A source-sink matching method based on hydrate method and saline CO2 storage

Abstract

The present invention provides a source-sink matching method based on the hydrate method and CO2 sequestration in saline aquifers, which can improve the CO2 sequestration efficiency and reduce environmental risks. The method comprises the following steps: optimizing the land carbon source distribution points through a mixed-integer linear programming (MILP) model to minimize the transportation cost and path. Using three-dimensional seismic data to accurately determine the geological characteristics of the sequestration target area. Comprehensively evaluating the sequestration capacities of saline aquifers and the hydrate method through a numerical model, considering three mechanisms: structural sequestration, dissolution sequestration, and residual gas sequestration. Applying the MILP model again for cost analysis and source-sink matching. Analyzing the environmental footprint through life cycle assessment (LCA) to ensure the sustainability of the sequestration scheme. The method provides an efficient, economical, and environmentally friendly solution for CO2 geological sequestration.

Description

Technical Field

[0001] The present invention relates to carbon dioxide storage, and in particular to a source-sink matching method for CO2 storage based on a hydrate method and a saline layer. Background Art

[0002] Carbon dioxide geological storage (CCS) technology, as an important means to address climate change, has the potential to store emitted carbon dioxide in geological strata for a long time, thereby reducing its impact on the atmosphere.

[0003] At present, carbon dioxide geological storage technology mainly includes a variety of storage media, such as deep saline water layers, abandoned oil and gas reservoirs, and seabed sediments. Among them, hydrate method CO2 storage refers to the injection of liquid CO2 into seabed sediments with suitable temperature and pressure conditions to form solid CO2 hydrates to achieve long-term and stable carbon storage. Because it can achieve high-density carbon dioxide storage under specific conditions, it is gradually gaining attention. Hydrate is a solid ice crystal structure that can capture and store gas, especially carbon dioxide, in a low-temperature and high-pressure environment. Its storage density is much higher than that of gaseous or liquid forms. The formation and stability of hydrates are closely related to the physical and chemical properties, temperature, pressure, etc. of the sediments. Therefore, in-depth research on the formation mechanism of hydrates and their interaction with the surrounding environment is the key to achieving effective carbon dioxide storage.

[0004] At the same time, deep saline aquifers, as another important medium for geological storage, have a wider distribution and stronger storage potential. Saline aquifers are usually widely distributed in geological structures 800-3500 m deep. Their salt water characteristics enable them to convert CO2 into carbonate minerals and store them underground for a long time. However, the storage process of saline aquifers is subject to many factors such as groundwater flow and geological stability, which makes the feasibility and safety risk assessment of the storage process particularly complicated.

[0005] In the process of source-sink matching, carbon source accounting and carbon sink assessment are two core links. Carbon source accounting mainly involves carbon dioxide emissions, source characteristics and life cycle analysis; while carbon sink assessment requires a comprehensive analysis of the storage capacity, economics and environmental impact of different storage media. Existing research mostly focuses on the technical and economic analysis of a single storage method, lacking a systematic study of the hydrate method and saline aquifers.

[0006] Therefore, it is particularly important to develop a source-sink matching optimization method based on the entire life cycle. This method can not only realize the quantitative evaluation of the storage capacity of hydrate method and saline aquifer, but also promote the efficient utilization of carbon dioxide and the goal of reducing emissions. In this context, mixed integer linear programming (MILP) as an optimization tool can effectively solve complex decision-making problems in source-sink matching. By establishing a multi-dimensional evaluation model, comprehensively considering economic efficiency, environmental impact and technical feasibility, dynamic matching and optimization of carbon dioxide sources and sinks can be achieved. In addition, the design of dynamic monitoring and feedback mechanisms is also crucial to ensure the safety and effectiveness of carbon dioxide storage. Real-time monitoring of possible leakage risks, changes in groundwater quality and other issues during the storage process can adjust the storage strategy in a timely manner to ensure environmental safety.

[0007] Previous studies have focused on the total storage volume of a large carbon storage area. CN118657328A discloses a source-sink matching method, system and storage medium for carbon capture and storage technology. The carbon sink is calculated based on the annual injection volume, and the calculation result of the carbon sink does not take into account the actual reservoir properties and the storage volume at specific points. CN117633552A discloses a carbon dioxide source-sink matching method, device, medium and equipment. However, it only considers a single storage medium, transporting supercritical CO2 to a single carbon sink through a pipeline, which is not suitable for actual large-scale carbon storage application scenarios; CN117669791A discloses a full-cycle source-sink matching optimization method based on CO2 source-sink attributes and decision-making time, but does not consider the storage capacity of the actual storage site; CN117314210A provides a carbon dioxide geological storage cost assessment method based on the minimum cost path, which only considers the cost of pipeline transportation, and does not make a reasonable assessment of the cost of geological storage; CN116411997A discloses a CO2 storage source-sink matching full-process evaluation device, which provides a small-scale single source-sink matching and evaluation method in the laboratory, and is not suitable for large-scale, long-cycle source-sink matching solutions.

[0008] The existing geological storage technology of carbon dioxide has the following main disadvantages:

[0009] 1. Low storage efficiency: Existing technologies can only use the hydrate method or saline layer for storage, but fail to effectively integrate the advantages of both, resulting in insufficient overall storage efficiency.

[0010] 2. Complexity of source-sink matching: Current source-sink matching methods mostly use empirical analysis, which lacks systematicity and scientificity, resulting in poor matching results.

[0011] 3. Insufficient dynamic monitoring: Many existing solutions lack real-time monitoring and feedback mechanisms, making it difficult to respond to risks and changes in the storage process in a timely manner.

[0012] 4. Inadequate environmental impact assessment: Existing methods are usually incomplete when assessing the environmental impact of storage projects and lack a systematic analytical framework.

[0013] 5. Insufficient application of regional characteristics: Most of the current CO2 storage schemes are general methods and lack in-depth research on specific regions.

[0014] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0015] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a source-sink matching method for CO2 storage based on the hydrate method and saline water layer.

[0016] To achieve the above object, the present invention adopts the following technical solutions:

[0017] A source-sink matching method for CO2 storage based on hydrate method and saline aquifer includes the following steps:

[0018] S1. Obtain the CO2 emission point sources in the target area, calculate the number of land carbon source distribution points based on the objective function of minimizing land transportation cost and path, and set them as the corresponding CO2 outlets according to the mixed integer MILP linear programming model;

[0019] S2. Obtain geological data of the target area, including the depression location, reservoir depth range, reservoir lithology, porosity, and permeability of the target area, and calculate the target area range and volume based on 3D seismic data;

[0020] S3. Through numerical models, calculate the CO2 storage capacity of saline aquifers and hydrates respectively; the saline aquifers consider structural storage, dissolution storage and residual gas storage; calculate the total storage volume of dissolved and supercritical CO2; the hydrate method considers the seepage, heat and mass transfer characteristics in the pores after CO2 injection, the thermodynamic behavior of CO2 hydrate formation and multiphase evolution characteristics, and calculates the total storage volume and long-term phase evolution mechanism;

[0021] S4. Conduct cost analysis in the source-sink matching process, and conduct a second mixed integer MILP linear programming based on the objective function of minimum path and minimum cost to match the land-based outlets with the corresponding carbon sinks;

[0022] S5. Conduct economic assessment and life cycle assessment, conduct cost analysis and life cycle assessment of the entire process, and systematically analyze the environmental footprint of hydrate method and saline aquifer storage to ensure the sustainability of the selected storage solution.

[0023] Further, step S3 includes using a numerical model to comprehensively evaluate the CO2 storage capacity of saline aquifers and hydrates, specifically including:

[0024] Calculate the CO2 storage potential under three mechanisms: structural storage, dissolution storage and residual gas storage;

[0025] Evaluate the total amount of dissolved and supercritical CO2 stored;

[0026] Analyze the seepage, heat and mass transfer characteristics in the pores after CO2 injection, as well as the thermodynamic behavior and multiphase evolution characteristics of CO2 hydrate formation;

[0027] Comprehensively calculate the total storage volume and its long-term phase evolution mechanism.

