Carbon dioxide salt water layer geological storage site selection method and system

Abstract

The invention relates to a carbon dioxide salt water layer geological storage site selection method and system, and belongs to the technical field of carbon dioxide energy conservation and emission reduction. The site selection method comprises the following steps: acquiring logging data and a geological data set of a target area, and identifying a potential salt water interval based on a preset rule; grading quantitative evaluation is carried out according to the identified potential salt water interval, and a corresponding evaluation index system is established; wherein the evaluation index system comprises a plurality of first-level evaluation indexes and a plurality of second-level evaluation indexes corresponding to each first-level evaluation index, and the first-level evaluation indexes comprise geological sequestration condition evaluation, sequestration capability condition evaluation and social environment condition evaluation; carrying out weight assignment on the evaluation indexes in the evaluation index system based on an index weight assignment method, and carrying out comprehensive quantitative evaluation to obtain a comprehensive evaluation score of each candidate target region; and taking the candidate target region with the highest comprehensive evaluation score as a storage site for geological storage of the carbon dioxide saline water layer. According to the invention, the scientificity and reliability of storage site selection can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of carbon dioxide energy conservation and emission reduction, and in particular to a method and system for selecting a site for geological storage of carbon dioxide in saline aquifers. Background Art

[0002] As the global climate change problem becomes increasingly serious, reducing greenhouse gas emissions has become a common goal of the international community. 2 ) is one of the main greenhouse gases, and its capture, utilization and storage (CCUS / CCS) technology is considered to be an effective way to achieve carbon emission reduction. 2 Geological storage is an important part of CCUS / CCS technology. 2 Injection into deep underground geological structures for long-term storage. Deep saline aquifers are considered ideal for CO storage due to their widespread distribution and large size. 2 Geological storage reservoirs are gradually being recognized and utilized.

[0003] In this context, how to scientifically and rationally select appropriate CO 2 Geological storage sites are particularly important. Multiple factors need to be considered in the site selection process, including geological conditions, storage potential, safety, and social environment. However, the common site selection evaluation system is mostly based on actual cases of high-porosity and high-permeability reservoirs abroad, and does not fully consider the formations with low porosity and low permeability characteristics such as the Ordos Basin. This leads to certain limitations in the existing evaluation system when applied to low-porosity and low-permeability formations, and it may not be able to accurately assess the storage potential and safety risks of such formations.

[0004] Therefore, when it comes to low-porosity and low-permeability reservoirs, how to improve the scientificity and reliability of storage site selection to ensure that large amounts of CO 2 It will not cause instability in the geological structure or other potential risks, which has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to improve the scientificity and reliability of storage site selection, the present application provides a method and system for geological storage site selection of carbon dioxide in saline aquifers.

[0006] In a first aspect, the present application provides a method for selecting a site for geological storage of carbon dioxide in a saline aquifer, which adopts the following technical solution: A method for selecting a site for geological storage of carbon dioxide in a saline aquifer, the method comprising: Acquire well log data and geological data sets for target areas; identifying potential saline water intervals based on the well logging data and geological data set based on preset rules; Conduct a graded quantitative assessment based on the identified potential saline layer segments and establish a corresponding assessment index system; wherein the assessment index system includes a plurality of primary assessment indicators and a plurality of secondary assessment indicators corresponding to each primary assessment indicator, wherein the primary assessment indicators include a geological storage condition assessment, a storage capacity condition assessment and a social environment condition assessment; Based on the indicator weight assignment method, the evaluation indicators in the evaluation indicator system are weighted, and a comprehensive quantitative evaluation is performed to obtain a comprehensive evaluation score for each candidate target area; The candidate target area with the highest comprehensive evaluation score is selected as the storage site for geological storage of carbon dioxide in saline aquifers.

[0007] By adopting the above technical solutions, a scientific evaluation index system was established based on the actual collected logging data and geological data sets, and a comprehensive quantitative evaluation of potential saline layers was carried out through the weight assignment method. This technical solution not only improves the accuracy and reliability of site selection, but also takes into account multiple factors such as geology, economy and social environment, ensuring CO 2 The long-term stability and safety of the storage project. This method can effectively screen the most suitable CO 2 Sealed.

[0008] Optionally, the well logging data includes various types of well logging curves and formation lithology data, formation thickness data, porosity data, permeability data, cap rock lithology data, cap rock thickness data, fault development data, land use status data, underground resource development status data, historical seismic activity and ground subsidence data obtained based on the well logging curves.

[0009] Optionally, the secondary evaluation indicators for evaluating the geological storage conditions include: reservoir lithology evaluation, reservoir thickness evaluation, porosity evaluation and permeability evaluation.

[0010] Optionally, the secondary evaluation indicators for evaluating the storage capacity conditions include: cap rock sealing assessment, burial depth assessment, storage potential assessment, and fracture assessment.

[0011] Optionally, the secondary assessment indicators of the social environmental conditions obtained by assessment include: underground resource development status assessment, land use status assessment, collapse and disaster area assessment, source-sink matching assessment and public acceptance assessment.

