A gas reservoir plugging agent and its preparation and application

Abstract

This invention discloses a gas storage tank leak-sealing agent, which contains the following components: 40-60 parts oil well cement, 1-2 parts carbonic anhydrase, 1-4 parts repair agent, 1-3 parts toughening agent, 1-2 parts filtration loss reducer, 1-2 parts retarder, 1-2 parts dispersant, and 3-8 parts filler; wherein the repair agent is as shown in formula (1), where R is C a H 2a+1 , where a is an integer from 1 to 16; x is an integer from 10000 to 20000; y is an integer from 10000 to 20000; and z is an integer from 5000 to 20000. The gas storage tank sealing agent provided by this invention has good sealing effect, as well as good flexural strength and compressive strength.

Description

Technical Field

[0001] This invention relates to a gas storage tank sealing agent, its preparation, and its application. Background Technology

[0002] As an emergency peak-shaving gas source, gas storage facilities bear alternating loads and high injection and production pressures during operation, leading to the formation of micro-annular gaps, micro-cracks, and even large fissures in the cement sheath, causing the cement sheath's sealing integrity to fail. Conventional plugging agents are ineffective in sealing cracks caused by alternating loads, and their salt resistance and pressure resistance need further improvement. To address these issues, this patent develops a gas storage facility plugging agent that uses repair agents and toughening agents to enhance the self-healing properties and strength of the cement. This agent exhibits good pressure resistance and, even when the gas storage facility load exceeds the elastic limit stress of the cement stone and micro-cracks are generated, it possesses a certain self-healing ability to seal these micro-cracks and prevent their further formation and propagation. Summary of the Invention

[0003] This invention was made to further improve the performance of gas storage sealing agents and expand the selection of sealing agents.

[0004] As one aspect of the present invention, a gas storage tank sealing agent is disclosed, comprising the following components:

[0005] 40-60 parts oil well cement (Grade G or Grade H), 1-2 parts carbonic anhydrase, 1-4 parts repair agent, 1-3 parts toughening agent, 1-2 parts filtration loss reducer, 1-2 parts retarder, 1-2 parts dispersant, and 3-8 parts filler; wherein the repair agent is as shown in formula (1).

[0006]

[0007] (1), where R is C a H 2a+1 , where a is an integer from 1 to 16; x is an integer from 10000 to 20000; y is an integer from 10000 to 20000; and z is an integer from 5000 to 20000.

[0008] In a feasible specific implementation, the aforementioned gas storage tank sealing agent also contains water.

[0009] In a specific achievable embodiment, the repair agent is prepared by the following method:

[0010] (1) Mix 10-15 parts by weight of dimethylaminopropylmethacrylamide, 12-15 parts by weight of bromoalkanes, and 50-60 parts by weight of acetone (solvent) evenly and react at 60°C for 24 hours.

[0011]

[0012] Where: R is C a H 2a+1 a = 1 - 16;

[0013] (2) Add 5-8 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 15-20 parts by weight of acrylamide. Under neutral conditions, add 0.5-1 parts by weight of ammonium sulfide and 0.5-1.0 parts by weight of azo initiator. React at 60-80°C.

[0014] In specific embodiments, the azo initiator is azobisisobutyramidine hydrochloride, azobisisobutyramimidazole hydrochloride, or azobiscyanopentanoic acid.

[0015]

[0016] (1), where: x: 10000-20000; y: 10000-20000; z: 5000-20000.

[0017] The toughening agent is as shown in formula (2) or formula (3):

[0018]

[0019] (2), wherein R1 is selected from methyl methacrylate, vinyl acetate, vinyl hexanoate, butyl acrylate, N,N-dimethylacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid; n is selected from an integer between 500 and 1000; m is selected from an integer between 1000 and 2000; p is selected from an integer between 500 and 800; and q is selected from an integer between 1000 and 1500.

[0020]

[0021] (3), wherein R2 is selected from methyl methacrylate, vinyl acetate, vinyl hexanoate, butyl acrylate, N,N-dimethylacrylamide, 2-acrylamido-2-methylpropanesulfonic acid; n is selected from integers from 600 to 1200; m is selected from integers from 1200 to 2000; p is selected from integers from 400 to 1000; and q is selected from integers from 800 to 1600.

[0022] In a feasible specific embodiment, the toughening agent is prepared by the following method:

[0023] 1): Mix 90-120 parts latex, 15-20 parts monomer A and 30-50 parts dodecanethiol evenly, heat to 50-80℃, and then add 5-8 parts chelating agent, 3-6 parts precipitant and 1-3 parts oxidizing agent.

[0024] 2): Mix 9-12 parts of monomer B, 3-5 parts of monomer 2-acrylamido-2-methylpropanesulfonic acid and 50-60 parts of distilled water evenly, adjust the pH to 2-6, and then add 5-10 parts of reducing agent.

[0025] 3): Add the liquid from step 2) dropwise to the liquid from step 1), and react at 60-80℃.

[0026] In a specific embodiment, in step 2), NaOH solution is added dropwise to adjust the pH value.

