Method and apparatus for obtaining rock mechanics parameters, computer device, storage medium

Abstract

An embodiment of the present application provides a method and apparatus for obtaining rock mechanical parameters, a computer device, and a storage medium. The method for obtaining rock mechanical parameters includes: obtaining a three-dimensional image and mineral phase composition of a micro-core; constructing a three-dimensional pore mineral structure model based on the three-dimensional image and the mineral phase composition; slicing the three-dimensional pore mineral structure model to obtain a two-dimensional pore mineral structure model; constructing a digital core geometric model based on the two-dimensional pore mineral structure model; and performing numerical simulation on the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model. The embodiment of the present application uses a micro-core sample and performs numerical simulation on the digital core geometric model established for the micro-core sample by combining the finite element method and the discrete element method, and can accurately and quickly obtain the rock mechanical parameters.

Description

Technical Field

[0001] The present invention relates to the technical fields of rock physics and petroleum logging, and particularly relates to a method and device for obtaining rock mechanical parameters, a computer device, and a storage medium. Background Art

[0002] In related technologies, reservoir rock samples are obtained by using petroleum drilling technologies, and the uniaxial compression and triaxial compression tests of the rock samples are carried out to analyze the process of the rock samples being compressed and fractured, so as to obtain static rock mechanical parameters. However, the rock samples obtained by using petroleum drilling technologies have limitations such as high cost, small quantity, poor quality, and long cycle, and it is difficult to obtain complete cores for some drillings. Summary of the Invention

[0003] The main purpose of the embodiments of the present application is to provide a method and device for obtaining rock mechanical parameters, a computer device, and a storage medium, which can avoid the limitations of obtaining rock samples by using petroleum drilling technologies and quickly obtain rock mechanical parameters.

[0004] To achieve the above object, in the first aspect of the embodiments of the present application, a method for obtaining rock mechanical parameters is provided. The method includes:

[0005] Obtaining a three-dimensional image and mineral phase composition of a micro-core;

[0006] Constructing a three-dimensional pore mineral structure model according to the three-dimensional image and the mineral phase composition;

[0007] Slicing the three-dimensional pore mineral structure model to obtain a two-dimensional pore mineral structure model;

[0008] Constructing a digital core geometric model according to the two-dimensional pore mineral structure model;

[0009] Performing numerical simulation on the compression and fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model.

[0010] In some embodiments, the performing numerical simulation on the compression and fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model includes:

[0011] Performing mesh division on the digital core geometric model according to the finite element method to obtain a set of elements;

[0012] Setting the mesh element mineral mechanical parameters for the mesh elements in the set of elements;

[0013] Constructing boundary constraint conditions;

[0014] Use the mineral mechanical parameters of the grid cells as the input parameters of the discrete element method, and numerically simulate the compression and fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the rock mechanical parameters of the digital core geometric model.

[0015] In some embodiments, setting the grid cell mineral mechanical parameters for the grid cells in the cell set includes:

[0016] Obtain the coordinates and pixel values of the pixel points in the digital core geometric model;

[0017] Match the coordinates with the grid cells in the cell set, and use the pixel value as the label of the corresponding grid cell;

[0018] Group the cell set according to the label to obtain grouped grid cells;

[0019] Set the grid cell mineral mechanical parameters for the grouped grid cells.

[0020] In some embodiments, the grid cell mineral mechanical parameters include cell boundary contact parameters. Using the grid cell mineral mechanical parameters as the input parameters of the discrete element method, and numerically simulating the compression and fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the rock mechanical parameters of the digital core geometric model includes:

[0021] Use the cell boundary contact parameters as the input parameters of the discrete element method, and numerically simulate the compression and fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the stress data and strain data of the digital core geometric model;

[0022] Obtain the rock mechanical parameters of the digital core geometric model according to the stress data and the strain data.

[0023] In some embodiments, after numerically simulating the compression and fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model, the rock mechanical parameter acquisition method further includes:

[0024] Obtain sample rock mechanical parameters;

[0025] Calibrate the rock mechanical parameters of the digital core geometric model according to the sample rock mechanical parameters.

