Method for evaluating geological storage suitability of carbon dioxide in saline water layer

Abstract

A saline water layer carbon dioxide geological sequestration suitability evaluation method comprises the steps that 1, a carbon dioxide geological sequestration suitability evaluation index hierarchical structure model is established and comprises four criterion layers and 16 index layers;

Description

Technical Field

[0001] The invention belongs to the field of geological technology, and in particular relates to a method for evaluating suitability of geological storage of carbon dioxide in saline layers. Background Art

[0002] For the evaluation of suitability of carbon dioxide geological storage in saline aquifers, most of the current methods use a combination of fuzzy comprehensive evaluation method and hierarchical analysis method to construct an evaluation index system, but the evaluation index settings are different, with more or less indicators, detailed or rough ( Figure 1 , Figure 2 , Figure 3 etc.), and the research objects are mostly sedimentary basins. Summary of the invention

[0003] In order to solve the deficiencies mentioned in the above-mentioned prior art, this study takes the structural units of the northwest plain area of ​​Shandong as the research object, and the research accuracy is higher. Based on the previous research, combined with the geological characteristics of the northwest plain area of ​​Shandong, the fuzzy comprehensive evaluation method and the hierarchical analysis method are combined to construct a saltwater carbon dioxide geological storage suitability evaluation index system with 4 criterion layers and 16 indicator layers, and the weight of each indicator is calculated. The present invention provides a saltwater carbon dioxide geological storage suitability evaluation method.

[0004] This application proposes a method for evaluating the suitability of geological storage of carbon dioxide in saline aquifers, comprising the steps of: 1. establishing a hierarchical structure model of indicators for evaluating the suitability of geological storage of carbon dioxide, including 4 criterion layers and 16 indicator layers;

[0005] Step 2: Construct a judgment matrix based on the hierarchical analysis method, select the 5-degree marking method to score each indicator, and obtain the weight of each evaluation indicator;

[0006] Step 3: Use the fuzzy comprehensive evaluation method to divide the reasonable value range and standard of each index suitable for the geological storage of CO2 in the saline aquifer in this study area;

[0007] Step 4: Comprehensive scoring: The comprehensive scoring result is obtained by multiplying the indicator score and the weight value of each indicator.

[0008]

[0009] P is the comprehensive score of CO2 geological storage suitability of the evaluation unit, Pi is the given index of the i-th evaluation index; Ai is the weight of the i-th evaluation index, and n is the total number of evaluation factors;

[0010] Step 5: Normalization: Normalize the comprehensive score to obtain the final evaluation score;

[0011] X'(X-Xmin)(Xmax-Xmin)

[0012] X' is the normalized value of the evaluation unit, X is the evaluation unit score value, Xmax is the maximum score of the evaluation unit, and Xmin is the minimum score of the evaluation unit;

[0013] Step 6: Confirmation of scoring results.

[0014] Specifically, the evaluation level in step 3 is divided into five levels, including: good, better, average, poor and poor, and the corresponding scores are 5, 4, 3, 2 and 1 points respectively.

[0015] Specifically, in step 6, 0.7-1.0 indicates good suitability, 0.4-0.7 indicates medium suitability, and 0-0.4 indicates poor suitability.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The tectonic units in the northwest Shandong plain area are taken as the research object, with higher research accuracy. The 16 optimized evaluation index layers are concise and fit the actual geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 This is a map showing the results of geothermal suitability assessment for geological storage of carbon dioxide in major sedimentary basins in my country;

[0020] Figure 2 This is the result of the suitability assessment of the carbon dioxide storage site in the saline layer in the northern part of the Central Depression of the Songliao Basin;

[0021] Figure 3 This is a map showing the suitability assessment results for geological storage of carbon dioxide in saline aquifers in the East China Sea shelf basin;

[0022] Figure 4 It is a hierarchical model of evaluation indicators for CO2 geological storage suitability;