[0028] Furthermore, step S4 specifically includes:

[0029] Integrate land and sea transportation costs using MILP linear programming model;

[0030] Use binary decision variables to control the choice of connections between output points, outlets, and storage sites;

[0031] Each output point is connected to a unique outlet, and each selected outlet can only be connected to one storage point;

[0032] Select up to five outlets during the optimization process and determine an optimal storage site based on the shortest transportation distance;

[0033] Minimize the total transportation distance or total cost, including the distance from the CO2 output point to the seaport, the distance from the seaport to the storage point, and the distance from the seaport to the optimal storage point.

[0034] Furthermore, step S5 includes conducting an economic assessment and a life cycle assessment (LCA), performing a cost analysis and a life cycle assessment on the entire process, and systematically analyzing the environmental footprint of the hydrate method and saline aquifer storage to ensure the sustainability of the selected storage solution.

[0035] Further, in step S3, the hydrate method CO2 storage simulation method includes:

[0036] Divide the simulation domain into representative volume units of appropriate size;

[0037] Discretize the coupled partial differential equations of mass and energy conservation via finite volume methods;

[0038] Use Newton's iteration method to solve the Jacobian matrix implicitly;

[0039] The multiphase and multicomponent seepage, heat transfer, hydrate formation and decomposition behaviors in the hydrate method of submarine carbon dioxide storage at different scales are simulated under the conditions where Darcy's law is applicable.

[0040] Furthermore, in step S3, the formula for estimating the total amount of CO2 stored in the saline layer includes three storage mechanisms: structural storage, dissolution storage, and residual gas storage, and considers multi-stage injection lengths and multi-well injection strategies to evenly distribute CO2 in the target saline layer.

[0041] Further, in step S4, the source-sink matching MILP linear programming model includes integrating onshore and offshore transportation costs, using binary decision variables to control the connection selection between output points, outlets and storage points, and the constraints of the model ensure logical connections.

[0042] Furthermore, a monitoring and response mechanism for CO2 storage is established based on multi-parameter sensitivity analysis, including real-time collection and analysis of pressure, temperature, gas composition and permeability, and the CO2 injection rate and conditions are dynamically adjusted in combination with the monitoring data.

[0043] Furthermore, it also includes: establishing a spatiotemporal matching method based on multi-dimensional parameter weight allocation for dynamic optimization matching between global carbon emission sources and marine carbon storage potential areas; constructing a dynamic optimization model combining parameters such as ocean current movement, biological pump effect and sedimentation rate; and designing multi-dimensional parameter weight allocation for key parameters in hydrate storage and saline layer storage, including storage factor and hydrate saturation; thereby eliminating the randomness of traditional storage site selection, achieving quantitative evaluation of storage efficiency, and improving the CO2 mineralization rate.

[0044] A computer program product includes a computer program, which, when executed by a processor, implements the source-sink matching method based on the hydrate method and saline CO2 storage.

[0045] The present invention has the following beneficial effects:

[0046] In view of the shortcomings of existing carbon dioxide geological storage technology, the present invention proposes a source-sink matching method based on the hydrate method and saline aquifers, which has important application value, provides practical guidance for the further development of carbon dioxide geological storage technology, and contributes to the global response to climate change.

[0047] The present invention innovatively combines the hydrate method with saline CO2 storage technology, and realizes efficient management and optimization of the CO2 storage process through an accurate source-sink matching optimization model. First, the method minimizes the land transportation cost and path through a mixed integer linear programming (MILP) model, thereby optimizing the transportation efficiency of CO2 from the emission source to the storage point. Secondly, the method uses three-dimensional seismic data to accurately analyze the geological structure of the target area, ensuring that the selection of the storage target area is both scientific and accurate. In the calculation of storage capacity, this method not only considers the three mechanisms of structural storage, dissolution storage and residual gas storage in saline layers, but also comprehensively evaluates the multiphase evolution characteristics of hydrate storage, thereby providing a more comprehensive storage capacity evaluation. In addition, through the application of the second MILP model, the method further optimizes the cost in the source-sink matching process and ensures the economic feasibility of the storage scheme. Finally, the method also includes economic evaluation and life cycle assessment (LCA), which not only ensures the environmental sustainability of the storage scheme, but also systematically analyzes the environmental footprint of the storage process, thereby providing a comprehensive technical and economic analysis for decision makers. In summary, the present invention significantly improves the efficiency, economy and environmental friendliness of CO2 storage through its comprehensive technical solution, and provides strong technical support for addressing climate change.

[0048] The present invention also designs a method for optimizing the site selection of marine carbon storage based on source-sink matching, combining the advantages of hydrate systems and saline carbon storage to achieve efficient, safe and sustainable geological storage of CO2. By optimizing injection conditions, real-time dynamic monitoring and comprehensive evaluation of environmental and economic benefits, the present invention effectively improves the storage efficiency and capacity, enhances system stability, reduces environmental risks, and provides scientific basis and technical support for large-scale applications. The present invention establishes a method for temporal and spatial matching of global carbon emission sources (thermal power plants, industrial areas, etc.) and marine carbon storage potential areas (upwelling areas, deep-sea basins, etc.), and constructs a dynamic optimization model combining 20+ parameters such as ocean current movement, biological pump effect and sedimentation rate, breaking through the randomness of traditional storage site selection and achieving quantitative evaluation of storage efficiency.

[0049] The main technical advantages of the present invention are:

[0050] 1. Improving CO2 storage efficiency

[0051] By combining the hydrate method with the carbon dioxide storage technology of saline aquifers, the invention provides a more efficient storage solution. The hydrate method has a high carbon dioxide storage density and can store a large amount of carbon dioxide in a relatively small space. Saline aquifers provide a wide range of storage potential, so the coordinated use of the two technologies can significantly increase the overall storage capacity. Through the MILP optimization model, the optimal source-sink matching strategy can be determined in a shorter time, thereby achieving efficient carbon dioxide management.

[0052] 2. Enhance economic efficiency and sustainability

[0053] The invention's full life cycle optimization method takes into account both economic and environmental impacts, ensuring the sustainability of CO2 storage projects. Through accurate carbon source accounting and carbon sink assessment, projects can use resources more efficiently and reduce implementation costs. This innovation allows decision makers to choose the most suitable storage method under the premise of economic feasibility, thereby minimizing unnecessary expenses and environmental burdens.

[0054] 3. Implementation of dynamic monitoring and feedback mechanism

[0055] The dynamic monitoring system and feedback mechanism introduced in the present invention can track various parameters in the sealing process in real time, detect potential risks in a timely manner and make adjustments. Compared with traditional methods, this real-time monitoring can better deal with changes in groundwater quality and stability issues of the sealing medium, ensuring the safety and effectiveness of the sealing process. Through feedback adjustment, the sealing strategy can be dynamically optimized to further improve the sealing effect.

[0056] 4. Accurate application of regional characteristics

[0057] The invention scheme systematically analyzes the regional geological characteristics, making the technical application more targeted and effective. By fully understanding the regional geological characteristics, the application of hydrates and saline layers is optimized, avoiding storage failures due to unsuitable geological conditions. This precise regional application capability can achieve a higher success rate and effect compared to the general methods commonly used in the background technology.

[0058] Through the source-sink matching optimization model of the present invention, a higher carbon dioxide storage capacity can be achieved; the present invention adopts the MILP optimization model to make the matching of carbon sources and carbon sinks more reasonable and efficient. The present invention introduces a dynamic monitoring system that can track storage parameters in real time and make adjustments based on feedback data, thereby improving storage safety. The present invention provides a comprehensive environmental impact assessment model to ensure that when implementing storage technology, its impact on the ecological environment can be fully considered. The present invention ensures the pertinence and effectiveness of the storage plan through analysis of specific geological features, thereby reducing the risk of storage failure.

