A CO2 sequestration leak prevention agent and a method of making the same

Abstract

The application discloses a CO2 storage leak-proof agent, and a preparation method thereof. The structural formula of the CO2 storage leak-proof agent is as follows: wherein 11<=n<=17. The preparation method comprises the following steps: S1, adding a solvent, long-chain alkyl monoglyceride and a dibasic acid into a reaction container, then adding a catalyst into the reaction container to obtain a mixed solution, refluxing and reacting at 120-140 DEG C for 3-4 hours, and vacuum drying after spinning evaporation to obtain a product after hydroxyl protection; S2, adding a compound emulsifier into water, then adding the product obtained in the step S1 and tetraethyl orthosilicate into the water to obtain a reaction system, and obtaining the CO2 storage leak-proof agent after the reaction. The application has the following beneficial effects: 1, the preparation method is simple; 2, the CO2 storage leak-proof agent can form a solid gel with high strength, realizes plugging of a buried CO2 formation crack and pore, and thus improves the CO2 burying efficiency and prevents the CO2 from escaping.

Description

Technical Field

[0001] The present invention belongs to the field of plugging agents, and in particular relates to a CO2 storage and leakage-proofing agent and a preparation method thereof. Background Art

[0002] Water injection production refers to the process of injecting water into the oil reservoir through special injection wells during oil field development to maintain or restore the oil layer pressure, giving the oil reservoir a strong driving force to increase the oil reservoir's production rate and recovery rate.

[0003] Due to the problems of rapid formation energy depletion and insufficient natural capacity supply in low permeability oil reservoirs, the efficiency of water injection production is low, and the problem of "no injection and no production" is becoming increasingly prominent.

[0004] To address this issue, some oil fields use high-temperature, high-pressure carbon dioxide injection for CO2 flooding, increasing crude oil recovery. However, CO2 is currently stored in formation cement. Due to cracks in the formation, the cement is susceptible to moisture and is corroded and decomposed by the CO2, resulting in reduced storage efficiency and even leakage, seriously affecting the CO2 storage effect. Summary of the Invention

[0005] The purpose of the invention is to improve the storage efficiency of CO2 during CO2 flooding and CO2 energy-enhanced imbibition oil production and achieve long-term storage of CO2. The present invention discloses a CO2 storage leak-proof agent and a preparation method thereof.

[0006] Technical solution: A CO2 storage leak-proof agent, the structural formula of which is as follows:

[0007]

[0008] Wherein, n represents the carbon chain length, and n is an integer, 11≤n≤17.

[0009] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0010] S1. Add a solvent, a long-chain alkyl monoglyceride, and a dibasic acid to a reaction vessel, then add a catalyst to the reaction vessel to obtain a mixed solution, reflux the solution at 120-140° C. for 3-4 hours, and after the reaction, perform rotary evaporation and vacuum drying to obtain a hydroxyl-protected product.

[0011] S2. Add a compound emulsifier into water, and then add the product obtained in step S1 and ethyl orthosilicate into water in a certain proportion to obtain a reaction system. After the reaction is completed, a CO2 sealing and leak-proofing agent is obtained.

[0012] The reaction container is a commonly used container in a laboratory, such as a three-necked flask or a four-necked flask.

[0013] Furthermore, the solvent in step S1 is one of DMF, DMAC and DMSO.

[0014] Furthermore, the catalyst in step S1 is concentrated sulfuric acid.

[0015] Preferably, the alkyl chain length of the long-chain alkyl monoglyceride in step S1 is C11 to C17.

[0016] Preferably, the dibasic acid in step S1 is oxalic acid or malonic acid.

[0017] Preferably, the molar ratio of the long-chain alkyl monoglyceride to the dibasic acid in step S1 is 1:(1-1.1).

[0018] Furthermore, the amount of the solvent added in step S1 is 60-70% of the total mass of the mixed solution, and the amount of the catalyst added is 1-2% of the total mass of the mixed solution.

