Anticorrosion treatment fluid as well as preparation method and application thereof

Abstract

The invention discloses an anti-corrosion treatment fluid, which is composed of the following components: 30-60% of betaine modified waterborne epoxy resin; 0.3%-8% of triethanolamine; 2%-25% of a curing agent; and the balance of water. The invention further discloses a preparation method of the preservative treatment fluid. The preparation method comprises the following specific steps: (1) preparing betaine with double bonds; (2) preparing betaine modified waterborne epoxy resin; and (3) uniformly stirring the formula amount of betaine modified water-borne epoxy resin, the formula amount of triethanolamine, the formula amount of curing agent and the formula amount of water to obtain the preservative treatment fluid. The invention further discloses the anti-corrosion treatment fluid, and the anti-corrosion treatment fluid prepared by the preparation method is used as an on-line repairing fluid of an underground pipe column for oil exploitation. The method can realize repair of a damaged anticorrosive layer of an anticorrosive oil pipe and anticorrosive maintenance of a non-anticorrosive oil pipe, effectively prolongs the service life of a pipe column, and improves the development effect of a water-driven oilfield.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-corrosion treatment in oil production, relates to in-situ targeted anti-corrosion treatment of downhole pipes (including oil pipes and casings), and specifically relates to an anti-corrosion treatment liquid and a preparation method and application thereof. Background Art

[0002] According to incomplete statistics, about 70% of Sinopec's production and about 80% of CNPC's production come from water-driven oil field development. Water-driven development is the cornerstone of ensuring national energy security.

[0003] Shengli Oilfield has 4.1 billion tons of water-driven reserves, accounting for 83.6% of Shengli Oilfield and 72.1% of annual oil production. As most Shengli Oilfields have entered a high water-cut period, the proportion of produced water is high; more than 95% of the water injected into the oilfield water drive is treated produced water.

[0004] Oilfield water has the characteristics of high mineralization, high chloride ion content, and strong corrosiveness. In addition, oilfield water also contains corrosive bacteria such as sulfate-reducing bacteria, and the downhole temperature and pressure of water injection wells are high. Downhole tubing (including tubing and casing) has been in service in the above-mentioned corrosive environment for a long time, and the surface anti-corrosion passivation layer or various anti-corrosion coatings often encounter corrosion, breakage and shedding, resulting in perforation and damage of the oil casing and the inability of oilfield production to operate normally. For example, there are 3,231 casing damage wells in an oilfield, and the proportion of casing damage caused by corrosion is about 50%; there are 3,254 operating water wells each year, and 34.3% of the operating wells are caused by tubing corrosion leakage and scaling test obstruction. It can be seen that the corrosion problem of oil casing in water injection wells is relatively common, which seriously affects the development and operation of water-driven oil reservoirs in oilfields.

[0005] For oil pipe corrosion damage, the current practice is to pull out the water injection string and replace it. However, the cost of pulling out the string is high, the workload is large, and the well is shut down for a long time, which affects oil field production. If the casing is damaged, it is usually plugged downhole, which is expensive (890,000 yuan per well on average) and has a complex implementation process. Since the casing cannot be pulled out and replaced, there is even a risk of scrapping the development well if the casing is severely damaged, which seriously affects the benefits of oil field development.

[0006] Therefore, some people have developed self-repairing anti-corrosion coatings. At present, there are two main types of self-repairing anti-corrosion coatings: the first type is a self-repairing anti-corrosion coating containing corrosion inhibitor microcapsules. The embedded microcapsules in this type of coating are damaged by external forces, causing the capsule wall to rupture; or the external environment changes cause the permeability of the capsule wall to change, and the outflow of corrosion inhibitors will produce a passivation film on the metal matrix, thereby achieving the purpose of slowing down metal corrosion. The second type is a self-repairing anti-corrosion coating containing embedded filling microcapsules. This type of coating is embedded with microcapsules with self-repairing properties. Through different triggering methods, such as: thermal triggering, radiation triggering, light triggering, mechanical triggering, ion triggering, etc., the capsule wall is ruptured or the permeability of the capsule wall changes due to changes in environmental parameters, causing the repair agent liquid in the capsule core to flow out, reacting with the pre-embedded catalyst in the coating or the catalytic factors in the environment, and finally achieving the curing of the repair agent to achieve the purpose of filling the cracks.

[0007] For example, Chinese invention patent application CN105289435A provides a method for preparing magnetic self-healing microcapsules, the specific steps of which are: preparing oxidized carbon material and magnetic carbon material as functional fillers in sequence, and adding the functional fillers to a urea-formaldehyde prepolymer solution, using an emulsion synthesis method to complete the preparation of the microcapsules, solving the problem of magnetic targeting of the microcapsules, using the magnetism of the microcapsules to orient the microcapsules on the surface of the metal substrate, realizing the preparation of a gradient coating, allowing the microcapsules to be arranged in an orderly manner in the coating, achieving full utilization of the microcapsules, and reducing defects in the coating; this is conducive to reducing the amount of microcapsules added to the coating and realizing the self-healing function of the coating.