[0026] In some embodiments, constructing the digital core geometric model according to the two-dimensional pore mineral structure model includes:

[0027] Obtain the pixel density and pixel size of the two-dimensional pore mineral structure model;

[0028] Construct the digital core geometric model according to the pixel density and the pixel size.

[0029] In some embodiments, the obtaining the three-dimensional image and mineral phase composition of the micro-core includes:

[0030] Obtain the three-dimensional image of the micro-core collected by a computed tomography device;

[0031] Obtain the mineral phase composition of the micro-core collected by an X-ray diffraction device.

[0032] A second aspect of the embodiments of the present application provides a device for obtaining rock mechanical parameters, the device includes:

[0033] An obtaining module, configured to obtain the three-dimensional image and mineral phase composition of the micro-core;

[0034] A first model construction module, configured to construct a three-dimensional pore mineral structure model according to the three-dimensional image and the mineral phase composition;

[0035] A slicing module, configured to slice the three-dimensional pore mineral structure model to obtain a two-dimensional pore mineral structure model;

[0036] A second model construction module, configured to construct a digital core geometric model according to the two-dimensional pore mineral structure model;

[0037] A numerical simulation module, configured to numerically simulate the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model.

[0038] A third aspect of the embodiments of the present application provides a computer device, the computer device includes a memory and a processor, wherein a program is stored in the memory, and when the program is executed by the processor, the processor is used to execute the method according to any one of the embodiments of the first aspect of the present application.

[0039] A fourth aspect of the embodiments of the present application provides a storage medium, the storage medium is a computer-readable storage medium, and the storage medium stores computer-executable instructions, and the computer-executable instructions are used to cause a computer to execute the method according to any one of the embodiments of the first aspect of the present application.

[0040] The method and device for obtaining rock mechanical parameters, computer equipment, and storage medium proposed in the embodiments of the present application obtain the three-dimensional image and mineral phase composition of a micro-core, construct a three-dimensional pore-mineral structure model based on the three-dimensional image and mineral phase composition, slice the three-dimensional pore-mineral structure model to obtain a two-dimensional pore-mineral structure model, construct a digital core geometric model based on the two-dimensional pore-mineral structure model, and perform numerical simulation on the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model. The embodiments of the present application simulate the compressive fracture process of the digital core geometric model through a numerical simulation method combining the finite element method and the discrete element method, can quickly obtain the rock mechanical parameters, and avoid the limitations in aspects such as rock sample acquisition and incomplete core. Description of the Drawings

[0041] Figure 1 is the first flowchart of the method for obtaining rock mechanical parameters provided by the embodiments of the present application;

[0042] Figure 2 is Figure 1 the flowchart of the specific method of step S150 in;

[0043] Figure 3 is Figure 2 the flowchart of the specific method of step S220 in;

[0044] Figure 4 is Figure 2 the flowchart of the specific method of step S240 in;

[0045] Figure 5 is the second flowchart of the method for obtaining rock mechanical parameters provided by the embodiments of the present application;

[0046] Figure 6 is Figure 1 the flowchart of the specific method of step S140 in;

[0047] Figure 7 is the module structure diagram of the device for obtaining rock mechanical parameters provided by the embodiments of the present application. Detailed Embodiments

[0048] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0049] It should be noted that although functional modules are divided in the schematic diagram of the device and the logical sequence is shown in the flowchart, in some cases, the steps shown or described can be executed in a different module division in the device or a different order in the flowchart. Terms such as "first" and "second" in the description, claims, and the above-mentioned drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs. The terms used herein are only for the purpose of describing embodiments of the present invention and are not intended to limit the present invention.

