Multi-field coupling natural hydrogen exploration selection method and electronic device

Abstract

The application provides a multi-field coupling natural hydrogen exploration selection method and electronic equipment, and relates to the technical field of natural hydrogen exploration. The method comprises the following steps: collecting comprehensive information of a target area; wherein the comprehensive information comprises geological data, gas component and isotope distribution information; wherein the geological data at least comprises underground water data, structure development data and lithology development data; determining the main source type of natural hydrogen in the target area based on the comprehensive information; based on the determined main source type of natural hydrogen and the geological data, constructing a three-dimensional geological body model of the target area by using a three-dimensional geological modeling software, and based on the gas component and the isotope distribution information; in the three-dimensional geological body model, loading a double-permeable medium seepage model based on Darcy's law, coupling a rare substance transfer field and a heat conduction field, performing transient numerical simulation to obtain natural hydrogen concentration distribution data in the target area, and determining a favorable area for natural hydrogen exploration according to the natural hydrogen concentration distribution data. The application can improve the universality and selection evaluation efficiency of the selection evaluation method for natural hydrogen.

Description

Technical Field

[0001] This invention relates to the field of natural hydrogen exploration technology, and in particular to a multi-field coupled natural hydrogen exploration site selection method and electronic equipment. Background Technology

[0002] The history of human energy utilization is a process of pursuing efficient energy use. Humans in the new era have placed higher demands on energy. Cleaner and more efficient energy sources, unlike traditional fossil fuels, represent the future direction of energy development. Hydrogen energy, due to its cleanliness and absolute zero carbon emissions, has gradually come into focus and become one of the key energy sources in the global energy revolution. With innovations in exploration, theory, and methods, previously overlooked underground natural hydrogen is gradually gaining attention again. Hydrogen levels of varying amounts have been discovered in many countries and regions. Hydrogen leaks with "fairy ring" structures have been detected, and records of hydrogen content in mines, oil and gas wells, and geothermal wells have also been found. Most of the discovered natural hydrogen is considered to be of inorganic origin, while some studies suggest that extremely low levels of soil hydrogen may be of microbial origin, and some may be formed from the deep pyrolysis of source rocks.

[0003] The evaluation methods for natural hydrogen exploration sites are currently in the research and development stage. Current methods can be categorized into two types: one involves weighted calculations based on relevant natural hydrogen factors to select exploration sites; the other relies on differences in natural hydrogen concentration at testing sites. The former lacks universality due to unclear weighting criteria, strong subjectivity, and fixed weight assignments, requiring adjustments to weighting relationships for different geological environments and hydrogen source characteristics, thus failing to adequately adapt to regional differences in natural hydrogen exploration. The latter method lacks depth, relying on natural hydrogen anomalies for evaluation. For example, surface natural hydrogen concentration cannot reflect the concentration within underground tectonic units, and underground natural hydrogen concentration cannot reflect the migration trends of natural hydrogen under fault-based systems. Therefore, existing methods for evaluating natural hydrogen exploration sites have limitations and shortcomings in practical applications, necessitating a more universal and procedural transformation. Summary of the Invention

[0004] This invention provides a multi-field coupled natural hydrogen exploration site selection method and electronic equipment to address the issue of improving the universality and efficiency of natural hydrogen site selection evaluation methods.

[0005] In a first aspect, embodiments of the present invention provide a method for selecting exploration sites for natural hydrogen using multi-field coupling, comprising: Collect comprehensive information about the target area; wherein the comprehensive information includes: geological data, gas composition and isotope distribution information; wherein the geological data includes at least groundwater data, tectonic development data and lithological development data; Based on the comprehensive information, determine the main source type of natural hydrogen in the target area; Based on the identified main sources of natural hydrogen and the geological data, a three-dimensional geological model of the target area is constructed using three-dimensional geological modeling software. The flow boundary, concentration boundary, thermal boundary, and mechanical boundary of the three-dimensional geological model are defined based on gas composition and isotope distribution information. In the three-dimensional geological model, a dual-permeability medium seepage model based on Darcy's law is loaded, and a rare substance transport field and a heat conduction field are coupled to perform transient numerical simulation to obtain natural hydrogen concentration distribution data in the target area, and favorable areas for natural hydrogen exploration are determined based on the natural hydrogen concentration distribution data.

[0006] In one possible implementation, determining the subsurface geological information of the target area based on the comprehensive information includes: The lithological distribution of the target area is determined based on the geological data. Based on the lithological distribution and the designated hydrogen source rocks, the primary source type of natural hydrogen in the target area is determined; wherein, the designated hydrogen source rocks include ophiolite, granite, basalt, uranium deposits, and hydrocarbon source rocks.

[0007] In one possible implementation, determining the subsurface geological information of the target area based on the comprehensive information further includes: Based on the distribution patterns of gas components and isotopes, the type of secondary natural hydrogen source was determined; The second source type includes inorganic origin and / or organic origin; The inorganic origins include Earth degassing, water-rock reaction, water radiation decomposition, and high-temperature decomposition; the organic origins include biological processes and organic matter pyrolysis.

[0008] In one possible implementation, constructing a three-dimensional geological model of the target area using three-dimensional geological modeling software includes: Use the software's built-in geometry tools to draw or import model files containing geodetic coordinates and actual geological information for each stratum to define porous media regions containing matrix and fractures.