[0012] Optionally, the step of assigning weights to the evaluation indicators in the evaluation indicator system based on an indicator weight assignment method, and performing a comprehensive quantitative evaluation to obtain a comprehensive evaluation score for each candidate target area includes: According to the secondary evaluation indicators in the evaluation indicator system, the relative weights of the secondary evaluation indicators are obtained based on the expert evaluation method; and a judgment matrix is ​​constructed according to the relative weights of the secondary evaluation indicators; The weights are calculated based on the analytic hierarchy process and consistency tests are performed to obtain the weights of the secondary evaluation indicators; Obtaining a corresponding first-level evaluation indicator weight according to the second-level evaluation indicator and the second-level evaluation indicator weight; A fuzzy comprehensive evaluation factor level matrix is ​​established according to the weights of the first-level evaluation indicators, and a comprehensive evaluation score for each candidate target area is obtained based on fuzzy mathematics.

[0013] By adopting the above technical solution, based on the combination of expert evaluation method and hierarchical analysis method, the scientific assignment of weights of each indicator in the evaluation index system is realized, and the fuzzy mathematics method is used to conduct a comprehensive quantitative evaluation of the candidate target areas. This technical solution makes full use of the experience of experts and the rigor of mathematical models to improve the accuracy and reliability of the evaluation. By constructing a judgment matrix and a factor level matrix, qualitative judgments are converted into quantitative scores, making the evaluation results more intuitive and easy to understand. Finally, by comparing the comprehensive evaluation scores, the target area most suitable for geological storage of carbon dioxide in saline aquifers can be determined, and the target area for CO2 can be selected. 2 It provides strong decision support for the site selection of storage projects.

[0014] Optionally, the step of selecting the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers includes: Sorting each candidate target area according to the comprehensive evaluation score, and selecting the candidate target area with the highest comprehensive evaluation score as the preferred target area; According to the location information of the preferred target area, the storage location of the geological storage of carbon dioxide in the saline aquifer is obtained.

[0015] By adopting the above technical solutions, the most suitable target area for CO can be scientifically and objectively selected from multiple candidate target areas. 2 The location of geological storage in saline aquifers; first, each candidate target area is quantitatively scored through a comprehensive evaluation model, and then ranked according to the score, and finally the area with the highest score is determined as the storage location. This technical solution not only takes into account multiple factors such as geology, economy, and environment, but also ensures the smooth implementation of the storage project through precise location information.

[0016] In the second aspect, the present application provides a system for selecting a site for geological storage of carbon dioxide in saline aquifers, which adopts the following technical solution: A site selection system for geological storage of carbon dioxide in saline aquifers, the site selection system comprising: An acquisition module for acquiring well logging data and geological data sets in a target area; an identification module, for identifying potential saline water layers based on preset rules according to the well logging data and geological data set; An evaluation index system establishment module is used to perform a graded quantitative evaluation based on the identified potential saline layer segment and establish a corresponding evaluation index system; wherein the evaluation index system includes a plurality of primary evaluation indicators and a plurality of secondary evaluation indicators corresponding to each of the primary evaluation indicators; A comprehensive evaluation module, used to assign weights to the evaluation indicators in the evaluation indicator system based on an indicator weight assignment method, and to perform a comprehensive quantitative evaluation to obtain a comprehensive evaluation score for each candidate target area; The storage site determination module is used to select the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers.

[0017] In a third aspect, the present application provides a computer device, which adopts the following technical solution: A computer device comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method as described in the first aspect.

[0018] In a fourth aspect, the present application provides a computer-readable storage medium, which adopts the following technical solution: A computer-readable storage medium stores a computer program that can be loaded by a processor and execute any one of the methods in the first aspect.

[0019] In summary, this application includes at least one of the following beneficial technical effects: by establishing a complete evaluation index system, adopting quantitative evaluation methods, reasonably determining index weights, effectively handling uncertain factors, and providing strong decision-making support, it aims to improve the scientificity, accuracy and reliability of site selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a first flow chart of a method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to one of the embodiments of the present application.

[0021] Figure 2 It is the location map of the study area and the interpretation result map of the saline layer from typical well logging obtained in the actual research process of this application.

[0022] Figure 3 The research area is 10005 and the length is 10 3 Distribution histogram of sand-to-ground ratio and single-layer thickness of favorable saline layer in this section.

[0023] Figure 4 The research area is 10005 and the length is 10 3Porosity and permeability distribution histogram of favorable saline water layer.

[0024] Figure 5 The research area is 10005 and the length is 10 3 The histogram of the cover layer-to-ground ratio and mud content distribution corresponding to the saline water layer in this section.

[0025] Figure 6 This is a second flow chart of a method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to one of the embodiments of the present application.

[0026] Figure 7 This is a third flow chart of a method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to one of the embodiments of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of this application more clear, the following Figure 1-7 It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] Currently, the selection of geological storage sites in saline aquifers is an important way to ensure CO 2 One of the key factors for the success of geological storage projects. An ideal storage site needs to meet multiple conditions, including but not limited to good geological stability, sufficient reservoir capacity, low permeability cap rock, and minimal impact on the surrounding environment and society. However, the current methods for evaluating and selecting CO 2 The methodologies for geological storage sites are mostly based on foreign empirical data and development models. These methods are mainly applicable to reservoirs with high porosity and permeability characteristics. For areas like the Ordos Basin, where the strata often exhibit low porosity and low permeability, the existing evaluation system may not be fully applicable, thus affecting the evaluation of CO2 storage sites under such special geological conditions. 2 Accurate assessment of storage potential and safety.

[0029] In particular, when it comes to reservoirs with low porosity and low permeability, the validity of traditional evaluation parameters such as sandstone content, porosity and permeability may be questioned. In this case, how to define appropriate geological storage standards to ensure that large amounts of CO 2 In addition, considering the unique geological structure differences in different regions, it is necessary to develop a set of CO2-based 2 A geological storage site selection evaluation system is particularly urgent.