[0008] Chinese invention patent application CN106867404A discloses a highly sensitive redox responsive self-healing anti-corrosion coating. The highly sensitive redox responsive self-healing anti-corrosion coating is composed of an organic-inorganic hybrid sol-gel coating and a magnetic smart nanocontainer doped inside the organic-inorganic hybrid sol-gel coating. The preparation process is: preparing a magnetic smart nanocontainer; dispersing the magnetic smart nanocontainer in an organic-inorganic hybrid gel, and then coating it on the surface of a magnesium alloy substrate to form a highly sensitive redox responsive self-healing anti-corrosion coating.

[0009] Chinese invention patent application CN107674548A discloses a method for preparing a magnetic gradient self-healing anti-corrosion coating. The specific steps are: adding magnetic nanoparticles encapsulating corrosion inhibitors to the coating, and applying an external magnetic field during the coating preparation process to make the magnetic nanoparticles distributed in a longitudinal gradient in the coating, and the concentration of nanoparticles near the metal surface is high.

[0010] Chinese invention patent application CN112961526A discloses a method for preparing a magnetic particle-enriched anti-corrosion and anti-fouling integrated self-repairing microcapsule, wherein epoxy resin, polyurethane, tung oil and other materials are used as self-repairing agents, and the core material is evenly dispersed in an aqueous solution by adding dispersants such as emulsifiers to form a stable "water-in-oil" microemulsion, and then urea and formaldehyde are condensed to coat the microdroplets to prepare microcapsules with uniform particle size and a core-shell structure, and magnetic nanospheres are in situ generated on the surface of the capsule wall to synthesize microcapsule particles with self-repairing and anti-corrosion effects, and the magnetic nanospheres are selectively deposited on the surface of the microcapsule by compounding an emulsifier to achieve the purpose of uniform and controllable.

[0011] Chinese invention patent application CN 102337070A discloses an antibacterial and anticorrosive coating material for the inner wall of an oilfield reinjection water pipeline. The material is based on a solvent-free organic fluorine-modified epoxy resin, hybridized with organic and inorganic fungicides and nanofillers, etc. In addition to having excellent antibacterial and anticorrosive properties, it also has self-cleaning and anti-fouling properties.

[0012] However, the above technical solutions all have the following shortcomings: downhole tubing (including oil pipes and casings) needs to be treated with anti-corrosion before use. Once the downhole tubing is put into use, in-situ targeted anti-corrosion cannot be performed, that is, the anti-corrosion operation of the downhole tubing can only be handled in advance, and no remediation can be achieved afterwards. Summary of the invention

[0013] Purpose of the invention: The present invention aims to improve the problems existing in the above-mentioned prior art, that is, the present invention discloses an anti-corrosion treatment liquid and its preparation method and application.

[0014] The anticorrosive treatment liquid of the present invention has a main agent of betaine modified waterborne epoxy resin with anionic and cationic groups. After the anticorrosive liquid is injected into the well, the cationic head group in the betaine modified waterborne epoxy resin is preferentially adsorbed on the pipe wall, and the anionic head group in the betaine modified waterborne epoxy resin floats on the pipe wall surface, repels sulfate-reducing bacteria, iron bacteria and saprophytes with negative charges on the surface, prevents bacteria from adhering to the pipe wall surface, and eliminates bacterial corrosion; at the same time, it also repels negatively charged suspended solids and oil droplets, prevents suspended solids and oil droplets from adhering to the pipe wall surface, keeps the pipe wall clean, reduces scaling and under-scale corrosion; and prevents the adsorption of polymers on the pipe wall in the polymer injection well.

[0015] Technical solution: An anti-corrosion treatment liquid, calculated by mass percentage, is composed of the following components:

[0016] Betaine modified waterborne epoxy resin 30% to 60%;

[0017] Triethanolamine 0.3% to 8%;

[0018] Curing agent 2% to 25%;

[0019] The balance is water.

[0020] Further, it is composed of the following components:

[0021] Betaine modified waterborne epoxy resin 40% to 50%;

[0022] Triethanolamine 0.5% to 3%;

[0023] Curing agent 4% to 15%;

[0024] The balance is water.

[0025] Furthermore, the curing agent is one or more of aliphatic amines, alicyclic amines and aromatic amines.

[0026] Furthermore, the fatty amine is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, boron trifluoride ethylamine, hexamethylenediamine and polyethylenepolyamine.

[0027] Furthermore, the alicyclic amine is at least one of 4,4'-diaminodicyclohexylmethane alicyclic amine and 1-methyl-2,4-cyclohexanediamine.

[0028] Furthermore, the aromatic amine is at least one of 1,3-phenylenediamine, m-phenylenediamine, 2-phenylimidazole, p-methylbenzyl chloride, 4,4-diaminophenylsulfone, and 4,4-diaminodiphenylmethane.