[0009] In one possible implementation, the loading of the dual-permeability medium seepage model based on Darcy's law includes: Enable dual-permeability media features in the Darcy's Law interface to distinguish between macroporous and microporous regions; The seepage model for dual-permeability media based on Darcy's law is as follows: ; In the formula, The seepage velocity vector, For fluid dynamic viscosity, For the permeability tensor, p is the pressure gradient vector; When the magnitude of the seepage velocity vector is greater than a set value, it is determined to be a large pore region; when the magnitude of the seepage velocity vector is less than or equal to the set value, it is determined to be a micropore region.

[0010] In one possible implementation, prior to performing the transient numerical simulation, the method further includes: Based on the geological data, the initial pore pressure, initial hydrogen concentration distribution, and initial temperature field of the three-dimensional geological model are determined.

[0011] In one possible implementation, the step involves loading a dual-permeability medium seepage model based on Darcy's law into the three-dimensional geological model, and coupling the rarefied material transport field and the heat conduction field to perform transient numerical simulations, including: Select the transient solver, set the time step, and couple the porous medium flow field, the rarefied mass transfer field, and the heat conduction field to perform a multiphysics solution.

[0012] In one possible implementation, when performing the multiphysics coupling solution, the maximum element size of the free tetrahedral mesh is set, and the mesh is refined based on the maximum element size at the upper interface where the main source of natural hydrogen in the three-dimensional geological model is located. The step of refining the mesh at the upper interface where the main source of natural hydrogen in the three-dimensional geological model is located, based on the maximum element size, includes: Construct a multi-layered hydrogen concentration matrix with time variation as the dimension and the grid cell center as the reference:

[0013] If we disregard breakage and conduction, the hydrogen concentration in the next unit time will be equal to the original concentration. Concentration of cells diffused through Darcy flow per unit time in the Gaben grid cell Then we have:

[0014] in, , The seepage velocity vector, For fluid dynamic viscosity, For the permeability tensor, p is the pressure gradient vector. For unit grid area, The unit time step.

[0015] In one possible implementation, determining the favorable area for natural hydrogen exploration based on the natural hydrogen concentration distribution data includes: Based on the spatial gradient of natural hydrogen concentration, natural hydrogen enrichment areas are identified, and these areas are designated as favorable areas for natural hydrogen exploration.

[0016] In a second aspect, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect or any possible implementation thereof.

[0017] In this embodiment of the invention, geological data, gas composition, and isotope distribution information of the target area are first collected systematically. This comprehensively reflects the characteristics of underground geological structure, fluids, and gas sources, laying a reliable data foundation for subsequent analysis. Based on this information, the main source types of natural hydrogen are identified, effectively focusing on the dominant hydrogen source rocks within the study area and eliminating interference from non-dominant rock layers. Subsequently, a geological model is constructed using 3D geological modeling software, and multiphysics field boundaries are precisely defined, achieving high-fidelity digital characterization of complex underground spatial structures and initial conditions. On this basis, a dual-permeability medium seepage model based on Darcy's law is loaded, and transient numerical simulations are performed by coupling rare matter transport fields and heat conduction fields. This process dynamically reproduces the spatiotemporal evolution of natural hydrogen migration and accumulation in porous media. Finally, favorable exploration areas are determined based on the concentration distribution data obtained from the simulation, transforming the site selection evaluation work from traditional static qualitative judgment to dynamic quantitative prediction, improving the objectivity of the evaluation results and increasing the accuracy of natural hydrogen exploration. Attached Figure Description

[0018] Figure 1 This is an application scenario diagram of the multi-field coupled natural hydrogen exploration site selection method provided in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the implementation of a multi-field coupled natural hydrogen exploration site selection method according to an embodiment of the present invention. Figure 3 This is a schematic diagram showing the hydrogen generation layer according to a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the initial hydrogen concentration distribution according to a specific embodiment of the present invention; Figure 5 This is a schematic diagram of a geological body containing hydrogen source strata according to a specific embodiment of the present invention; Figure 6 yes Figure 5Schematic diagram of the corresponding upper strata and fault features; Figure 7 yes Figure 6 A schematic diagram of the corresponding concentration gradient distribution. Detailed Implementation

[0019] Currently, comprehensive evaluation methods for favorable areas include the following five: Geological analysis method: This method screens favorable areas based on fundamental geological data such as stratigraphy, structure, and lithology. Its advantages are strong foundational knowledge, low cost, and suitability for preliminary delineation; its disadvantages are reliance on experience-based judgment, high subjectivity, and limited accuracy.

[0020] Geophysical exploration (seismic, gravity, electrical, etc.): Identifies subsurface structures through differences in physical properties. Its advantages include wide coverage, the ability to reveal deep information, and high resolution; its disadvantages include high equipment costs, complex data processing, and a high degree of ambiguity in its solutions.

[0021] Geochemical exploration (soil / water chemical indicators, isotope analysis, etc.): directly detects chemical signals related to the target. Its advantages are high sensitivity and strong indicative power, making it suitable for target area delineation; its disadvantages are susceptibility to surface environmental interference (pollution, climate), high sampling density requirements, and limited coverage.

