Urban-level CO2 geological storage suitability evaluation and analysis method based on GIS

Abstract

The invention relates to the technical field of CO2 geological sequestration, in particular to a GIS-based city-level CO2 geological sequestration suitability evaluation and analysis method, which makes reasonable carbon emission reduction policies and plans to promote low-carbon economic development. The method comprises the following steps: S1, determining index factors related to CO2 geological sequestration suitability, and constructing a CO2 geological sequestration suitability evaluation index system; s2, measuring the weight of each index factor in the index system in suitability evaluation; s3, acquiring multi-source data of a plurality of sub-regions in the target region; s4, performing index factor space weighting calculation by applying a space analysis method to obtain a CO2 geological sequestration suitability evaluation result; and S5, grading the suitability evaluation result to obtain a city-level CO2 geological storage suitability grading map.

Description

Technical Field

[0001] The present invention relates to the technical field of geological storage of CO 2 , and particularly to a method for evaluating the suitability of urban-level CO 2 geological storage based on GIS. Background Art

[0002] With the acceleration of the industrialization process, the global carbon dioxide (CO 2 ) emissions have increased significantly, leading to increasingly serious environmental problems such as the greenhouse effect and global climate change. To address climate change and reduce greenhouse gas emissions, many countries and regions have begun to seek effective emission reduction strategies. Among them, carbon capture and storage (CCS) technology, as an important emission reduction means, has received extensive attention. The CCS technology aims to capture and store the CO 2 generated in industrial and energy production processes underground to reduce the CO 2 concentration in the atmosphere. Geological storage refers to injecting the captured CO 2 into deep underground geological structures and using the physical and chemical properties of the strata to ensure the long-term safe storage of CO 2 . Suitable storage sites should have good sealing, storage capacity, and safety to prevent the leakage of CO 2 . Selecting the appropriate geological structure and evaluating its suitability are the keys to the successful implementation of CO2 geological storage.

[0003] Although some preliminary work has been carried out on the site selection and geological suitability evaluation of CO 2 storage sites at home and abroad, scientific research institutions, universities, and state-owned enterprises have achieved some preliminary results in aspects such as the site selection in saline aquifers, oil and gas reservoirs, and coal seams, and have initially completed the evaluation of the suitability of CO 2 geological storage at the regional and basin levels in China, and have drawn relevant charts and atlases. However, there is currently no systematic evaluation of the suitability of storage in specific regions. In the process of urbanization, CO 2 emission sources are often concentrated in urban areas. Therefore, it is particularly important to carry out the suitability evaluation of CO 2 geological storage at the urban level. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method for evaluating the suitability of urban-level CO 2 geological storage based on GIS, which can formulate reasonable carbon emission reduction policies and plans and promote the development of a low-carbon economy.

[0005] In the first aspect, the present invention provides a method for evaluating the suitability of urban-level CO 2Geological storage suitability evaluation and analysis method, the method comprising:

[0006] S1. Determine the index factors related to CO 2 geological storage suitability, and construct an evaluation index system for CO2 geological storage suitability;

[0007] CO 2 geological storage suitability is determined by the geological conditions of the storage project, including: a suitable reservoir-caprock combination to meet a sufficiently large storage volume; a stable geological structure to ensure the safety of storage; evaluate the social economy of storage;

[0008] Select the index factors related to CO 2 geological storage suitability from three aspects of reservoir-caprock suitability, storage safety, and economy;

[0009] S2. Measure the weights of each index factor in the suitability evaluation in the index system;

[0010] S3. Obtain multi-source data of multiple sub-regions within the target area;

[0011] S4. Apply spatial analysis methods to perform spatial weighted calculation of index factors to obtain the CO 2 geological storage suitability evaluation result;

[0012] S5. Classify the suitability evaluation result to obtain a city-level CO 2 geological storage suitability classification map.

[0013] Furthermore, the secondary indicators of reservoir-caprock suitability include: caprock lithology, reservoir porosity, reservoir permeability, reservoir thickness, reservoir lithology, and reservoir depth.

[0014] Furthermore, the secondary indicators of storage safety include peak ground acceleration of earthquake, terrestrial heat flow value, and distance to active fault.

[0015] Furthermore, the secondary indicators of economy include population density, land use degree, and carbon source density.