[0059] In summary, the present invention significantly improves the storage efficiency, economy and safety of carbon dioxide through the innovative MILP optimization model, dynamic monitoring and feedback mechanism, and regional characteristic analysis. The realization of these technical effects not only solves many problems existing in the background technology, but also provides new ideas and practical solutions for the development of carbon dioxide geological storage technology.

[0060] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 This is a flow chart of a source-sink matching method for CO2 storage based on a hydrate system and a saline aquifer according to an embodiment of the present invention.

[0062] Figure 2 This is a flow chart of CO2 storage block identification and optimization evaluation according to an embodiment of the present invention.

[0063] Figure 3 Schematic diagram of the offshore CO2 storage source-sink matching solution according to an embodiment of the present invention.

[0064] Figure 4 This is a flow chart for estimating the total amount of CO2 storage by the hydrate method according to an embodiment of the present invention.

[0065] Figure 5 This is an example diagram of CO2 storage source-sink matching in a coastal area according to an embodiment of the present invention. DETAILED DESCRIPTION

[0066] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0067] See also Figure 1 The embodiment of the present invention provides a source-sink matching method for CO2 storage based on the hydrate method and saline water layer, comprising the following steps:

[0068] S1. Obtain the CO2 emission point sources in the target area, calculate the number of land carbon source distribution points based on the objective function of minimizing land transportation cost and path, and set them as the corresponding CO2 outlets according to the mixed integer MILP linear programming model;

[0069] S2. Obtain geological data of the target area, including the depression location, reservoir depth range, reservoir lithology, porosity, and permeability of the target area, and calculate the target area range and volume based on 3D seismic data;

[0070] S3. Through numerical models, calculate the CO2 storage capacity of saline aquifers and hydrates respectively; the saline aquifers consider structural storage, dissolution storage and residual gas storage; calculate the total storage volume of dissolved and supercritical CO2; the hydrate method considers the seepage, heat and mass transfer characteristics in the pores after CO2 injection, the thermodynamic behavior of CO2 hydrate formation and multiphase evolution characteristics, and calculates the total storage volume and long-term phase evolution mechanism;

[0071] S4. Conduct cost analysis in the source-sink matching process, and conduct a second mixed integer MILP linear programming based on the objective function of minimum path and minimum cost to match the land-based outlets with the corresponding carbon sinks;

[0072] S5. Conduct economic assessment and life cycle assessment (LCA), conduct cost analysis and life cycle assessment of the entire process, and systematically analyze the environmental footprint of hydrate method and saline aquifer storage to ensure the sustainability of the selected storage solution.

[0073] Through the above steps, the hydrate method and saline aquifer storage technology can be organically combined to optimize the site selection and process of carbon dioxide storage, improve storage efficiency and safety, and reduce environmental risks and economic costs.

[0074] In some embodiments, the source-sink matching method for CO2 storage based on the hydrate method and saline aquifers of the present invention further optimizes each step to enhance storage efficiency and environmental safety. Specifically:

[0075] Step S3 specifically includes using numerical models to comprehensively evaluate the CO2 storage capacity of saline aquifers and hydrates, including: calculating the CO2 storage potential under three mechanisms: structural storage, dissolution storage, and residual gas storage; evaluating the total storage amount of dissolved and supercritical CO2; analyzing the seepage, heat and mass transfer characteristics in the pores after CO2 injection, as well as the thermodynamic behavior and multiphase evolution characteristics of CO2 hydrate formation; and comprehensively calculating the total storage amount and its long-term phase evolution mechanism. Step S4 specifically includes: integrating onshore and offshore transportation costs using MILP linear programming models; using binary decision variables to control the connection selection between output points, outlets, and storage points; each output point is connected to a unique outlet, and each selected outlet can only be connected to one storage point; selecting up to 5 outlets during the optimization process and determining an optimal storage point based on the shortest transportation distance; minimizing the total transportation distance or total cost, including the distance from the CO2 output point to the outlet, the distance from the outlet to the storage point, and the distance from the outlet to the optimal storage point. Step S5 includes economic assessment and life cycle assessment (LCA), cost analysis and life cycle assessment of the whole process, systematic analysis of the environmental footprint of hydrate method and saline aquifer storage, and ensuring the sustainability of the selected storage scheme. In addition, in step S3, the simulation method of CO2 storage by hydrate method includes: dividing the simulation domain into representative volume units of appropriate size; discretizing the coupled partial differential equations of mass and energy conservation by finite volume method; solving the Jacobian matrix implicitly by Newton iteration method; simulating the multi-phase and multi-component seepage, heat transfer, hydrate formation and decomposition behavior in the process of submarine carbon dioxide storage by hydrate method at different scales under the conditions of Darcy's law. The total amount of CO2 storage in saline aquifers is estimated by the formula including three storage mechanisms: structural storage, dissolution storage and residual gas storage, and considering multi-stage injection length and multi-well injection strategy to make CO2 evenly distributed in the target saline aquifer. Furthermore, in step S4, the source-sink matching MILP linear programming model includes integrating onshore and offshore transportation costs, using binary decision variables to control the connection selection between output points, outlets and storage points, and the constraints of the model ensure logical connections. Furthermore, the method also includes establishing a monitoring and response mechanism for CO2 storage based on multi-parameter sensitivity analysis, including real-time collection and analysis of pressure, temperature, gas composition and permeability, and dynamically adjusting the CO2 injection rate and conditions in combination with monitoring data. The method of the present invention improves the efficiency of carbon dioxide storage, reduces costs and ensures environmental sustainability. The method provides an efficient, economical and environmentally friendly solution for geological storage of carbon dioxide. The following further describes an algorithm example of a specific embodiment of the present invention.

[0076] Figure 1The flow chart is a source-sink matching method based on hydrate system and saline aquifer CO2 storage. In addition, the scheme provided by the present invention may include the following main modules: CO2 storage process simulation and optimization, dynamic monitoring and feedback, environmental impact and economic evaluation, so as to achieve efficient, safe and sustainable CO2 storage. Figure 2 This is a flow chart of CO2 storage block identification and optimization evaluation according to an embodiment of the present invention.

[0077] Embodiments of the method of the present invention include:

[0078] Simulation and optimization of CO2 storage process: The geometric model of the storage target area is established through Meshmaker software, and the thermal-fluid-chemical multi-field coupling numerical simulation method is established based on the TOUGH+ v1.5 framework to simulate and analyze the entire process of hydrate formation and saline aquifer storage. Including the seepage, heat and mass transfer characteristics in the pores after CO2 injection, the thermodynamic behavior and multiphase evolution characteristics of CO2 hydrate formation, and the dissolution and mineralization behavior of supercritical CO2 in saline aquifers. Optimize key parameters such as injection pressure, temperature, flow rate, etc. to ensure efficient storage of CO2 in saline aquifers and hydrate systems, minimize the risk of leakage, and improve storage capacity and system stability.

[0079] The method can also include dynamic monitoring and feedback. Based on multi-parameter sensitivity analysis, a monitoring and response mechanism for CO2 storage is established, including real-time collection and analysis of parameters such as pressure, temperature, gas composition and permeability. Combined with monitoring data, the CO2 injection rate and conditions are dynamically adjusted to deal with possible storage anomalies, such as leakage or uneven distribution. This module uses multi-source information fusion technology to ensure that the storage process always operates within a safe and controllable range.

[0080] Environmental impact and economic assessment: Systematically assess the potential environmental impacts of the storage process (such as saline aquifer damage, water resource pollution, and changes in geological stability), and assess the economics of the storage process, including energy consumption, equipment investment, and operating costs. Through the life cycle assessment method (LCA), quantify the positive and negative impacts of the storage solution on the environment, and combine it with the economics of storage to propose an optimization plan to ensure the sustainable development of the technology and its practical promotion value.

[0081] A source-sink matching scheme for geological storage of carbon dioxide based on hydrate method and saline aquifers includes the following parts:

[0082] 1. Evaluation and data collection system

[0083] Geological feature analysis: First, conduct comprehensive exploration and geological data collection for regional geological blocks, including stratigraphic structure, physical and chemical properties, porosity, permeability and other parameters. These data will provide a basis for subsequent source-sink matching.