[0022] Remote sensing technology infers underground conditions through indirect indicators such as surface vegetation and landforms. Its advantages are speed and efficiency, suitability for large-scale (especially remote) assessments, and relatively low cost; its disadvantages are significant susceptibility to weather and vegetation variations, difficulty in interpreting indirect indicators, and limited accuracy.

[0023] Numerical simulation integrates multi-source data for modeling and prediction. Its advantages include quantifying the influence of multiple factors, dynamically simulating the process, and improving scientific rigor; its disadvantages include reliance on high-quality data, complex parameter settings, and the possibility that assumptions may deviate from reality.

[0024] Regarding the evaluation methods for natural hydrogen gas selection, research is currently in its early stages. Existing methods often combine geological analysis with expert-assigned values. The specific steps are as follows: 1. First, collect basic data on regional geology, remote sensing, geochemistry, and geophysics. Use remote sensing interpretation of the Andromeda Galaxy and geothermal anomalies to screen potential areas; 2. Using existing natural hydrogen source identification templates, determine the main sources of natural hydrogen, focusing on the primary sources within the study area; 3. Establish a geometric model of the Darcy flow geological body defined by boundary and initial conditions, including locating the hydrogen source and identifying the system's multiphysics fields, establishing the geological body model, loading the Darcy flow model, and applying load to the model; 5. Finally, conduct a natural hydrogen gas selection evaluation.

[0025] Numerical simulations possess powerful predictive capabilities, providing strong support for the study of hydrogen Darcy flow. Advanced software such as COMSOL, combined with Darcy's law and heat and mass transfer models, enables multi-physics coupled simulations of hydrogen storage systems, aiding in the optimization of structural design. Cutting-edge technologies such as dynamic mode decomposition provide in-depth analysis of the turbulent structure and evolution of hydrogen jets.

[0026] This invention aims to provide a multi-field coupled method for natural hydrogen exploration site selection by integrating geological analysis and numerical simulation. This method conducts in-depth analysis of collected subsurface lithological data of the exploration area, combines current research findings on the genesis of natural hydrogen, determines the type and distribution characteristics of hydrogen source rocks in the exploration area, and further considers the influence of groundwater on natural hydrogen occurrence. Based on this, it identifies the main source types of natural hydrogen in the study area, constructs a 3D geological model, and performs data-driven modeling of the main natural hydrogen-generating strata. This enables the evaluation of exploration site selection under a multi-physics coupled natural hydrogen three-dimensional accumulation system, ultimately forming a comprehensive methodology for natural hydrogen exploration and development site selection.

[0027] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0028] Figure 1 This diagram illustrates an application scenario of the multi-field coupled natural hydrogen exploration site selection method provided in this invention. Figure 1 As shown, geological data, gas composition, and isotope distribution information of the target area are collected through different information collection terminals. The above comprehensive information of the target area is then sent to the server via the network. The server centrally analyzes the comprehensive information, sorts out the collected data, filters out valuable information, and determines the underground geological conditions of the target area. This allows for a comprehensive analysis and judgment of whether the target area is suitable for natural hydrogen exploration, and the selection of natural hydrogen exploration areas, thereby improving the accuracy of exploration.

[0029] Figure 2 This is a flowchart illustrating the implementation of a multi-field coupled natural hydrogen exploration site selection method according to an embodiment of the present invention, as shown below. Figure 2 The steps shown are as follows: S201, Collect comprehensive information on the target area; the comprehensive information includes: geological data, gas composition and isotope distribution information; the geological data includes at least groundwater data, tectonic development data and lithological development data.

[0030] The execution subject of each embodiment of this application can be a server, processor, microprocessor, or other device with data processing capabilities. In actual implementation, the specific implementation method of the execution subject can be selected according to actual needs. This embodiment does not impose any special restrictions on this, as long as it is a device with data processing capabilities.

[0031] The target area refers to the candidate research area in the preliminary exploration stage of natural hydrogen exploration and development. In the specific implementation process, groundwater data such as groundwater depth and groundwater flow direction are obtained by drilling and logging in the target area.

[0032] The structural and lithological development data were obtained by researchers through field investigations, instrumental detection, laboratory analysis, and data integration.

[0033] In addition, soil gas samples are collected from the target area, optionally at least two samples per square kilometer, and the gas composition of the target area is determined based on multiple soil gas samples. Soil samples are collected from the target area, and soil isotope distribution information is obtained through laboratory testing. Optionally, at least three samples are collected per square kilometer, and the gas composition of the target area is determined based on multiple soil gas samples.

[0034] S202, based on comprehensive information, determines the main source type of natural hydrogen in the target area.

[0035] The origin of natural hydrogen can be divided into inorganic and organic origins. The main source rocks for hydrogen are ophiolite, granite, basalt, uranium deposits, and hydrocarbon source rocks. Based on the collected data and the distribution of potential hydrogen-generating rocks, the main sources of natural hydrogen are identified, usually with no fewer than two main sources.

[0036] In this embodiment, comprehensive analysis of the main sources of natural hydrogen in the target area can be achieved by integrating geological data, gas composition, and isotope distribution information.

[0037] S203, based on the identified main sources of natural hydrogen and geological data, uses 3D geological modeling software to construct a 3D geological model of the target area, and defines the flow boundary, concentration boundary, thermal boundary and mechanical boundary of the 3D geological model based on gas composition and isotope distribution information.