[0023] Figure 5 It is a bar chart of the weights of each indicator;

[0024] Figure 6 It is a scoring standard table for CO2 geological storage suitability evaluation indicators;

[0025] Figure 7 It is a flow chart for suitability assessment of geological storage of carbon dioxide in saline aquifers. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] A method for evaluating the suitability of carbon dioxide geological storage in saline aquifers is shown in the figure. Step 1: Based on previous studies and the geological characteristics of the northwest plain area of ​​Shandong Province, a hierarchical model of evaluation indicators for the suitability of carbon dioxide geological storage was established, including 4 criterion layers and 16 indicator layers ( Figure 4 );

[0028] Step 2: Construct a judgment matrix based on the hierarchical analysis method, select the 5-degree annotation method to have experts score or refer to the data to score each indicator, and obtain the weight of each evaluation indicator ( Figure 5 );

[0029] Step 3: Use the fuzzy comprehensive evaluation method to divide the reasonable value range and standard of each indicator suitable for the geological storage of CO2 in the saline aquifer in this study area ( Figure 6 ), the evaluation level is divided into five levels, including: good, better, average, poor and poor, and the corresponding scores are 5, 4, 3, 2 and 1 points respectively.

[0030] Step 4: Comprehensive scoring: The indicator score is multiplied and added with the weight value of each indicator to obtain the comprehensive scoring result;

[0031]

[0032] Where: P is the comprehensive score of CO2 geological storage suitability of the evaluation unit, Pi is the given index of the i-th evaluation indicator; Ai is the weight of the i-th evaluation indicator, and n is the total number of evaluation factors;

[0033] Step 5: Normalization: Normalize the comprehensive score to obtain the final evaluation score;

[0034] X'(X-Xmin)(Xmax-Xmin)

[0035] In the formula: X' is the normalized value of the evaluation unit, X is the evaluation unit score value, Xmax is the maximum score of the evaluation unit, and Xmin is the minimum score of the evaluation unit;

[0036] Step 6: Scoring results: 0.7-1.0 indicates good suitability, 0.4-0.7 indicates medium suitability, and 0-0.4 indicates poor suitability.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating suitability of geological storage of carbon dioxide in saline aquifers, characterized by: include Step 1: Establish a hierarchical model of CO2 geological storage suitability evaluation indicators, including 4 criterion layers and 16 indicator layers; Step 2: Construct a judgment matrix based on the hierarchical analysis method, select the 5-degree marking method to score each indicator, and obtain the weight of each evaluation indicator; Step 3: Use the fuzzy comprehensive evaluation method to divide the reasonable value range and standard of each index suitable for the geological storage of CO2 in the saline aquifer in this study area; Step 4: Comprehensive scoring: The comprehensive scoring result is obtained by multiplying the indicator score and the weight value of each indicator. P is the comprehensive score of CO2 geological storage suitability of the evaluation unit, Pi is the given index of the i-th evaluation index; Ai is the weight of the i-th evaluation index, and n is the total number of evaluation factors; Step 5: Normalization: Normalize the comprehensive score to obtain the final evaluation score; X'(X-Xmin)(Xmax-Xmin) X' is the normalized value of the evaluation unit, X is the evaluation unit score value, Xmax is the maximum score of the evaluation unit, and Xmin is the minimum score of the evaluation unit; Step 6: Confirmation of scoring results.

2. The method for evaluating suitability of carbon dioxide geological storage in saline aquifers according to claim 1, characterized in that: The evaluation level in step 3 is divided into five levels, including: good, better, average, poor and poor, and the corresponding scores are 5, 4, 3, 2 and 1 points respectively.

3. The method for evaluating suitability of carbon dioxide geological storage in saline aquifers according to claim 1, characterized in that: In step 6, 0.7-1.0 indicates good suitability, 0.4-0.7 indicates medium suitability, and 0-0.4 indicates poor suitability.

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