[0030] Based on this, an embodiment of the present application discloses a method for selecting a site for geological storage of carbon dioxide in saline aquifers.

[0031] Reference Figure 1 , a method for selecting a site for geological storage of carbon dioxide in a saline aquifer, the method comprising: Step S101, obtaining well logging data and geological data sets of a target area; In some embodiments, well logging data and geological data sets are collected in the target area. Well logging data are the basis for evaluating the geological storage potential, including but not limited to various well logging curves and stratigraphic lithology data, stratigraphic thickness data, porosity data, permeability data, cap rock lithology data and cap rock thickness data based on the interpretation of well logging curves; geological data sets include fault development data, land use status data, underground resource development status data, historical seismic activity and ground subsidence data, etc.; by collecting these data, the suitability of the storage site can be more comprehensively evaluated, reducing the risks that may arise in the future storage process.

[0032] Specifically, formation lithology data are used to identify potential saline water layers, formation thickness data are used to assess the degree of development of saline water layers, porosity data and permeability data are used to assess the injectability and storability of saline water layers, cap rock lithology data and cap rock thickness data are used to assess the sealing property of the cap rock, fault development data are used to assess potential leakage risks, land use status data are used to assess ground environmental factors, underground resource development status data are used to assess conflicts with existing resource development, and historical seismic activity and ground subsidence data are used to assess regional stability.

[0033] Step S102, identifying potential saline water layers based on well logging data and geological data sets based on preset rules; Among them, the strata with pore space are identified as potential saline layers, which are CO 2 Ideal locations for storage: Potential saline intervals can be screened from well logging data by setting specific parameter thresholds (e.g., shale content, porosity, single layer thickness); Reference Figure 2 As shown in the figure, the location map of the study area and the interpretation result map of the saline water layer of typical well logging obtained in the actual research process of this application are fully utilized. The 192 well logging data collected in the Yushen area of ​​the Ordos Basin have been fully utilized. From the Meso-Neoproterozoic to the Cretaceous period of the Mesozoic Era, the Ordos Basin experienced the transformation of marine sedimentary system, marine-continental transitional sedimentary system and continental sedimentary system, forming multiple sets of sedimentary strata dominated by sandstone and mudstone. In addition to the accumulation layers of oil, natural gas, coal, minerals, water resources, etc., there are still many strata that are not filled with resources, such as the widespread and large-scale deep saline water layers, which can be used as CO 2 Geological storage sites.

[0034] Reference Figure 2 As shown in b, the logging data contains rich stratigraphic lithology information. The existing logging data processing and interpretation are mostly for detailed interpretation of oil and gas layers, such as Figure 2 The permeability in (b) only explains the natural gas section of the Shihezi Formation, and lacks an explanation for the non-resource layers above the oil and gas layers. Therefore, the understanding of the development layers, burial depth, porosity and permeability, caprock and sealing conditions of the potential saline aquifer is relatively shallow, and the precise description of the saline aquifer and the quantification and evaluation of the site selection indicators are inaccurate.

[0035] Reference Figure 2 As shown in Figure c, based on this, this application carried out basic work such as stratigraphic sub-layer division and comparison, mud content calculation, porosity and permeability interpretation for non-oil and gas layers, and finally determined that the layers with mud content less than 40%, porosity greater than 5%, and single layer thickness greater than 2 meters in the interpretation results were marked as potential saline layers.

[0036] Step S103, performing a graded quantitative assessment based on the identified potential saline water layer segments, and establishing a corresponding assessment index system; The evaluation index system includes multiple first-level evaluation indicators and multiple second-level evaluation indicators corresponding to each first-level evaluation indicator. The first-level evaluation indicators include geological storage condition assessment, storage capacity condition assessment and social environment condition assessment; In the embodiment of the present application, the first-level evaluation index in the evaluation index system includes geological storage conditions, storage capacity conditions and social environment conditions, and each first-level evaluation index corresponds to multiple second-level evaluation indicators. By establishing an evaluation index system, a standardized and systematic evaluation of potential saline layers can be performed to ensure the objectivity and comparability of the evaluation results.

[0037] Among them, geological storage conditions are used to evaluate the injectability and storability of potential saline aquifers, storage capacity conditions are used to evaluate the sealing and storage capacity of selected saline aquifers, and social and environmental conditions are used to evaluate the ground environmental factors of the selected area.

[0038] It should be noted that CO 2 As the reverse process of oil and gas accumulation, the site selection of saline layer geological storage should follow the rules of "storage, capping, enclosure, transportation and protection" similar to oil and gas accumulation, and follow the comprehensive site selection idea of ​​"underground combined with ground". 2 Geological storage projects focus on three basic issues: injectivity and injection rate, that is, whether the available injection wells can be used to inject CO at a sufficient rate. 2 ; Second, capacity and safety, that is, whether there is enough space to accommodate the required CO during the project life cycle 2 , and CO 2 The third is social economy and public acceptance, that is, the stored CO2 Will it cause social and environmental impacts? Therefore, this application proposes three CO storage conditions: geological storage conditions, storage capacity conditions, and social and environmental conditions. 2 The site selection principle for geological storage in saline aquifers is used as the first-level evaluation indicator.