[0038] In one possible implementation, a three-dimensional geological model of the target area is constructed using three-dimensional geological modeling software, including: Use the software's built-in geometry tools to draw or import model files containing geodetic coordinates and actual geological information for each stratum to define porous media regions containing matrix and fractures. The clear delineation of matrix and fractures within the porous media regions closely reflects the true structural characteristics of underground rocks, avoiding errors caused by the single-medium assumption in traditional models.

[0039] In practical implementation, 3D geological modeling software is used to create digital geological bodies. Optionally, in this embodiment, the 3D geological modeling software is COMSOL Multiphysics 3D geological modeling software.

[0040] The 3D geological modeling software incorporates built-in geometric tools, allowing researchers to create geological models of the target area (including coal seams, aquifer structures, and porous media such as matrix and fractures) based on geological data, or import external models to construct relevant geological model files for the target area. Optionally, the external model files can be in formats such as STEP and IGES. The files include the geodetic coordinates of the target area and actual geological information for each stratum, providing a precise geometric basis for subsequent boundary delineation, parameter loading, and numerical simulation. This ensures the model accurately reflects the subsurface geological structure of the target area, improving the reliability and accuracy of subsequent simulation results.

[0041] Based on the main sources of natural hydrogen, the main hydrogen-supplying rock strata in the study area are identified. Gas composition and isotope distribution information obtained through surveys or field measurements are used to define flow boundaries, concentration boundaries, thermal boundaries, and mechanical boundaries.

[0042] S204. In the three-dimensional geological model, a dual-permeability medium seepage model based on Darcy's law is loaded, and the rare matter transfer field and heat conduction field are coupled to perform transient numerical simulation to obtain the natural hydrogen concentration distribution data in the target area, and the favorable area for natural hydrogen exploration is determined based on the natural hydrogen concentration distribution data.

[0043] In the specific implementation process, physical field interfaces are added to the 3D geological modeling software, including: Porous Media Flow, Transport of Diluted Species, Solid Mechanics, and Heat Transfer.

[0044] Among them, Porous Media Flow: Select the Darcy's Law interface to describe the percolation of hydrogen in porous media (suitable for low flow rate scenarios). Transport of Diluted Species: Enable the Convection and Diffusion module to simulate hydrogen concentration distribution; Solid Mechanics and Heat Transfer: Adding Linear Elastic Material to couple stress field and permeability evolution.

[0045] In the aforementioned three-dimensional geological model, a dual-permeability medium seepage model based on Darcy's law is loaded, and the rare matter transport field (using the Convection and Diffusion module) and the heat conduction field (adding Linear ElasticMaterial) are coupled. The transient solution type is selected, and the time step and total simulation duration are set (e.g., the time step is 100,000 years and the total simulation duration is 3 million years). The solver is configured as a multiphysics coupled solver, and numerical simulation is performed to finally obtain the natural hydrogen concentration distribution data at different time points and different spatial locations within the target area.

[0046] Finally, the simulated natural hydrogen concentration distribution data were analyzed, and gradient intervals were divided according to the spatial distribution characteristics of the concentration. Areas with concentrations higher than a set concentration (e.g., 0.5 mol / m³) were identified as natural hydrogen enrichment areas, which are the favorable areas for natural hydrogen exploration.

[0047] In this embodiment, geological data, gas composition, and isotope distribution information of the target area are first collected systematically. This comprehensively reflects the characteristics of underground geological structure, fluids, and gas sources, laying a reliable data foundation for subsequent analysis. Based on this information, the main source types of natural hydrogen are identified, effectively focusing on the dominant hydrogen source rocks within the study area and eliminating interference from non-dominant rock layers. Subsequently, a geological model is constructed using 3D geological modeling software, and multiphysics field boundaries are precisely defined, achieving high-fidelity digital characterization of complex underground spatial structures and initial conditions. On this basis, a dual-permeability medium seepage model based on Darcy's law is loaded, and transient numerical simulations are performed by coupling rare matter transport fields and heat conduction fields. This process dynamically reproduces the spatiotemporal evolution of natural hydrogen migration and accumulation in porous media. Finally, favorable exploration areas are determined based on the concentration distribution data obtained from the simulation, transforming the site selection evaluation work from traditional static qualitative judgment to dynamic quantitative prediction, improving the objectivity of the evaluation results and increasing the accuracy of natural hydrogen exploration.

[0048] In one possible implementation, the subsurface geological information of the target area is determined based on comprehensive information, including: Determine the lithological distribution of the target area based on geological data; Based on the lithological distribution and the identified hydrogen source rocks, determine the primary source type of natural hydrogen in the target area; among which, the identified hydrogen source rocks include ophiolite, granite, basalt, uranium deposits, and hydrocarbon source rocks.

[0049] Currently, the main known sources of hydrogen include five types: ophiolite, granite, basalt, uranium deposits, and hydrocarbon source rocks. Natural hydrogen originates from four main sources: serpentinization (water-rock reaction), radiation decomposition of water, deep mantle degassing, and pyrolysis of deep hydrocarbon source rocks.