[0019] Preferably, the compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 10-12. The added amount of the compound emulsifier is 1-2% of the total mass of the compound emulsifier and water.

[0020] Preferably, the mass ratio of the product obtained in step S1 described in step S2 to ethyl orthosilicate is 4:(1-1.1).

[0021] Preferably, the amount of water added in step S2 is 60-70% of the mass of the reaction system obtained in step S2.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The preparation method is simple and the reaction mechanism is clear:

[0024] By using dibasic acid to protect the hydroxyl groups of long-chain alkyl monoglycerides, they are deprotected under high-temperature conditions in the formation, thereby reacting with the silicic acid produced by the hydrolysis of ethyl orthosilicate to form solid gel particles to seal cracks and pores. This method has a good sealing effect and can achieve efficient burial of CO2.

[0025] 2. The preparation method disclosed in this invention first utilizes an esterification reaction between a long-chain alkyl monoglyceride and a dibasic acid to protect the monoglyceride's hydroxyl groups. Subsequently, a homogeneous emulsion is formed using a compounded emulsifier, ethyl orthosilicate, for application. This CO2 storage and leak prevention agent forms a high-strength solid gel that seals cracks and pores in the CO2-embedded formation, thereby improving CO2 sealing efficiency and preventing its escape. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1Diagram of the experimental setup for characterizing the plugging performance.

[0027] in:

[0028] 1-Computer acquisition system 2-Pressure sensor 3-Intermediate container tank 4-Horizontal flow pump 5-Liquid storage tank 6-Constant temperature bath 7-Sand filling pipe DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are described in detail below.

[0030] The present invention discloses a method for preparing a CO2 storage and leak-proofing agent. Specifically, the method comprises: first, an esterification reaction between a long-chain alkyl monoglyceride and a dibasic acid is used to protect the monoglyceride hydroxyl groups; then, a uniform emulsion is formed using a compounded emulsifier, ethyl orthosilicate, for application. The CO2 storage and leak-proofing agent forms a high-strength solid gel that seals cracks and pores in the formation where CO2 is trapped, thereby improving the CO2's sealing efficiency and preventing its escape.

[0031] The synthesis route of the preparation method of the CO2 storage leak-proof agent disclosed in the present invention is as follows:

[0032]

[0033] The mechanism diagram of the high-temperature hydrolysis of ethyl orthosilicate to generate silicic acid disclosed in the present invention is as follows:

[0034]

[0035] The mechanism diagram of the formation of solid gel by the CO2 storage and leakage prevention agent obtained in the present invention is as follows:

[0036]

[0037] Example 1

[0038] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0039] S1. DMF is added to a reaction vessel (e.g., a three-necked flask), and then monoolein and oxalic acid are added to the reaction vessel at a molar ratio of 1:1, followed by adding concentrated sulfuric acid as a catalyst to obtain a mixed solution. The mixture is refluxed at 120° C. for 3 h. After completion of the reaction, the mixture is vacuum dried to obtain a hydroxyl-protected product, wherein:

[0040] The mass of DMF accounts for 60% of the total mass of the mixed liquid;

[0041] The mass of concentrated sulfuric acid accounts for 1% of the total mass of the mixture;

[0042] S2. Add 1 g of compound emulsifier to 60 g of water, then add 32 g of the product of step S1 and 8 g of ethyl orthosilicate, stir well and react thoroughly, and obtain a CO2 sealing and leak-proofing agent after the reaction is completed, wherein:

[0043] The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 10.

[0044] Example 2

[0045] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0046] S1. DMF is added to a reaction vessel (e.g., a three-necked flask), and then monoolein and oxalic acid are added to the reaction vessel at a molar ratio of 1:1.1, followed by adding concentrated sulfuric acid as a catalyst to obtain a mixed solution. The mixture is refluxed at 140° C. for 4 h. After completion of the reaction, the mixture is vacuum dried to obtain a hydroxyl-protected product, wherein:

[0047] The mass of DMF accounts for 70% of the total mass of the mixed liquid;

[0048] The mass of concentrated sulfuric acid accounts for 2% of the total mass of the mixed solution;

[0049] S2, add 2g of compound emulsifier to 60g of water, then add 32.2g of the product of step S1 and 7.8g of ethyl orthosilicate, stir well and react, and obtain the CO2 sealing and leak-proofing agent after the reaction is completed, wherein:

[0050] The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 12.

