Method for constructing a model of mixed component clay mineral particles and use thereof

Abstract

The application provides a construction method of a mixed component clay mineral particle model and application thereof. The construction method comprises the following steps: clay mineral main component single cell model construction, clay mineral main component super cell model construction, clay mineral mixed period model construction, and clay mineral nano particle model construction. The model composition is closer to the actual clay mineral situation, no real sample needs to be collected, is not affected by the sample source and quantity, can be used for repeated experiments, is simulated by a computer, saves manpower, is particularly suitable for mechanism research of physical and chemical properties and interaction relationship of clay mineral layers or particles, and provides a basic model for deep microcosmic, visualized and quantified research of well wall stability.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration and development, and more specifically, to a method for constructing a mixed-component clay mineral particle model and its application. Background Technology

[0002] During oil drilling, the hydration, expansion, and dispersion of clay minerals can easily lead to wellbore instability, significantly increasing drilling risks. Traditional methods for studying the expansion and dispersion mechanisms of clay minerals involve macroscopic measurements of properties such as expansion amount and shear tensile strength using instruments, but these methods are insufficient for microscopic studies, lacking effective means to investigate the expansion and dispersion mechanisms at the molecular level of clay minerals.

[0003] Molecular simulations can be used to study the cellular structure at the molecular level, allowing for direct observation of the microstructural changes in clay mineral cells and the acquisition of microscopic performance parameters. This provides a basis for better explaining the expansion and dispersion mechanisms of clay minerals. A prerequisite for simulation research is the construction of a molecular model that closely approximates the actual structure of shale and mudstone.

[0004] Currently, clay minerals mainly consist of components such as montmorillonite, illite, and kaolinite. Modeling clay minerals involves numerical simulations to perform physical modeling from a macroscopic perspective, primarily used to study properties such as formation pressure and porosity distribution.

[0005] Patent CN104007463A provides an artificial shale physical model, its manufacturing method, and its application. The manufacturing method of the artificial shale physical model includes: uniformly mixing an adhesive with stone powder, wherein the adhesive is an epoxy resin adhesive, and the stone powder comprises 10%-70% quartz, 10%-80% kaolin, 4%-25% organic carbon powder, and 3%-10% calcite, with the adhesive accounting for 5%-35% of the total mass of the stone powder; filling the adhesive-stone powder mixture into a mold, fixing it horizontally on a pressure device, adjusting the vertical pressure to 80-300 MPa, and fixing it for at least 24 hours for preliminary curing; demolding, and drying the preliminarily cured shale sample at 30-50℃ to obtain the artificial shale physical model.

[0006] Patent CN103713320A discloses a method for establishing a rock physics model of organic-rich mudstone and shale. The method is as follows: by fully considering the influence of pore shape using Wu's (1966) two-dimensional pore surface ratio and / or Berryman's (1980) four special three-dimensional pore morphologies, the critical porosity limit for different pore types is eliminated by using the differential equivalent medium theory, and organic matter is used as the solid inclusion of the rock. The Brown-Korringa equation is used for solid substitution to establish a rock physics model of organic-rich mudstone and shale that can predict elastic wave velocity.

[0007] Patent CN104007485 A provides a method for establishing a petrophysical model of complex-porosity mudstone and shale. Based on an improved Xu-Payne theory, this model addresses the complex pore characteristics of carbonate reservoirs by incorporating organic matter distribution and classifying pore types into matrix pores and kerogen pores. Matrix pores are further divided into intragranular pores, intergranular pores, and fractures, characterized by aspect ratios of 0.8, 0.15, and 0.01, respectively. Kerogen pores are microfractures filled with hydrocarbons and are characterized by an aspect ratio of 0.01. The mixture of kerogen and hydrocarbons is replaced by solids using the Brown-Korringa equation, with an assumed aspect ratio of 0.8. This establishes a petrophysical model of mudstone and shale that considers the influence of organic matter and complex pore types.