[0050] In natural hydrogen exploration, the source type of hydrogen is controlled by the type of underground rocks. Ophiolite forms hydrogen through serpentinization. Redox reactions between iron-bearing minerals and water can also form hydrogen. Other sources include igneous rocks with iron ore, shallow or deep environments, and basalt with banded iron formations (BIF). Granite containing potassium minerals can radiatively decompose water to form a certain amount of hydrogen. Simultaneously, iron-bearing minerals such as biotite can form hydrogen through water-rock reactions. Water in contact with other radioactive nuclides such as uranium, thorium, and potassium can also form hydrogen through radiative decomposition. In practice, the source of hydrogen can be determined using a pre-set judgment model. When the lithological distribution of the target area includes any one or more of ophiolite, granite, basalt, uranium deposits, and source rocks, the primary source type of natural hydrogen can be further determined by combining water-rock reaction-related judgment models.

[0051] In the specific implementation process, such as Figure 3 As shown, hydrogen-generating layers can be displayed in a three-dimensional geological model based on the primary source type of natural hydrogen.

[0052] In this embodiment, the systematic analysis of geological data clarifies lithological distribution, providing a precise spatial basis for identifying hydrogen source rocks. Targeted screening based on five defined types of hydrogen source rocks quickly eliminates interference from non-primary source rocks, focusing on lithological types with actual hydrogen generation potential. A comprehensive assessment of development scale and hydrogen generation conditions ensures the accuracy of primary source type identification, providing a clear hydrogen source direction for subsequent model construction and simulation. This avoids simulation result deviations caused by ambiguous hydrogen source identification, enhancing the overall targeting of the exploration site selection method.

[0053] In the specific implementation process, the environment of the same target area is complex, and there may be multiple sources of natural hydrogen. In different embodiments, there are multiple ways to determine the source of natural hydrogen.

[0054] In one possible implementation, determining the subsurface geological information of the target area based on comprehensive information also includes: Based on the distribution patterns of gas components and isotopes, the type of secondary natural hydrogen source was determined; The second source type includes inorganic origin and / or organic origin; Among them, inorganic origins include Earth degassing, water-rock reaction, water radiation decomposition, and high-temperature decomposition; organic origins include biological processes and organic matter pyrolysis.

[0055] The aforementioned embodiments primarily determine the primary source type of natural hydrogen based on water-rock reactions by identifying lithological distribution and defining hydrogen source rocks. However, other hydrogen sources exist in actual production and daily life. In practical implementation, a pre-set template is used to identify the main sources of natural hydrogen based on the collected or tested hydrogen-containing gas components and isotope distribution patterns. These sources may be inorganic, primarily due to terrestrial degassing, water-rock reactions, water radiation decomposition, and high-temperature decomposition; or organic, primarily due to biological processes and organic matter pyrolysis.

[0056] Optionally, Earth degassing can be determined by whether the gaseous components contain inert gases without characteristics; water-rock reactions can be determined by whether there is evidence of mineral alteration; water radiation decomposition can be determined by whether there is enrichment of radioactive nuclides; high-temperature decomposition can be determined by whether the temperature reaches the conditions for inorganic high-temperature hydrogen generation; and the organic origin can be determined by determining whether there are established organic organisms or organic matter.

[0057] In this embodiment, precise analysis of gas composition and isotope distribution patterns verifies the rationality of the first source type from a chemical characteristic perspective, forming a dual discrimination system of "lithology-chemical characteristics." The clarification of the second source type further refines the hydrogen genesis, avoiding the limitations that may exist with single lithology discrimination. The clear distinction between organic and inorganic genesis provides a scientific basis for parameter settings in subsequent models, making the model more closely resemble actual hydrogen generation mechanisms. It also enhances the comprehensiveness and reliability of the source discrimination results, thereby improving the accuracy of the final exploration area selection.

[0058] In one possible implementation, loading a dual-permeability medium seepage model based on Darcy's law includes: Enable the dual-permeability media feature in the Darcy's Law interface to distinguish between macroporous and microporous regions.

[0059] In the specific implementation process, open the "Darcy's Law" interface in the 3D geological modeling software, and enable the "Dual-Permeability Medium" feature in the settings panel of this interface. Based on the lithological characteristics and pore structure analysis results of the target area, set the pore regions. Through the software's parameter association function, make the porosity, permeability, and other parameters of the dual-permeability medium correspond one-to-one with the lithological regions in the 3D geological body model, and complete the loading of the dual-permeability medium seepage model.

[0060] In this embodiment, by enabling the dual-permeability medium feature and distinguishing between macropore and micropore regions, the influence of pore structure differences in different lithological regions on hydrogen seepage can be accurately reflected, avoiding the deficiency of a single seepage model that cannot distinguish the seepage characteristics of different media. The loading of the dual-permeability medium seepage model makes the simulation of hydrogen seepage underground more realistic, accurately capturing the rapid migration of hydrogen in macropore regions and the slow diffusion characteristics in micropore regions. This provides a precise seepage mechanics basis for subsequent concentration distribution simulations, enhancing the scientific rigor of the simulation results.

[0061] In one possible implementation, prior to performing the transient numerical simulation, the following is also included: Based on geological data, the initial pore pressure, initial hydrogen concentration distribution, and initial temperature field of the three-dimensional geological model were determined.

[0062] In actual implementation, the pore pressure at different depths or in different rock layers can be determined by combining the distribution of rock strata in geological materials and groundwater data, or pore pressure detection sensors can be arranged at different locations in the exploration well to collect pore pressure data.