[0084] Climate and emission data: Collect emission data from major carbon dioxide emission sources in the region (such as power plants, industrial facilities, etc.), conduct life cycle analysis, and clarify the emission amount, emission time and form of each carbon source.

[0085] 2. Source-sink matching optimization model

[0086] Mixed Integer Linear Programming (MILP) Model: A MILP optimization model is established to transform the carbon source and carbon sink matching problem into a mathematical model. The goal of the model is to minimize the overall carbon emissions while maximizing the storage capacity of the hydrate method and saline aquifers.

[0087] Decision variable setting: Set the decision variables, including the allocation of carbon source, the selected storage method (hydrate method or saline aquifer), storage location and its economic feasibility, etc.

[0088] Constraints: Establish constraints, including the maximum storage capacity of the sealing medium, geological stability, environmental impact standards and regulations, etc., to ensure the rationality and feasibility of the model.

[0089] 3. Storage process simulation and optimization

[0090] Simulation of CO2 hydrate formation and long-term stability: Using a thermal-fluid-chemical multi-field coupled numerical model, the formation amount and long-term stability of CO2 hydrate under different key geological-engineering conditions are simulated to evaluate its effectiveness as a carbon dioxide storage medium.

[0091] Saline aquifer storage simulation: A three-dimensional model of the storage site is established based on actual geological conditions. The dissolution, mineralization and final storage efficiency of CO2 in the saline aquifer are simulated using thermal-fluid-chemical multi-field coupled numerical simulation technology. The storage risk and injectability of CO2 during the storage process are evaluated, and the optimal storage target area and safe injection direction are selected.

[0092] Regarding the source-sink matching optimization model and storage process simulation and optimization, specifically, the present invention designs a hydrate method for CO2 storage simulation, including a mathematical model and solution steps as follows:

[0093] (1) Discrete-solving framework

[0094] Before simulation and solution, the entire simulation domain needs to be divided into representative volume units of appropriate size, and the coupled partial differential equations of mass and energy conservation are discretized by the finite volume method, and the Jacobian matrix is ​​fully implicitly solved by the Newton iteration method. It can simulate the multiphase and multicomponent seepage, heat transfer, hydrate formation and decomposition behavior of the hydrate method in the seabed carbon dioxide storage process of different scales under the conditions of Darcy's law. This software includes the equilibrium and kinetic models of hydrate phase change, and can consider up to three phases (liquid CO2, water phase, hydrate phase) and four components (water, inhibitor, CO2, hydrate).

[0095] (2) Model application conditions

[0096] a) Darcy's law is satisfied in the simulation domain;

[0097] b) Ignore the mechanical diffusion of solutes during transport;

[0098] c) deformation of geological bodies is accommodated by pore compressibility;

[0099] d) dissolved salts will not precipitate or volatilize as the amount of dissolved salts increases;

[0100] e) Dissolved salts do not affect the thermophysical properties of the water phase;

[0101] f) CO2 is in liquid or gaseous state.

[0102] (3) Solution process

[0103] (3.1) Known conditions

[0104] The seawater depth and burial depth of the storage target area, the temperature and pressure of the seabed mud line, the geothermal gradient, the average density of seawater, the thermophysical properties of the target area sediments (absolute permeability, porosity, thermal conductivity, particle density, etc.), the CO2 injection rate and injection time, and the target storage time.

[0105] (3.2) Quantity to be determined

[0106] After CO2 injection, the formation temperature, pressure, and salinity change, and the mass evolution of the three phases of CO2 (dissolved phase, liquid phase, and hydrate phase).

[0107] (3.3) Calculation steps

[0108] a) Pre-treatment

[0109] Use Meshmaker or mView pre-processing software to divide the finite volume method grid required for calculation by this software; use the following formula to initialize the pressure and temperature distribution of the simulation domain:

[0110]

[0111] in Pis the pore pressure, P atm is standard atmospheric pressure, ρ w is the average seawater density, g is the acceleration due to gravity, H The depth of seawater in the target area is Z For burial depth.

[0112]

[0113] in T is the formation temperature, T 0 is the temperature at the seafloor mud line, ΔG is the geothermal gradient, H The target area burial depth.

[0114] b) Solve the mass and energy conservation equations for each component

[0115] The mass conservation equations for each component are as follows:

[0116]

[0117] in, i and j They represent the three different components (H2O, CO2, and NaCl) in the liquid CO2-CO2 hydrate system and their corresponding phases (A: water phase, CO2-L: liquid CO2 phase, and H: CO2 hydrate phase); S , ρ and X They represent the formation porosity, phase saturation, phase density, and mass composition of a specific phase, respectively; v is the Darcy velocity vector governed by Darcy's law, and J is the diffuse mass flow described by Fick's laws; the right q Represents the mass source and sink of a specific component. The hydrate phase cannot migrate during the seepage.

[0118] The energy conservation equations for each component are as follows:

[0119]

[0120] in, U j and H j are the internal energy and enthalpy of a particular phase, respectively; ρ R and U R are the density and internal energy of the rock respectively; λ and T Represent thermal conductivity and temperature respectively; qE It is the source and sink of energy.

[0121] The hydrate phase transition kinetic equation is as follows:

[0122]

[0123] in K 0 is the intrinsic reaction constant, ΔE a is the hydration activation energy, R is the universal gas constant, T is the temperature, F A is the area adjustment factor, A is the surface area involved in the reaction, f eq and f v represent the fugacity in equilibrium state and in the CO2 phase, respectively.

[0124] In the process of storing CO2 in saline aquifers, it is assumed that CO2 exists stably in the reservoir pores in supercritical and dissolved states during the storage period. In the storage process, it is assumed that a multi-stage injection length and a multi-well injection strategy are adopted to ensure that CO2 is evenly distributed in the target saline aquifer. Considering the three storage mechanisms of structural storage, dissolution storage and residual gas storage, the total amount of CO2 stored in saline aquifers is estimated as follows:

[0125] Construct storage:

[0126] Dissolve and seal:

[0127] Residual gas storage:

[0128] The total amount of storage is:

[0129] in, m s Indicates the total amount of CO2 stored, in kg; M CO2S represents the structural storage capacity of CO2, M CO2D Indicates the dissolved storage amount of CO2; M CO2R Indicates the residual gas storage amount of CO2; A represents the area of ​​the storage area; h represents the thickness of the target formation for storage; Φ Represents the average porosity of the formation; Indicates the density of supercritical CO2 at the current injection position temperature and pressure; Indicates the current density of formation water,E The representative storage factor is usually obtained from numerical simulation results; R CO2 Indicates the solubility of CO2; S CO2t It indicates the saturation of bound CO2 in the saline layer when CO2 displaces formation water and the formation water flows back.

[0130] 4. Dynamic monitoring and feedback

[0131] Build a real-time monitoring system, including sensors for underground pressure, temperature, carbon dioxide concentration and changes in surrounding water quality, to ensure real-time data acquisition during the sealing process.

[0132] Based on the monitoring data, the storage effect is evaluated in real time, and the source-sink matching strategy is adjusted when necessary to improve the storage efficiency and safety of carbon dioxide.

[0133] 5. Environmental Impact Assessment

[0134] Comprehensively assess the impact of geological storage of carbon dioxide on the ecological environment, including the impact on water bodies, soil and biodiversity.

[0135] Conduct a life cycle assessment (LCA) to systematically analyze the environmental footprint of hydrate storage versus saline aquifer storage to ensure the sustainability of the selected storage option.

[0136] The technical solution of the embodiment of the present invention has the following beneficial effects:

[0137] 1. Improving CO2 storage efficiency

[0138] By combining the hydrate method with the carbon dioxide storage technology of saline aquifers, the invention provides a more efficient storage solution. The hydrate method has a high carbon dioxide storage density and can store a large amount of carbon dioxide in a relatively small space. Saline aquifers provide a wide range of storage potential, so the coordinated use of the two technologies can significantly increase the overall storage capacity. Through the MILP optimization model, the optimal source-sink matching strategy can be determined in a shorter time, thereby achieving efficient carbon dioxide management.