[0029] Furthermore, the curing agent is a mixture of polyethylene polyamine, 1-methyl-2,4-cyclohexanediamine and boron trifluoride ethylamine, and the mass ratio thereof is 1:(0.1-10):(0.1-15).

[0030] A method for preparing the anticorrosion treatment liquid described in any one of the above, comprising the following specific steps:

[0031] (1) Preparation of betaine with double bonds;

[0032] (2) preparing betaine modified waterborne epoxy resin;

[0033] (3) Evenly stir the formulated amount of betaine-modified water-based epoxy resin, the formulated amount of triethanolamine, the formulated amount of curing agent, and the formulated amount of water to obtain an anti-corrosion treatment liquid.

[0034] Further, in parts by mass, step (1) comprises the following steps:

[0035] (11), taking 8.5 to 23.9 parts of an unsaturated tertiary amine and 3.64 to 15.93 parts of a first organic solvent into a reaction container and mixing them uniformly to obtain a mixed solution;

[0036] (12) 5.76 to 29.7 parts of an unsaturated acid and 2.47 to 19.8 parts of a second organic solvent are mixed uniformly to obtain an unsaturated acid second organic solvent solution, and then the unsaturated acid second organic solvent solution is added dropwise to the mixed solution obtained in step (11) while stirring, to obtain a mixed solution after the addition is completed.

[0037] (13) The mixed solution obtained in step (12) is heated to 40-90° C. for reaction for 2-24 h, preferably heated to 50-60° C. for reaction for 6-10 h, then cooled to room temperature to precipitate a white solid, and then washed with a third organic solvent for at least 3 times to obtain betaine with a double bond.

[0038] Furthermore, in step (11), no more than 6 parts of polymerization inhibitor are added and mixed evenly to obtain a mixed solution.

[0039] Furthermore, the polymerization inhibitor is one of benzaldehyde, p-toluenesulfonamide, 2,6-di-tert-butyl-p-cresol, and tetrachlorobenzoquinone.

[0040] Furthermore, the molecular formula of the unsaturated tertiary amine is CH 2 =CH-C n H 2n -N(CH 3 ) 2 , wherein n is a positive integer, and n=1 to 12, preferably n=1 to 3;

[0041] C n H 2n It is a C1-C12 straight chain alkylene group or a C3-C12 branched chain alkylene group.

[0042] Furthermore, the first organic solvent is at least one of ethanol, isopropanol and carbon tetrachloride.

[0043] Furthermore, the molecular formula of the unsaturated acid is CH 2 =CH-C n H 2n -COOH, wherein n is an integer, and n=0 to 9;

[0044] When n=1~9, C n H 2n It is a C1-C9 straight chain alkylene group or a C3-C9 branched chain alkylene group.

[0045] Furthermore, the second organic solvent is at least one of benzene, acetone and carbon tetrachloride.

[0046] Furthermore, in step (12), the dropping speed is controlled to be 1 drop / 3 to 5 seconds.

[0047] Furthermore, the third organic solvent is one of acetone, ether and petroleum ether with a boiling point of 30°C-60°C.

[0048] Further, in parts by mass, step (2) comprises the following steps:

[0049] (21) Take 4 to 6 parts of sodium hydroxide, add 3.6 to 5.5 parts of water to dissolve and obtain a sodium hydroxide aqueous solution;

[0050] (22), adding 15.7 to 43.7 parts of the betaine with double bonds obtained in step (1), adding an appropriate amount of water until the mass fraction of the betaine with double bonds is 40% to 60%, and stirring the reaction for at least half an hour to obtain a reaction solution;

[0051] (23) Take 60 to 130 parts of water-based epoxy resin in a colorless and transparent reaction container (such as glass), stir at a low speed, then add 0.005 to 10 parts of photoinitiator, and then add the reaction solution obtained in step (22) while stirring, and carry out photoreaction under natural light for at least 1 hour to obtain betaine-modified water-based epoxy resin.

[0052] Furthermore, the water-based epoxy resin in step (23) is one or more of bisphenol A epoxy resin, bisphenol S epoxy resin, and brominated epoxy resin.

[0053] Furthermore, the photoinitiator in step (23) is one of fluorinated diphenyl titanocene, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl) butanone, 2,4,6 (trimethylbenzoyl) diphenyl phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, bis (4-tert-butylbenzene) iodine hexafluorophosphate and ethyl 4-(N,N-dimethylamino) benzoate.

[0054] Furthermore, the light reaction time of step (23) is 1 to 9 hours, and the stirring speed of the low-speed stirring in step (23) is 100 to 500 rpm.

[0055] The anti-corrosion treatment liquid described in any one of the above items, or the anti-corrosion treatment liquid prepared by any one of the above preparation methods is used as an online repair liquid for downhole pipes in petroleum production.