[0063] Optionally, the hydrogen concentration distribution at different locations can be obtained by sampling at different locations, or the hydrogen concentration distribution can be determined by combining the hydrogen generation potential of the hydrogen-generating layer.

[0064] Optionally, temperature values ​​at different locations can be obtained by placing temperature sensors or infrared spectrometers at different locations in the exploration well.

[0065] Among them, the pore pressure, hydrogen concentration and temperature values ​​are discrete. In order to reflect the changing trend of each, interpolation is performed based on the measured data of the target area to determine the initial pore pressure, initial hydrogen concentration distribution and initial temperature field.

[0066] After determining the initial pore pressure, initial hydrogen concentration distribution, and initial temperature field, the distribution status can be displayed in the corresponding 3D geological body model of the target area using 3D geological modeling software. For example... Figure 4 An example diagram of hydrogen concentration distribution is shown.

[0067] In this embodiment, the initial pore pressure, initial hydrogen concentration distribution, and initial temperature field are all determined based on measured geological data of the target area and reasonable interpolation calculations, avoiding deviations from reality in the initial conditions caused by subjective assumptions. Precise initial conditions provide a reliable starting point for transient numerical simulation, ensuring that the simulation process can accurately reflect the migration, diffusion, and accumulation patterns of hydrogen underground.

[0068] In one possible implementation, a dual-permeability medium seepage model based on Darcy's law is loaded into a three-dimensional geological model, and a rarefied material transport field and a heat conduction field are coupled to perform transient numerical simulations, including: Select the transient solver, set the time step, and couple the porous medium flow field, the rarefied mass transfer field, and the heat conduction field to perform a multiphysics solution.

[0069] The software establishes a coupling relationship between the porous media flow field, the rare matter transport field, and the heat conduction field. The seepage velocity of the porous media flow field serves as the input to the convection term of the rare matter transport field, influencing the convective diffusion process of hydrogen. The temperature distribution of the heat conduction field indirectly affects the porous media flow field and the rare matter transport field by influencing fluid viscosity and rock permeability. The software's multiphysics coupling solver is enabled, and the solution accuracy is set. The coupled governing equations are numerically solved to obtain data on the natural hydrogen concentration, pressure, and temperature distributions at different time points.

[0070] In this embodiment, the selection of the transient solver and the appropriate time step setting can fully simulate the dynamic accumulation process of natural hydrogen on a million-year scale, avoiding the shortcomings of steady-state simulations that cannot reflect temporal evolution. The coupled solution of multiple physics fields considers the interactions between seepage, mass transfer, and heat transfer, conforming to the complex physicochemical processes of natural hydrogen accumulation, and is more comprehensive than single-physics field simulations. The adaptive time step algorithm and high-precision solution settings improve computational efficiency while ensuring simulation accuracy, ensuring that the simulation results accurately reflect the spatiotemporal variation of hydrogen concentration, and providing numerical support for the delineation of favorable regions.

[0071] In one possible implementation, when performing multiphysics coupling solutions, the maximum element size of the free tetrahedral mesh is set, and the mesh is refined based on the maximum element size at the upper interface where the main source of natural hydrogen in the three-dimensional geological model is located.

[0072] In this embodiment, the selection of free tetrahedral meshes can adapt to the complex geometry of 3D geological models, ensuring the integrity and rationality of mesh generation. The setting of the maximum element size balances simulation accuracy and computational efficiency. Mesh refinement at the upper interface, where the main source of natural hydrogen is located, accurately captures the key process of hydrogen migration upwards from the hydrogen-generating layer, avoiding parameter abrupt changes caused by overly coarse meshes in critical areas. The setting of boundary layer features and equation-based automatic mesh refinement further improve the simulation accuracy of fractured regions and areas with drastic parameter changes, reduce numerical discretization errors, and make the results of multiphysics coupling solutions more closely reflect reality, improving the accuracy of concentration distribution analysis and favorable zone delineation.

[0073] In one possible implementation, favorable areas for natural hydrogen exploration are determined based on natural hydrogen concentration distribution data, including: Based on the spatial gradient of natural hydrogen concentration, areas rich in natural hydrogen were identified, and these areas were designated as favorable areas for natural hydrogen exploration.

[0074] Optionally, the spatial gradient can be pre-set. For example, based on the concentration distribution characteristics, five concentration gradient intervals can be defined: ≤0.05 mol / m³ (background region), 0.05-0.1 mol / m³ (low concentration region), 0.1-0.3 mol / m³ (medium concentration region), 0.3-0.5 mol / m³ (higher concentration region), and >0.5 mol / m³ (high concentration region).

[0075] Optionally, the hydrogen gradient can be determined based on the hydrogen concentration distribution in the target area. However, due to varying environmental complexities in different regions, the distribution of natural hydrogen differs. For example, the lowest hydrogen concentration in the target area might be 0.1 mol / m³, while the highest reaches 0.8 mol / m³, rendering the above concentration gradient division inapplicable. Therefore, to adapt to different exploration needs, dividing the hydrogen gradient based on the actual hydrogen distribution in the research area, i.e., the target area, can improve the accuracy of determining favorable areas for natural hydrogen exploration.

