is of great significance. For shale gas reservoirs, the mechanical parameters are highly heterogeneous and anisotropic in space, which makes it difficult to predict the distribution law of geostress. When establishing a geomechanical model, the use of a traditional homogeneous model will produce a large deviation from the actual formation. Therefore, it is necessary to deepen the understanding of the mechanical properties of underground reservoirs and accurately construct the reservoir geomechanical parameter field to reasonably predict the spatial distribution of geostress. Summary of the invention

[0006] The present invention optimizes the geomechanical parameters of the three-dimensional geomechanical model by using logging and inversion data, thereby improving the accuracy of the three-dimensional geomechanical model and thus improving the accuracy of the finite element simulation results.

[0007] To achieve the above object, the present invention provides a method for establishing a three-dimensional geomechanical model to predict geostress, comprising:

[0008] Establish a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir;

[0009] Calculate geomechanical parameter curves based on one-dimensional geomechanical data of the reservoir;

[0010] Based on the calculated geomechanical parameter curve, a three-dimensional geomechanical model of the surrounding rock formation is established;

[0011] The geostress is predicted based on the three-dimensional geomechanical model.

[0012] Furthermore, establishing a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir includes:

[0013] Adding overburden, underburden and side strata outside the reservoir to obtain a new model;

[0014] The new model is regularized into a rectangle and the 3D finite element mesh of the surrounding rock formations is added at each boundary.

[0015] Furthermore, the calculation of the geomechanical parameter curve based on the one-dimensional geomechanical data of the reservoir includes calculating the dynamic elastic modulus according to the time difference data of the longitudinal wave and the shear wave. The calculation formula of the dynamic elastic modulus is:

[0016]

[0017]

[0018] Among them, ρ b is the rock density, in g / cm 3 ; Δt s and Δt P are the time differences of transverse and longitudinal waves respectively.

[0019] Furthermore, the dynamic Young's modulus and Poisson's ratio are calculated:

[0020]

[0021]

[0022] Among them, E dyn is the dynamic Young's modulus, ν dyn is the dynamic Poisson’s ratio;

[0023] The calculation formula from the dynamic modulus to the static model is:

[0024] E sta =a×E dyn +b

[0025] ν sta =a×ν dyn +b

[0026] Among them, E sta is the static Young's modulus, ν sta is the static Poisson's ratio.

[0027] Furthermore, establishing a three-dimensional geomechanical model for the surrounding rock formation includes:

[0028] Using the calculated mechanical parameter curve, the mechanical parameter trend line is fitted to obtain the extrapolated mechanical parameter curve;

[0029] Using the extrapolated mechanical parameter curve, a three-dimensional geomechanical model of the surrounding rock formation is constructed under the constraints of the inversion results.

[0030] Furthermore, it also includes using the extrapolated mechanical parameter curve to perform variogram analysis in space;

[0031] The Gaussian random simulation method is used to construct a three-dimensional geomechanical model of the surrounding rock strata.

[0032] Furthermore, based on the 3D geomechanical model, the Schlumberger 3D geomechanics module VISAGE was used to determine the original site stress, including the minimum horizontal principal stress, the maximum horizontal principal stress and the overlying rock pressure.

[0033] According to another aspect of the present invention, there is provided a device for establishing a three-dimensional geomechanical model to predict ground stress, comprising:

[0034] A mesh building module is used to build a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir;

[0035] A parameter calculation module calculates the geomechanical parameter curve based on the one-dimensional geomechanical data of the reservoir;

[0036] Model building module, which builds a three-dimensional geomechanical model of the surrounding rock formation based on the calculated geomechanical parameters;

[0037] The stress prediction module predicts ground stress based on the three-dimensional geomechanical model.

[0038] According to another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0039] A memory storing executable instructions;

[0040] A processor runs the executable instructions in the memory to implement the method of establishing a three-dimensional geomechanical model to predict geostress.

[0041] According to another aspect of the present invention, a non-transitory computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the method of establishing a three-dimensional geomechanical model to predict ground stress is implemented.

[0042] The method and system for establishing an accurate three-dimensional geomechanical model of the present invention have the following characteristics: compared with traditional geomechanical models that often assign fixed values ​​to the elastic moduli of overlying and basement rock strata, the present invention uses the extrapolation and inversion results of logging curves to more finely model the properties of surrounding rock formations, making the surrounding rock formations more consistent with the actual geological conditions and obtaining more refined finite element numerical simulation results.