[0016] Furthermore, use the analytic hierarchy process to compare storage safety, storage economy, and reservoir-caprock suitability pairwise, construct a judgment matrix of the first-level indicators, and then compare the secondary indicators in the three aspects of reservoir-caprock suitability, storage safety, and economy pairwise to construct a judgment matrix of the secondary indicator system, calculate the weights of each evaluation indicator within its level, reflect the relative importance of each evaluation indicator to the upper-level evaluation indicator, and then perform consistency tests level by level to ensure reasonable consistency, and finally obtain the weights of each indicator evaluation factor.

[0017] Furthermore, the data sources include existing literature, monographs, various geological surveys, and the research results of engineering geology and hydrogeological exploration reports. Through coordinate system conversion, spatial interpolation, and spatial resampling operations on the data, multi-source heterogeneous data fusion is carried out, and multi-source heterogeneous data with different structures, different resolutions, and different attributes is unified to the same spatio-temporal reference to provide a unified spatial data base for the CO 2 geological storage suitability evaluation. The coordinate systems of all types of data are uniformly converted to GCS_WGS_1984. For data such as reservoir physical properties and terrestrial heat flow values, spatial interpolation is performed using the natural neighbor tool of ArcGIS based on the test point data.

[0018] Furthermore, using the raster data processing method in the spatial overlay analysis tool ArcGIS10.8 provided by the geographic information system software, the study area is discretized into multiple grids with a certain unit, and the raster calculator in the spatial overlay analysis tool ArcGIS10.8 provided by the geographic information system software is used to calculate the calculation results of the dimensionless score superposition weight values of the spatial grid data to obtain the suitability index;

[0019] Formula for calculating the comprehensive evaluation index of suitability: Z q =∑T i A i

[0020] In the formula: T i is the score of each evaluation index; A i is the weight of each evaluation index.

[0021] Furthermore, construct a judgment (pairwise comparison) matrix, and use a ij to represent the comparison result of the i-th factor relative to the j-th factor:

[0022]

[0023] Furthermore, use the judgment matrix to calculate the weights of each index and perform a consistency test:

[0024] Geometrically average (root method) the row vectors of matrix A, and then normalize them to obtain the weights and eigenvector W of each evaluation index:

[0025]

[0026] Calculate the maximum eigenvalue:

[0027] Calculate the consistency index CI (Consistency Index), random consistency index RI (Random Index), and consistency ratio CR (Consistency Ratio):

[0028]

[0029] When CR < 0.1, it is considered that the matrix has satisfactory consistency.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: From three aspects of reservoir-caprock suitability, storage safety, and economy, the present invention establishes a municipal-level CO 2 sequestration suitability evaluation index system, calculates the weights of evaluation indexes by using the analytic hierarchy process, uses GIS means to perform multi-factor spatial superposition on the scores and weights of each index of the suitability evaluation, and has important guiding and reference values for CO 2 geological sequestration site selection. Specific Embodiments

[0031] In the description of the present application, those skilled in the art should know that the present application can be implemented as a method, a device, an electronic device, and a computer-readable storage medium. Therefore, the present application can be specifically implemented in the following forms: complete hardware, complete software (including firmware, resident software, microcode, etc.), and a combination of hardware and software. In addition, in some embodiments, the present application can also be implemented in the form of a computer program product in one or more computer-readable storage media, and the computer-readable storage medium contains computer program code.

[0032] The above computer-readable storage media can adopt any combination of one or more computer-readable storage media. Computer-readable storage media include: electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination of the above. More specific examples of computer-readable storage media include: portable computer disks, hard disks, random access memories, read-only memories, erasable programmable read-only memories, flash memories, optical fibers, compact disc read-only memories, optical storage devices, magnetic storage devices, or any combination of the above. In the present application, the computer-readable storage media can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, device, or component.

[0033] In the technical solution of the present application, the acquisition, storage, use, processing, etc. of data all comply with the relevant provisions of national laws.

[0034] The present application describes the provided method, device, and electronic device.

[0035] It should be understood that all can be implemented by computer-readable program instructions, and these computer-readable program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, thereby producing a machine, and these computer-readable program instructions are executed by a computer or other programmable data processing devices.

[0036] These computer-readable program instructions can also be stored in a computer-readable storage medium that can cause a computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable storage medium produce an instruction device product with a function / operation.

[0037] The computer-readable program instructions can also be loaded onto a computer, other programmable data processing apparatus or other devices, so that a series of operation steps are executed on the computer, other programmable data processing apparatus or other devices to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus can provide a process for implementing the specified function / operation.