[0027] In a specific embodiment, monomer A is selected from one of methyl methacrylate, vinyl acetate, vinyl hexanoate, butyl acrylate, N,N-dimethylacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid. The active double bonds in monomer A make it easy to copolymerize with other monomers, and the double bonds form a hyperconjugated system, which improves the thermal stability, salt resistance and water loss resistance of cement stone.

[0028] In a specific embodiment, monomer B is selected from acrylic acid or styrene. Monomer B, as a hard monomer, can increase the compressive strength of latex cement stone.

[0029] Latex: Polybutadiene latex (molecular weight 25-30W, viscosity 30-60 mPa·s, emulsion particle size 100-300 nanometers). As a soft monomer, latex can improve the impact strength of cement stone in latex cement stone.

[0030] Chelating agents: ethylenediaminetetraacetic acid, benzoic acid, citric acid.

[0031] Precipitating agent: Sodium pyrophosphate or sodium tripolyphosphate

[0032] Oxidizing agent: Hydrogen peroxide, cumene

[0033] Reducing agent: glucose or FeSO4·7H2O

[0034] Filtration loss reducer: one or more of hydroxyethyl methyl cellulose, bentonite and sodium alkyl sulfonate.

[0035] Retarder: One or more of the compound products of sodium calcium ethylenediaminetetramethylenephosphonate and phosphoric acid.

[0036] Dispersant: One or more of the following: triethylhexyl phosphate, sodium dodecyl sulfate, glucon, and fatty acid polyethylene glycol ester.

[0037] As another aspect of the present invention, a method for preparing the above-mentioned gas storage tank sealing agent is involved:

[0038] The oil well cement, carbonic anhydrase, repair agent, toughening agent, filtration loss reducer, retarder, dispersant and filler are mixed with water.

[0039] As another aspect of the present invention, the application of the above-mentioned gas storage plugging agent in oil and gas development is involved.

[0040] The gas storage tank sealing agent provided by this invention has a good sealing effect, as well as good flexural strength and compressive strength. Detailed Implementation

[0041] To make the objectives, technical explanations, and advantages of this invention clearer, the technical explanations of the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] Unless otherwise stated, the parts referred to in this application are parts by weight.

[0043] Example 1

[0044] The preparation method of the repair agent is as follows:

[0045] Step 1: Mix 10 parts by weight of dimethylaminopropylmethacrylamide, 12 parts by weight of undecane bromo, and 50 parts by weight of acetone (solvent) evenly and react at 60°C for 24 hours.

[0046] Step 2: Add 5 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 15 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.5 parts by weight of ammonium sulfide and 0.5 parts by weight of azobisisobutyramidine hydrochloride, and react at 60°C for 12 hours to obtain the desired repair agent.

[0047] 1, where: x: 15200; y: 11000; z: 6200.

[0048] Preparation of toughening agent:

[0049] Step 1: Mix 90 parts latex, 15 parts methyl methacrylate and 30 parts dodecyl mercaptan evenly, heat to 50°C, then add 5 parts ethylenediaminetetraacetic acid, 3 parts sodium pyrophosphate and 1 part oxidant cumene hydrogen peroxide to obtain mixed solution I.

[0050] Step 2: Mix 9 parts acrylic acid, 3 parts 2-acrylamido-2-methylpropanesulfonic acid and 50 parts distilled water evenly, then add NaOH solution to adjust the pH to 2, and then add 5 parts glucose as a reducing agent to obtain mixed solution II.

[0051] Step 3: Add mixed solution II dropwise to mixed solution I and heat at 60°C for 4 hours.

[0052] The toughening agent's molecular structure is as follows:

[0053]

[0054] in:

[0055] n: 850; m: 1100; p: 520; q: 1300.

[0056] Leak sealant:

[0057] Mix 55 parts cement (Grade G) + 1 part carbonic anhydrase + 1 part repair agent + 1 part toughening agent + 1 part hydroxyethyl methyl cellulose + 1 part sodium calcium ethylenediaminetetramethylenephosphonate + 1 part triethylhexyl phosphate + 3 parts rubber granules (20-40 mesh) + 35 parts water to obtain the sealant.

[0058] Example 2

[0059] Preparation of the repair agent:

[0060] Step 1: Mix 15 parts by weight of dimethylaminopropylmethacrylamide, 15 parts by weight of bromododecane, and 60 parts by weight of acetone (solvent) evenly, and react at 80°C for 24 hours.

[0061] Step 2: Add 8 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 20 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 1 part by weight of ammonium sulfide and 1.0 part by weight of azobisisobutyrazoline hydrochloride, and react at 80°C for 12 hours to obtain the desired repair agent.

[0062] 1, where: x: 15300; y: 11700; z: 8500.

[0063] Preparation method of toughening agent:

[0064] Step 1: Mix 100 parts latex, 18 parts monomer A vinyl acetate and 40 parts dodecyl mercaptan evenly, heat to 60°C, and then add 6 parts chelating agent, 5 parts precipitant and 2 parts oxidizing agent cumene hydrogen peroxide.

[0065] Step 2: Mix 10 parts of monomer B acrylic acid, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 60 parts of distilled water evenly, then add NaOH solution dropwise to adjust the pH to 5, and then add 8 parts of reducing agent FeSO4·7H2O.