[0076] In different embodiments, areas with relatively high hydrogen concentrations are identified as natural hydrogen enrichment areas based on the spatial gradient of natural hydrogen concentration, and these natural hydrogen enrichment areas are identified as favorable areas for natural hydrogen exploration in the target area.

[0077] In this embodiment, zoning based on the spatial gradient of natural hydrogen concentration can intuitively reflect the degree of hydrogen accumulation and spatial distribution patterns, avoiding the shortcomings of subjectively delineating favorable areas in traditional methods. Identifying enriched areas as favorable exploration areas directly links hydrogen resource potential with exploration targets, ensuring the resource value of these areas. Quantitative analysis of the concentration gradient makes the boundaries and extent of favorable areas clearer, providing precise spatial guidance for subsequent well placement and exploration scope determination. It also enhances the scientific rigor and operability of favorable area delineation, making exploration work more targeted and efficient.

[0078] The above describes different improvement directions for 3D geological modeling software. The following describes the execution flow of 3D geological modeling software with specific examples.

[0079] First, based on actual data from drilling, logging, and geophysical exploration, a three-dimensional geological model that reflects the real underground conditions is constructed.

[0080] The model includes the reservoir geometry, porosity, permeability, temperature field, pressure field, and initial hydrogen distribution; and uses the simulation tool's built-in geometry tools to draw or import 3D models (such as coal seam and aquifer structures), defining porous media regions (matrix, fractures, etc.); the specific operation involves first establishing... Figure 5 The geological body shown is the main source of hydrogen, followed by... Figure 6 The upper strata and fault features are established as shown.

[0081] Then, the "Darcy's Law" seepage model is connected, and the "dual-permeability medium" feature is enabled to distinguish between macropore and micropore regions.

[0082] Specifically, from the Materials node, select a preset material (such as hydrogen or water) and automatically load parameters such as density and thermal conductivity; manually input or define material properties using formulas, such as setting a Darcy flow model that varies with temperature. This includes the following steps: 1. Perform single-field settings, including electromagnetics: apply Electric Potential to the conductor surface and set Scattering Boundary Condition at the outer boundary; fluid dynamics: define Velocity at the inlet and set Pressure to zero at the outlet.

[0083] 2. Configure coupling settings, including thermo-mechanical coupling: the temperature field is automatically transferred to the structural mechanics interface through the Thermal Expansion module to generate thermal strain; fluid-structure coupling: enable the Fluid-Structure Interaction interface and set the No-Slip condition at the fluid-solid interface.

[0084] 3. Enable the "Dual Osmosis Media" feature in the "Darcy's Law" interface to distinguish between macroporous and microporous regions, and input... This creates the Darcy flow conditions for hydrogen gas that distinguish between macropores and micropores. In the formula, The seepage velocity vector, For fluid dynamic viscosity, For the permeability tensor, p is the pressure gradient vector.

[0085] In the specific implementation process, regions with a seepage velocity vector greater than a set value are identified as macroporous areas; regions with a seepage velocity vector less than or equal to a set value are identified as microporous areas. The set value is an expert-based value determined by considering the geographical location and environmental conditions of the target area.

[0086] 4. Based on the actual geological environment, set the initial pore pressure, hydrogen concentration distribution (such as the original hydrogen saturation at hydrogen anomaly points), and temperature field.

[0087] 5. Set the maximum element size, select the Free Tetrahedral mesh under the Mesh node, and refine the mesh at the upper interface where the main source of natural hydrogen is located; add a Boundary Layer feature for natural hydrogen, specify 5-15 mesh layers and set the thickness growth rate (1.2-1.5), and accurately analyze the near-wall flow; activate the Based on Equations option, and the system will automatically refine the high stress or high temperature gradient region according to the PDE solution error.

[0088] Here, let S be the area of ​​a unit grid, and construct a multi-layered hydrogen concentration matrix with time variation as the dimension and the grid cell center as the reference:

[0089] If we disregard breakage and conduction, the hydrogen concentration in the next unit time will be equal to the original concentration. Concentration diffused through Darcy flow within a cell of the Gaben grid Then we have:

[0090] in, The hydrogen concentration per unit time for the next grid cell. T is the unit time step, and S is the grid area.

[0091] right Integrate both sides with respect to time t, and define the integration interval (assuming it is [ ]). ]), for both sides of the equation in the time interval [ , Integral within the inner boundary, i.e.:

[0092] Since μ and k typically do not change with time, they can be extracted from the integral sign:

[0093] Furthermore, because basin simulation software can obtain the reservoir's temperature and pressure paths, fluid charging history, and the evolution of fluid chemical composition throughout its geological history, it can also provide... Physical quantities in geological history. The establishment of "digital cores" in multiphysics finite element software can reflect the true pore distribution and mineral grain contact relationships, clearly defining the migration paths of natural hydrogen, thus clearly defining […]. The cumulative change in hydrogen during the stage.

[0094] When t-t0 approaches 1s, we can obtain , where i is related to the actual depth and mesh division, and n is related to the position of the mesh cell projected on the plane.

[0095] In the actual implementation, the upper part is a sandstone reservoir with a porosity of 18% and a permeability of 80 mD, and the lower part is a shale hydrogen-generating layer with a porosity of 5% and a permeability of 0.01 mD. An anticline trap structure exists in the upper part of the selected area. A stable hydrogen source supplying 1000 tons of hydrogen per million years is set at the bottom of the model. This data is based on previous summaries of the organic thermal evolution sources of natural hydrogen. The simulated geological time is set to 3 million years.