[0039] In one embodiment of the present application, the secondary evaluation indicators for evaluating the geological storage conditions include: reservoir lithology evaluation, reservoir thickness evaluation, porosity evaluation and permeability evaluation; through the above secondary evaluation indicators, it can be preliminarily determined whether the selected layer has CO 2 Injectability and storability.

[0040] Reservoir lithology is used to evaluate the selection of clastic rocks and carbonate rocks as potential storage layers, and reservoir thickness assessment is used to determine whether the selected layer has sufficient thickness to accommodate CO 2 The porosity is used to determine whether the porosity of the saline layer meets the minimum injection conditions, and the permeability is used to determine whether the permeability of the saline layer meets the CO 2 Injection rate requirements.

[0041] For reservoir thickness assessment, refer to Figure 3 As shown in the figure, the research area is 1005 sections and the length is 10 3 The distribution histogram of the sand-to-ground ratio and single-layer thickness of the favorable saline layer is shown in Figure 1. 3 The frequency distribution of the sand-to-land ratio of each layer shows that the saline layer with a sand-to-land ratio of less than 0.3 can be considered as an unsuitable layer, the saline layer with a sand-to-land ratio between 0.3 and 0.4 can be considered as a relatively suitable layer, and the saline layer with a sand-to-land ratio greater than 0.4 can be considered as a very suitable layer. In addition, the single-layer thickness of the favorable saline layer can also be used as a CO 2 An evaluation index for geological storage site selection. For saline layers with a single layer thickness greater than 2 meters suitable for injection and storage projects, the distribution histogram of the single layer thickness of each layer group and layer section is shown in Figure 3 In the right figure, the single-layer thickness of the 1,500-meter favorable saline layer (761 favorable saline layers) ranges from 2 to 18 meters, and the single-layer thickness of the 103-meter favorable saline layer (1,384 favorable saline layers) ranges from 2 to 20 meters.

[0042] according to Figure 3 In the right picture, the 5-segment and the length 10 3The frequency distribution of the thickness of the single layer of saline water layers in each section shows that the saline water layers with a single layer thickness of less than 2m can be considered as unsuitable sections, the saline water layers with a single layer thickness between 2 and 6m can be considered as relatively suitable sections, and the saline water layers with a single layer thickness of more than 6m can be considered as very suitable sections. The lower limit of 2 meters as the thickness of the favorable saline water layer is based on engineering construction and cost considerations. In fact, oil and gas reservoirs are also developed in sandstones with a single layer thickness of less than 2 meters or even less than 1 meter. With the gradual advancement of technology, saline water layers with a single layer thickness of less than 2 meters can also be developed and utilized as favorable storage areas.

[0043] For porosity and permeability assessment, refer to Figure 4 As shown in the figure, the research area is 1005 sections and the length is 10 3 The porosity and permeability distribution histogram of the favorable saline water layer in the study area of ​​this application is interpreted by the Wyllie time-averaged equation corrected by the shale content. The dominant potential saline water layer sections 1005 and 10 3 The porosity distribution histogram is shown in Figure 4 Left: The porosity distribution range of the favorable saline layer in the Qian5 section is 0 to 0.148, with an average porosity of 8.3%; 3 The porosity distribution range of the favorable saline layer in this section is 0-0.128, and the average porosity is 8.5%. 3 The frequency distribution of the porosity of saline water layers can be used to determine the frequency distribution of the porosity of saline water layers. Saline water layers with a porosity of less than 5% can be considered as unsuitable layers, saline water layers with a porosity between 5% and 8% can be considered as relatively suitable layers, and saline water layers with a porosity greater than 8% can be considered as very suitable layers.

[0044] In addition, this application predicts the permeability of non-oil and gas layers based on the exponential relationship between the core test permeability and porosity fitting of the natural gas layer in the block, and the potential saline layer sections of 1005 and 1000 are advantageous. 3 The permeability distribution histogram is shown in Figure 4 In the right figure, the permeability distribution range of the favorable saline water layer in the 1005 section is 0~8.324mD, with a length of 10 3 The permeability distribution range of the favorable saline water layer in this section is 0~12.349mD. 3 The frequency distribution of permeability of saline water layers can be used to determine the frequency distribution of permeability of saline water layers. The saline water layers with permeability less than 0.25 mD can be considered as unsuitable layers, the saline water layers with permeability between 0.25 and 1.5 mD can be considered as relatively suitable layers, and the saline water layers with permeability greater than 1.5 mD can be considered as very suitable layers.

[0045] In one embodiment of the present application, the secondary evaluation indicators for evaluating the storage capacity include: cap rock sealing evaluation, burial depth evaluation, storage potential evaluation, and fracture evaluation. By studying whether the selected favorable saline layer has sealing and storage capacity, it is determined whether it can store CO 2 Permanently and safely sealed for hundreds of years.

[0046] The caprock sealing property is used to evaluate the capillary sealing, hydrodynamic sealing and overpressure sealing capabilities of the caprock. The main factors affecting the caprock sealing property include caprock lithology, caprock thickness, caprock ratio (ratio of mudstone thickness in the caprock to total caprock thickness), mud content, and storage pressure. The burial depth assessment is used to determine whether the burial depth of the saline layer meets the CO 2 The requirements for supercritical state, storage potential assessment is used to calculate the theoretical storage capacity and effective storage capacity of saline aquifers, and fracture assessment is used to evaluate the impact of fractures on storage safety.