[0051] In the field of petroleum engineering applications, rock mechanics parameters such as elastic modulus, Poisson's ratio, and compressive strength are important input parameters for studying reservoir pore pressure prediction, in-situ stress calculation, fracture effect evaluation, and other application problems. Accurately and quickly obtaining rock mechanics parameters is of great significance for solving these application problems. In related technologies, the uniaxial compression, triaxial compression, and shear tests of indoor rock samples are carried out to analyze the process of rock sample compression and fracture, and static rock mechanics parameters are obtained. However, reservoir rock samples obtained through oil drilling have limitations such as high cost, poor quality, and long cycle, and it is difficult to obtain cores with satisfactory integrity in some wells.

[0052] Based on this, the main purpose of the embodiments of this application is to propose a method for obtaining rock mechanics parameters. By selecting micro-core samples that are easier to obtain, it avoids the problems of high cost, poor quality, long cycle, and non-satisfactory integrity of reservoir rock samples obtained through oil drilling. By obtaining the three-dimensional image and mineral phase composition of the micro-core samples, a digital core geometric model is constructed, and the numerical simulation of the compression and fracture process of the digital core geometric model is carried out according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model. By combining the finite element method and the discrete element method to perform numerical simulation on the digital core geometric model, the rock mechanics parameters can be accurately and quickly obtained.

[0053] The method for obtaining rock mechanics parameters, its device, computer equipment, and storage medium provided by the embodiments of this application will be specifically described through the following embodiments. First, the method for obtaining rock mechanics parameters in the embodiments of this application will be described.

[0054] Referring to Figure 1 , according to the method for obtaining rock mechanics parameters in the first aspect embodiment of this application, the method for obtaining rock mechanics parameters includes but is not limited to steps S110 to S150.

[0055] S110, obtain the three-dimensional image and mineral phase composition of the micro-core;

[0056] S120. Construct a three-dimensional pore-mineral structure model based on the three-dimensional image and mineral phase composition.

[0057] S130. Slice the three-dimensional pore-mineral structure model to obtain a two-dimensional pore-mineral structure model.

[0058] S140. Construct a digital core geometric model based on the two-dimensional pore-mineral structure model.

[0059] S150. Numerically simulate the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model.

[0060] In step S110, a three-dimensional image of the micro-core is collected by a computed tomography device, and the mineral phase composition of the micro-core is collected by an X-ray diffraction device. The computed tomography device can be a high-resolution micron CT. By scanning the micro-core, projection data of each angle of the micro-core is obtained, and the projection data is converted into a two-dimensional grayscale image of the core cross-section through a built-in mathematical algorithm of the device, and then the two-dimensional grayscale image is analyzed into a three-dimensional grayscale image through a combination algorithm. The mineral phase composition is the mineral composition of the micro-core and the proportion of each mineral composition.

[0061] In step S120, there are various irregular pores inside the micro-core, and these pores directly affect the mechanical properties of the micro-core. In order to accurately obtain the rock mechanics parameters, in the embodiment of the present application, a three-dimensional pore-mineral structure model is constructed based on the three-dimensional grayscale image collected by the computed tomography device and the mineral phase composition collected by the X-ray diffraction device. The specific process is as follows: Smooth and denoise the three-dimensional grayscale image according to non-local mean filtering to obtain a smooth image; Determine the threshold grayscale interval according to the threshold segmentation method; Match the threshold grayscale interval with the mineral phase composition to establish a mapping relationship between the threshold grayscale interval and the mineral phase composition; Judge the grayscale value of the pixel points in the smooth image to be in the threshold grayscale interval, and obtain the mineral phase composition of the pixel points corresponding to the grayscale value of the smooth image according to the mapping relationship between the threshold grayscale interval and the mineral phase composition. When the mineral phase composition corresponding to all pixel points in the smooth image is determined, the three-dimensional pore-mineral structure model is established.

[0062] In steps S130 to S140, set the two-dimensional profile and slice thickness. When the slice instruction slice is received, slice the three-dimensional pore-mineral structure model according to the two-dimensional profile and the slice thickness to obtain a two-dimensional pore-mineral structure model. The slice thickness can be 1 pixel, and a digital core geometric model is constructed according to the pixel point density and pixel point size of the two-dimensional pore-mineral structure model.