[0066] Step 3: Add the liquid from Step 2 to the liquid from Step 1, and heat at 70°C for 4 hours.

[0067] The toughening agent's molecular structure is as follows:

[0068]

[0069] Where: n: 950; m: 1150; p: 790; q: 1350.

[0070] Leak sealant:

[0071] Mix 50 parts cement (Grade H) + 2 parts carbonic anhydrase + 2 parts repair agent + 2 parts toughening agent + 2 parts filtration loss reducer bentonite + 2 parts retarder phosphoric acid + 2 parts dispersant sodium dodecyl sulfate + 3 parts filler asbestos fiber (diameter 1-10 micrometers, length 10-100 micrometers) + 40 parts water to obtain the sealant.

[0072] Example 3

[0073] Preparation of the repair agent:

[0074] Step 1: Mix 12 parts by weight of dimethylaminopropylmethacrylamide, 15 parts by weight of bromopentadecane, and 55 parts by weight of acetone (solvent) evenly, and react at 70°C for 24 hours.

[0075] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 18 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.8 parts by weight of ammonium sulfide and 0.8 parts by weight of azodicyanovalerate, and react at 60°C for 12 hours to obtain the desired repair agent.

[0076] 1, where: x: 17600; y: 14600; z: 9900.

[0077] Toughening agent preparation method:

[0078] Step 1: Mix 100 parts latex, 20 parts vinyl hexanoate monomer and 40 parts dodecyl mercaptan evenly, heat to 80°C, and then add 5 parts chelating agent citric acid, 6 parts precipitating agent sodium tripolyphosphate and 3 parts oxidizing agent cumene hydroperoxide.

[0079] Step 2: Mix 9 parts of monomer B acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 60 parts of distilled water thoroughly. Adjust the pH to 5 by adding NaOH solution dropwise, and then add 8 parts of reducing agent FeSO4·7H2O.

[0080] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0081] The toughening agent has the following molecular formula:

[0082]

[0083] Where n: 990; m: 1750; p: 780; q: 1150.

[0084] The plugging agent is made of: 50 parts oil well cement (Grade G) + 1 part carbonic anhydrase + 4 parts repair agent + 3 parts toughening agent + 2 parts filtrate loss reducer sodium alkyl sulfonate + 2 parts retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant guar gum + 6 parts mica flakes (20-40 mesh) + 40 parts water.

[0085] Example 4

[0086] Preparation of the repair agent:

[0087] Step 1: Mix 12 parts by weight of dimethylaminopropylmethacrylamide, 15 parts by weight of hexadecane bromo, and 55 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0088] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 16 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 1 part by weight of ammonium sulfide and 0.9 parts by weight of azobisisobutyrazoline hydrochloride, and react at 70°C for 12 hours to obtain the desired repair agent.

[0089] 1, where: x: 13100; y: 17400; z: 5900.

[0090] Preparation of toughening agent:

[0091] Step 1: Mix 120 parts latex, 18 parts monomer A butyl acrylate and 40 parts dodecanethiol evenly, heat to 60°C, and then add 8 parts chelating agent ethylenediaminetetraacetic acid, 6 parts precipitating agent sodium tripolyphosphate and 3 parts oxidizing agent cumene hydroperoxide.

[0092] Step 2: Mix 10 parts of monomer B acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid and 60 parts of distilled water evenly, then add NaOH solution to adjust the pH to 6, and then add 8 parts of reducing agent glucose.

[0093] Step 3: Add the liquid from Step 2 to Step 1 dropwise, and heat at 80°C for 4 hours.

[0094] The toughening agent's molecular structure is as follows:

[0095]

[0096] Where n: 650; m: 1350; p: 670; q: 1250.

[0097] The plugging agent is composed of: 60 parts oil well cement (H grade) + 2 parts carbonic anhydrase + 1 part repair agent + 1 part toughening agent + 1 part filtration loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 1 part phosphoric acid + 2 parts dispersant fatty acid polyethylene glycol ester + 4 parts filler quartz (10-30 mesh) + 55 parts water. Mix them to obtain the plugging agent.

[0098] Example 5

[0099] Preparation of the repair agent:

[0100] Step 1: Mix 15 parts by weight of dimethylaminopropylmethacrylamide, 12 parts by weight of bromooctadecane, and 55 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0101] Step 2: Add 7 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 19 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.6 parts by weight of ammonium sulfide and 0.8 parts by weight of azobisisobutyramidine hydrochloride, and react at 70°C for 12 hours to obtain the desired repair agent.

[0102] 1, where: x: 16400; y: 17200; z: 11800.

[0103] Preparation of toughening agent:

[0104] Step 1: Mix 100 parts latex, 20 parts monomer AN,N-dimethylacrylamide and 40 parts dodecyl mercaptan evenly, heat to 60°C, and then add 8 parts chelating agent benzoic acid, 6 parts precipitating agent sodium pyrophosphate and 2 parts oxidizing agent cumene hydroperoxide.