[0047] For the evaluation of caprock sealing, refer to Figure 5 , which is the research area of ​​10005 sections and 10 3 The caprock-to-ground ratio and mud content distribution histogram of the corresponding saline water layer of the 1005th section. The caprock above the saline water layer of the study area is the mudstone section of 1001-1004 and the mudstone of Liujiagou Formation. The average cumulative thickness of the mudstone section of 1001-1004 is 165.08m, and the average cumulative thickness of the mudstone section of Liujiagou Formation is 257.98m. 3 The caprock above the saline water layer is the mudstone section of Chang 102, Chang 101 and Chang 9, with an average cumulative thickness of 165.09m. The mudstone with good continuity above the sandstone reservoir can be regarded as the caprock, and the sandstone-mudstone interbedded caprock has good sealing property. Therefore, the cumulative thickness of the caprock in the sandstone-mudstone formation is relatively large, which is difficult to be used as a site selection evaluation indicator. This application uses the caprock ratio and mud content as the evaluation indicators for the macroscopic sealing property and CO 2 One of the indicators of geological storage caprock storage capacity conditions, according to Figure 5 The distribution diagram of cover-to-ground ratio and mud content shows that the cover-to-ground ratio of the mudstone cap layer in the Ordos Basin is not suitable for the cover layer when it is less than 0.6, the cover-to-ground ratio is between 0.6 and 0.7, it is a relatively suitable cover layer, and the cover-to-ground ratio is greater than 0.7. Similarly, when the mud content of the cap layer is less than 0.6, it is not suitable for the cover layer, the mud content is between 0.6 and 0.7, it is a relatively suitable cover layer, and the mud content is greater than 0.7. It is a very suitable cover layer.

[0048] Regarding the storage potential mentioned above, in saline aquifers CO 2When evaluating geological storage sites, the storage potential assessment indicators mainly depend on the size of the enclosed area, theoretical storage potential, effective storage potential, storage potential per unit area, service life, etc. Because the size of the planar area of ​​different favorable saline layer sections is different in different regions, it is more objective to use the theoretical storage capacity per unit area and the effective storage capacity per unit area as site selection assessment indicators.

[0049] In one embodiment of the present application, the secondary assessment indicators of social and environmental conditions include: underground resource development status assessment, land use status assessment, collapse and disaster area assessment, source-sink matching assessment and public acceptance assessment; these indicators combine ground environmental and social factors to determine whether the selected area has the feasibility of carrying out CCS projects.

[0050] Among them, the current status of underground resource development is used to assess the conflict with existing resource development, the current land use status is used to assess the impact of land use planning on site selection, the subsidence and disaster area assessment is used to assess the impact of adverse geological effects on project implementation, the source-sink matching assessment is used to assess the scale, distance, transportation route and cost of carbon sources, and public acceptance is used to assess the impact of the project on local residents and the level of government support.

[0051] It should be noted that the distance to the carbon source is related to the transportation cost. The closer the distance, the lower the cost. The transportation route is affected by the ground conditions in the selected area. Generally, pipeline transportation can be used when the distance is short and the scale is large, while tank truck transportation can be used when the distance is long and the scale is small. 2 The comprehensive cost of capture, transportation, injection and storage is a key factor affecting the operation of the project. In addition, public acceptance depends on the distance of the CCS project from the residential area, the local population density, the impact of the CCS project on local residents, and the government’s support for CCS emission reduction projects. 2 The farther the storage site is from the residential area, the smaller the population density and the 2 The smaller the impact of storage on local residents and the greater the government's support for CCS projects, the higher the public acceptance will be.

[0052] Step S104, assigning weights to the evaluation indicators in the evaluation indicator system based on the indicator weight assignment method, and performing a comprehensive quantitative evaluation to obtain a comprehensive evaluation score for each candidate target area; Among them, different evaluation indicators have different degrees of influence on site selection. The importance of each indicator can be quantified through the weight assignment method, and the comprehensive score of each candidate target area can be calculated.

[0053] In some embodiments, the weight of each secondary indicator relative to the primary indicator can be determined based on the analytic hierarchy process (AHP), and then the candidate target area can be comprehensively scored in combination with fuzzy mathematics or entropy weight method.

[0054] Step S105: selecting the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers.

[0055] Among them, the candidate target area with the highest comprehensive evaluation score was selected as the storage site because this area performed best in all evaluation indicators and was most likely to achieve safe and effective CO 2 Archive.

[0056] In the above implementation, a scientific evaluation index system was established based on the analysis of the actual well logging data and geological data sets collected, and a comprehensive quantitative evaluation of the potential saline layer was carried out through the weight assignment method. This technical solution not only improves the accuracy and reliability of site selection, but also takes into account multiple factors such as geology, economy and social environment, ensuring the CO 2 The long-term stability and safety of the storage project. This method can effectively screen the most suitable CO 2 Sealed.

[0057] Reference Figure 6 As an implementation method of step S104, the steps of weighting the evaluation indicators in the evaluation indicator system based on the indicator weighting method and performing comprehensive quantitative evaluation to obtain the comprehensive evaluation score of each candidate target area include: Step S201, according to the secondary evaluation indicators in the evaluation indicator system, the relative weights of the secondary evaluation indicators are obtained based on the expert evaluation method; Among them, the expert evaluation method is a commonly used weight assignment method, which evaluates the importance of each secondary evaluation indicator through the knowledge and experience of experts in the field, so as to obtain the relative weight of each indicator.