[0063] In step S150, the finite element method is used to solve continuous deformation problems, and the discrete element method is used to solve discontinuous deformation problems. Since the micro-core sample undergoes processes such as elastic deformation, crack initiation, plastic damage, and fracture, which are continuous-discontinuous deformation problems, the embodiments of the present application combine the finite element method and the discrete element method to model the compressive fracture process of the micro-core sample, which can reproduce the phenomena of pore structure deformation, pore connectivity expansion, and overall failure of the rock sample during the progressive compression of the core, and can accurately and quickly obtain rock mechanical parameters.

[0064] The method for obtaining rock mechanical parameters proposed by the embodiments of the present application includes obtaining the three-dimensional image and mineral phase composition of the micro-core, constructing a three-dimensional pore-mineral structure model based on the three-dimensional image and mineral phase composition, slicing the three-dimensional pore-mineral structure model to obtain a two-dimensional pore-mineral structure model, constructing a digital core geometric model based on the two-dimensional pore-mineral structure model, numerically simulating the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method, and obtaining the rock mechanical parameters of the digital core geometric model. The embodiments of the present application select micro-core samples that are relatively easy to obtain, avoiding problems such as high cost, poor quality, long cycle, and non-compliance with integrity conditions of reservoir rock samples obtained by oil drilling, and can accurately and quickly obtain rock mechanical parameters by numerically simulating the digital core geometric model through the combination of the finite element method and the discrete element method.

[0065] In some embodiments, as Figure 2 shown, step S150 specifically includes but is not limited to steps S210 to S240.

[0066] S210, perform mesh division on the digital core geometric model according to the finite element method to obtain an element set;

[0067] S220, set the mesh element mineral mechanical parameters for the mesh elements in the element set;

[0068] S230, construct boundary constraint conditions;

[0069] S240, use the mesh element mineral mechanical parameters as input parameters for the discrete element method, and numerically simulate the compressive fracture process of the digital core geometric model according to the input parameters and boundary constraint conditions to obtain the rock mechanical parameters of the digital core geometric model.

[0070] In step S210, according to the finite element method, the problem of solving rock mechanics parameters is simplified into a digital core geometric model, and the digital core geometric model is divided into multiple element sets. It should be noted that the digital core geometric model can be meshed by numerical simulation preprocessing software such as Cubit-trelis, HyperMesh, and trelis to obtain an element set, where the element set is multiple mesh elements and the multiple mesh elements are connected to each other. Taking trelis as an example for meshing, by configuring options such as the shape, size, and meshing ratio of the element mesh, and executing the mesh command, the digital core geometric model is divided into multiple mesh elements. When the shape of the set element mesh is a triangle, after executing the mesh command, the digital core geometric model will be divided into multiple triangular mesh elements.

[0071] In step S220, if the shape of the mesh element is a triangle, then set the mesh element mineral mechanics parameters for the multiple triangular mesh elements in the element set.

[0072] In step S230, construct boundary constraint conditions, where the boundary constraint conditions are the constraint conditions for numerical simulation to make the numerical simulation calculation converge. In the indoor uniaxial rock sample fracturing test, by fixing the bottom of the rock sample and applying a downward force on the upper part of the rock sample, the rock sample is fractured. To simulate the indoor uniaxial rock sample fracturing test, the boundary constraint conditions constructed in the embodiments of the present application are that the fixed speed at the bottom of the rock sample is 0 and the top moves downward at a certain speed.

[0073] In step S240, the mesh element mineral mechanics parameters include element basic mechanics parameters and element boundary contact parameters. Among them, the element basic mechanics parameters include density, elastic modulus, and Poisson's ratio. The element boundary contact parameters are input parameters specified by the discrete element method and can be calculated according to the element basic mechanics parameters. Take the element basic mechanics parameters as the initial mechanics parameters of the digital core geometric model, input the element boundary contact parameters into the discrete element method. If the element boundary contact parameter is greater than the boundary constraint condition, it means that the micro-core rock sample is fractured; if it is less than the boundary constraint condition, it means that the micro-core rock sample is not fractured. Update the basic mechanics parameters by changing the boundary contact parameter to obtain the final rock mechanics parameters.