[0043] The present invention predicts the geomechanical parameter logging data of the entire well section, combines the inversion results, further constructs a three-dimensional geomechanical parameter model of the overlying and underlying strata, adjusts and optimizes the geomechanical parameter model, and improves the accuracy of the geomechanical model. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0045] Figure 1 The present invention is a flow chart of a method for establishing a three-dimensional geomechanical model to predict geostress.

[0046] Figure 2 The present invention is a flowchart of a method for accurately establishing a three-dimensional geomechanical model according to an embodiment of the present invention.

[0047] Figure 3 4 is a diagram of the expanded finite element mesh result according to an embodiment of the present invention.

[0048] Figure 4This is a diagram of one-dimensional geomechanical modeling results according to an embodiment of the present invention.

[0049] Figure 5 It is a trend line fitting result diagram of the elastic modulus curve in the whole well section according to an embodiment of the present invention.

[0050] Figure 6 This is a diagram showing the modeling results of overlying rock layers and basement rock layers properties of a three-dimensional geomechanical model according to an embodiment of the present invention.

[0051] Figure 7 1 is a finite element simulation result diagram according to an embodiment of the present invention, the left diagram is the minimum horizontal principal stress result, and the right diagram is the maximum horizontal principal stress result. DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0053] In the process of unconventional oil and gas exploration and development, the study of reservoir geostress is of great significance. For shale gas reservoirs, the mechanical parameters are highly heterogeneous and anisotropic in space, which makes it difficult to predict the distribution law of geostress. When establishing a geomechanical model, the use of a traditional homogeneous model will produce a large deviation from the actual formation. Therefore, it is necessary to deepen the understanding of the mechanical properties of underground reservoirs and accurately construct the reservoir geomechanical parameter field to reasonably predict the spatial distribution of geostress.

[0054] The present invention predicts the geomechanical parameter logging data of the entire well section, combines the inversion results, further constructs a three-dimensional geomechanical parameter model of the overlying and underlying strata, adjusts and optimizes the geomechanical parameter model, and improves the accuracy of the geomechanical model.

[0055] Embodiment 1

[0056] like Figure 1 As shown, the present invention provides a method for establishing a three-dimensional geomechanical model to predict ground stress, comprising:

[0057] Establish a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir;

[0058] Calculate geomechanical parameter curves based on one-dimensional geomechanical data of the reservoir;

[0059] Based on the calculated geomechanical parameter curve, a three-dimensional geomechanical model of the surrounding rock formation is established;

[0060] The geostress is predicted based on the three-dimensional geomechanical model.

[0061] This embodiment aims at the fact that the results of conventional three-dimensional geomechanical modeling are restricted by basic data, and the geomechanical parameters of the surrounding rock are inaccurate, which has a significant impact on the results of numerical simulation. Based on the trend and inversion results of logging data, the surrounding rock parameters of the geomechanical model are optimized to improve the accuracy of the numerical simulation results.

[0062] Specifically, the implementation process of establishing a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir is as follows:

[0063] For areas with well-developed reservoir bedding, strong heterogeneity and complex lithology, in order to more objectively describe the reservoir and interlayer plane heterogeneity, it is necessary to establish a structural model, fault model, lithofacies model and attribute model of the study area to provide a three-dimensional geomechanical basis for subsequent research.

[0064] The existing reservoir model is improved by adding more rock layers and structural details. First, the grid range of the reservoir model is extended to the surface, and then the new rock layer is given initial parameters with similar initial parameter values ​​to the reservoir to complete the description of the overburden formation. Similarly, after the reservoir grid is extended below the reservoir to serve as the lower rock layer of the reservoir, the model is regularized into a rectangle and grid cells of the surrounding rock are added on each of the four vertical boundaries. Secondly, the geomechanical parameters of the original geological model are embedded in the model.

[0065] In order to simulate the real diagenetic environment of deep reservoirs, vector displacement field and continuous displacement compatible equations were selected. Overburden, basement rock and surrounding rock were added around the study area, and materials equivalent to the elastoplastic model were filled to eliminate the direct stress of the rock. The equivalent steel plate constitutive equation was selected to eliminate stress concentration, and steel plate constraints were added in the surrounding area.

[0066] For example, the constitutive equation for the linear elastic-stress-strain relationship is:

[0067]

[0068] Vector displacement field equation:

[0069]

[0070] Continuous displacement equation:

[0071]

[0072]

[0073] Based on the deep reservoir diagenesis theory, the irregular reservoir is filled into a regular rectangular reservoir using equivalent materials at the periphery of the reservoir to eliminate the stress concentration generated in the subsequent stress simulation.