[0008] The above patents belong to the field of geophysical research, and the models are all macroscopic physical models, which cannot reflect the microscopic structure at the molecular level of clay minerals. Therefore, they are not very applicable to the study of the expansion and dispersion mechanism of clay minerals. Another type of patent models the several components that make up clay minerals separately. These models have a single component and cannot fully reflect the mixing properties of clay minerals. Moreover, these models are all supercells, which can only reflect interlayer properties and cannot study the interactions between clay particles. Summary of the Invention

[0009] To address the problems existing in the prior art, this invention proposes a method for constructing a mixed-component clay mineral particle model, providing a more realistic basic model for the simulation study of clay mineral hydration expansion and dispersion mechanisms, and laying the foundation for in-depth, microscopic, visual, and quantitative research on wellbore stability.

[0010] One of the objectives of this invention is to provide a method for constructing a mixed-component clay mineral particle model, comprising the following steps: (1) constructing a single-cell model of the main clay mineral components, (2) constructing a supercell model of the main clay mineral components, (3) constructing a mixed-period model of clay minerals, and (4) constructing a clay mineral nanoparticle model.

[0011] Preferably, the model of the mixed component clay mineral particles can be constructed using one of the following software: Materials Studio, LAMMPS, Gromacs, and AMBER; more preferably, Materials Studio software can be used.

[0012] The clay minerals mainly include at least one of montmorillonite, illite, and kaolinite. The mixed clay minerals may be clay minerals with two or three of montmorillonite and illite as main components. The two or three of the main components mentioned above may be arranged in a layer ratio structure within the clay minerals, for example, 1:1, 2:2, 1:2, 1:1:1, 2:2:2, etc.

[0013] Step (1) of the construction method of the present invention includes constructing a cell box based on the cell parameters of the main components of clay minerals, adding corresponding atoms to the cell box according to the coordinates of the atomic parameters of each cell, and obtaining a single cell model of each main component; preferably, the single cell model is constructed using the Build crystals tool of Materials Studio software.

[0014] Step (2) of the construction method of the present invention includes expanding the single cell models of each main component obtained in step (1) to establish supercell models of the main components of clay minerals and optimizing the structure of each supercell model; preferably, the supercell model is constructed using the supercell tool of Materials Studio software.

[0015] Preferably, a supercell model of at least one of the following clay mineral main components is established: 4a×2b×1c, 4a×4b×1c, 2a×4b×1c, and 6a×2b×1c; more preferably, a 4a×2b×1c supercell model is established.

[0016] Preferably, structural optimization of each supercell model includes: selecting Ultra-fine accuracy, Universal force field, Charge using QEq, Ewald electrostatic summation method, Atom-based van der Waals term summation method, and selecting a cutoff radius of [value missing].

[0017] Step (3) of the construction method of the present invention includes cutting the supercell model after structural optimization obtained in step (2) from the layer, building a layered structure on the cut model according to the actual proportion of each component of the clay mineral to be simulated; optimizing the built model, and when there is more than one layered structure, selecting the structure with the lowest energy as the mixed periodic model of the clay mineral.

[0018] Among them, cutting the supercell model from the layer means cutting from the (0 0 1) plane of the supercell model. The (001) plane is the layer. After each supercell is cut from the layer, the cells of each component can be stacked layer by layer to form a model.

[0019] Preferably, the supercell model is cut using the Cleave surface tool of Materials Studio software to obtain a supercell model with all cell boxes having an included angle of 90°.

[0020] Preferably, the Build Layers tool of Materials Studio software is used to build a layered structure on the cut supercell model.

[0021] Preferably, optimizing the layered structure includes: selecting Fine or Ultra-fine for accuracy, Universal for force field, Charge using QEq for charge, Ewald for electrostatic summation, and Atom based for van der Waals term summation.

[0022] Step (4) of the construction method of the present invention includes implementing nanoparticle modeling instructions on the hybrid periodic model obtained in step (3) to obtain nanoparticle models with different diameters;

[0023] Preferably, the Nanocluster command in the Build Nanostructure tool is used to input the required particle diameter and build a nanoparticle model.