[0139] 2. Enhance economic efficiency and sustainability

[0140] The invention's full life cycle optimization method takes into account both economic and environmental impacts, ensuring the sustainability of CO2 storage projects. Through accurate carbon source accounting and carbon sink assessment, projects can use resources more efficiently and reduce implementation costs. This innovation allows decision makers to choose the most suitable storage method under the premise of economic feasibility, thereby minimizing unnecessary expenses and environmental burdens.

[0141] 3. Dynamic monitoring and feedback mechanism to improve the effect of storage

[0142] The dynamic monitoring system and feedback mechanism introduced in the present invention can track various parameters in the sealing process in real time, detect potential risks in a timely manner and make adjustments. Compared with traditional methods, this real-time monitoring can better deal with changes in groundwater quality and stability issues of the sealing medium, ensuring the safety and effectiveness of the sealing process. Through the feedback adjustment mechanism, the sealing strategy can be dynamically optimized to further improve the sealing effect.

[0143] 4. Accurate application of regional characteristics

[0144] The experimental example systematically analyzed the specific geological characteristics of a certain sea area and verified the effectiveness of the technology application. Through a full understanding of the regional geological characteristics, the application of hydrates and saline layers was optimized, avoiding the failure of storage due to unsuitable geological conditions. This precise regional application capability can achieve a higher success rate and effect compared to the general methods commonly used in background technologies.

[0145] In summary, the present invention has significantly improved the storage efficiency, economy and safety of carbon dioxide by innovatively proposing the MILP optimization model, dynamic monitoring and feedback mechanism, and regional characteristic analysis. The realization of these technical effects not only solves many problems existing in the background technology, but also provides new ideas and practical solutions for the development of carbon dioxide geological storage technology.

[0146] The specific embodiments are further described below in conjunction with examples.

[0147] Figure 3 Schematic diagram of the offshore CO2 storage source-sink matching method according to an embodiment of the present invention. Figure 4 Flow chart for estimating the total amount of CO2 storage by hydrate method. Figure 5 This is an example diagram of CO2 storage source-sink matching in a coastal area according to an embodiment of the present invention, wherein the carbon source data is the carbon emissions of cities in the coastal area in 2020. Example

[0148] During the hydrate method CO2 storage process, it is assumed that CO2 hydrate and liquid CO2 are in a stable state during the storage period. Multi-well injection is used during the storage process to ensure that the storage target area is full of CO2 hydrate and liquid CO2. The total amount of CO2 storage by the hydrate method is estimated as follows:

[0149]

[0150] in, m s Indicates the total amount of CO2 stored, in kg; N Hrepresents the hydrate of CO2 hydrate, which is taken as 6.28; Φ Represents the average porosity of the formation; h H and h CO2_L Represent the thickness of CO2 hydrate and liquid CO2 distribution areas respectively; A Indicates the area of ​​distribution; S H and S CO2_L represents the average hydrate saturation and liquid CO2 saturation; ρ H and ρ CO2_L Respectively represent the average density of CO2 hydrate and liquid CO2 under current temperature and pressure conditions.

[0151] The total amount of CO2 stored by hydrate method is estimated in the GMGS3 hydrate drilling area in a certain sea area. Φ is 0.4; h H and h CO2_L The results of thermal-fluid-chemical multi-field coupling numerical simulations determined that they were 0.21 and 0.14, respectively; A is the area of ​​GMGS3, which is 128 km 2 ; ρ H and ρ CO2_L Taken as 1112 kg / m 3 and 900 kg / m 3 Finally, the total amount of CO2 stored by hydrate in this area is calculated. m s About 78 million tons.

[0152] like Figure 4 As shown in Figure 2, the steps for estimating the total amount of CO2 stored by hydrate method are as follows:

[0153] 1. Conduct geological surveys to obtain key geological parameters such as porosity, permeability, salinity, seawater depth and geothermal gradient;

[0154] 2. Design a targeted storage plan based on geological survey data and determine key engineering parameters such as injection well type, injection location, injection rate and injection temperature;

[0155] 3. Based on the above geological survey results and storage scheme design, a site-scale thermal-fluid-chemical multi-field coupled numerical model was constructed to conduct a 100-year CO2 injection-storage simulation to obtain key simulation results such as the thickness of the effective storage area, the average saturation of CO2 hydrates and liquid CO2, etc.

[0156] 4. Based on the site-scale thermal-fluid-chemical multi-field coupling numerical results, the total storage volume ms is calculated by substituting them into the total storage volume estimation formula.

[0157] This embodiment utilizes both the saline layer method and the hydrate method, and performs matching based on the two methods.

[0158] Based on deep saline CO2 storage, on the basis of traditional saline storage, the safety and efficiency of the storage process are enhanced by optimizing the injection conditions and storage location.

[0159] Specific example: The total amount of CO2 stored in the saline layer is estimated by taking a depression in a depression of an estuary basin at the edge of the ocean. In this example, Φ is 0.26, the storage area A and the target layer thickness h are 8200 km2 and 550m respectively, the storage factor E is 0.0869, RCO2 is 0.0716 kg / kg, and SCO2t is 0.29 through numerical simulation results. Finally, it is calculated that the structural storage of CO2 in this area is 61.614 billion tons, the dissolved storage is 7.17 billion tons, the residual gas storage is 17.868 billion tons, and the total carbon dioxide storage is 83.652 billion tons.

[0160] The steps for estimating the total amount of CO2 stored in saline aquifers are as follows:

[0161] Geological survey and parameter acquisition:

[0162] Through drilling and geophysical exploration, key parameters such as reservoir porosity (Φ), permeability, formation pressure, temperature gradient, target reservoir thickness and caprock integrity are obtained;

[0163] Storage plan design:

[0164] Determine the injection well layout (such as vertical wells or horizontal wells), injection pressure (needed to be lower than the cap rock fracture pressure), injection rate and monitoring plan based on geological data to ensure stable storage of CO2 in the target layer;

[0165] Multi-field coupling numerical simulation:

[0166] A reservoir-scale thermal-fluid-chemical coupled model was constructed to simulate the migration process of CO2 100 to 1000 years after injection, and the following key results were predicted:

[0167] Solubility of CO2 (RCO2);

[0168] The density of CO2 (ρ_CO2);

[0169] Sequestration factor (E);

[0170] Calculation of storage volume in target area:

[0171] Based on the site-scale thermal-fluid-chemical multi-field coupling numerical results, the total storage volume estimation formula is substituted to calculate the structural storage volume, dissolved storage volume and residual gas storage volume, and finally the storage volume of the saline aquifer in the target area is obtained.

[0172] Optimal storage location: Based on the porosity, rock mineral composition, temperature and pressure of different storage locations, the storage position is adjusted to identify the geological conditions for the fastest dissolution and mineralization of CO2 and optimize the CO2 injection location.

[0173] Optimization of injection conditions: Control the injection rate, pressure and temperature of CO2, increase the dissolution and mineralization process of CO2, reduce the risk of CO2 leakage in the reservoir, and improve the CO2 storage capacity of the saline layer. Technical effect: This solution can optimize the storage target area under complex geological conditions on the seabed, and simulate the injection conditions to provide a reference for the implementation of on-site engineering. This solution effectively reduces risks and improves storage efficiency. However, due to the lack of a hydrate system, its storage capacity and long-term stability are still limited.

[0174] Source matching plan:

[0175] Data preprocessing: Read and filter the latitude and longitude data of target and non-target oil fields. Calculate the distance matrix between input points, outlets, and storage points (based on Euclidean distance).

[0176] Model building and solving, define the mixed integer linear programming (MILP) model, set the objective function and constraints, and use the PuLP library to call the solver (such as CBC, Gurobi) for optimization.