[0105] Step 2: Mix 10 parts of monomer B acrylic acid, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid and 50 parts of distilled water evenly, then add NaOH solution to adjust the pH to 3, and then add 6 parts of reducing agent FeSO4·7H2O.

[0106] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0107] The plugging agent is composed of: 50 parts oil well cement (Grade G) + 2 parts carbonic anhydrase + 2 parts repair agent + 3 parts toughening agent + 1 part hydroxyethyl methyl cellulose + 1 part sodium alkyl sulfonate + 1 part sodium calcium ethylenediaminetetramethylenephosphonate + 1 part phosphoric acid + 1 part fatty acid polyethylene glycol ester + 2 parts asbestos fiber (diameter 1-10 micrometers, length 10-100 micrometers) + 2 parts plant fiber (diameter 1-20 micrometers, length 50-500 micrometers) + 40 parts water. Mix these ingredients to obtain the plugging agent.

[0108] The toughening agent's molecular structure is as follows:

[0109]

[0110] in,

[0111] n: 560; m: 1660; p: 770; q: 1150.

[0112] Example 6

[0113] Preparation of the repair agent:

[0114] Step 1: Mix 15 parts by weight of dimethylaminopropylmethacrylamide, 12 parts by weight of bromohexane, and 50 parts by weight of acetone (solvent) evenly, and react at 70°C for 24 hours.

[0115] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 16 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.7 parts by weight of ammonium sulfide and 0.8 parts by weight of azodicyanovalerate, and react at 80°C for 12 hours to obtain the desired repair agent.

[0116] 1, where x: 16500; y: 17200; z: 11500.

[0117] Preparation of toughening agent:

[0118] Step 1: Mix 100 parts latex, 18 parts monomer A methyl methacrylate and 40 parts dodecyl mercaptan evenly, heat to 60°C, and then add 6 parts chelating agent, 4 parts precipitant and 2 parts oxidizing agent cumene hydrogen peroxide.

[0119] Step 2: Mix 12 parts of monomer B styrene, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 60 parts of distilled water thoroughly. Adjust the pH to 5 by adding NaOH solution dropwise, and then add 8 parts of reducing agent glucose.

[0120] Step 3: Add the liquid from Step 2 to Step 1 dropwise, and heat at 80°C for 4 hours.

[0121] The toughening agent's molecular structure is as follows:

[0122]

[0123] in,

[0124] n: 880; m: 1850; p: 550; q: 850.

[0125] The plugging agent is made of: 50 parts oil well cement (H grade) + 2 parts carbonic anhydrase + 3 parts repair agent + 3 parts toughening agent + 2 parts filtration loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 4 parts filler rubber particles (20-40 mesh) + 50 parts water.

[0126] Example 7

[0127] Preparation of the repair agent:

[0128] Step 1: Mix 15 parts by weight of dimethylaminopropylmethacrylamide, 15 parts by weight of bromobutane, and 60 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0129] Step 2: Add 8 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 18 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.6 parts by weight of ammonium sulfide and 0.8 parts by weight of azobisisobutyramidine hydrochloride, and react at 80°C for 12 hours to obtain the desired repair agent.

[0130] 1, where x: 16300; y: 17400; z: 6600.

[0131] The toughening agent is prepared as follows:

[0132] Step 1: Mix 100 parts of polybutadiene latex, 20 parts of monomer A vinyl acetate and 50 parts of dodecanethiol evenly, heat to 80°C, and then add 8 parts of chelating agent benzoic acid, 3 parts of precipitant sodium tripolyphosphate and 3 parts of oxidant cumene hydroperoxide.

[0133] Step 2: Mix 11 parts of monomer B styrene, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 60 parts of distilled water thoroughly. Adjust the pH to 5 by adding NaOH solution dropwise, and then add 10 parts of reducing agent FeSO4·7H2O.

[0134] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0135] The toughening agent's molecular structure is as follows:

[0136]

[0137] in,

[0138] n, 1150; m: 1360; p: 770; q: 950.

[0139] The plugging agent is composed of: 55 parts oil well cement (Grade G) + 2 parts carbonic anhydrase + 2 parts repair agent + 2 parts toughening agent + 2 parts filtration loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 8 parts filler mica flakes (20-40 mesh) + 45 parts water. Mix them to obtain the plugging agent.

[0140] Example 8

[0141] The specific preparation method of the repair agent is as follows:

[0142] Step 1: Mix 12 parts by weight of dimethylaminopropylmethacrylamide, 14 parts by weight of bromopentane, and 50 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0143] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 18 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.6 parts by weight of ammonium sulfide and 0.8 parts by weight of azobisisobutyrazoline hydrochloride, and react at 80°C for 12 hours to obtain the desired repair agent.

[0144] 1, where x: 15500; y: 12300; z: 7700.

[0145] The toughening agent is prepared as follows:

[0146] Step 1: Mix 110 parts latex, 18 parts vinyl hexanoate monomer and 40 parts dodecanethiol evenly, heat to 60°C, and then add 8 parts chelating agent citric acid, 5 parts precipitating agent sodium tripolyphosphate and 2 parts oxidizing agent cumene hydroperoxide.