[0074] In some embodiments, as Figure 3 shown, step S220 specifically includes but is not limited to steps S310 to S340.

[0075] S310, obtain the coordinates and pixel values of the pixel points in the digital core geometric model;

[0076] S320, match the coordinates with the mesh elements of the element set, and use the pixel value as the label of the corresponding mesh element;

[0077] S330. Group the unit set according to the labels to obtain grouped grid units;

[0078] S340. Set the grid unit mineral mechanical parameters for the grouped grid units.

[0079] In steps S310 to S340, obtain the coordinates and pixel values of each pixel point in the digital core set model, match the coordinates of the pixel points with the coordinates of the grid units to obtain the corresponding grid units, and use the pixel values of the pixel points as the labels of the grid units. Since each pixel point has a determined mineral composition, label the grid units according to the pixel values of the pixel points, so that the grid units also have determined mineral compositions. If the mineral compositions between the grid units are the same, it means that the grid units are in the same grouped grid unit, and set the corresponding grid unit mineral mechanical parameters for each grouped grid unit.

[0080] In some embodiments, as Figure 4 shown, step S240 specifically includes but is not limited to steps S410 to S420.

[0081] S410. Take the unit boundary contact parameter as the input parameter of the discrete element method, and numerically simulate the compressive fracture process of the digital core geometric model according to the input parameter and the boundary constraint conditions to obtain the stress data and strain data of the digital core geometric model;

[0082] S420. Obtain the rock mechanical parameters of the digital core geometric model according to the stress data and strain data.

[0083] In steps S410 to S420, input the unit boundary contact parameter into the discrete element method. If the unit boundary contact parameter is greater than the boundary constraint condition, it means that the digital core geometric model has fractured. Take the direction parallel to the velocity direction applied to the top of the digital core geometric model as the axial direction, and the direction perpendicular to the axial direction as the lateral direction. Obtain the contact force in the axial direction and the area of the contact surface, and obtain the axial stress data according to the ratio of the contact force in the axial direction to the contact surface area. Obtain the axial displacement according to the axial velocity and the model time, and obtain the axial strain data according to the ratio of the axial displacement to the model length. The calculation method of the lateral strain data is the same as that of the axial strain data, which will not be elaborated here. Draw a curve with the strain data as the x-axis and the stress data as the y-axis, and take the slope of the relatively straight part of the curve as the elastic modulus, that is, the ratio of the stress data to the strain data in this part; take the ratio of the axial strain data to the lateral strain data in this part as the Poisson's ratio, and take the stress data at the peak point in the curve as the compressive strength, and obtain the rock mechanical parameters according to the elastic modulus, Poisson's ratio, and compressive strength.

[0084] In some embodiments, as Figure 5As shown, after step S150, the method for obtaining rock mechanical parameters specifically includes, but is not limited to, steps S510 to S520.

[0085] S510, obtain the rock mechanical parameters of the sample;

[0086] S520, calibrate the rock mechanical parameters of the digital core geometric model according to the rock mechanical parameters of the sample.

[0087] In steps S510 to S520, the rock mechanical parameters of the sample are the rock mechanical parameters at the macroscopic scale, which are obtained from indoor fracturing tests on large-sized rock samples. The rock mechanical parameters of the digital core geometric model are the rock mechanical parameters at the microscopic scale, that is, obtained by numerical simulation using micro-sized rock samples. Due to the size effect of the rock samples, the conversion relationship of rock mechanical parameters from the microscopic scale to the macroscopic scale can be obtained based on the rock mechanical parameters of the digital core geometric model and the rock mechanical parameters of the sample. By adding sample rock mechanical parameters such as porosity, brittle mineral content, and size effect to obtain the conversion relationship, and adjusting the rock mechanical parameters of the digital core geometric model according to this conversion relationship to calibrate the rock mechanical parameters of the digital core geometric model and optimize the digital core geometric model.