[0058] Step S202, constructing a judgment matrix according to the relative weights of the secondary evaluation indicators; Among them, the judgment matrix is ​​a tool that converts qualitative judgments into a computable form. By constructing a judgment matrix, the expert's judgment can be quantified. Specifically, based on the experts' scores on the importance of each secondary evaluation indicator, a judgment matrix is ​​constructed, and the matrix elements represent the ratio of the relative importance of the corresponding indicators.

[0059] Step S203, calculating weights based on the hierarchical analysis method and performing consistency check to obtain secondary evaluation index weights; Among them, the analytic hierarchy process (AHP) is a systematic decision-making method that obtains weights by calculating the eigenvectors of the judgment matrix and ensures the rationality of the judgment through consistency testing; Exemplarily, by calculating the maximum eigenvalue and the corresponding eigenvector of the judgment matrix, a weight set is obtained, and then the consistency index (CI) and consistency ratio (CR) are calculated to perform a consistency check, thereby ensuring the scientificity and rationality of the evaluation index weights and eliminating errors caused by inconsistent judgment matrices.

[0060] Step S204, obtaining the corresponding first-level evaluation indicator weight according to the second-level evaluation indicator and the second-level evaluation indicator weight; wherein the first-level evaluation indicator is a comprehensive reflection of multiple second-level evaluation indicators, and the weight of the first-level indicator can be obtained by aggregating the weight of the second-level evaluation indicator.

[0061] For example, geological storage conditions include secondary evaluation indicators such as porosity and permeability. The weight of "geological storage conditions" can be obtained by taking the weighted average of the weights of these secondary evaluation indicators.

[0062] Step S205, establishing a fuzzy comprehensive evaluation factor level matrix according to the first-level evaluation index weights, and obtaining a comprehensive evaluation score for each candidate target area based on fuzzy mathematics.

[0063] Among them, fuzzy mathematics is a method for dealing with uncertainty problems. It quantifies the pros and cons of the evaluation object by establishing a factor level matrix and fuzzy comprehensive evaluation: In an embodiment of the present application, a factor level matrix is ​​established based on the weights of the first-level evaluation indicators. The matrix elements represent the performance of the candidate target areas under each evaluation indicator. Then, the comprehensive score of each candidate target area can be calculated using the fuzzy comprehensive evaluation method, thereby converting the qualitative evaluation into a quantitative score, making the evaluation results of the candidate target areas comparable and facilitating the final decision.

[0064] In the above implementation, based on the combination of expert evaluation method and hierarchical analysis method, the scientific assignment of weights of each indicator in the evaluation index system is realized, and the fuzzy mathematics method is used to conduct a comprehensive quantitative evaluation of the candidate target areas. This technical solution makes full use of the experience of experts and the rigor of mathematical models to improve the accuracy and reliability of the evaluation. By constructing a judgment matrix and a factor level matrix, qualitative judgments are converted into quantitative scores, making the evaluation results more intuitive and easy to understand. Finally, by comparing the comprehensive evaluation scores, the target area most suitable for geological storage of carbon dioxide in saline aquifers can be determined, which is the CO 2 It provides strong decision support for the site selection of storage projects.

[0065] Reference Figure 7 As an implementation method of step S105, the step of selecting the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers includes: Step S301, sorting each candidate target area according to the comprehensive evaluation score, and selecting the candidate target area with the highest comprehensive evaluation score as the preferred target area; Among them, the comprehensive evaluation score reflects the overall performance of each candidate target area in all evaluation indicators, ensuring that the selection of the storage site is based on a systematic and comprehensive evaluation rather than a single indicator or subjective judgment.

[0066] Step S302, obtaining a storage location for geological storage of carbon dioxide in a saline aquifer based on the location information of the preferred target area.

[0067] Specifically, after determining the preferred target area, its geographical location information needs to be accurately determined in order to facilitate the actual sealing operation; illustratively, the geographical location information of the preferred target area is 118° east longitude and 40° north latitude, which will be used for subsequent geological sealing projects. By ensuring that the sealing project can be accurately located at the most suitable location, the efficiency and accuracy of project implementation are improved.

[0068] In the above embodiment, the most suitable target area for CO is selected scientifically and objectively from multiple candidate target areas. 2 The geographical location of the geological storage in the saline aquifer; each candidate target area is quantitatively scored through a comprehensive evaluation model, and the scores are ranked according to the scores, and the area with the highest score is finally determined as the storage location. This technical solution not only takes into account multiple factors such as geology, economy, and environment, but also ensures the smooth implementation of the storage project through accurate location information.

[0069] Based on the practical application of the above technical solution of this application, the applicant obtained and predicted the development characteristics and distribution law of saline water layers in low-porosity and low-permeability sandstone reservoirs based on the data of 192 exploration wells in the Yushen area of ​​the Ordos Basin, analyzed the sealing of multiple sets of mudstone caprocks and the sealing potential of multi-layered sandstone reservoirs, and comprehensively considered the influence of land use status and ground environmental factors, and finally proposed a set of CO2 storage methods suitable for low-porosity and low-permeability saline water layers. 2 The geological storage site suitability assessment index system (as shown in the following table).