[0024] The second objective of this invention is to provide the application of the method for constructing the mixed-component clay mineral particle model in petroleum exploration and development.

[0025] The present invention has the following beneficial effects:

[0026] (1) It provides a more realistic basic model for clay mineral research, which can then enable in-depth microscopic, visual and quantitative research.

[0027] (2) It is not limited by the source of traditional experimental samples or the number of tests, and can be used for repeated simulation studies, saving manpower and improving research efficiency. Attached Figure Description

[0028] Figure 1 This is a single-cell model of montmorillonite.

[0029] Figure 2 This is an illite single-cell model.

[0030] Figure 3 This is a single-cell model of kaolinite.

[0031] Figure 4 This is a montmorillonite supercell model.

[0032] Figure 5 This is an illite supercell model.

[0033] Figure 6 This is a supercell model for kaolinite.

[0034] Figure 7 The mixed periodic model is a 1:1:1 mixture of illite, kaolinite, and montmorillonite.

[0035] Figure 8 This is a front view of a 1:1:1 illite, kaolinite, and montmorillonite nanoparticle model with a diameter of 100 nm.

[0036] Figure 9 This is a top view of a 1:1:1 illite, kaolinite, and montmorillonite nanoparticle model with a diameter of 100 nm.

[0037] Figure 10 The results are simulations of the water molecule concentration distribution between montmorillonite and illite layers at a 1:1 scale. Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0039] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0040] This invention provides a modeling method for constructing a clay mineral particle model with mixed components. The composition of this model is closer to the actual clay mineral situation. It does not require the collection of real samples, is not affected by the source or quantity of experimental samples, can be used for repeatable experiments, and can be simulated by computer, saving manpower. It is particularly suitable for the study of the physicochemical properties and interaction mechanisms of clay mineral interlayers or particles, and provides a basic model for in-depth microscopic, visual, and quantitative research on wellbore stability.

[0041] This invention provides a method for constructing a mixed-component clay mineral particle model, including steps such as constructing a single-cell model of the main clay mineral components, constructing a supercell model, constructing a mixed periodic model, and constructing a nanoparticle model.

[0042] According to a preferred embodiment of the present invention, the construction method is accomplished using the Materials Studio simulation software package.

[0043] According to a preferred embodiment of the present invention, the construction is performed in the Visualizer interface of the Materials Studio software.

[0044] According to a preferred embodiment of the present invention, the construction method includes the following steps:

[0045] (1) Construction of single-cell model of major components of clay minerals

[0046] Based on the unit cell parameters of the main components of clay minerals, a unit cell box is constructed. According to the coordinates of the atomic parameters of each unit cell, corresponding atoms are added to the unit cell box to obtain the single unit cell model of each main component of clay minerals.

[0047] (2) Construction of supercell model of major components of clay minerals

[0048] The single-cell model in step (1) is expanded to establish a supercell model of the main components of clay minerals, and the structure of each supercell model is optimized.

[0049] (3) Construction of clay mineral mixing periodic model

[0050] After the supercell model in step (2) is optimized, it is cut from the layers. According to the actual proportion of each component of the clay mineral to be simulated, the cut model is constructed into a layered structure. The constructed model is then optimized. When there is more than one layered structure, the structure with the lowest energy is selected as the mixed periodic model of the clay mineral.

[0051] (4) Construction of clay mineral nanoparticle model

[0052] Apply nanoparticle modeling instructions to the hybrid periodic model in step (3) to obtain nanoparticle models with different diameters.

[0053] According to a more preferred embodiment of the present invention, the construction method includes the following steps:

[0054] (1) Construction of single-cell model of major components of clay minerals

[0055] Using the Build crystals tool in Materials Studio software, a unit cell box is constructed based on the unit cell parameters of the main components of clay minerals. According to the coordinates of the atomic parameters of each unit cell, the corresponding atoms are added to the unit cell box to obtain the single unit cell model of each main component of clay minerals.