[0147] Step 2: Mix 11 parts of monomer styrene B, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 60 parts of distilled water thoroughly. Adjust the pH to 4 by adding NaOH solution dropwise, and then add 8 parts of reducing agent glucose.

[0148] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0149] The toughening agent's molecular structure is as follows:

[0150]

[0151] Where n: 1140; m: 1200; p: 400; q: 800.

[0152] The plugging agent is made of: 50 parts oil well cement (Grade G) + 1 part carbonic anhydrase + 2 parts repair agent + 2 parts toughening agent + 2 parts filtration loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 6 parts filler shell (20-50 mesh) + 40 parts water.

[0153] Example 9

[0154] The specific preparation method of the repair agent is as follows:

[0155] Step 1: Mix 12 parts by weight of dimethylaminopropylmethacrylamide, 13 parts by weight of bromododecane, and 50-60 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0156] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 16 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.6 parts by weight of ammonium sulfide and 0.8 parts by weight of azobisisobutyramidine hydrochloride, and react at 80°C for 12 hours to obtain the desired repair agent.

[0157] 1, where x: 19600; y: 18400; z: 12100.

[0158] The toughening agent is prepared as follows:

[0159] Step 1: Mix 100 parts latex, 18 parts monomer A butyl acrylate and 40 parts dodecyl mercaptan evenly, heat to 70°C, and then add 6 parts chelating agent benzoic acid, 6 parts precipitating agent sodium tripolyphosphate and 2 parts oxidizing agent cumene hydroperoxide.

[0160] Step 2: Mix 11 parts of monomer B styrene, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 55 parts of distilled water thoroughly. Adjust the pH to 5 by adding NaOH solution dropwise, and then add 6 parts of reducing agent glucose.

[0161] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0162] The toughening agent's molecular structure is as follows:

[0163]

[0164] in,

[0165] n: 1200; m: 2000; p: 1000; q: 1600.

[0166] The plugging agent is made of: 50 parts oil well cement (Grade G) + 2 parts carbonic anhydrase + 3 parts repair agent + 3 parts toughening agent + 2 parts filtration loss reducer hydroxyethyl methyl cellulose + 2 parts retarder sodium calcium ethylenediaminetetramethylenephosphonate + 1 part dispersant gluconol + 4 parts filler quartz (10-30 mesh) + 40 parts water.

[0167] Example 10

[0168] The specific preparation method of the repair agent is as follows:

[0169] Step 1: Mix 15 parts by weight of dimethylaminopropylmethacrylamide, 12 parts by weight of bromopentadecane, and 55 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0170] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 18 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.6 parts by weight of ammonium sulfide and 0.8 parts by weight of azobisisobutyramidine hydrochloride, and react at 80°C for 12 hours to obtain the desired repair agent.

[0171] 1, where x: 16900; y: 13400; z: 11700.

[0172] The toughening agent is prepared as follows:

[0173] Step 1: Mix 110 parts latex, 18 parts monomer AN,N-dimethylacrylamide and 40 parts dodecyl mercaptan evenly, heat to 60°C, and then add 6 parts chelating agent citric acid, 4 parts precipitating agent sodium pyrophosphate and 2 parts oxidizing agent cumene hydroperoxide.

[0174] Step 2: Mix 9 parts of monomer B styrene, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 50 parts of distilled water evenly, then add NaOH solution to adjust the pH to 5, and then add 9 parts of reducing agent glucose.

[0175] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0176] The toughening agent's molecular structure is as follows:

[0177]

[0178] Where n: 880; m: 1880; p: 880; q: 1200.

[0179] Leakage plugging agent: 60 parts oil well water (Grade G) mud + 1 part carbonic anhydrase + 3 parts repair agent + 2 parts toughening agent + 1 part filtration loss reducer sodium dodecyl sulfate + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 3 parts filler mica flakes (20-40 mesh) + 50 parts water, mix to obtain the leakage plugging agent.

[0180] Example 11

[0181] The specific preparation method of the repair agent is as follows:

[0182] Step 1: Mix 11 parts by weight of dimethylaminopropylmethacrylamide, 13 parts by weight of hexadecane bromo, and 50-60 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0183] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 16 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.8 parts by weight of ammonium sulfide and 0.6 parts by weight of azobisisobutyrazoline hydrochloride, and react at 80°C for 12 hours to obtain the desired repair agent.

[0184] 1, where x: 18800; y: 11700; z: 5500

[0185] The toughening agent is prepared as follows:

[0186] Step 1: Mix 110 parts latex, 15 parts vinyl hexanoate monomer and 50 parts dodecyl mercaptan evenly, heat to 60°C, and then add 6 parts chelating agent benzoic acid, 4 parts precipitating agent sodium tripolyphosphate and 2 parts oxidizing agent cumene hydroperoxide.

[0187] Step 2: Mix 12 parts of monomer B acrylic acid, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 55 parts of distilled water thoroughly. Adjust the pH to 6 by adding NaOH solution dropwise, and then add 7 parts of reducing agent FeSO4·7H2O.

[0188] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0189] Where: n: 660; m: 1140; p: 770; q: 1250.