[0056] Furthermore, the application comprises the following steps:

[0057] S1. Use pretreatment liquid to pickle the wellbore to be treated:

[0058] Inject low-concentration acidic liquid into the tubing and / or the annulus of the casing in a forward or reverse manner, and let it react for at least 30 minutes. After the reaction is complete, backwash the well with water. When the water quality at the inlet and outlet is consistent, the backwashing of the well is terminated, wherein:

[0059] The water discharge capacity is at least 500L / min;

[0060] S2, replace the anti-corrosion treatment liquid:

[0061] S21. Calculate the amount of anti-corrosion treatment fluid

[0062] When the anti-corrosion treatment fluid is used to repair the inner wall of the oil pipe, the volume of the anti-corrosion treatment fluid required for the inner wall repair of the oil pipe is V 1 = length of the oil pipe to be repaired × 3.14 × inner radius of the oil pipe 2 , unit is m 3 ;

[0063] When the anti-corrosion treatment fluid is used for the outer wall of the oil pipe or the inner wall of the casing, the volume of the anti-corrosion treatment fluid V required for the repair of the outer wall of the oil pipe or the inner wall of the casing 2 = length of the oil pipe to be repaired × (3.14 × inner radius of the casing 2 -3.14×outer radius of the tubing 2 ), unit is m 3 ;

[0064] S22, replace the anti-corrosion treatment liquid with the amount of anti-corrosion treatment liquid obtained in step S21, shut down the well for reaction for at least 24 hours, and the oil pipe repair is completed; backwash the well for at least 2 weeks, and then normal water injection can be performed.

[0065] Furthermore, the acidic liquid in step S1 consists of the following components:

[0066] 5% to 10% of acidic substances, 1% to 5% of corrosion inhibitors, 1% to 5% of non-ionic surfactants, and the balance is water.

[0067] Furthermore, the acidic substance is one or more of hydrochloric acid, citric acid and malic acid.

[0068] Furthermore, the corrosion inhibitor is a purchased commercial pickling corrosion inhibitor (such as a commercial pickling corrosion inhibitor whose main component is di-o-toluene thiourea, such as a commercial pickling corrosion inhibitor whose main component is sodium toluene triazole, and a commercial pickling corrosion inhibitor whose main component is benzotriazole). When cleaning metal pipes with acidic substances, adding the pickling corrosion inhibitor can inhibit the corrosion of the metal material by the acidic substance. After addition, the corrosion rate of the pipe column meets the requirements of the SY / T5405-1996 "Performance Test Method and Evaluation Index of Corrosion Inhibitors for Acidification".

[0069] Furthermore, the nonionic surfactant is one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide and polyether.

[0070] The water injection conditions of oilfield injection wells are harsh. The downhole temperature is high, up to 130°C; the pressure is high, up to 70MPa. The injected water contains oil (1-100mg / L), sulfate-reducing bacteria (2.5-6000 / ml), iron bacteria, saprophytes, etc., which cause oil, bacteria and their metabolites to adhere to the wall of the downhole tubing; at the same time, the downhole tubing is covered with corrosion and scaling products.

[0071] In view of the above problems, the present invention integrates the functions of antibacterial and anti-scaling, and has simple preparation method and treatment process.

[0072] When repairing downhole tubing, first inject acid pretreatment fluid to remove scale and oil, peel off the metal surface attachments, and expose the surface metal; then inject anti-corrosion treatment fluid.

[0073] The anticorrosion treatment liquid disclosed in the present invention and its preparation method and application have the following beneficial effects:

[0074] 1. After the anti-corrosion treatment liquid is injected into the well, the cationic head groups in the betaine modified waterborne epoxy resin are preferentially adsorbed on the pipe wall, and the anionic head groups float on the surface of the pipe wall, repelling sulfate-reducing bacteria, iron bacteria and saprophytes with negative charges on the surface, preventing bacteria from adhering to the pipe wall surface and eliminating bacterial corrosion; at the same time, it also repels negatively charged suspended solids and oil droplets, preventing suspended solids and oil droplets from adhering to the pipe wall surface, keeping the pipe wall clean, reducing scaling and under-scale corrosion; and preventing the adsorption of polymers on the pipe wall in polymer injection wells.

[0075] 2. The betaine-modified water-based epoxy resin adsorbed on the pipe wall undergoes grafting and three-dimensional cross-linking underground to form an anti-corrosion protective layer on the metal surface.

[0076] 3. The present invention can repair the damaged anti-corrosion layer of the anti-corrosion oil pipe and the anti-corrosion maintenance of the non-anti-corrosion oil pipe, effectively prolong the life of the pipe column and improve the development effect of the water-driven oil field. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 Schematic diagram of the effect of the synthesis temperature of betaine with double bonds on the strength of the anti-corrosion treatment liquid after solidification.

[0078] Figure 2 Schematic diagram of the effect of the consolidation temperature of the anti-corrosion treatment liquid on the strength after consolidation. Specific implementation method:

[0079] The specific embodiments of the present invention are described in detail below.