[0088] In some embodiments, as Figure 6 shown, step S140 specifically includes, but is not limited to, steps S610 to S620.

[0089] S610, obtain the pixel density and pixel size of the two-dimensional pore mineral structure model;

[0090] S620, construct a digital core geometric model according to the pixel density and pixel size.

[0091] In steps S610 to S620, the two-dimensional pore mineral structure model can be square slice data. According to the product of the density of the pixels in this square slice data, for example, 1000*1000, and the pixel size of 1 μm, the size of the two-dimensional digital core geometric model is 1 mm, and a square with a side length of 1 mm is used as the digital core geometric model.

[0092] Next, with reference to Figures 1 to 6 a specific embodiment is used to describe in detail the method for obtaining rock mechanical parameters according to the embodiments of the present invention. It should be understood that the following description is only an exemplary illustration and not a specific limitation of the invention.

[0093] The micro-core is scanned using high-resolution micro-CT to obtain the three-dimensional gray-scale image of the skeleton structure and the mineral phase composition of the micro-core. The non-uniform filtering is performed on the three-dimensional gray-scale image of the skeleton structure to obtain a smoothed image. The mineral phase composition corresponding to the pixels of the smoothed image is obtained according to the threshold segmentation method to construct a three-dimensional pore-mineral structure model. The three-dimensional pore-mineral structure model is sliced to obtain a two-dimensional pore-mineral structure model. The digital core geometric model is established based on the pixel density and pixel size of the two-dimensional pore-mineral structure model. The digital core geometric model is divided into triangular meshes to obtain a set of elements. The triangular meshes in the set of elements are marked, and the triangular meshes are grouped according to the marks to obtain grouped mesh elements. The mechanical parameters of the mesh elements are set for the grouped mesh elements, and the boundary constraint conditions are applied to simulate the compression and fracture process of the micro-core. The axial stress-strain data and lateral strain data of the digital core geometric model at different time steps are obtained. The rock mechanical parameters of the core at the micro-scale are obtained based on the axial stress-strain data and lateral strain data, and the sample rock mechanical parameters are used to calibrate the rock mechanical parameters at the micro-scale.

[0094] The embodiment of the present application also provides a device for obtaining rock mechanical parameters. As Figure 7 shown, the device for obtaining rock mechanical parameters can implement the above method for obtaining rock mechanical parameters. The device includes an acquisition module 710, a first model construction module 720, a slicing module 730, a second model construction module 740, and a numerical simulation module 750. The acquisition module 710 is used to acquire the three-dimensional image and the mineral phase composition of the micro-core; the first model construction module 720 is used to construct a three-dimensional pore-mineral structure model according to the three-dimensional image and the mineral phase composition; the slicing module 730 is used to slice the three-dimensional pore-mineral structure model to obtain a two-dimensional pore-mineral structure model; the second model construction module 740 is used to construct a digital core geometric model according to the two-dimensional pore-mineral structure model; the numerical simulation module 750 is used to numerically simulate the compression and fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanical parameters of the digital core geometric model.

[0095] The device for obtaining rock mechanical parameters in the embodiment of the present application is used to execute the method for obtaining rock mechanical parameters in the above embodiment, and its specific processing process is the same as that of the method for obtaining rock mechanical parameters in the above embodiment, and will not be described in detail here.