[0056] (2) Construction of supercell model of major components of clay minerals

[0057] Using the supercell tool in Materials Studio software, 4a×2b×1c supercell structures of each major component of clay minerals were established. The supercell structures of montmorillonite and illite were subjected to isomorphous lattice substitution. The structures of each supercell model were optimized.

[0058] (3) Construction of clay mineral mixing periodic model

[0059] Using the Cleave surface tool in Materials Studio software, the (0 0 1) planes of the optimized supercell model were cut. Based on the actual proportions of each component of the clay mineral to be simulated, the cut model was constructed into a layered structure. The constructed model was then structurally optimized.

[0060] When there is more than one type of layered structure, the structure with the lowest energy is selected as the mixed periodic model for clay minerals. For example, clay minerals containing two main components can be superimposed in a 1:1 layer ratio, a 1:2 layer ratio, a 2:1 layer ratio, a 2:2 layer ratio, etc. For superpositions of more than two layers, multiple mixed periodic models are first established according to different superposition orders, and then the structure with the lowest energy is selected as the mixed periodic model for the clay minerals.

[0061] (4) Construction of clay mineral nanoparticle model

[0062] Using the Nanocluster command in the Build Nanostructure tool of Materials Studio software, the specific diameter value is input according to the required particle diameter to establish a hybrid periodic model to implement the nanoparticle model.

[0063] Example 1

[0064] Method for constructing a montmorillonite, illite, and kaolinite model with a layer ratio of 1:1:1

[0065] (1) Construction of single-cell models of montmorillonite, illite, and kaolinite

[0066] In the Visualizer interface of Materials Studio software, the Build crystals tool is used to construct unit cell boxes based on the unit cell parameters of montmorillonite, illite, and kaolinite. According to the corresponding atomic coordinates of each unit cell model (unit cell parameters and atomic coordinates can be obtained from the American Mineral Crystal Structure Database), the corresponding atoms are added to the unit cell boxes using the Atom command to obtain single-cell models of montmorillonite, illite, and kaolinite (e.g., ...). Figure 1 , 2 (As shown in Figure 3).

[0067] (2) Construction of supercell models of montmorillonite, illite, and kaolinite

[0068] Supercell was used to construct 4a×2b×1c supercell structures for montmorillonite, illite, and kaolinite, respectively. Isomorphic lattice substitution was then performed on the supercell structures of montmorillonite and illite. For montmorillonite, in the silicon-oxygen tetrahedra of the supercell model, one in every 32 Si atoms was replaced by Al, and in the aluminum-oxygen octahedra, one in every eight Al atoms was replaced by Mg. Six sodium ions were added between the layers to balance the six negative charges generated by the isomorphic substitution. For illite, one in every eight Si atoms on the tetrahedral layers was replaced by Al, and adjacent atoms could not be substituted simultaneously. Eight potassium ions were added between the layers to balance the eight negative charges generated by the isomorphic substitution. The supercell models of kaolinite, lattice-substituted montmorillonite, and illite were then structurally optimized (e.g., Figure 4 , 5 As shown in Figure 6), the parameter selections are as follows: Ultra-fine for precision, Universal for Forcefield, Charge using QEq for charge, Ewald for Electrostatic summation, Atom based for van der Waals term summation, and the cutoff radius is...

[0069] (3) Construction of a 1:1:1 illite-kaolinite-montmorillonite mixed periodic model

[0070] The (0 0 1) planes of the optimized supercell models of montmorillonite, illite, and kaolinite were cut using the Cleave surface tool to obtain supercell models with 90° included angles between the cell boxes. The Build Layers tool was used to build 1:1:1 layered structures of the cut models in the following sequences: ① illite-montmorillonite-kaolinite, ② illite-kaolinite-montmorillonite, and ③ montmorillonite-illite-kaolinite. The structures of each built model were optimized using the following parameters: Ultra-fine precision, Universal Forcefield, Charge using QEq, Ewald electrostatic summation method, and Atom based van der Waals term summation method. The model with the lowest energy was selected as the 1:1:1 montmorillonite, illite, and kaolinite mixed periodic model (e.g., Figure 7 (As shown).