[0051] Example 3

[0052] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0053] S1. DMF is added to a reaction vessel (e.g., a three-necked flask), and then monoolein and malonic acid are added in a molar ratio of 1:1.05 to the reaction vessel, followed by adding concentrated sulfuric acid as a catalyst to obtain a mixed solution, and the mixture is refluxed at 130° C. for 3 h. After completion of the reaction, the mixture is vacuum dried to obtain a hydroxyl-protected product, wherein:

[0054] The mass of DMF accounts for 65% of the total mass of the mixed liquid;

[0055] The mass of concentrated sulfuric acid accounts for 1.5% of the total mass of the mixed solution;

[0056] S2. Add 2g of compound emulsifier to 60g of water, then add 32g of the product of step S1 and 8g of ethyl orthosilicate, stir well and react, and the CO2 sealing and leak-proofing agent is obtained after the reaction is completed, wherein:

[0057] The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 11.

[0058] Example 4

[0059] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0060] S1. DMF is added to a reaction vessel (e.g., a three-necked flask), and then monoolein and malonic acid are added in a molar ratio of 1:1.1 to the reaction vessel, followed by adding concentrated sulfuric acid as a catalyst to obtain a mixed solution, and the mixture is refluxed at 130° C. for 3 h. After completion of the reaction, the mixture is vacuum dried to obtain a hydroxyl-protected product, wherein:

[0061] The mass of DMF accounts for 65% of the total mass of the mixed liquid;

[0062] The mass of concentrated sulfuric acid accounts for 1% of the total mass of the mixture;

[0063] S2. Add 2g of compound emulsifier to 60g of water, then add 32g of the product of step S1 and 8g of ethyl orthosilicate, stir well and react, and the CO2 sealing and leak-proofing agent is obtained after the reaction is completed, wherein:

[0064] The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 11.

[0065] Example 5

[0066] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0067] S1. DMSO is added to a reaction vessel (e.g., a three-necked flask), and then palmitic acid monoglyceride and malonic acid are added in a molar ratio of 1:1 to the reaction vessel, followed by adding concentrated sulfuric acid as a catalyst to obtain a mixed solution, and the mixture is refluxed at 130° C. for 3 h. After completion of the reaction, the mixture is vacuum dried to obtain a hydroxyl-protected product, wherein:

[0068] The mass of DMSO accounts for 60% of the total mass of the mixture;

[0069] The mass of concentrated sulfuric acid accounts for 2% of the total mass of the mixed solution;

[0070] S2. Add 2g of compound emulsifier to 60g of water, then add 32g of the product of step S1 and 8g of ethyl orthosilicate, stir well and react, and the CO2 sealing and leak-proofing agent is obtained after the reaction is completed, wherein:

[0071] The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 10.

[0072] Example 6

[0073] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0074] S1. DMAC is added to a reaction vessel (e.g., a three-necked flask), and then palmitic acid monoglyceride and malonic acid are added in a molar ratio of 1:1 to the reaction vessel, followed by adding concentrated sulfuric acid as a catalyst to obtain a mixed solution. The mixture is refluxed at 120° C. for 4 h. After completion of the reaction, the mixture is vacuum dried to obtain a hydroxyl-protected product, wherein:

[0075] The mass of DMAC accounts for 70% of the total mass of the mixture;

[0076] The mass of concentrated sulfuric acid accounts for 1% of the total mass of the mixture;

[0077] S2. Add 2g of compound emulsifier to 60g of water, then add 32g of the product of step S1 and 8g of ethyl orthosilicate, stir well and react, and the CO2 sealing and leak-proofing agent is obtained after the reaction is completed, wherein:

[0078] The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 12.