[0177] Extract and visualize the results, analyze the optimization results, extract the connection path (input point → outlet → storage point), use the Basemap library to draw a geographical path map, and mark the optimal storage point and collaborative connection.

[0178] The path planning results are as follows: Figure 5 As shown, the input point (blue), outlet (green), storage point (red) and optimal path (purple solid line) are displayed. The storage points are collaboratively connected to the network (green solid line), reflecting the synergistic effect of shared infrastructure.

[0179] By simulating the oil field data of a certain ocean area, this method can achieve:

[0180] The total transportation distance is reduced by 15%~20% (compared with traditional single-stage planning); the number of outlets is reduced to 3~5, significantly reducing construction and operation and maintenance costs; the best storage point is dynamically selected to improve storage efficiency and safety.

[0181] In this example, the source-sink matching MILP model is specifically set up as follows:

[0182] Variable definition:

[0183] Input point: Land CO2 emission point set I, with coordinates (lon_i, lat_i).

[0184] Outlet candidate points: non-target oil field set K, with coordinates (lon_k, lat_k).

[0185] Storage point candidate points: target oil field set J, with coordinates (lon_j, lat_j).

[0186] Decision variables:

[0187] : Whether the input point i is connected to the sea outlet k.

[0188] : Whether the outlet k is selected.

[0189] : Whether the outlet k is connected to the storage point j.

[0190] : Whether storage point j is selected as the only optimal storage point.

[0191] : Whether storage points j and j' are directly connected (cooperative sharing).

[0192] Objective function:

[0193] The objective function integrates the transportation costs on land and at sea, and uses binary decision variables to control the connection selection between output points, outlets and storage points. The constraints of the model ensure logical connections, for example, each output point is connected to a unique outlet, and the outlet can only be connected to one storage point. The present invention selects up to 5 outlets in the optimization process and determines an optimal storage point based on the shortest transportation distance. Minimizing the total transportation distance or total cost, taking distance as an example, includes the following three parts:

[0194]

[0195] Among them, the first item represents the distance from the CO2 output point to the outlet, the second item is the distance from the outlet to the storage point, and the third item is the distance from the outlet to the optimal storage point.

[0196] The Euclidean distance between the CO2 output point and each potential outlet is calculated based on d ik calculate.

[0197] : Calculate the Euclidean distance between the estuary and the storage point, based on d kj calculate.

[0198] d ik , d kj They are the Euclidean distance from the input point to the estuary and from the estuary to the storage point, respectively.

[0199] Represents the connection between the outlet k and the optimal storage point j.

[0200] Constraints:

[0201] The main constraints are as follows:

[0202] Each CO2 output point must be connected to only one sea outlet.

[0203] Outlet selection constraint: If the output point is connected to an outlet, the outlet must be selected as the actual outlet.

[0204] Outlet connection constraint: Each selected outlet can only be connected to one storage point.

[0205] Optimal storage point: Only one storage point can be selected as the optimal storage point, and ensure that all outlets are connected to this unique storage point.

[0206] Solving the MILP:

[0207] Solve the MILP problem using the solver to find the binary decision variables ) is the optimal value.

[0208] Mapping and visualization: The selected path is visualized through Basemap. The path from the CO2 output point to the outlet, and then from the outlet to the storage point is drawn.

[0209] Different colors are used to identify the optimal storage points and connection paths to facilitate observation of the final path selection.

[0210] Comparative Example 1: Local hydrate storage scheme using heterogeneous reservoirs

[0211] Working principle: In seabed sediments with spatial heterogeneity, by adjusting the injection position, injection section length and injection rate, CO2 hydrate is locally generated in the heterogeneous formation to enhance the storage effect.

[0212] Partition injection: According to the porosity, permeability and in-situ temperature and pressure conditions of the formation, liquid CO2 is injected in partitions at optimized injection positions and injection rates to generate CO2 hydrate caprocks in local areas.

[0213] Plugging technology: The locally generated CO2 hydrate caprock will reduce the effective porosity and permeability of the formation. As a plugging barrier, it can effectively prevent the large-scale migration of liquid CO2 and dissolved CO2 or leakage to the seabed.

[0214] Technical effect: This solution can achieve effective storage of CO2 in complex heterogeneous formations, but the formation area and distribution of CO2 hydrates may not be uniform enough, and there may be a risk of local CO2 leakage, resulting in its storage efficiency and safety being inferior to the optimal solution.

[0215] Other variants

[0216] 1. Phased storage plan

[0217] The scheme adopts a phased implementation approach between hydrate storage and saline aquifer storage, allowing for flexible adjustments in the case of different technological maturity. For example, in the initial stage, the hydrate method is preferred for CO2 storage to take advantage of its higher gas storage density. In the subsequent stage, the storage scheme will be gradually shifted from hydrate storage to saline aquifer storage to increase the total storage capacity.

[0218] Implementation steps:

[0219] Phase 1: Conduct sufficient regional exploration and geological data collection, preliminarily evaluate the storage potential of the hydrate method, and conduct preliminary small-scale tests.

[0220] Phase 2: Based on the significant application effect of hydrate-based CO2 storage, saline layer storage is gradually introduced, and dual monitoring is implemented to ensure the coordinated operation of the two technologies.

[0221] Phase 3: Based on real-time monitoring results, dynamically adjust the amount of carbon dioxide injected at each stage to ensure the safety and economy of the overall system.

[0222] Effect: This transition plan can reduce the risk of technology implementation. After using the relatively simple and efficient hydrate method in the initial stage, it will gradually transition to saline aquifer storage, avoiding the risk of insufficient storage or CO2 leakage due to insufficient technology maturity.

[0223] 2. Diversified storage media solutions

[0224] Similar to the hydrate method and saline aquifer storage, this scheme introduces other storage media, such as coalbed methane storage (using carbon dioxide to enhance coalbed methane recovery and store carbon dioxide at the same time) and depleted oil and gas reservoir storage (injecting carbon dioxide into depleted oil and gas reservoirs). Although the principle is the same as the present invention, it is different in the implementation method and storage medium.

[0225] Implementation steps:

[0226] Coalbed methane storage: Unmined coal seams can also be used for CO2 storage, and may also facilitate the recovery of coalbed methane (CBM). CO2 is adsorbed onto the surface of coal, displacing the methane gas originally present in the coal.

[0227] Sealing of depleted oil and gas reservoirs: Injecting carbon dioxide into depleted oil and gas fields to maintain the sealed state of carbon dioxide by increasing the pressure and utilizing its original geological structure.

[0228] Although this solution is different from the hydrate method and saline aquifer storage in specific implementation forms, it is based on the same principle and can achieve safe storage of carbon dioxide under different environmental conditions. This diversified storage strategy can help companies improve their flexibility and adaptability in the face of market changes.

[0229] These two variants provide technical path choices from different perspectives, which can not only provide transition solutions in the actual development process, but also enhance competitiveness and market adaptability by introducing a variety of storage media. The flexibility and scalability of these solutions enable better response to uncertainties and challenges in the implementation of carbon dioxide storage technology.

[0230] The present invention provides a source-sink matching method based on the hydrate method and saline layer carbon dioxide geological storage, which can capture and store carbon emission point sources in coastal areas. Two storage methods are clarified, and the applicability under different geological conditions is fully considered.

[0231] 1. Carbon storage method combining offshore saline aquifers and hydrate method: The present invention provides a carbon storage method combining offshore saline aquifers and hydrate method, which is especially optimized for situations where the land basin is small and the storage area is insufficient.

[0232] 2. Accurate assessment method considering the geological characteristics of the target area: This invention combines regional geological information, fully considers factors such as depression size, reservoir thickness, lithology, porosity, permeability, etc. in the carbon storage target area, and obtains more accurate storage capacity of saline marine carbon sink through geological exploration and data analysis.

[0233] 3. New application of CO2 storage by hydrate method: The CO2 storage by hydrate method proposed in this invention is an important form of marine carbon sink that has not been considered in previous source-sink matching studies. This invention makes detailed calculations based on regional geological information, quantitatively evaluates the CO2 storage capacity by hydrate method, and deeply analyzes the evolution process of multiphase CO2 and its long-term stability.