[0071] (4) Construction of the 1:1:1 illite-kaolinite-montmorillonite nanoparticle model

[0072] Using the Nanocluster command in the Build Nanostructure tool, input the desired particle diameter to build a 1:1:1 mixed nanoparticle model of montmorillonite, illite, and kaolinite (e.g., Figure 8 , Figure 9 As shown, the nanoparticles have a diameter of 100 nm.

[0073] Example 2

[0074] Method for constructing a 1:1 montmorillonite and illite model

[0075] (1) Construction of single-cell models of montmorillonite and illite

[0076] In the Visualizer interface of Materials Studio software, the Build crystals tool is used to construct unit cell boxes based on the unit cell parameters of montmorillonite and illite. According to the corresponding atomic coordinates of each unit cell model (unit cell parameters and atomic coordinates can be obtained from the American Mineral Crystal Structure Database), the corresponding atoms are added to the unit cell boxes through the Atom command to obtain the single unit cell models of montmorillonite and illite respectively.

[0077] (2) Construction of montmorillonite and illite supercell models

[0078] Using the Supercell tool, 4a×2b×1c supercell structures of montmorillonite and illite were established respectively. Isomorphic lattice substitution was then performed on the supercell structures of montmorillonite and illite using the same method as in Example 1. The supercell models of montmorillonite and illite after lattice substitution were then optimized with the following parameters: Ultra-fine precision, Universal Forcefield, Charge using QEq, Ewald electrostatic summation method, Atom based van der Waals term summation method, and cutoff radius.

[0079] (3) Construction of a 1:1 montmorillonite-illite mixed periodic model

[0080] The (0 01) plane of the optimized montmorillonite and illite supercell model was cut using the Cleave surface tool to obtain a supercell model with a 90° angle between the cell boxes. Then, the Build Layers tool was used to build a 1:1 layered structure of the cut model in the order of montmorillonite-illite. Finally, the structure of the built model was optimized. The specific parameters were: Ultra-fine for accuracy, Universal for Forcefield, Charge using QEq for charge, Ewald for Electrostatic summation, and Atom based for van der Waals term summation, to obtain a 1:1 montmorillonite and illite mixed periodic model.

[0081] (4) Construction of a 1:1 montmorillonite-illite nanoparticle model

[0082] Using the Nanocluster command in the Build Nanostructure tool, input the required particle diameter to build a 1:1 montmorillonite-illite nanoparticle model.

[0083] Example 3

[0084] Method for constructing a 1:2 montmorillonite and illite model

[0085] (1) Construction of single-cell models of montmorillonite and illite

[0086] In the Visualizer interface of Materials Studio software, the Build crystals tool is used to construct a unit cell based on the unit cell parameters of montmorillonite and illite. According to the corresponding atomic coordinates of each unit cell model (unit cell parameters and atomic coordinates can be obtained from the American Mineral Crystal Structure Database), the corresponding atoms are added to the unit cell using the Atom command item to obtain the single unit cell model of montmorillonite and illite.

[0087] (2) Construction of montmorillonite and illite supercell models

[0088] Using the Supercell tool, 4a×2b×1c supercell structures of montmorillonite and illite were constructed respectively. Isomorphic lattice substitution was then performed on the supercell structures of montmorillonite and illite using the same method as in Example 1. The supercell models of montmorillonite and illite after lattice substitution were then optimized with the following parameters: Ultra-fine precision, Universal Forcefield, Charge using QEq, Ewald electrostatic summation method, Atom based van der Waals term summation method, and cutoff radius.