[0070] When using this site selection evaluation system to select the target area for CCS projects, the importance of various evaluation indicators is different, such as the porosity and permeability of saline water layers, which determine the CO 2The index of injectability is more important than the sand-to-land ratio and cover-to-land ratio, and the index weight assignment method can be used for comprehensive evaluation. Commonly used index weight assignment and ranking methods include the analytic hierarchy process combined with the fuzzy mathematics method and the entropy weight method. The analytic hierarchy process aims to determine the weight of each evaluation index, and its weight determination method depends on the expert scoring. The fuzzy mathematics method is to establish a fuzzy comprehensive evaluation factor level matrix for each candidate target area, and then combine the index weight matrix determined by the analytic hierarchy process to perform comprehensive scoring and ranking; the entropy weight method first scores each candidate target area based on the hierarchical evaluation range of each index, such as very suitable, relatively suitable, and unsuitable range, and then calculates the weight based on the entropy weight method and comprehensively ranks. Different weight calculation methods will produce different site selection ranking results, so the target area optimization conclusion is only for reference. In the actual site-level site selection, more on-site investigation and inspection should be combined to form a more comprehensive and comprehensive site selection plan.

[0071] In the research process of this application, firstly, geological storage conditions are used as the primary indicator for site selection evaluation of CCS projects, aiming to find underground sites suitable for CO 2 The reservoir of the saline aquifer geological storage project should be initially determined to have CO 2 Injectability and sealability correspond to the four secondary evaluation indicators of reservoir lithology, reservoir thickness, porosity and permeability. It should be noted that the saltwater layer with porous sandstone, sand-to-ground ratio greater than 0.4, single-layer saltwater layer thickness greater than 6 meters, average porosity greater than 8%, and average permeability greater than 1.5mD can be preferred as a very suitable layer.

[0072] Secondly, the storage capacity condition is the first-level indicator for the site selection and evaluation of CCS projects, which aims to further determine whether the selected saline layer has sealing and storage capacity, corresponding to the four second-level evaluation indicators of cap rock sealing, burial depth, storage potential, and fracture. It should be noted that it is preferred to develop multiple sets of continuous mudstone, with cap rock ratio and average mud content greater than 0.7, cap rock breakthrough pressure and fracture pressure both large, and meet the requirements of CO 2 The supercritical state burial depth, the large storage potential per unit area, and the area avoiding large faults are used as CO 2 Advantageous target area for geological storage of saline aquifers.

[0073] Finally, social and environmental conditions, as the primary indicator for the site selection evaluation of CCS projects, aim to identify sites with the feasibility of carrying out CCS projects in combination with ground environment and social factors, corresponding to the five secondary evaluation indicators of underground resource development status, land use status, subsidence and disaster areas, source-sink matching, and public acceptance. It should be noted that the preferred sites for CCS projects are those that avoid underground resource development areas, do not involve ecological red lines, are far away from disaster areas such as subsidence, and have high public acceptance.

[0074] In summary, the CO2 gasification method established in this application is suitable for low porosity and low permeability reservoirs. 2 The evaluation index system for geological storage site selection in saline aquifers provides guidance and basis for the site selection of target-level and field-level CCS projects in low-porosity and low-permeability formations such as the Ordos Basin, which is conducive to the use of existing logging data by high-carbon emission coal chemical, coal-fired power and other enterprises to carry out CO 2 Implementation and engineering promotion of saline aquifer geological storage projects.

[0075] The embodiment of the present application also discloses a site selection system for geological storage of carbon dioxide in saline aquifers.

[0076] A site selection system for geological storage of carbon dioxide in saline aquifers, the site selection system comprising: An acquisition module for acquiring well logging data and geological data sets in a target area; An identification module for identifying potential saline water intervals based on pre-set rules according to well logging data and geological data sets; An evaluation index system establishment module is used to perform graded quantitative evaluation based on the identified potential saline layer segments and establish a corresponding evaluation index system; wherein the evaluation index system includes a plurality of first-level evaluation indicators and a plurality of second-level evaluation indicators corresponding to each first-level evaluation indicator; A comprehensive evaluation module is used to assign weights to the evaluation indicators in the evaluation indicator system based on the indicator weight assignment method, and to perform a comprehensive quantitative evaluation to obtain a comprehensive evaluation score for each candidate target area; The storage site determination module is used to select the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers.

[0077] In the above implementation, by systematically collecting and analyzing the well logging data and geological data sets of the target area, a comprehensive quantitative evaluation of multiple candidate areas is conducted based on scientific preset rules, evaluation index system and weight assignment method, and finally the most suitable storage location is selected. This technical solution has the advantages of high data processing efficiency, scientific and transparent evaluation process, and reliable results, providing a strong guarantee for the safe geological storage of carbon dioxide.

[0078] The technical solution of this application is based on a systematic screening process, taking into account factors such as basin size and depth, geological characteristics, hydrogeology, geological thermodynamic characteristics, natural resources, and infrastructure; it is also closely related to economic, political, and social factors. It aims to fully consider the distribution range, storage conditions, storage capacity, and storage potential of underground saline aquifers, and combine the actual ground conditions to avoid ecological red line areas, mining areas, resource mining areas, and human activity areas, and finally determine the CO 2 The site selection and advantageous target area delineation of saline aquifer geological storage. This technical solution can significantly improve the CO 2Increase the success rate of storage projects and reduce risks.

[0079] The carbon dioxide saline aquifer geological storage site selection system of the embodiment of the present application can implement any of the above-mentioned carbon dioxide saline aquifer geological storage site selection methods, and the specific working process of each module in the carbon dioxide saline aquifer geological storage site selection system can refer to the corresponding process in the above-mentioned method embodiment.