[0038] The following describes the present application. Specific embodiments:

[0040] A method for evaluating and analyzing the suitability of urban-level CO geological storage based on GIS according to the present invention 2 Specifically includes the following steps:

[0041] S1. Determine the index factors related to the suitability of CO geological storage, and construct an evaluation index system for the suitability of CO geological storage; 2 The suitability of CO geological storage is determined by the geological conditions of the storage project, including: a suitable reservoir-caprock combination to meet a sufficiently large storage volume; a stable geological structure to ensure the safety of storage; and an assessment of the social and economic benefits of storage; 2 Select the index factors related to the suitability of CO geological storage from three aspects: reservoir-caprock suitability, storage safety, and economy;

[0042] CO 2 The suitability of geological storage is determined by the geological conditions of the storage project, including: a suitable reservoir-caprock combination to meet a sufficiently large storage volume; a stable geological structure to ensure the safety of storage; and an assessment of the social and economic benefits of storage;

[0043] Select the index factors related to the suitability of CO geological storage from three aspects: reservoir-caprock suitability, storage safety, and economy; 2 Index factors related to the suitability of CO geological storage;

[0044] S2. Measure the weights of each index factor in the index system in the suitability assessment;

[0045] S3. Obtain multi-source data of multiple sub-regions within the target area;

[0046] S4. Apply a spatial analysis method to perform spatial weighted calculation of the index factors to obtain the evaluation result of the suitability of CO geological storage; 2 Evaluation result of the suitability of CO geological storage;

[0047] S5. Classify the suitability evaluation results to obtain a city-level CO geological storage suitability classification map. 2 City-level CO geological storage suitability classification map.

[0048] Among them, the secondary indicators of reservoir-cap rock suitability include: cap rock lithology, reservoir porosity, reservoir permeability, reservoir thickness, reservoir lithology, and reservoir depth;

[0049] The secondary indicators of storage security include peak ground acceleration, terrestrial heat flow value, and distance to active fault;

[0050] The secondary indicators of economy include population density, land use degree, and carbon source density;

[0051] Fault development classification criteria:

[0052]

[0053] Peak ground acceleration classification criteria:

[0054]

[0055] Reservoir thickness classification criteria:

[0056]

[0057] Reservoir porosity classification criteria:

[0058]

[0059] Population density classification criteria:

[0060]

[0061] Carbon source density classification criteria:

[0062]

[0063] Land use degree classification criteria:

[0064]

[0065] Apply the analytic hierarchy process to make pairwise comparisons among storage security, storage economy, and reservoir-cap rock suitability, construct the judgment matrix of the first-level indicators, and then make pairwise comparisons among the secondary indicators in the three aspects of reservoir-cap rock suitability, storage security, and economy respectively to construct the judgment matrix of the secondary indicator system. Calculate the weights of each evaluation indicator within its level to reflect the relative importance of each evaluation indicator to the upper-level evaluation indicator. Then conduct consistency tests level by level to ensure reasonable consistency, and finally obtain the weights of each index evaluation factor;

[0066] Steps of the analytic hierarchy process:

[0067] ① Analyze the relationships among various indicators and establish the hierarchical structure of the system:

[0068] Table 1 CO 2Hierarchical Structure of Geological Storage Suitability Evaluation

[0069]

[0070] ② Structural Judgment (Pairwise Comparison) Matrix. Let a ij represent the comparison result of the i-th factor relative to the j-th factor:

[0071]

[0072] ③ Calculate the weights of each index using the judgment matrix and conduct a consistency test:

[0073] Geometrically average the row vectors of matrix A (root method), and then normalize them to obtain the weights and eigenvector W of each evaluation index:

[0074]

[0075] Calculate the maximum eigenvalue:

[0076] Calculate the consistency index CI (Consistency Index), random consistency index RI (Random Index), and consistency ratio CR (Consistency Ratio):

[0077]

[0078] When CR < 0.1, it is considered that the matrix has satisfactory consistency.

[0079] Data sources include existing literature, monographs, various geological surveys, and research report results of engineering geology and hydrogeological exploration. By performing coordinate system conversion, spatial interpolation, and spatial resampling operations on the data, multi-source heterogeneous data fusion is carried out, and multi-source heterogeneous data with different structures, resolutions, and attributes is unified to the same spatio-temporal reference for CO 2 geological storage suitability evaluation to provide a unified spatial data base for all types of data. The coordinate systems of all types of data are uniformly converted to GCS_WGS_1984. For data such as reservoir physical properties and terrestrial heat flow values, spatial interpolation is performed using the natural neighbor tool of ArcGIS based on the test point data.