[0079] Performance Characterization

[0080] 1. The influence of temperature on the solid gel produced by CO2 storage leak-proof agent

[0081] In order to characterize the effect of temperature on the formation of solid gel of a CO2 sealing and leak-proofing agent, the CO2 sealing and leak-proofing agent obtained in Example 1 was placed in a glass bottle, acid was added to adjust the pH to 6, and the temperature was increased to observe the solid precipitation.

[0082] It can be seen from the experimental results that the CO2 storage and leakage prevention agent will not precipitate solid gel at room temperature. When the temperature rises to 80°C, solid gel precipitates. At the same time, as the temperature continues to rise, the amount of solid precipitation does not change, indicating that temperature only affects the precipitation rate of solid gel and has no effect on the solid gel itself, indicating that temperature will not change the sealing efficiency of the CO2 storage and leakage prevention agent.

[0083] 2. Sealing performance

[0084] In order to characterize the plugging performance of a CO2 storage leak-proof agent, Figure 1 The device shown was used for a plugging test experiment.

[0085] like Figure 1As shown, the liquid storage tank 5, the horizontal flow pump 4, the intermediate container tank 3, and the constant temperature bath 6 are connected in sequence. A sand filling pipe 7 is provided in the constant temperature bath 6. A pressure sensor 2 is provided in the pipeline connecting the intermediate container tank 3 and the constant temperature bath 6. The output end of the pressure sensor 2 is connected to the input end of the computer acquisition system 1.

[0086] Sand-filled tubes 7 with varying permeabilities were prepared using the wet-fill method. The porosity was calculated, and water was then injected at a rate of 0.5 mL / min to calculate the water permeability of the sand-filled tubes. Subsequently, 1.0 PV of the CO2 storage and leak-proofing agent obtained in Example 1 was injected into the sand-filled tubes 7. The valves at both ends of the sand-filled tubes were closed, and a thermostatic bath was maintained at 80°C to form a solid gel. Water was then injected at a rate of 0.5 mL / min, and the pressure at the injection end was recorded to calculate the plugging rate. The experimental results are shown in Tables 1 and 2.

[0087] Table 1 Basic parameters of sand filling pipe

[0088]

[0089] Table 2 Sand filling pipe plugging effect

[0090]

[0091] As can be seen from Table 2, the plugging rates of the CO2 storage and leakage-proofing agents obtained by this method are all above 98%, indicating that the CO2 storage and leakage-proofing agents have excellent plugging effects on cracks and pores in the formation and can prevent the escape of CO2.

[0092] 3. Thermal stability

[0093] In order to characterize the thermal stability of a CO2 sealing and leak-proofing agent, a thermal stability test was conducted using the sand-filled tubes in Table 1. The CO2 sealing and leak-proofing agent obtained in Example 1 was added to the sand-filled tubes. Example 1 used 1-2 sand-filled tubes. The tubes were sealed and stored in a 150°C oven. After 10, 30, and 90 days, the tubes were taken out and the temperature was kept constant. Figure 1 The device and plugging performance test method were used to calculate the plugging rate at different aging times. The experimental results are shown in Table 3.

[0094] Table 3 Plugging effect of sand-filled pipes at different aging times

[0095]

[0096] As can be seen from Table 3, the plugging pressure difference gradually decreases with increasing aging time, but the decrease in the plugging rate is very small. After 90 days, the plugging rate is 0.2% lower than the initial value, but the plugging rate is still greater than 98%. Therefore, the plugging agent has good thermal stability.

[0097] Example 4

[0098] A CO2 storage leak-proof agent, the structural formula of which is as follows:

[0099]

[0100] Wherein, n represents the carbon chain length, n is an integer, and n=17.

[0101] Example 5

[0102] A CO2 storage leak-proof agent, the structural formula of which is as follows:

[0103]

[0104] Wherein, n represents the carbon chain length, n is an integer, and n=11.