[0080] In the several embodiments provided in this application, it should be understood that the provided methods and systems can be implemented in other ways. For example, the system embodiments described above are only illustrative; for example, the division of a certain module is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules can be combined or integrated into another system, or some features can be ignored or not executed.

[0081] The embodiment of the present application also discloses a computer device.

[0082] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a method for selecting a site for geological storage of carbon dioxide in a saline layer as described above is implemented.

[0083] The embodiment of the present application also discloses a computer-readable storage medium.

[0084] A computer-readable storage medium stores a computer program that can be loaded by a processor and execute any of the above-mentioned methods for selecting a site for geological storage of carbon dioxide in a saline aquifer.

[0085] Among them, computer-readable storage media can be any tangible medium that contains or stores a program, which can be used by or in conjunction with an instruction execution system, apparatus or device; the program code contained on the computer-readable medium can be transmitted using any appropriate medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0086] It should be noted that in the above embodiments, the description of each embodiment has different emphases, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Any feature disclosed in this specification (including the abstract and drawings), unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

Claims

1. A method for selecting a site for geological storage of carbon dioxide in saline aquifers, characterized in that: The site selection method includes: Acquire well log data and geological data sets for target areas; identifying potential saline water intervals based on the well logging data and geological data set based on preset rules; Conduct a graded quantitative assessment based on the identified potential saline layer segments and establish a corresponding assessment index system; wherein the assessment index system includes a plurality of primary assessment indicators and a plurality of secondary assessment indicators corresponding to each primary assessment indicator, wherein the primary assessment indicators include a geological storage condition assessment, a storage capacity condition assessment and a social environment condition assessment; Based on the indicator weight assignment method, the evaluation indicators in the evaluation indicator system are weighted, and a comprehensive quantitative evaluation is performed to obtain a comprehensive evaluation score for each candidate target area; The candidate target area with the highest comprehensive evaluation score is selected as the storage site for geological storage of carbon dioxide in saline aquifers.

2. A method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to claim 1, characterized in that: Well logging data include various well logging curves and formation lithology data, formation thickness data, porosity data, permeability data, cap rock lithology data and cap rock thickness data obtained based on the well logging curves. The geological data set includes fault development data, land use status data, underground resource development status data, historical seismic activity and ground subsidence data.

3. A method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to claim 2, characterized in that: The secondary evaluation indicators for evaluating the geological storage conditions include: reservoir lithology evaluation, reservoir thickness evaluation, porosity evaluation and permeability evaluation.

4. A method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to claim 2, characterized in that: The secondary evaluation indicators for evaluating the storage capacity conditions include: cap rock sealing assessment, burial depth assessment, storage potential assessment, and fracture assessment.

5. A method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to claim 2, characterized in that: The secondary assessment indicators of the social environmental conditions obtained in the assessment include: assessment of the status of underground resource development, assessment of the status of land use, assessment of subsidence and disaster areas, assessment of source-sink matching and assessment of public acceptance.

6. A method for selecting a site for geological storage of carbon dioxide in saline aquifers according to any one of claims 1 to 5, characterized in that: The steps of assigning weights to the evaluation indicators in the evaluation indicator system based on the indicator weight assignment method and performing comprehensive quantitative evaluation to obtain a comprehensive evaluation score for each candidate target area include: According to the secondary evaluation indicators in the evaluation indicator system, the relative weights of the secondary evaluation indicators are obtained based on the expert evaluation method; Constructing a judgment matrix according to the relative weights of the secondary evaluation indicators; The weights are calculated based on the analytic hierarchy process and consistency tests are performed to obtain the weights of the secondary evaluation indicators; Obtaining a corresponding first-level evaluation indicator weight according to the second-level evaluation indicator and the second-level evaluation indicator weight; A fuzzy comprehensive evaluation factor level matrix is ​​established according to the weights of the first-level evaluation indicators, and a comprehensive evaluation score for each candidate target area is obtained based on fuzzy mathematics.

7. A method for selecting a site for geological storage of carbon dioxide in a saline aquifer according to claim 6, characterized in that: The step of selecting the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers comprises: Sorting each candidate target area according to the comprehensive evaluation score, and selecting the candidate target area with the highest comprehensive evaluation score as the preferred target area; According to the location information of the preferred target area, the storage location of the geological storage of carbon dioxide in the saline aquifer is obtained.

8. A system for selecting a site for geological storage of carbon dioxide in saline aquifers, characterized in that: The site selection system comprises: An acquisition module for acquiring well logging data and geological data sets in a target area; an identification module, for identifying potential saline water layers based on preset rules according to the well logging data and geological data set; An evaluation index system establishment module is used to perform a graded quantitative evaluation based on the identified potential saline layer segment and establish a corresponding evaluation index system; wherein the evaluation index system includes a plurality of primary evaluation indicators and a plurality of secondary evaluation indicators corresponding to each of the primary evaluation indicators; A comprehensive evaluation module, used to assign weights to the evaluation indicators in the evaluation indicator system based on an indicator weight assignment method, and to perform a comprehensive quantitative evaluation to obtain a comprehensive evaluation score for each candidate target area; The storage site determination module is used to select the candidate target area with the highest comprehensive evaluation score as the storage site for geological storage of carbon dioxide in saline aquifers.

9. A computer device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 7 when executing the program.

10. A computer-readable storage medium, characterized in that: A computer program is stored which can be loaded by a processor and execute the method according to any one of claims 1 to 7.

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