[0096] The rock mechanics parameter acquisition device proposed in the embodiments of the present application obtains the three-dimensional image and mineral phase composition of a micro-core, constructs a three-dimensional pore mineral structure model based on the three-dimensional image and mineral phase composition, slices the three-dimensional pore mineral structure model to obtain a two-dimensional pore mineral structure model, constructs a digital core geometric model based on the two-dimensional pore mineral structure model, numerically simulates the compression and fracture process of the digital core geometric model according to the finite element method and the discrete element method, and obtains the rock mechanics parameters of the digital core geometric model. By selecting an easily obtainable micro-core sample, the embodiments of the present application avoid problems such as high cost, poor quality, long cycle, and non-compliance with integrity conditions of reservoir rock samples obtained by oil drilling, and can accurately and quickly obtain rock mechanics parameters through numerical simulation of the digital core geometric model by combining the finite element method and the discrete element method.

[0097] The embodiments of the present application also provide a computer device, including:

[0098] At least one processor, and,

[0099] A memory communicatively connected to the at least one processor; wherein,

[0100] The memory stores instructions, and the instructions are executed by the at least one processor so that when the at least one processor executes the instructions, the method according to any one of the embodiments in the first aspect of the present application is implemented.

[0101] This computer device includes: a processor, a memory, an input / output interface, a communication interface, and a bus.

[0102] The processor can be implemented in ways such as a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided by the embodiments of the present application;

[0103] The memory can be implemented in forms such as a ROM (Read Only Memory), a static storage device, a dynamic storage device, or a RAM (Random Access Memory). The memory can store an operating system and other application programs. When implementing the technical solutions provided by the embodiments of this specification through software or firmware, the relevant program codes are stored in the memory and are called by the processor to execute the rock mechanics parameter acquisition method of the embodiments of the present application;

[0104] The input / output interface is used to implement information input and output;

[0105] A communication interface for implementing communication interaction between this device and other devices, which can achieve communication through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.); and

[0106] A bus for transmitting information between various components of the device (such as a processor, a memory, an input / output interface, and a communication interface);

[0107] Among them, the processor, the memory, the input / output interface, and the communication interface are communicatively connected to each other inside the device through the bus.

[0108] The embodiment of the present application also provides a storage medium, which is a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the method for obtaining rock mechanics parameters according to the embodiment of the present application.

[0109] As a non-transitory computer-readable storage medium, the memory can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory may include high-speed random access memory and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories can be connected to the processor through a network. Examples of the above networks include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0110] The embodiments described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0111] Those skilled in the art can understand that Figures 1 to 6 the technical solutions shown in do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than those shown in the figures, or combine some steps, or different steps.

[0112] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0113] Those of ordinary skill in the art will understand that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or a suitable combination thereof.

[0114] As used in the specification of this application and the above-mentioned drawings, the terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances so that the embodiments of this application described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0115] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the relationship between associated objects and indicates that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist simultaneously. Here, A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (one)" or a similar expression thereof refers to any combination of these items, including any combination of single items or plural items. For example, at least one (one) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0116] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical, or other forms.

[0117] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0118] In addition, each functional unit in various embodiments of the present application can be integrated into a 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 a software functional unit.

[0119] If the above-mentioned integrated 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 technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media that can store programs such as USB flash drives, mobile hard disks, read-only memory (ROM for short), random access memory (RAM for short), magnetic disks, or optical discs.

[0120] The preferred embodiments of the embodiments of the present application have been described above with reference to the drawings, but this does not limit the scope of rights of the embodiments of the present application. Any modification, equivalent replacement, and improvement made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall be within the scope of rights of the embodiments of the present application.

Claims

1. A method for obtaining rock mechanics parameters, characterized in that, The method includes: Obtaining a three-dimensional image and mineral phase composition of a micro-core; Constructing a three-dimensional pore-mineral structure model based on the three-dimensional image and the mineral phase composition; Slicing the three-dimensional pore-mineral structure model to obtain a two-dimensional pore-mineral structure model; Constructing a digital core geometric model based on the two-dimensional pore-mineral structure model; Performing numerical simulation on the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model; The performing numerical simulation on the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model includes: Performing mesh division on the digital core geometric model according to the finite element method to obtain an element set; Setting the mesh element mineral mechanics parameters for the mesh elements in the element set; Constructing boundary constraint conditions; Taking the mesh element mineral mechanics parameters as the input parameters of the discrete element method, and performing numerical simulation on the compressive fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the rock mechanics parameters of the digital core geometric model; The setting the mesh element mineral mechanics parameters for the mesh elements in the element set includes: Obtaining the coordinates and pixel values of the pixel points in the digital core geometric model; Matching the coordinates with the mesh elements of the element set, and taking the pixel value as the label of the corresponding mesh element; Grouping the element set according to the label to obtain grouped mesh elements; Setting the mesh element mineral mechanics parameters for the grouped mesh elements.