[0190] The plugging agent is composed of: 45 parts oil well cement (H grade) + 1 part carbonic anhydrase + 2 parts repair agent + 3 parts toughening agent + 1 part filtration loss reducer bentonite + 2 parts retarder phosphoric acid + 1 part dispersant sodium dodecyl sulfate + 1 part fatty acid polyethylene glycol ester + 2 parts filler rubber particles (20-40 mesh) + 2 parts shell (20-50 mesh) + 35 parts water. Mix them together to obtain the plugging agent.

[0191] Example 12

[0192] The self-healing ability of cement is enhanced by using repair agent A. The preparation steps are as follows:

[0193] The specific preparation method of the repair agent is as follows:

[0194] Step 1: Mix 15 parts by weight of dimethylaminopropylmethacrylamide, 12 parts by weight of bromooctadecane, and 50 parts by weight of acetone (solvent) evenly, and react at 60°C for 24 hours.

[0195] Step 2: Add 6 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 16 parts by weight of acrylamide to the above solution, add sodium hydroxide dropwise until the pH is 7, add 0.6 parts by weight of ammonium sulfide and 0.7 parts by weight of cyanopentanoic acid, and react at 80°C for 12 hours to obtain the desired repair agent.

[0196] 1, where x: 19900; y: 12100; z: 13600

[0197] The toughening agent is prepared as follows:

[0198] Step 1: Mix 120 parts latex, 18 parts monomer A vinyl acetate and 44 parts dodecanethiol evenly, heat to 66°C, and then add 6 parts chelating agent ethylenediaminetetraacetic acid, 5 parts precipitating agent sodium tripolyphosphate and 2 parts oxidizing agent cumene hydroperoxide.

[0199] Step 2: Mix 11 parts of monomer B styrene, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 55 parts of distilled water evenly, then add NaOH solution to adjust the pH to 3, and then add 8 parts of reducing agent glucose.

[0200] Step 3: Add the liquid from Step 2 to Step 1 and heat at 70°C for 4 hours.

[0201] Where: n: 790; m: 1460; p: 760; q: 1230.

[0202] The sealant is:

[0203] Mix 50 parts oil well cement (Grade H) + 1 part carbonic anhydrase + 2 parts repair agent + 2 parts toughening agent + 1 part filtrate loss reducer sodium alkyl sulfonate + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 1 part dispersant sodium dodecyl sulfate + 5 parts filler shell (20-50 mesh) + 40 parts water to obtain the plugging agent.

[0204] Comparative Example 1:

[0205] It does not contain toughening agents, and the other steps are the same as in Example 1.

[0206] 55 parts cement (Grade G) + 1 part carbonic anhydrase + 1 part repair agent + 1 part hydroxyethyl methyl cellulose + 1 part sodium calcium ethylenediaminetetramethylenephosphonate + 1 part triethylhexyl phosphate + 3 parts rubber granules (20-40 mesh) + 35 parts water.

[0207] Comparative Example 2:

[0208] It does not contain repair agents, and the other steps are the same as in Example 2.

[0209] Comparative Example 2 consisted of: 50 parts cement (Grade H) + 2 parts carbonic anhydrase + 2 parts toughening agent + 2 parts filtration loss reducer bentonite + 2 parts retarder phosphoric acid + 2 parts dispersant sodium dodecyl sulfate + 3 parts filler asbestos fiber (diameter 1-10 micrometers, length 10-100 micrometers) + 40 parts water.

[0210] Comparative Example 3

[0211] It does not contain repair agents, and the other steps are the same as in Example 3.

[0212] 50 parts oil well cement (Grade G) + 1 part carbonic anhydrase + 3 parts toughening agent + 2 parts filtration loss reducer sodium alkyl sulfonate + 2 parts retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant guar gum + 6 parts mica flakes (20-40 mesh) + 40 parts water.

[0213] Comparative Example 4

[0214] Without the repair agent, the other steps are the same as in Example 4.

[0215] 60 parts oil well cement (H grade) + 2 parts carbonic anhydrase + 1 part toughening agent + 1 part filtration loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 1 part phosphoric acid + 2 parts dispersant fatty acid polyethylene glycol ester + 4 parts filler quartz (10-30 mesh) + 55 parts water.

[0216] Comparative Example 5

[0217] Without toughening agents, the other steps are the same as in Example 5.

[0218] The plugging agent consists of: 50 parts oil well cement (Grade G) + 2 parts carbonic anhydrase + 2 parts repair agent + 1 part hydroxyethyl methyl cellulose + 1 part sodium alkyl sulfonate + 1 part sodium calcium ethylenediaminetetramethylenephosphonate + 1 part phosphoric acid + 1 part fatty acid polyethylene glycol ester + 2 parts asbestos fiber (diameter 1-10 micrometers, length 10-100 micrometers) + 2 parts plant fiber (diameter 1-20 micrometers, length 50-500 micrometers) + 40 parts water.

[0219] Comparative Example 6

[0220] Without toughening agents, the other steps are the same as in Example 6.

[0221] The plugging agent consists of: 50 parts oil well cement (H grade) + 2 parts carbonic anhydrase + 3 parts repair agent + 2 parts filtration loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 4 parts filler rubber particles (20-40 mesh) + 50 parts water.