[0080] Using the raster data processing method in the spatial overlay analysis tool ArcGIS10.8 provided by the geographic information system software, the study area is discretized into multiple grids with a certain unit, and the raster calculator in the spatial overlay analysis tool ArcGIS10.8 provided by the geographic information system software is used to calculate the calculation results of the dimensionless score superposition weight values of the spatial raster data to obtain the suitability index;

[0081] Comprehensive evaluation index calculation formula for suitability: Z q = ∑T i A i

[0082] In the formula: T i is the score of each evaluation index; A i is the weight of each evaluation index.

[0083] The evaluation results of the suitability of CO 2 geological storage are divided into five levels: most suitable, suitable, relatively suitable, poor suitability, and unsuitable by using the equal quantity division method to divide the levels.

Claims

1. A GIS-based city-level CO2 geological storage suitability evaluation and analysis method, characterized in that: The method comprises: S1. Determine the index factors related to the suitability of CO2 geological storage and build a CO2 geological storage suitability evaluation index system; The suitability of CO2 geological storage is determined by the geological conditions of the storage project, including: suitable reservoir-caprock combination to meet a sufficiently large storage volume; stable geological structure to ensure the safety of storage; and assessment of the socio-economic feasibility of storage; The index factors related to the suitability of CO2 geological storage are selected from three aspects: reservoir and caprock suitability, storage safety, and economy. S2, the weight of each indicator factor in the measurement indicator system in the suitability assessment; S3, obtaining multi-source data of multiple sub-regions within the target area; S4. Apply spatial analysis methods to perform spatial weighted calculation of indicator factors to obtain the suitability assessment results of CO2 geological storage; S5. Classify the suitability assessment results to obtain a city-level CO2 geological storage suitability classification map.

2. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: The secondary indicators of reservoir and caprock suitability include: caprock lithology, reservoir porosity, reservoir permeability, reservoir thickness, reservoir lithology, and reservoir depth.

3. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: The secondary indicators of storage safety include peak seismic acceleration, geothermal heat flow value, and distance to active faults.

4. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: Secondary economic indicators include population density, land use, and carbon source density.

5. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: The hierarchical analysis method is used to compare the sealing safety, sealing economy and reservoir-caprock suitability in pairs, and a judgment matrix of the first-level indicators is constructed. Then, the second-level indicators in the three aspects of reservoir-caprock suitability, sealing safety and economy are compared in pairs, and a judgment matrix of the second-level indicator system is constructed. The weights of the evaluation indicators at each level within their level are calculated to reflect the relative importance of each evaluation indicator to the evaluation indicators at the previous level. Then, consistency tests are carried out level by level to ensure reasonable consistency, and finally the weights of the evaluation factors of each indicator are obtained.

6. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: The data sources include existing literature, monographs, various geological surveys, engineering geology and hydrogeological exploration research reports. By performing coordinate system conversion, spatial interpolation and spatial resampling operations on the data, multi-source heterogeneous data are fused, and multi-source heterogeneous data with different structures, resolutions and attributes are unified under the same time and space benchmark, providing a unified spatial data base for CO2 geological storage suitability evaluation. The coordinate systems of all types of data are uniformly converted into GCS_WGS_1984, and the reservoir properties, geothermal heat flow values ​​and other data are spatially interpolated using the natural neighbor tool of ArcGIS based on the test point data.

7. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: Using the raster data processing method in ArcGIS 10.8, a spatial overlay analysis tool provided by the geographic information system software, the study area is discretized into multiple grids with certain units. Using the raster calculator in ArcGIS 10.8, a spatial overlay analysis tool provided by the geographic information system software, the dimensionless score overlay weight value of the spatial raster data is calculated to obtain the suitability index. The calculation formula of the comprehensive evaluation index of suitability is: Z q =∑T i A i Where: T i Score each evaluation indicator; A i is the weight of each evaluation index.

8. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: The suitability assessment results of CO2 geological storage are divided into five levels: most suitable, suitable, relatively suitable, poor suitability and unsuitable.

9. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: Construct a judgment (pairwise comparison) matrix, using a ij Represents the comparison result of the i-th factor relative to the j-th factor:

10. The GIS-based city-level CO2 geological storage suitability evaluation and analysis method according to claim 1, characterized in that: The judgment matrix is ​​used to calculate the weight of each indicator and perform consistency test: The row vectors of matrix A are geometrically averaged (square root method) and then normalized to obtain the weights of each evaluation index and the eigenvector W: Calculate the largest eigenvalue: Calculate the consistency index CI (Consistency Index), random consistency index RI (Random Index) and consistency ratio CR (Consistency Ratio): When CR < 0.1, the matrix is ​​considered to have satisfactory consistency.

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