[0074] Specifically, the implementation process of calculating the geomechanical parameter curve based on the one-dimensional geomechanical data of the reservoir is:

[0075] The dynamic elastic modulus is calculated based on the time difference data of the longitudinal wave and the shear wave. The calculation formula of the dynamic elastic modulus is:

[0076]

[0077]

[0078] Among them, ρ b is the rock density, in g / cm 3 ; Δt s and Δt P are the time differences of transverse and longitudinal waves respectively.

[0079] Based on the above formula, the dynamic Young's modulus and Poisson's ratio are obtained:

[0080]

[0081]

[0082] Among them, E dyn is the dynamic Young's modulus, ν dyn is the dynamic Poisson's ratio.

[0083] The calculation formula from the dynamic modulus to the static model is:

[0084] E sta =a×E dyn +b

[0085] ν sta =a×ν dyn +b

[0086] Among them, E sta is the static Young's modulus, ν sta is the static Poisson's ratio.

[0087] Specifically, based on the calculated geomechanical parameter curve, the implementation process of establishing a three-dimensional geomechanical model for the surrounding rock formation is as follows:

[0088] This embodiment takes the elastic modulus curve as an example. Due to the lack of acoustic logging data for the entire well section, the calculated elastic modulus curve only includes the reservoir section, which limits the property modeling of the overlying and basement extension strata in the three-dimensional geomechanical model. The traditional modeling method gives the overlying and basement elastic parameters as constants. Different from this, the elastic parameter curve of the entire well section is obtained by fitting the elastic parameter trend line using the calculated elastic parameter curve.

[0089] Using the elastic parameter curve of the whole well section, the variogram analysis is performed in space. In the analysis process, the parameters mainly include the range and the base value. The range can express the degree of change of the spatial attribute. The change of each small layer attribute is obtained through the variogram, and the correlation of the data is obtained within the range allowed by the space.

[0090] Under the participation of the fitted curve, inversion result constraints and variogram, the Gaussian random simulation method is used to construct the overlying and basement property model. Compared with the traditional method of setting the elastic modulus parameter for the surrounding rock as a constant value, this method establishes the overlying and basement stratum mechanical property model in a combination of well and seismic data, which reflects the characteristics of regional property distribution to the greatest extent and provides a more accurate data basis for subsequent numerical simulation.

[0091] Specifically, the implementation process of predicting ground stress based on the three-dimensional geomechanical model is as follows:

[0092] Based on the geomechanical model, finite element simulation is used, and a comprehensive analysis method of fluid simulation and stress simulation is adopted. Through the convergence of the maximum unbalanced force and repeated iterations of the ground stress, the reservoir diagenesis process is analyzed and simulated, and the geomechanical simulation is comprehensively studied and evaluated.

[0093] Various loads and boundary conditions are applied to the block model. Different settings will affect the stress and strain changes caused by the current production and development operations. Among them, the formation temperature, pore pressure and three-phase in-situ stress of the reservoir should be consistent with the data measured in the initial rock mechanics experiment of the reservoir, and finally simulate the rock diagenesis process.

[0094] The three-dimensional pore pressure model is calculated based on the predicted hydrostatic pressure, overburden formation pressure, pore pressure, etc. on a single well, combined with the acoustic time difference data extracted from seismic data. The original site stress, including the minimum horizontal principal stress, the maximum horizontal principal stress and the overburden formation pressure, is determined using the Schlumberger three-dimensional geomechanics module VISAGE. The three-dimensional geomechanics modeling results are used for the three-dimensional spatial representation and evaluation of reservoir mechanics.

[0095] Embodiment 2

[0096] In the process of unconventional oil and gas exploration and development, the study of reservoir geostress is of great significance. For shale gas reservoirs, the mechanical parameters are highly heterogeneous and anisotropic in space. When establishing a geomechanical model, it is necessary to deepen the understanding of the mechanical properties of underground reservoirs and accurately construct the reservoir geomechanical parameter field to reasonably predict the spatial distribution of geostress. The terrestrial shale gas reservoir resources in the Sichuan Basin of China are rich. The platform-scale model has a finer resolution to construct a geomechanical model, accurately depict the geostress field around the well, better serve the drilling and fracturing optimization design, and provide support for shale gas production capacity construction.

[0097] Reference Figure 2-7 As shown, this embodiment takes a well platform of a continental shale gas reservoir in the Sichuan Basin of China as an example, and uses the method provided by the present invention to perform fine three-dimensional geomechanical modeling.

[0098] In order to fully demonstrate the use of logging data and inversion results to accurately model the overburden and basement rock layers and further improve the accuracy of 3D geological modeling, the specific process of 3D geomechanical modeling is as follows: Figure 2 shown.