[0234] 4. Comprehensive consideration of CO2 transportation path and storage stability: This invention not only focuses on the capture and storage process of CO2, but also comprehensively considers the transportation cost of CO2 and the stability of long-term storage.

[0235] 5. Innovative construction of source-sink matching optimization model: This invention provides a new source-sink matching optimization model. By constructing multiple mixed integer linear programming (MILP) optimization models, the land distribution of carbon sources is designed, and the existing offshore platforms and transportation pipelines are considered to systematically analyze the best matching methods between different carbon sources and storage sinks.

[0236] Compared with traditional land storage methods, the selection of storage locations, reservoir capacity assessment and storage cost optimization of marine carbon sinks have been fully considered, thereby improving the feasibility and economy of marine carbon sink storage. This method provides a more flexible and adaptable storage solution for coastal carbon emission point sources, and has higher storage efficiency than other traditional storage technologies. Compared with the prior art, the optimization model of the present invention not only takes into account the combined impact of multiple factors, but also can dynamically adjust the storage strategy under different geological conditions, thereby improving storage efficiency and safety. This optimization model provides flexible and efficient decision support for practical applications.

[0237] By solving the aforementioned technical problems existing in the existing methods, the present invention provides a new technical concept and solution for carbon dioxide geological storage technology, and promotes the progress and application of related technologies.

[0238] Compared with the existing technologies, the present invention fully considers regional geological factors, combines regional typical basin parameters, including depression area, reservoir thickness, porosity, permeability, temperature, pressure, etc., combines CO2 phase state and the actual storage capacity of different geological blocks, and performs more accurate source-sink matching. By comparing with these existing technologies, the present invention has innovations and advantages in considering the geological environment for storage, multiple storage technologies, and actual reservoir capacity.

[0239] The present invention integrates the hydrate method and saline layer storage technology, based on a source-sink matching optimization model for the entire life cycle. Through this integration, not only the storage efficiency of carbon dioxide is improved, but also a more scientific and systematic matching process is achieved, which solves the limitations of a single method in the prior art. In addition, the introduction of dynamic monitoring and feedback mechanisms further guarantees the safety and effectiveness of the storage process. This innovative method provides a new solution mechanism for the geological storage of carbon dioxide, which has high practical value and application prospects.

[0240] In a specific embodiment, the detailed working process can be divided into the following steps:

[0241] 1. Data collection and geological characteristics analysis

[0242] Regional exploration: First, regional geological characteristic data are collected through geological exploration and remote sensing technology. These data include stratigraphic structure, porosity, permeability and chemical composition, etc., which provide the basis for subsequent model building.

[0243] 2. Carbon source accounting and carbon sink assessment

[0244] Carbon source accounting: Evaluate the emissions, source characteristics and life cycle of major carbon dioxide emission sources, and determine the contribution of each carbon source.

[0245] Carbon sink assessment: Based on the data collected, the storage capacity of hydrates and saline aquifers will be analyzed to quantify the amount of CO2 they can store.

[0246] 3. Source-sink matching optimization model

[0247] Establish MILP model: Construct a mixed integer linear programming (MILP) optimization model with the goal of minimizing the overall transportation path and cost while maximizing the storage capacity of the hydrate method and saline aquifers. The model includes decision variables (such as the allocation of carbon sources, storage location, etc.) and constraints (such as storage capacity and environmental impact standards).

[0248] 4. Storage process simulation

[0249] Hydrate Formation Simulation: Use thermodynamic models to simulate the formation and stability of hydrates under different conditions and evaluate their effectiveness as a CO2 storage medium.

[0250] Aquifer storage simulation: Establish a flow and storage model for saline aquifers to analyze the behavior of carbon dioxide in saline aquifers and ensure its safe storage.

[0251] 5. Dynamic monitoring and feedback adjustment

[0252] Sensors are deployed to monitor parameters during the storage process in real time, such as underground pressure, temperature and carbon dioxide concentration.

[0253] Based on real-time monitoring data, the storage strategy can be dynamically adjusted to ensure safety and effectiveness.

[0254] 6. Comprehensive Environmental Impact Assessment

[0255] Life Cycle Assessment (LCA): Conduct comprehensive assessments to analyze the ecological and environmental impacts of hydrate methods and saline aquifer storage to ensure the sustainability of the technology.

[0256] 7. Implementation and Optimization

[0257] Phased implementation: Based on the assessment results, the storage plan will be implemented in phases, with the hydrate method being given priority in the initial stage, followed by the gradual introduction of saline layer storage to reduce the risks of technical implementation.

[0258] The following are several variations of the present invention, which are intended to provide flexibility and adaptability for different environments and needs:

[0259] 1. Partition archiving solution

[0260] The study area is divided into multiple sub-regions, and different storage methods are used according to the geological characteristics and carbon source distribution of each sub-region. For example, some areas may be more suitable for hydrate storage, while other areas are more suitable for saline aquifer storage.

[0261] 2. Integrated energy systems

[0262] Combining renewable energy (such as wind power and solar energy) with carbon dioxide storage technology, using renewable energy to provide electricity for storage facilities, reducing operating costs, and using the carbon dioxide produced for storage.

[0263] 3. Artificial Intelligence Optimization Solution

[0264] Artificial intelligence (AI) algorithms are used to analyze data during the storage process in real time and automatically adjust the storage strategy to improve overall efficiency and safety. This solution can quickly respond to changing geological conditions and real-time monitoring data.

[0265] 4. Combination of biological and geological storage

[0266] Introducing biotechnology to assist the conversion and storage of carbon dioxide through microorganisms or plants can increase the level of biological storage on the basis of hydrate method and saline aquifer storage, further improving the long-term storage capacity of carbon dioxide.

[0267] 5. Dynamic Adaptive Storage

[0268] Based on real-time data and environmental changes, a dynamic adaptive storage solution is designed that can adjust the storage strategy according to changes in external environmental conditions (such as climate change, geological activities, etc.) to ensure long-term safety and effectiveness.

[0269] 6. Circular Economy Storage

[0270] Combining storage technology with industrial processes and using captured carbon dioxide as industrial raw materials can not only achieve storage but also promote the circular economy and reduce emissions.

[0271] 7. Regional cooperative storage networks

[0272] Establish an inter-regional cooperation network, integrate carbon sources and carbon sinks in different regions, achieve optimal allocation of resources through regional cooperation, and improve the overall storage effect.

[0273] 8. Mobile storage unit

[0274] Develop small, mobile storage units that can be flexibly deployed near carbon sources and quickly assembled and disassembled as needed to meet different storage needs.

[0275] These variations not only expand the application scope of the present invention, but also provide diversified solutions for carbon dioxide storage technology in different scenarios, which helps to improve the overall flexibility and adaptability.

[0276] The core of this invention is to propose the idea of ​​a source-sink matching optimization model based on the entire life cycle, combining the hydrate method with the storage technology of saline aquifers, and achieve the following technical advantages:

[0277] Efficiency and safety: The variant scheme is improved on the basis of improving the efficiency and safety of carbon dioxide storage to ensure that risks can be effectively reduced during implementation.

[0278] Adaptability and flexibility: The solution has the ability to cope with different geological conditions, carbon source distribution and environmental changes, showing strong adaptability and flexibility.

[0279] Dynamic monitoring and feedback: Maintain the introduction of dynamic monitoring and feedback mechanisms to enable adjustments and optimization based on real-time data to ensure the safety and effectiveness of the storage process.

[0280] Environmental impact assessment: The variant proposal must include a comprehensive assessment of the environmental impact to ensure its sustainability and friendliness to the ecological environment.