[0080] Example 1

[0081] An anticorrosive treatment liquid, calculated by mass percentage, consists of the following components:

[0082] Betaine modified waterborne epoxy resin 45%;

[0083] Triethanolamine 2.5%;

[0084] Curing agent 11.5%;

[0085] The balance is water.

[0086] Furthermore, the curing agent is a mixture of aliphatic amine and alicyclic amine in equal mass ratio.

[0087] Furthermore, the fatty amine is a mixture of boron trifluoride ethylamine and polyethylene polyamine in a mass ratio of 1:1.

[0088] Furthermore, the alicyclic amine is 1-methyl-2,4-cyclohexanediamine.

[0089] A method for preparing the anticorrosion treatment liquid described in any one of the above, comprising the following specific steps:

[0090] (1) Preparation of betaine with double bonds;

[0091] (2) preparing betaine modified waterborne epoxy resin;

[0092] (3) Evenly stir the formulated amount of betaine-modified water-based epoxy resin, the formulated amount of triethanolamine, the formulated amount of curing agent, and the formulated amount of water to obtain an anti-corrosion treatment liquid.

[0093] Further, in parts by mass, step (1) comprises the following steps:

[0094] (11), taking 10 parts of an unsaturated tertiary amine and 10 parts of a first organic solvent, placing them in a reaction container and mixing them evenly to obtain a mixed solution;

[0095] (12) 20 parts of the unsaturated acid and 15 parts of the second organic solvent are mixed evenly to obtain an unsaturated acid second organic solvent solution, and then the unsaturated acid second organic solvent solution is added dropwise to the mixed solution obtained in step (11) while stirring, and a mixed solution is obtained after the addition is completed.

[0096] (13) The mixed solution obtained in step (12) is heated to 60° C., reacted for 12 hours, and then cooled to room temperature to precipitate a white solid, which is then washed three times with a third organic solvent to obtain betaine with a double bond.

[0097] Furthermore, in step (11), 3 parts of polymerization inhibitor are added and mixed evenly to obtain a mixed solution.

[0098] Furthermore, the molecular formula of the unsaturated tertiary amine is CH 2 =CH-C n H 2n -N(CH 3) 2 , where n is a positive integer, and n=3;

[0099] C n H 2n It is a C4 straight chain alkylene group.

[0100] Furthermore, the first organic solvent is a mixture of ethanol, isopropanol and carbon tetrachloride in equal mass ratios.

[0101] Furthermore, the polymerization inhibitor is benzaldehyde.

[0102] Furthermore, the molecular formula of the unsaturated acid is CH 2 =CH-C n H 2n -COOH, wherein n is an integer and n=0;

[0103] Furthermore, the second organic solvent is a mixture of benzene, acetone and carbon tetrachloride in equal mass ratios.

[0104] Furthermore, in step (12), the dripping speed is controlled to deliver one drop every 4 seconds.

[0105] Furthermore, the third organic solvent is acetone.

[0106] Further, in parts by mass, step (2) comprises the following steps:

[0107] (21) Take 5 parts of sodium hydroxide and add 5 parts of water to dissolve to obtain a sodium hydroxide aqueous solution;

[0108] (22) adding 20 parts of the betaine with double bonds obtained in step (1), adding an appropriate amount of water until the mass fraction of the betaine with double bonds is 40% to 60%, stirring and reacting for half an hour to obtain a reaction solution;

[0109] (23) Take 80 parts of water-based epoxy resin in a colorless and transparent reaction container (such as glass), stir at a low speed, then add 1 part of photoinitiator, and then add the reaction solution obtained in step (22) while stirring, and carry out photoreaction under natural light for 2 hours to obtain betaine-modified water-based epoxy resin.

[0110] Furthermore, the water-based epoxy resin in step (23) is a mixture of bisphenol A epoxy resin, bisphenol S epoxy resin and brominated epoxy resin in equal mass ratios.

[0111] Furthermore, the photoinitiator in step (23) is diphenyltitanium fluoride.

[0112] Furthermore, the stirring speed of the low-speed stirring in step (23) is 300 rpm.

[0113] The anti-corrosion treatment liquid described in any one of the above items, or the anti-corrosion treatment liquid prepared by any one of the above preparation methods is used as an online repair liquid for downhole pipes in petroleum production.

[0114] Furthermore, the application comprises the following steps:

[0115] S1. Use pretreatment liquid to pickle the wellbore to be treated:

[0116] Inject low-concentration acidic liquid into the tubing and casing annulus in a normal displacement manner, react for 60 minutes, backwash the well with water after the reaction is completed, and end the backwashing of the well after the water quality at the inlet and outlet is consistent, wherein:

[0117] The water displacement is 600L / min;

[0118] S2, replace the anti-corrosion treatment liquid:

[0119] S21. Calculate the amount of anti-corrosion treatment fluid

[0120] When the anti-corrosion treatment fluid is used to repair the inner wall of the oil pipe, the volume of the anti-corrosion treatment fluid required for the inner wall repair of the oil pipe is V 1 = length of the oil pipe to be repaired × 3.14 × inner radius of the oil pipe 2 , unit is m 3 ;