[0099] First, a 3D finite element mesh was established based on the 3D geological model. The initial mesh size was 300×278×60 (horizontal×longitudinal×vertical), with a total of 5 million cells. In order to correctly simulate the boundary conditions of the reservoir, it was necessary to add overburden, underburden, and side strata outside the reservoir. To control the total number of meshes, the cell size was gradually enlarged, and the total number of cells in the overall model reached 8.63 million (330×308×85). Figure 3 The three-dimensional finite element mesh of the study area is given. The left side is the model with the addition of overburden and underburden, and the right side is the overall finite element model of the reservoir within the study area.

[0100] Next, geomechanical parameters are calculated based on one-dimensional geomechanical data, including Young's modulus, Poisson's ratio, etc. The existing well data are analyzed, the density curve is used to calculate the overburden pressure, and the Eaton method is used to calculate the formation pore pressure. On this basis, the elastic modulus curve of the reservoir is calculated, such as Figure 4 As shown, the dynamic and static conversion relationships between rock mechanical parameters and the relationships between rock mechanical parameters are further obtained, and the intersection diagram of the relationships between rock mechanical parameters is drawn using the data.

[0101] After the dynamic and static conversion of rock mechanics parameters, the calculation relationship between dynamic rock mechanics parameters and static parameters of rock mechanics parameters in the study area can be established, thereby obtaining the continuous rock mechanics curve of the study well. The elastic modulus curve calculated is only distributed in the reservoir section. The relationship between the existing logging curves of Young's modulus and Poisson's ratio is fitted to further obtain the curves extending upward to the surface and downward to the basement, and the quality of the curve is controlled. Figure 5 It is a trend line fitting result diagram of the elastic modulus curve in the whole well section according to an embodiment of the present invention.

[0102] Next, the surrounding rock formation is modeled in three dimensions. Using the extrapolated elastic modulus curve, under the constraints of the inversion results, the elastic modulus attribute modeling is performed to obtain a more accurate three-dimensional geomechanical model. Figure 6 This is a diagram showing the modeling results of overlying rock layers and basement rock layers properties of a three-dimensional geomechanical model according to an embodiment of the present invention.

[0103] Finally, the geostress field is obtained based on the three-dimensional geomechanical simulation. Using the obtained three-dimensional geomechanical model, the three-dimensional geomechanical parameters are determined, the boundary conditions are set, the pore pressure model is determined, and the original field stress is determined by numerical simulation using finite element simulation software, including the minimum horizontal principal stress, the maximum horizontal principal stress, and the overlying rock pressure. Figure 7 1 is a finite element simulation result diagram according to an embodiment of the present invention, the left diagram is the minimum horizontal principal stress result, and the right diagram is the maximum horizontal principal stress result.

[0104] Embodiment 3

[0105] This embodiment provides a device for establishing a three-dimensional geomechanical model to predict geostress, including:

[0106] A mesh building module is used to build a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir;

[0107] A parameter calculation module calculates the geomechanical parameter curve based on the one-dimensional geomechanical data of the reservoir;

[0108] Model building module, which builds a three-dimensional geomechanical model of the surrounding rock formation based on the calculated geomechanical parameters;

[0109] The stress prediction module predicts ground stress based on the three-dimensional geomechanical model.

[0110] The mesh building module first adds overburden, underburden and side strata outside the reservoir to obtain a new model; then the new model is regularized into a rectangle and a three-dimensional finite element mesh of the surrounding rock strata is added at each boundary.

[0111] The parameter calculation module calculates the dynamic elastic modulus based on the time difference data of the longitudinal wave and the shear wave. The calculation formula of the dynamic elastic modulus is:

[0112]

[0113]

[0114] Among them, ρ b is the rock mass density, in g / cm 3 ; Δt s and Δt P are the time differences of transverse and longitudinal waves respectively.

[0115] Calculate the dynamic Young's modulus and Poisson's ratio:

[0116]

[0117]

[0118] Among them, E dyn is the dynamic Young's modulus, ν dyn is the dynamic Poisson’s ratio;

[0119] The calculation formula from the dynamic modulus to the static model is:

[0120] E sta =a×E dyn +b

[0121] ν sta =a×ν dyn +b

[0122] Among them, E sta is the static Young's modulus, ν sta is the static Poisson's ratio.

[0123] The model building module uses the calculated mechanical parameter curve to fit the mechanical parameter trend line to obtain the extrapolated mechanical parameter curve; the extrapolated mechanical parameter curve is used to construct a three-dimensional geomechanical model of the surrounding rock formation under the constraints of the inversion results. Furthermore, the extrapolated mechanical parameter curve is used to perform variogram analysis in space; the Gaussian random simulation method is used to construct a three-dimensional geomechanical model of the surrounding rock formation.