[0089] (3) Construction of a 1:2 montmorillonite-illite mixed periodic model

[0090] The (0 01) plane of the optimized montmorillonite and illite supercell models was cut using the Cleave surface tool to obtain supercell models with 90° included angles between the cell boxes. The Build Layers tool was used to build 1:2 layered structures of the cut models in the order of ① montmorillonite-illite-illite and ② illite-montmorillonite-illite. The structures of each built model were optimized. The specific parameters were: Ultra-fine for accuracy, Universal for Forcefield, Charge using QEq for charge, Ewald for Electrostatic summation, and Atom based for van der Waals term summation. The model with the lowest energy was selected as the 1:2 montmorillonite-illite mixed periodic model.

[0091] (4) Construction of a 1:2 montmorillonite-illite nanoparticle model

[0092] Using the Nanocluster command in the Build Nanostructure tool, input the required particle diameter to build a 1:2 montmorillonite-illite nanoparticle model.

[0093] Example 4

[0094] Method for constructing a 2:2 montmorillonite and illite model

[0095] (1) Construction of single-cell models of montmorillonite and illite

[0096] In the Visualizer interface of Materials Studio software, the Build crystals tool is used to construct a unit cell based on the unit cell parameters of montmorillonite and illite. According to the corresponding atomic coordinates of each unit cell model (unit cell parameters and atomic coordinates can be obtained from the American Mineral Crystal Structure Database), the corresponding atoms are added to the unit cell using the Atom command to obtain the single unit cell model of montmorillonite and illite.

[0097] (2) Construction of montmorillonite and illite supercell models

[0098] Using the Supercell tool, 4a×2b×1c supercell structures of montmorillonite and illite were constructed respectively. Isomorphic lattice substitution was performed on the supercell structures of montmorillonite and illite using the same method as in Example 1. The supercell models of montmorillonite and illite after lattice substitution were then optimized with the following parameters: Ultra-fine precision, Universal Forcefield, Charge using QEq, Ewald electrostatic summation method, Atom based van der Waals term summation method, and cutoff radius.

[0099] (3) Construction of a 2:2 montmorillonite-illite mixed periodic model

[0100] The (0 0 1) plane of the optimized montmorillonite and illite supercell models was cut using the Cleave surface tool to obtain supercell models with 90° included angles between the cell boxes. The Build Layers tool was used to build layered structures of the cut models in the following sequences: ① montmorillonite-montmorillonite-illite and ② montmorillonite-illite-montmorillonite. The structures of each built model were optimized. The specific parameters were: Ultra-fine for accuracy, Universal for Forcefield, Charge using QEq for charge, Ewald for Electrostatic summation, and Atom based for van der Waals summation. The model with the lowest energy was selected as the 2:2 montmorillonite-illite mixed periodic model.

[0101] (4) Construction of a 2:2 montmorillonite and illite nanoparticle model

[0102] Using the Nanocluster command in the Build Nanostructure tool, input the required particle diameter to build a 2:2 montmorillonite and illite nanoparticle model.

[0103] Example 5

[0104] Hydration simulations were performed on the nanoparticle model (nanoparticle diameter 10 nm) obtained in Example 2. After adding 48 water molecules between the montmorillonite and illite layers, the concentration distribution of the interlayer water molecules was calculated (see details in [link to results]). Figure 10 , Figure 10 The horizontal axis represents the distance between the two layers, and the vertical axis represents the concentration of water molecules. Figure 10 As can be seen, two sharp peaks appear along the 001 plane, indicating that water molecules are distributed in two layers along the direction parallel to the plane. The other two curves along the 101 and 010 planes are gentle, indicating that water molecules are evenly distributed along the direction perpendicular to the plane, without stratification.

[0105] For Example 2, the simulated interlayer spacing was compared with the actual interlayer spacing (the interlayer spacing of actual nanoparticles with a diameter of 10 nm and a montmorillonite layer ratio of 1:1). The results are shown in Table 1. The two values ​​are close, indicating that the modeling method and model of the present invention have high accuracy.

[0106] Table 1 Comparison of interlayer spacing data

[0107]

[0108] Comparative Example 1:

[0109] Simple montmorillonite component model without mixing period

[0110] A nanoparticle model of the single montmorillonite component was established using the same method as in Example 2.