2. The method for obtaining rock mechanics parameters according to claim 1, characterized in that, The mesh element mineral mechanics parameters include element boundary contact parameters. The taking the mesh element mineral mechanics parameters as the input parameters of the discrete element method, and performing numerical simulation on the compressive fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the rock mechanics parameters of the digital core geometric model includes: Taking the element boundary contact parameters as the input parameters of the discrete element method, and performing numerical simulation on the compressive fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the stress data and strain data of the digital core geometric model; Obtaining the rock mechanics parameters of the digital core geometric model according to the stress data and the strain data.

3. The method for obtaining rock mechanics parameters according to claim 1, characterized in that After performing numerical simulation on the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model, the rock mechanics parameter acquisition method further includes: Obtaining sample rock mechanics parameters; Performing parameter calibration on the rock mechanics parameters of the digital core geometric model according to the sample rock mechanics parameters.

4. The method for obtaining rock mechanics parameters according to any one of claims 1 to 3, characterized in that The constructing a digital core geometric model based on the two-dimensional pore-mineral structure model includes: Obtaining the pixel point density and pixel point size of the two-dimensional pore-mineral structure model; Constructing the digital core geometric model according to the pixel point density and the pixel point size.

5. The method for obtaining rock mechanics parameters according to any one of claims 1 to 3, characterized in that The obtaining of the three-dimensional image and mineral phase composition of the micro-core includes: Obtaining the three-dimensional image of the micro-core collected by a computed tomography device; Obtaining the mineral phase composition of the micro-core collected by an X-ray diffraction device.

6. Rock mechanics parameter acquisition device, characterized in that, The device includes: An obtaining module, configured to obtain the three-dimensional image and mineral phase composition of the micro-core; A first model construction module, configured to construct a three-dimensional pore mineral structure model according to the three-dimensional image and the mineral phase composition; A slicing module, configured to slice the three-dimensional pore mineral structure model to obtain a two-dimensional pore mineral structure model; A second model construction module, configured to construct a digital core geometric model according to the two-dimensional pore mineral structure model; A numerical simulation module, configured to numerically simulate the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model; The numerically simulating the compressive fracture process of the digital core geometric model according to the finite element method and the discrete element method to obtain the rock mechanics parameters of the digital core geometric model includes: Performing mesh division on the digital core geometric model according to the finite element method to obtain an element set; Setting the mesh element mineral mechanics parameters for the mesh elements in the element set; Constructing boundary constraint conditions; Taking the mesh element mineral mechanics parameters as input parameters of the discrete element method, and numerically simulating the compressive fracture process of the digital core geometric model according to the input parameters and the boundary constraint conditions to obtain the rock mechanics parameters of the digital core geometric model; The setting the mesh element mineral mechanics parameters for the mesh elements in the element set includes: Obtaining the coordinates and pixel values of the pixel points in the digital core geometric model; Matching the coordinates with the mesh elements of the element set, and taking the pixel value as the label of the corresponding mesh element; Grouping the element set according to the label to obtain grouped mesh elements; Setting the mesh element mineral mechanics parameters for the grouped mesh elements.

7. Computer device, characterized in that, The computer device includes a memory and a processor. Among them, a program is stored in the memory, and when the program is executed by the processor, the processor is used to execute: The method according to any one of claims 1 to 5.

8. A storage medium, the storage medium being a computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by a computer, the computer is used to execute: The method according to any one of claims 1 to 5.

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