[0222] Comparative Example 7

[0223] It does not contain repair agents or toughening agents, and the other steps are the same as in Example 7.

[0224] The plugging agent consists of: 55 parts oil well cement (Grade G) + 2 parts carbonic anhydrase + 2 parts filtrate loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 8 parts filler mica flakes (20-40 mesh) + 45 parts water.

[0225] Comparative Example 8

[0226] It does not contain repair agents or toughening agents, and the other steps are the same as in Example 8.

[0227] The plugging agent consists of: 50 parts oil well cement (Grade G) + 1 part carbonic anhydrase + 2 parts filtrate loss reducer hydroxyethyl methyl cellulose + 1 part retarder sodium calcium ethylenediaminetetramethylenephosphonate + 2 parts dispersant fatty acid polyethylene glycol ester + 6 parts filler shell (20-50 mesh) + 40 parts water.

[0228] The self-healing efficiency of the products obtained in Examples 1-12 and Comparative Examples 1-4 was tested, and the results are shown in Table 1.

[0229] According to the requirements specified in GB / T 19139-2012 "Test Methods for Cement in Oil Wells", cubic specimens with a side length of 50.8 mm were prepared using a mold. After curing at 60℃ for 3 days, the specimens were removed and artificially created by splitting them using the Brazilian splitting method. They were then placed in a 60℃ water bath for further curing. Permeability was tested 14 days after self-healing, and the self-healing efficiency was determined by the permeability.

[0230] Self-repair efficiency = (Permeability after 14 days of self-healing / Initial permeability) × 100%

[0231] Table 1 Self-healing efficiency of plugging agent under different crack widths

[0232]

[0233] As can be seen from Table 1, under the condition of a crack width of 0.1 mm, the self-healing efficiency of Examples 1-12 all reached 100%, while that of Comparative Examples 1-4 was 99.2%-99.5%.

[0234] Under the condition of a crack width of 0.15 mm, the self-healing efficiency of Examples 1-12 all reached 100%, while that of Comparative Examples 1-4 was 99.0%-99.2%.

[0235] Under the condition of a crack width of 0.2 mm, the self-healing efficiency of Examples 1-12 all reached 100%, while that of Comparative Examples 1-4 was 98.2%-98.5%.

[0236] Under the condition of a crack width of 0.25 mm, the self-repair efficiency of Examples 1-12 was 100%, while that of Comparative Examples 1-4 was only 97.1%-97.8%. This indicates that the repair agent can effectively improve the self-repair ability of the sealing agent, and is more conducive to improving the self-repair ability of cracks caused by different pressure conditions in gas storage facilities.

[0237] The flexural strength and compressive strength of the products obtained in Examples 1-12 and Comparative Examples 5-8 were tested, and the results are shown in Table 2.

[0238] Test method for flexural strength:

[0239] (1) The concrete flexural strength test specimen is a rectangular beam-shaped specimen, usually using standard-sized specimens, i.e. 100mm×100mm×500mm.

[0240] (2) The curing time for the specimens is 28 days.

[0241] (3) The main equipment for testing the flexural strength of concrete includes a testing machine, a pressure gauge and a support device.

[0242] (4) Place the specimen on the testing machine and ensure that the specimen is placed completely and stably on the support equipment; apply the predetermined force through the control system of the testing machine; during the test, the deformation of the specimen and the change of the test force should be recorded. When the test force reaches the predetermined value, stop the test and record the test force and the deformation of the specimen at the time of fracture.

[0243] (5) Calculate the flexural strength of the specimen = the maximum force measured in the experiment / the cross-sectional moment of the specimen.

[0244] The compressive strength test method is as follows: inject the sealing agent... After curing in a cylindrical copper mold for 28 days, the core was removed using a core-taking tool, and the triaxial mechanical properties of the cement were tested using a triaxial rock testing system.

[0245] As shown in Table 2, after 28 days of curing, the flexural strength of Examples 1-12 was 7.15-7.98 MPa, while that of Comparative Examples 5-6 was 5.78-6.15 MPa. The flexural strength of Examples 1-12 was higher than that of Comparative Examples 5-6.

[0246] Above 1MPa.

[0247] After 28 days of curing, the compressive strength of Examples 1-12 was 45.38-46.99 MPa, and the compressive strength of Comparative Examples 5-6 was 42.23-42.56 MPa. The compressive and flexural strengths of Examples 1-12 were both higher than those of Comparative Examples 5-6.

[0248] Above 2.82 MPa. This indicates that the toughening agent can effectively increase the compressive and flexural strength of the sealant.

[0249] Comparative Examples 7 and 8, which do not contain repair or toughening agents, showed further reductions in compressive and flexural strength compared to Examples 1-12. Comparing Example 7 and Comparative Example 7, after 28 days of curing, the flexural strength of Example 7 was 7.98 MPa, while that of Comparative Example 7 was only 5.61 MPa. The compressive strength of Example 7 was 46.83 MPa, while that of Comparative Example 7 was only 40.32 MPa.