[0111] Taking the model of Example 2 as an example, and using a non-mixing-period montmorillonite component model as a control, the interlayer spacing data were compared, and the results are shown in Table 2. The simulated and measured interlayer spacing values ​​of the two are quite similar, indicating that the accuracy of this modeling method is high. However, single-component modeling can only study the properties of single-component clay.

[0112] Table 2 Comparison of interlayer spacing data between mixed-period and non-mixed-period cycles

[0113]

[0114] Comparative Example 2:

[0115] The model was established using the same steps as in Example 2, except that the force fields were calculated using COMPASS II and Dreiding respectively. Taking the model of Example 2 as an example, the interlayer spacing data were compared, and the results are shown in Table 3 below.

[0116] Table 3 Comparison of interlayer spacing data for different force fields

[0117]

Claims

1. A method for constructing a mixed-component clay mineral particle model, comprising the following steps: (1) Construction of single-cell models of major clay mineral components; (2) Construction of supercell models of major clay mineral components: The single-cell models of each major component obtained in step (1) are expanded to establish supercell models of at least one of the following: 4a×2b×1c, 4a×4b×1c, 2a×4b×1c, and 6a×2b×1c. The structure of each supercell model is optimized; (3) Construction of mixed periodic models of clay minerals: The supercell models obtained in step (2) after structural optimization are cut from the layers. Specifically, the Cleave function of Materials Studio software is used. The surface tool is used to cut the supercell model to obtain a supercell model with a cell box angle of 90°. According to the actual proportion of each component of the clay mineral to be simulated, the cut model is constructed into a layered structure. The constructed model is optimized. When there is more than one layered structure, the structure with the lowest energy is selected as the mixed periodic model of the clay mineral. (4) Construction of clay mineral nanoparticle model; The main components of the clay mineral include at least one of montmorillonite, illite and kaolinite.

2. The method for constructing a mixed-component clay mineral particle model according to claim 1, characterized in that: The mixed-component clay mineral particle model was constructed using one of the following software: Materials Studio, LAMMPS, Gromacs, or AMBER.

3. The method for constructing a mixed-component clay mineral particle model according to any one of claims 1 to 2, characterized in that... Step (1) includes: Based on the unit cell parameters of the main components of clay minerals, a unit cell box is constructed. According to the coordinates of the atomic parameters of each unit cell, corresponding atoms are added to the unit cell box to obtain the single unit cell model of each main component.

4. The method for constructing a mixed-component clay mineral particle model according to claim 3, characterized in that: Use the Build crystals tool in Materials Studio software to build a single-cell model.

5. The method for constructing a mixed-component clay mineral particle model according to any one of claims 1 to 2, characterized in that... Step (2) includes: Use the supercell tool in Materials Studio software to build a supercell model.

6. The method for constructing a mixed-component clay mineral particle model according to claim 5, characterized in that: The structural optimization of each supercell model includes: selecting Universal force field, Charge using QEq charge, Ewald electrostatic summation method, Atom based van der Waals term summation method, and selecting a cutoff radius of 7~12 Å.

7. The method for constructing a mixed-component clay mineral particle model according to claim 1, characterized in that: The Build Layers tool in Materials Studio software was used to build a layered structure on the cut supercell model; And / or, Optimization of layered structures includes: selecting Universal for the force field, Charge using QEq for the charge, Ewald for the Electrostatic summation method, and Atom based for the van der Waals term summation method.

8. The method for constructing a mixed-component clay mineral particle model according to any one of claims 1 to 2, characterized in that... Step (4) includes: Apply nanoparticle modeling instructions to the hybrid periodic model obtained in step (3) to obtain nanoparticle models with different diameters.

9. The method for constructing a mixed-component clay mineral particle model according to claim 8, characterized in that: Using the Nanocluster command in the Build Nanostructure tool, input the desired particle diameter to build a nanoparticle model.

10. The application of the method for constructing a mixed-component clay mineral particle model according to any one of claims 1 to 9 in petroleum exploration and development.

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