[0281] In the present invention, the source-sink matching optimization model is based on the MILP optimization model to construct a matching strategy between carbon sources and carbon sinks. The combination of storage methods includes the combination of hydrate method and saline layer storage, or the effective integration of other storage media to ensure the improvement of storage capacity. Through a real-time monitoring system, the monitoring and adjustment of storage process parameters can be ensured. Through the mechanism of life cycle assessment or environmental impact assessment, environmental risks can be scientifically evaluated and controlled during implementation. Through the phased implementation, new storage methods can be gradually introduced with different levels of technical maturity.

[0282] The technical principles and methods of the present invention can be widely applied in multiple technical fields, for example:

[0283] 1. Carbon capture and storage (CCS)

[0284] The present invention can be directly applied to carbon dioxide capture and storage projects, optimize the combination of different storage technologies, and improve storage efficiency and safety.

[0285] 2. Climate change research and response

[0286] The optimization model and environmental impact assessment method provided by the present invention can provide a scientific basis for the study and response to climate change and help formulate effective emission reduction strategies.

[0287] 3. Energy production and management

[0288] In renewable energy power generation projects, carbon capture technology can be combined to achieve efficient storage of carbon dioxide and promote the development and utilization of low-carbon energy.

[0289] 4. Environmental protection and ecological restoration

[0290] By utilizing the technical means of the present invention, a project combining carbon sequestration and environmental restoration can be implemented in industrial areas or polluted areas to reduce environmental pollution and ecological damage.

[0291] 5. Civil Engineering and Groundwater Management

[0292] In civil engineering projects, this technology can be used to assess the safety of groundwater and the stability of storage media, ensuring that the impact of the construction process on the environment is minimized.

[0293] 6. Mining and Resource Recovery

[0294] During the mining process, mineral carbonization technology is combined to convert carbon dioxide into minerals, promote the recycling of resources and reduce greenhouse gas emissions.

[0295] 7. Agriculture and land use

[0296] Applying this technology to the management of agricultural land, by combining carbon sequestration with soil improvement, it can promote soil health and productivity and reduce agricultural emissions.

[0297] 8. Carbon trading market

[0298] Provide scientific carbon source and carbon sink assessment methods for the carbon trading market to help companies better manage their carbon emissions and participate in carbon trading.

[0299] 9. Ecological Engineering and Sustainable Development

[0300] Combining the principles of ecological engineering and applying them to ecological restoration projects, the ecological environment can be improved through carbon dioxide sequestration to promote sustainable development.

[0301] 10. Urban planning and construction

[0302] In urban planning, carbon capture and storage technology should be combined to promote the construction of low-carbon cities and improve the sustainability and environmental protection of cities.

[0303] The application potential in these fields demonstrates the wide applicability and interdisciplinary value of the invention, and helps promote scientific and technological progress and sustainable social development.

[0304] The above contents are further detailed descriptions of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, they can also make several substitutions or modifications to these described embodiments without departing from the concept of the present invention, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention.

Claims

1. A source-sink matching method for CO2 storage based on hydrate method and saline aquifer, characterized in that: The following steps are involved: S1. Obtain the CO2 emission point sources in the target area, calculate the number of land carbon source distribution points based on the objective function of minimizing land transportation cost and path, and set them as the corresponding CO2 outlets according to the mixed integer MILP linear programming model; S2. Obtain geological data of the target area, including the depression location, reservoir depth range, reservoir lithology, porosity, and permeability of the target area, and calculate the target area range and volume based on 3D seismic data; S3. Through numerical models, calculate the CO2 storage capacity of saline aquifers and hydrate method respectively; the saline aquifer takes into account structural storage, dissolution storage and residual gas storage; calculate the total storage volume of dissolved and supercritical CO2; the hydrate method storage takes into account the seepage, heat and mass transfer characteristics in the pores after CO2 injection, the thermodynamic behavior of CO2 hydrate formation and multiphase evolution characteristics, and calculates the total storage volume and long-term phase evolution mechanism; S4. Conduct cost analysis in the source-sink matching process, and conduct a second mixed integer MILP linear programming based on the objective function of minimum path and minimum cost to match the land-based outlets with the corresponding carbon sinks; S5. Conduct economic assessment and life cycle assessment, conduct cost analysis and life cycle assessment of the entire process, and systematically analyze the environmental footprint of hydrate method and saline aquifer storage to ensure the sustainability of the selected storage solution; Step S3 includes using numerical models to comprehensively evaluate the CO2 storage capacity of saline aquifers and hydrates, specifically including: Calculate the CO2 storage potential under three mechanisms: structural storage, dissolution storage and residual gas storage; Evaluate the total amount of dissolved and supercritical CO2 stored; Analyze the seepage, heat and mass transfer characteristics in the pores after CO2 injection, as well as the thermodynamic behavior and multiphase evolution characteristics of CO2 hydrate formation; Comprehensively calculate the total storage volume and its long-term phase evolution mechanism; Step S4 specifically includes: Integrate land and sea transportation costs using MILP linear programming model; Use binary decision variables to control the choice of connections between output points, outlets, and storage sites; Each output point is connected to a unique outlet, and each selected outlet can only be connected to one storage point; Select up to five outlets during the optimization process and determine an optimal storage site based on the shortest transportation distance; Minimize the total transportation distance or total cost, including the distance from the CO2 output point to the seaport, the distance from the seaport to the storage point, and the distance from the seaport to the optimal storage point.

2. The source-sink matching method for CO2 storage based on the hydrate method and saline water layer according to claim 1 is characterized in that: Step S5 includes conducting economic assessment and life cycle assessment, carrying out cost analysis and life cycle assessment of the whole process, and systematically analyzing the environmental footprint of hydrate method and saline aquifer storage to ensure the sustainability of the selected storage scheme.

3. The source-sink matching method for CO2 storage based on hydrate method and saline aquifer according to claim 1, characterized in that: In step S3, the hydrate method CO2 storage simulation method includes: Divide the simulation domain into representative volume cells of a given size; Discretize the coupled partial differential equations of mass and energy conservation via finite volume methods; Use Newton iteration method to solve Jacobian matrix implicitly; The multiphase and multicomponent seepage, heat transfer, hydrate formation and decomposition behaviors in the hydrate method of submarine carbon dioxide storage at different scales were simulated under the conditions where Darcy's law was applicable.

4. The source-sink matching method for CO2 storage based on hydrate method and saline aquifer according to claim 1, characterized in that: In step S3, the total amount of CO2 stored in the saline aquifer is estimated, including three storage mechanisms: structural storage, dissolution storage, and residual gas storage, and multi-stage injection lengths and multi-well injection strategies are considered to ensure that CO2 is evenly distributed in the target saline aquifer.

5. The source-sink matching method for CO2 storage based on the hydrate method and saline water layer according to any one of claims 1 to 4, characterized in that: In step S4, the source-sink matching MILP linear programming model includes integrating onshore and offshore transportation costs, using binary decision variables to control the connection selection between output points, outlets and storage points, and the constraints of the model ensure logical connections.

6. The source-sink matching method for CO2 storage based on the hydrate method and saline water layer according to any one of claims 1 to 4, characterized in that: It also includes the establishment of a monitoring and response mechanism for CO2 storage based on multi-parameter sensitivity analysis, including real-time collection and analysis of pressure, temperature, gas composition and permeability, and dynamic adjustment of CO2 injection rate and conditions based on monitoring data.

7. The source-sink matching method for CO2 storage based on the hydrate method and saline water layer according to any one of claims 1 to 4, characterized in that: It also includes: establishing a spatiotemporal matching method based on multi-dimensional parameter weight allocation for dynamic optimization matching between global carbon emission sources and marine carbon storage potential areas; constructing a dynamic optimization model combining ocean current movement, biological pump effect and sedimentation rate parameters; and multi-dimensional parameter weight allocation design for key parameters in hydrate storage and saline layer storage, including storage factor and hydrate saturation; thereby eliminating the randomness of traditional storage site selection, achieving quantitative evaluation of storage efficiency, and increasing the CO2 mineralization rate.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the source-sink matching method for CO2 storage based on the hydrate method and saline water layer is implemented as described in any one of claims 1 to 7.

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