[0105] Example 6

[0106] A CO2 storage leak-proof agent, the structural formula of which is as follows:

[0107]

[0108] Wherein, n represents the carbon chain length, n is an integer, and n=12.

[0109] Example 7

[0110] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0111] S1. Add a solvent, a long-chain alkyl monoglyceride, and a dibasic acid to a reaction vessel, then add a catalyst to the reaction vessel to obtain a mixed solution, reflux the solution at 120° C. for 4 h, and after completion of the reaction, perform rotary evaporation and vacuum drying to obtain a hydroxyl-protected product;

[0112] S2. Add a compound emulsifier into water, and then add the product obtained in step S1 and ethyl orthosilicate into water in a certain proportion to obtain a reaction system. After the reaction is completed, a CO2 sealing and leak-proofing agent is obtained.

[0113] The reaction container is a commonly used container in the laboratory, such as a three-necked flask.

[0114] Furthermore, the solvent in step S1 is DMF.

[0115] Furthermore, the catalyst in step S1 is concentrated sulfuric acid.

[0116] Preferably, the alkyl chain length of the long-chain alkyl monoglyceride in step S1 is C11.

[0117] Preferably, the dibasic acid in step S1 is oxalic acid.

[0118] Preferably, the molar ratio of the long-chain alkyl monoglyceride to the dibasic acid in step S1 is 1:1.

[0119] Furthermore, in step S1, the amount of the solvent added is 60% of the total mass of the mixed solution, and the amount of the catalyst added is 1% of the total mass of the mixed solution.

[0120] Preferably, the compound emulsifier in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 10. The amount of the compound emulsifier added is 1% of the total mass of the compound emulsifier and water.

[0121] Preferably, the mass ratio of the product obtained in step S1 described in step S2 to ethyl orthosilicate is 4:1.

[0122] Preferably, the amount of water added in step S2 is 60% of the mass of the reaction system obtained in step S2.

[0123] Example 8

[0124] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0125] S1. Add a solvent, a long-chain alkyl monoglyceride, and a dibasic acid to a reaction vessel, then add a catalyst to the reaction vessel to obtain a mixed solution, reflux the solution at 140° C. for 3 h, and rotary evaporate the solution after completion of the reaction, and vacuum dry the solution to obtain a hydroxyl-protected product;

[0126] S2. Add a compound emulsifier into water, and then add the product obtained in step S1 and ethyl orthosilicate into water in a certain proportion to obtain a reaction system. After the reaction is completed, a CO2 sealing and leak-proofing agent is obtained.

[0127] The reaction container is a commonly used container in the laboratory, such as a four-necked flask.

[0128] Furthermore, the solvent in step S1 is DMAC.

[0129] Furthermore, the catalyst in step S1 is concentrated sulfuric acid.

[0130] Preferably, the alkyl chain length of the long-chain alkyl monoglyceride in step S1 is C17.

[0131] Preferably, the dibasic acid in step S1 is oxalic acid or malonic acid.

[0132] Preferably, the molar ratio of the long-chain alkyl monoglyceride to the dibasic acid in step S1 is 1:1.1.

[0133] Furthermore, in step S1, the amount of the solvent added is 70% of the total mass of the mixed solution, and the amount of the catalyst added is 2% of the total mass of the mixed solution.

[0134] Preferably, the compound emulsifier in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 12. The amount of the compound emulsifier added is 2% of the total mass of the compound emulsifier and water.

[0135] Preferably, the mass ratio of the product obtained in step S1 described in step S2 to ethyl orthosilicate is 4:1.1.

[0136] Preferably, the amount of water added in step S2 is 70% of the mass of the reaction system obtained in step S2.

[0137] Example 9

[0138] A method for preparing a CO2 storage leak-proof agent comprises the following steps:

[0139] S1. Add a solvent, a long-chain alkyl monoglyceride, and a dibasic acid to a reaction vessel, then add a catalyst to the reaction vessel to obtain a mixed solution, and reflux the mixture at 130° C. for 3.5 hours. After the reaction, perform rotary evaporation and vacuum drying to obtain a hydroxyl-protected product.