[0250] Comparing Example 8 and Comparative Example 8, after 28 days of curing, the flexural strength of Example 8 was 7.73 MPa, while that of Comparative Example 8 was only 5.62 MPa. The compressive strength of Example 8 was 46.91 MPa, while that of Comparative Example 8 was only 40.35 MPa. This indicates that compared to using toughening agents alone, using repair agents and toughening agents simultaneously is more effective in improving the compressive and flexural strength of the sealant.

[0251] Table 2. Test of flexural / compressive strength of sealant

[0252]

[0253] The embodiments disclosed above are merely illustrative of the present invention and should not be considered as limiting the scope of protection of the present invention.

Claims

1. A gas storage tank leak-sealing agent, characterized in that, The gas storage tank sealing agent contains the following components: 40-60 parts oil well cement, 1-2 parts carbonic anhydrase, 1-4 parts repair agent, 1-3 parts toughening agent, 1-2 parts filtration loss reducer, 1-2 parts retarder, 1-2 parts dispersant, and 3-8 parts filler; wherein the repair agent is as shown in formula (1). (1), where R is C a H 2a+1 , where a is an integer from 1 to 16; x is an integer from 10000 to 20000; y is an integer from 10000 to 20000; and z is an integer from 5000 to 20000.

2. The gas storage tank sealing agent according to claim 1, characterized in that, The gas storage tank sealing agent also contains water.

3. The gas storage tank sealing agent according to claim 1, characterized in that, The repair agent is prepared by the following method: (1) Mix 10-15 parts by weight of dimethylaminopropylmethacrylamide, 12-15 parts by weight of bromoalkanes and 50-60 parts by weight of acetone evenly, and react at 60°C for 24 hours. (2) Add 5-8 parts by weight of 2-methyl-2-acrylamidopropanesulfonic acid and 15-20 parts by weight of acrylamide. Under neutral conditions, add 0.5-1 parts by weight of ammonium sulfide and 0.5-1.0 parts by weight of azo initiator. React at 60-80°C.

4. The gas storage tank sealing agent according to claim 3, characterized in that, The azo initiator is azobisisobutyramidine hydrochloride, azobisisobutyramimidazole hydrochloride, or azobisisobutyramic acid.

5. The gas storage tank sealing agent according to claim 1, characterized in that, The toughening agent is as shown in formula (2) or formula (3): (2), wherein R1 is selected from methyl methacrylate, vinyl acetate, vinyl hexanoate, butyl acrylate, N,N-dimethylacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid; n is selected from an integer between 500 and 1000; m is selected from an integer between 1000 and 2000; p is selected from an integer between 500 and 800; and q is selected from an integer between 1000 and 1500. (3), wherein R2 is selected from methyl methacrylate, vinyl acetate, vinyl hexanoate, butyl acrylate, N,N-dimethylacrylamide, 2-acrylamido-2-methylpropanesulfonic acid; n is selected from integers from 600 to 1200; m is selected from integers from 1200 to 2000; p is selected from integers from 400 to 1000; and q is selected from integers from 800 to 1600.

6. The gas storage tank sealing agent according to claim 5, characterized in that, The toughening agent is prepared by the following method: 1) Mix 90-120 parts latex, 15-20 parts monomer A and 30-50 parts dodecanethiol evenly, heat to 50-80℃, and then add 5-8 parts chelating agent, 3-6 parts precipitant and 1-3 parts oxidizing agent. 2) Mix 9-12 parts of monomer B, 3-5 parts of monomer 2-acrylamido-2-methylpropanesulfonic acid and 50-60 parts of distilled water evenly, adjust the pH value to 2-6, and then add 5-10 parts of reducing agent. 3) Add the liquid from step 2) dropwise to the liquid from step 1), and react at 60-80℃; Wherein, monomer A is selected from one of methyl methacrylate, vinyl acetate, vinyl hexanoate, butyl acrylate, N,N-dimethylacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid; and monomer B is selected from acrylic acid or styrene.

7. The gas storage tank sealing agent according to claim 6, characterized in that, The latex is polybutadiene latex; the chelating agent is selected from ethylenediaminetetraacetic acid, benzoic acid, or citric acid; the precipitating agent is selected from sodium pyrophosphate or sodium tripolyphosphate; the oxidizing agent is cumene hydroperoxide; the reducing agent is glucose or FeSO4·7H2O; and the filtration loss reducing agent is selected from one or more of hydroxyethyl methyl cellulose, bentonite, and sodium alkyl sulfonate.

8. The gas storage tank sealing agent according to claim 6, characterized in that, The retarder is one or more of the compound products of sodium calcium ethylenediaminetetramethylenephosphonate and phosphoric acid; the dispersant is selected from one or more of the compound products of triethylhexylphosphonic acid, sodium dodecyl sulfate, glucon, and fatty acid polyethylene glycol esters.

9. A method for preparing the gas storage tank sealing agent according to any one of claims 1-8, characterized in that, include: The oil well cement, carbonic anhydrase, repair agent, toughening agent, filtration loss reducer, retarder, dispersant and filler are mixed with water.

10. The application of the gas storage plugging agent according to any one of claims 1-8 in oil and gas development.

Images