[0096] Finally, the simulation results are analyzed, and evaluation charts and data are output.

[0097] In the first 800,000 years of the simulation, hydrogen rises, and free hydrogen, driven by buoyancy, accumulates at the highest point of the trap, causing the gas concentration to continuously increase. The simulated hydrogen concentration is as follows: Figure 7 As shown.

[0098] This invention also provides an electronic device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described in the above method embodiments. Exemplarily, the electronic device may be a smartphone, tablet computer, laptop computer, desktop computer, smart speaker, smartwatch, etc., and is not limited thereto.

[0099] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0100] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A multi-field coupled method for selecting exploration sites for natural hydrogen, characterized in that, include: Collect comprehensive information about the target area; wherein the comprehensive information includes: geological data, gas composition and isotope distribution information; wherein the geological data includes at least groundwater data, tectonic development data and lithological development data; Based on the comprehensive information, determine the main source type of natural hydrogen in the target area; Based on the identified main sources of natural hydrogen and the geological data, a three-dimensional geological model of the target area is constructed using three-dimensional geological modeling software. The flow boundary, concentration boundary, thermal boundary, and mechanical boundary of the three-dimensional geological model are defined based on gas composition and isotope distribution information. In the three-dimensional geological model, a dual-permeability medium seepage model based on Darcy's law is loaded, and a rare substance transfer field and a heat conduction field are coupled to perform transient numerical simulation on a million-year scale to obtain natural hydrogen concentration distribution data in the target area, and favorable areas for natural hydrogen exploration are determined based on the natural hydrogen concentration distribution data. The determination of the underground geological information of the target area based on the comprehensive information includes: The lithological distribution of the target area is determined based on the geological data. Based on the lithological distribution and the identified hydrogen source rock, determine the primary source type of natural hydrogen in the target area; Determining the underground geological information of the target area based on the comprehensive information also includes: Based on the distribution patterns of gas components and isotopes, the type of secondary natural hydrogen source was determined; The loading of the dual-permeability medium seepage model based on Darcy's law includes: Enable dual-permeability media features in the Darcy's Law interface to distinguish between macroporous and microporous regions; A region is defined as having large pores when the magnitude of the seepage velocity vector is greater than a set value; a region is defined as having micropores when the magnitude of the seepage velocity vector is less than or equal to a set value. The step of determining favorable areas for natural hydrogen exploration based on the natural hydrogen concentration distribution data includes: Based on the spatial gradient of natural hydrogen concentration, natural hydrogen enrichment areas are identified, and these areas are designated as favorable areas for natural hydrogen exploration.

2. The method according to claim 1, characterized in that, The designated hydrogen source rocks include ophiolite, granite, basalt, uranium deposits, and hydrocarbon source rocks.

3. The method according to claim 1, characterized in that, The second source type includes inorganic origin and / or organic origin; The inorganic origins include Earth degassing, water-rock reaction, water radiation decomposition, and high-temperature decomposition; the organic origins include biological processes and organic matter pyrolysis.

4. The method according to claim 1, characterized in that, The process of constructing a three-dimensional geological model of the target area using three-dimensional geological modeling software includes: Use the built-in geometry tools of 3D geological modeling software to draw or import model files containing geodetic coordinates and actual geological information of each layer to define porous media regions containing matrix and fractures.

5. The method according to claim 1, characterized in that, The seepage model for dual-permeability media based on Darcy's law is as follows: ； In the formula, The seepage velocity vector, For fluid dynamic viscosity, Let ∇p be the permeability tensor and ∇p be the pressure gradient vector.

6. The method according to claim 1, characterized in that, Before performing the transient numerical simulation, the following steps are also included: Based on the geological data, the initial pore pressure, initial hydrogen concentration distribution, and initial temperature field of the three-dimensional geological model are determined.

7. The method according to claim 1, characterized in that, In the three-dimensional geological model, a dual-permeability medium seepage model based on Darcy's law is loaded, and a rarefied material transport field and a heat conduction field are coupled to perform transient numerical simulations, including: Select the transient solver, set the time step, and couple the porous medium flow field, the rarefied mass transfer field, and the heat conduction field to perform a multiphysics solution.

8. The method according to claim 7, characterized in that, When performing the multiphysics coupling solution, the maximum element size of the free tetrahedral mesh is set, and the mesh is refined based on the maximum element size at the upper interface where the main source of natural hydrogen in the three-dimensional geological model is located. The step of refining the mesh at the upper interface where the main source of natural hydrogen in the three-dimensional geological model is located, based on the maximum element size, includes: Construct a multi-layered hydrogen concentration matrix with time variation as the dimension and the grid cell center as the reference: If we disregard breakage and conduction, the hydrogen concentration in the next unit time will be equal to the original concentration. Concentration of cells diffused through Darcy flow per unit time in the Gaben grid cell Then we have: in, , The seepage velocity vector, For fluid dynamic viscosity, Let ∇p be the permeability tensor and ∇p be the pressure gradient vector. For unit grid area, The unit time step.

9. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method as described in any one of claims 1 to 8.

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