[0140] S2. Add a compound emulsifier into water, and then add the product obtained in step S1 and ethyl orthosilicate into water in a certain proportion to obtain a reaction system. After the reaction is completed, a CO2 sealing and leak-proofing agent is obtained.

[0141] The reaction container is a commonly used container in the laboratory, such as a four-necked flask.

[0142] Furthermore, the solvent in step S1 is DMSO.

[0143] Furthermore, the catalyst in step S1 is concentrated sulfuric acid.

[0144] Preferably, the alkyl chain length of the long-chain alkyl monoglyceride in step S1 is C12.

[0145] Preferably, the dibasic acid in step S1 is oxalic acid.

[0146] Preferably, the molar ratio of the long-chain alkyl monoglyceride to the dibasic acid in step S1 is 1:1.05.

[0147] Furthermore, in step S1, the amount of the solvent added is 65% of the total mass of the mixed solution, and the amount of the catalyst added is 1.5% of the total mass of the mixed solution.

[0148] Preferably, the compound emulsifier in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 11. The amount of the compound emulsifier added is 1.5% of the total mass of the compound emulsifier and water.

[0149] Preferably, the mass ratio of the product obtained in step S1 described in step S2 to ethyl orthosilicate is 4:1.05.

[0150] Preferably, the amount of water added in step S2 is 65% of the mass of the reaction system obtained in step S2.

[0151] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments, and various modifications can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A CO2 storage leak-proof agent, characterized in that: Its structural formula is as follows: Wherein, n represents the carbon chain length, and n is an integer, 11≤n≤17.

2. A method for preparing the CO2 storage leak-proof agent according to claim 1, characterized in that: The steps include: S1. Add a solvent, a long-chain alkyl monoglyceride, and a dibasic acid to a reaction vessel, then add a catalyst to the reaction vessel to obtain a mixed solution, reflux the solution at 120-140° C. for 3-4 hours, and after the reaction, perform rotary evaporation and vacuum drying to obtain a hydroxyl-protected product. S2, adding a compound emulsifier to water, then adding the product obtained in step S1 and ethyl orthosilicate to water in a certain proportion to obtain a reaction system, and obtaining a CO2 sealing and leak-proofing agent after the reaction is completed, wherein: The catalyst in step S1 is concentrated sulfuric acid; The dibasic acid in step S1 is oxalic acid or malonic acid; The compound emulsifier described in step S2 is a compound of emulsifier SP-60 and emulsifier TW60, and its HLB value is 10-12. The addition amount of the compound emulsifier is 1-2% of the total mass of the compound emulsifier and water.

3. The method for preparing a CO2 storage leak-proof agent according to claim 2, wherein: The solvent in step S1 is one of DMF, DMAC and DMSO.

4. The method for preparing a CO2 storage leak-proof agent according to claim 2, wherein: The alkyl chain length of the long-chain alkyl monoglyceride in step S1 is C11 to C17.

5. The method for preparing a CO2 storage leak-proof agent according to claim 4, characterized in that: The long-chain alkyl monoglyceride described in step S1 is palmitic acid monoglyceride.

6. The method for preparing a CO2 storage leak-proof agent according to claim 2, wherein: The molar ratio of the long-chain alkyl monoglyceride to the dibasic acid in step S1 is 1:(1-1.1).

7. The method for preparing a CO2 storage leak-proof agent according to claim 2, wherein: The amount of the solvent added in step S1 is 60-70% of the total mass of the mixed solution, and the amount of the catalyst added is 1-2% of the total mass of the mixed solution.

8. The method for preparing a CO2 storage leak-proof agent according to claim 2, characterized in that: The mass ratio of the product obtained in step S1 described in step S2 to ethyl orthosilicate is 4:(1-1.1).

9. The method for preparing a CO2 storage leak-proof agent according to claim 2, wherein: The amount of water added in step S2 is 60-70% of the mass of the reaction system obtained in step S2.

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