[0124] Based on the three-dimensional geomechanical model, the stress prediction module uses Schlumberger's three-dimensional geomechanical module VISAGE to determine the original site stress, including the minimum horizontal principal stress, the maximum horizontal principal stress and the overlying rock pressure.

[0125] Embodiment 4

[0126] This embodiment provides an electronic device, the electronic device comprising:

[0127] A memory storing executable instructions;

[0128] A processor runs the executable instructions in the memory to implement the above-mentioned method of establishing a three-dimensional geomechanical model to predict ground stress.

[0129] Embodiment 5

[0130] This embodiment provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for establishing a three-dimensional geomechanical model to predict geostress is implemented.

[0131] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0132] In summary, the present invention predicts the geomechanical parameter logging data of the entire well section, combines the inversion results, further constructs a three-dimensional geomechanical parameter model of the overlying and underlying strata, adjusts and optimizes the geomechanical parameter model, and improves the accuracy of the geomechanical model.

[0133] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for establishing a three-dimensional geomechanical model to predict ground stress. It is characterized in that include: Establish a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir; Calculate geomechanical parameter curves based on one-dimensional geomechanical data of the reservoir; Based on the calculated geomechanical parameter curve, a three-dimensional geomechanical model of the surrounding rock formation is established; The geostress is predicted based on the three-dimensional geomechanical model.

2. The method for predicting ground stress by establishing a three-dimensional geomechanical model according to claim 1, It is characterized in that The three-dimensional finite element mesh of the surrounding rock formation is established based on the three-dimensional geological model of the reservoir, including: Adding overburden, underburden and side strata outside the reservoir to obtain a new model; The new model is regularized into a rectangle and the 3D finite element mesh of the surrounding rock formations is added at each boundary.

3. The method for predicting ground stress by establishing a three-dimensional geomechanical model according to claim 1, It is characterized in that The calculation of geomechanical parameter curve based on one-dimensional geomechanical data of the reservoir includes calculating the dynamic elastic modulus according to the time difference data of longitudinal wave and shear wave. The calculation formula of dynamic elastic modulus is: Among them, ρ b is the rock mass density, in g / cm 3 ; Δt s and Δt P are the time differences of transverse and longitudinal waves respectively.

4. The method for establishing a three-dimensional geomechanical model to predict geostress according to claim 3, It is characterized in that Calculate the dynamic Young's modulus and Poisson's ratio: Among them, E dyn is the dynamic Young's modulus, ν dyn is the dynamic Poisson’s ratio; The calculation formula from the dynamic modulus to the static model is: E sta =a×E dyn +b n sta =a×n dyn +b Among them, E sta is the static Young's modulus, ν sta is the static Poisson's ratio.

5. The method for establishing a three-dimensional geomechanical model to predict ground stress according to claim 1, It is characterized in that The establishment of a three-dimensional geomechanical model for the surrounding rock strata includes: Using the calculated mechanical parameter curve, the mechanical parameter trend line is fitted to obtain the extrapolated mechanical parameter curve; Using the extrapolated mechanical parameter curve, a three-dimensional geomechanical model of the surrounding rock formation is constructed under the constraints of the inversion results.

6. The method for establishing a three-dimensional geomechanical model to predict geostress according to claim 5, It is characterized in that Further including using the extrapolated mechanical parameter curve to perform variogram analysis in space; The Gaussian random simulation method is used to construct a three-dimensional geomechanical model of the surrounding rock strata.

7. The method for establishing a three-dimensional geomechanical model to predict geostress according to claim 1, It is characterized in that Based on the 3D geomechanical model, the Schlumberger 3D geomechanics module VISAGE is used to determine the original site stress, including the minimum horizontal principal stress, the maximum horizontal principal stress and the overlying rock pressure.

8. A device for establishing a three-dimensional geomechanical model to predict ground stress, It is characterized in that include: A mesh building module is used to build a three-dimensional finite element mesh for the surrounding rock formation based on the three-dimensional geological model of the reservoir; A parameter calculation module calculates the geomechanical parameter curve based on the one-dimensional geomechanical data of the reservoir; Model building module, which builds a three-dimensional geomechanical model of the surrounding rock formation based on the calculated geomechanical parameters; The stress prediction module predicts ground stress based on the three-dimensional geomechanical model.

9. An electronic device, It is characterized in that The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method for establishing a three-dimensional geomechanical model to predict geostress as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the method for establishing a three-dimensional geomechanical model to predict geostress as described in any one of claims 1 to 7 is implemented.

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