[0121] When the anti-corrosion treatment fluid is used for the outer wall of the oil pipe or the inner wall of the casing, the volume of the anti-corrosion treatment fluid V required for the repair of the outer wall of the oil pipe or the inner wall of the casing 2 = length of the oil pipe to be repaired × (3.14 × inner radius of the casing 2 -3.14×outer radius of the tubing 2 ), unit is m 3 ;

[0122] S22, replace the anti-corrosion treatment liquid with the amount of anti-corrosion treatment liquid obtained in step S21, shut down the well for reaction for 36 hours, and the oil pipe repair is completed; backwash the well for 3 weeks, and then inject water normally.

[0123] Furthermore, the acidic liquid in step S1 consists of the following components:

[0124] 8% acidic substance, 3% corrosion inhibitor, 3% non-ionic surfactant, and the balance is water.

[0125] Furthermore, the acidic substance is hydrochloric acid.

[0126] Furthermore, the corrosion inhibitor is a purchased commercial pickling corrosion inhibitor (a commercial pickling corrosion inhibitor whose main component is di-o-toluene thiourea (content is above 98wt%)). When cleaning metal pipes with acidic substances, adding the pickling corrosion inhibitor can inhibit the corrosion of the metal material by the acidic substances. After addition, the corrosion rate of the pipe column meets the requirements of the standard SY / T5405-1996 "Performance Test Method and Evaluation Index of Corrosion Inhibitor for Acidification".

[0127] Furthermore, the nonionic surfactant is fatty alcohol polyoxyethylene ether.

[0128] Example 2

[0129] An anticorrosive treatment liquid, calculated by mass percentage, consists of the following components:

[0130] Betaine modified waterborne epoxy resin 30%;

[0131] Triethanolamine 0.3%;

[0132] Curing agent 2%;

[0133] The balance is water.

[0134] Furthermore, the curing agent is a mixture of aliphatic amine, alicyclic amine and aromatic amine in equal mass ratio.

[0135] Furthermore, the fatty amine is a mixture of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, boron trifluoride ethylamine, hexamethylenediamine and polyethylene polyamine in equal mass ratios.

[0136] Furthermore, the alicyclic amine is a mixture of 4,4'-diaminodicyclohexylmethane alicyclic amine and 1-methyl-2,4-cyclohexanediamine in equal mass ratio.

[0137] Furthermore, the aromatic amine is a mixture of 1,3-phenylenediamine, m-phenylenediamine, 2-phenylimidazole, p-methylbenzyl chloride, 4,4-diaminophenylsulfone and 4,4-diaminodiphenylmethane in equal mass ratios.

[0138] A method for preparing the anticorrosion treatment liquid described in any one of the above, comprising the following specific steps:

[0139] (1) Preparation of betaine with double bonds;

[0140] (2) preparing betaine modified waterborne epoxy resin;

[0141] (3) Evenly stir the formulated amount of betaine-modified water-based epoxy resin, the formulated amount of triethanolamine, the formulated amount of curing agent, and the formulated amount of water to obtain an anti-corrosion treatment liquid.

[0142] Further, in parts by mass, step (1) comprises the following steps:

[0143] (11), taking 8.5 parts of an unsaturated tertiary amine and 3.64 parts of a first organic solvent into a reaction container and mixing them evenly to obtain a mixed solution;

[0144] (12) 5.76 parts of the unsaturated acid and 2.47 parts of the second organic solvent are mixed uniformly to obtain an unsaturated acid second organic solvent solution, and then the unsaturated acid second organic solvent solution is added dropwise to the mixed solution obtained in step (11) while stirring. After the addition is completed, a mixed solution is obtained.

[0145] (13) The mixed solution obtained in step (12) is heated to 40° C., reacted for 24 hours, and then cooled to room temperature to precipitate a white solid, which is then washed five times with a third organic solvent to obtain betaine with a double bond.

[0146] Furthermore, in step (11), 0.01 parts of an inhibitor is added and mixed evenly to obtain a mixed solution.

[0147] Furthermore, the polymerization inhibitor is p-toluenesulfonamide.

[0148] Furthermore, the molecular formula of the unsaturated tertiary amine is CH 2 =CH-C n H 2n -N(CH 3 ) 2 , where n is a positive integer and n=1;

[0149] C n H 2n It is a C1 straight chain alkylene group.

[0150] Furthermore, the first organic solvent is ethanol.

[0151] Furthermore, the molecular formula of the unsaturated acid is CH 2 =CH-C n H 2n -COOH, wherein n is an integer and n=1, C n H 2n It is a C1 straight chain alkylene group.

[0152] Furthermore, the second organic solvent is benzene.

[0153] Furthermore, in step (12), the dropping speed is controlled to be 1 drop / 3s.

[0154] Furthermore, the third organic solvent is diethyl ether.

[0155] Further, in parts by mass, step (2) comprises the following steps:

[0156] (21) Take 4 parts of sodium hydroxide and add 3.6 parts of water to dissolve to obtain a sodium hydroxide aqueous solution;

[0157] (22), adding 15.7 parts of the betaine with double bonds obtained in step (1), adding an appropriate amount of water to a mass fraction of 40% of the betaine with double bonds, stirring and reacting for half an hour to obtain a reaction solution;

[0158] (23) Take 60 parts of water-based epoxy resin in a colorless and transparent reaction container (such as glass), stir at a low speed, then add 0.005 parts of photoinitiator, and then add the reaction solution obtained in step (22) while stirring, and carry out photoreaction under natural light for 9 hours to obtain betaine-modified water-based epoxy resin.

[0159] Furthermore, the water-based epoxy resin in step (23) is bisphenol A epoxy resin.

[0160] Furthermore, the photoinitiator in step (23) is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone.

[0161] Furthermore, the stirring speed of the low-speed stirring in step (23) is 100 rpm.

[0162] The anti-corrosion treatment liquid described in any one of the above items, or the anti-corrosion treatment liquid prepared by any one of the above preparation methods is used as an online repair liquid for downhole pipes in petroleum production.

[0163] Furthermore, the application comprises the following steps:

[0164] S1. Use pretreatment liquid to pickle the wellbore to be treated:

[0165] Inject low-concentration acidic liquid into the oil pipe in a reverse displacement manner, react for 30 minutes, backwash the well with water after the reaction is completed, and end the backwashing of the well after the water quality at the inlet and outlet is consistent, wherein:

[0166] The water displacement is 500L / min;

[0167] S2, replace the anti-corrosion treatment liquid:

[0168] S21. Calculate the amount of anti-corrosion treatment fluid

[0169] When the anti-corrosion treatment fluid is used to repair the inner wall of the oil pipe, the volume of the anti-corrosion treatment fluid required for the inner wall repair of the oil pipe is V 1 = length of the oil pipe to be repaired × 3.14 × inner radius of the oil pipe 2 , unit is m 3 ;

[0170] When the anti-corrosion treatment fluid is used for the outer wall of the oil pipe or the inner wall of the casing, the volume of the anti-corrosion treatment fluid V required for the repair of the outer wall of the oil pipe or the inner wall of the casing 2 = length of the oil pipe to be repaired × (3.14 × inner radius of the casing 2 -3.14×outer radius of the tubing 2 ), unit is m 3 ;

[0171] S22, replace the anti-corrosion treatment liquid with the amount of anti-corrosion treatment liquid obtained in step S21, shut down the well for reaction for 24 hours, and the oil pipe repair is completed; backwash the well for 2 weeks, and then inject water normally.

[0172] Furthermore, the acidic liquid in step S1 consists of the following components:

[0173] 5% acidic substance, 1% corrosion inhibitor, 1% non-ionic surfactant, and the balance is water.

[0174] Furthermore, the acidic substance is citric acid.

[0175] Furthermore, the corrosion inhibitor is a purchased commercial pickling corrosion inhibitor (a commercial pickling corrosion inhibitor whose main component is sodium methylbenzotriazole (its content is at least 98wt%)). When cleaning metal pipes with acidic substances, adding the pickling corrosion inhibitor can inhibit the corrosion of the metal material by the acidic substances. After adding, the corrosion rate of the pipe column meets the requirements of the SY / T5405-1996 "Test Method and Evaluation Index of Corrosion Inhibitor Performance for Acidification".

[0176] Furthermore, the nonionic surfactant is alkylphenol polyoxyethylene ether.

[0177] Example 3

[0178] An anticorrosive treatment liquid, calculated by mass percentage, consists of the following components:

[0179] Betaine modified waterborne epoxy resin 60%;

[0180] Triethanolamine 8%;

[0181] Curing agent 25%;

[0182] The balance is water.

[0183] Furthermore, the curing agent is aromatic amine.

[0184] Furthermore, the aromatic amine is 1,3-phenylenediamine.

[0185] A method for preparing the anticorrosion treatment liquid described in any one of the above, comprising the following specific steps:

[0186] (1) Preparation of betaine with double bonds;

[0187] (2) preparing betaine modified waterborne epoxy resin;

[0188] (3) Evenly stir the formulated amount of betaine-modified water-based epoxy resin, the formulated amount of triethanolamine, the formulated amount of curing agent, and the formulated amount of water to obtain an anti-corrosion treatment liquid.

[0189] Further, in parts by mass, step (1) comprises the following steps:

[0190] (11), taking 23.9 parts of an unsaturated tertiary amine and 15.93 parts of a first organic solvent into a reaction container and mixing them uniformly to obtain a mixed solution;

[0191] (12) 29.7 parts of the unsaturated acid and 19.8 parts of the second organic solvent are mixed uniformly to obtain an unsaturated acid second organic solvent solution, and then the unsaturated acid second organic solvent solution is added dropwise to the mixed solution obtained in step (11) while stirring, to obtain a mixed solution after the addition is completed.

[0192] (13) The mixed solution obtained in step (12) is heated to 90° C., reacted for 2 hours, and then cooled to room temperature to precipitate a white solid, which is then washed 6 times with a third organic solvent to obtain betaine with a double bond.

[0193] Furthermore, in step (11), 6 parts of polymerization inhibitor are added and mixed evenly to obtain a mixed solution.

[0194] Furthermore, the polymerization inhibitor is 2,6-di-tert-butyl-p-cresol.

[0195] In another embodiment, the inhibitor is chloranil.

[0196] Furthermore, the molecular formula of the unsaturated tertiary amine is CH 2 =CH-C n H 2n -N(CH 3 ) 2 , where n is a positive integer, and n=12;

[0197] C n H 2n It is a C12 straight chain alkylene group.

[0198] In another embodiment, n=3, C n H 2n It is a C3 branched alkylene group.

[0199] In yet another embodiment, n=12, C n H 2nIt is a C12 branched alkylene group.

[0200] In another embodiment, n=6, C n H 2n It is a C6 branched alkylene group.

[0201] Furthermore, the first organic solvent is isopropanol.

[0202] In another embodiment, the first organic solvent is carbon tetrachloride.

[0203] Furthermore, the molecular formula of the unsaturated acid is CH 2 =CH-C n H 2n -COOH, wherein n is an integer, and n=9, C n H 2n It is a C9 straight chain alkylene group.

[0204] In another embodiment, when n=3, C n H 2n It is a C3 branched alkylene group.

[0205] In yet another embodiment, when n=9, C n H 2n It is a C9 branched alkylene group.

[0206] In another embodiment, when n=6, C n H 2n It is a C6 branched alkylene group.

[0207] Furthermore, the second organic solvent is acetone.

[0208] In another embodiment, the second organic solvent is carbon tetrachloride.

[0209] Furthermore, in step (12), the dripping acceleration is controlled to be 1 drop / 5s.

[0210] Furthermore, the third organic solvent is petroleum ether with a boiling point of 30°C.

[0211] In yet another embodiment, the third organic solvent is petroleum ether with a boiling point of 60°C.

[0212] In another embodiment, the third organic solvent is petroleum ether with a boiling point of 42°C.

[0213] Further, in parts by mass, step (2) comprises the following steps:

[0214] (21) Take 6 parts of sodium hydroxide and add 5.5 parts of water to dissolve to obtain a sodium hydroxide aqueous solution;

[0215] (22), adding 43.7 parts of betaine with double bonds obtained in step (1), adding appropriate amount of water to make the mass fraction of betaine with double bonds reach 60%, stirring and reacting for at least half an hour to obtain a reaction solution;

[0216] (23) Take 130 parts of water-based epoxy resin in a colorless and transparent reaction container (such as glass), stir at a low speed, then add 10 parts of photoinitiator, and then add the reaction solution obtained in step (22) while stirring, and carry out photoreaction under natural light for 1 hour to obtain betaine-modified water-based epoxy resin.

[0217] Furthermore, the water-based epoxy resin in step (23) is bisphenol S epoxy resin.

[0218] In another embodiment, the water-based epoxy resin in step (23) is a brominated epoxy resin.

[0219] Furthermore, the photoinitiator in step (23) is 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide.

[0220] In another embodiment, the photoinitiator in step (23) is 1-hydroxycyclohexyl phenyl ketone.

[0221] In yet another embodiment, the photoinitiator in step (23) is bis(4-tert-butylbenzene)iodonium hexafluorophosphate.

[0222] In another embodiment, the photoinitiator in step (23) is ethyl 4-(N,N-dimethylamino)benzoate.

[0223] Furthermore, the stirring speed of the low-speed stirring in step (23) is 500 rpm.

[0224] The anti-corrosion treatment liquid described in any one of the above items, or the anti-corrosion treatment liquid prepared by any one of the above preparation methods is used as an online repair liquid for downhole pipes in petroleum production.

[0225] Furthermore, the application comprises the following steps:

[0226] S1. Use pretreatment liquid to pickle the wellbore to be treated:

[0227] Inject low-concentration acidic liquid into the annulus of the casing in a reverse displacement manner, react for 100 minutes, backwash the well with water after the reaction is completed, and end the backwashing of the well when the water quality at the inlet and outlet is consistent, wherein:

[0228] The water displacement is 800L / min;

[0229] S2. Replacement of anti-corrosion treatment fluid:

[0230] S21. Calculate the amount of anti-corrosion treatment fluid

[0231] When the anti-corrosion treatment fluid is used to repair the inner wall of the oil pipe, the volume of the anti-corrosion treatment fluid required for the inner wall repair of the oil pipe is V 1 = length of the oil pipe to be repaired × 3.14 × inner radius of the oil pipe 2 , unit is m 3 ;

[0232] When the anti-corrosion treatment fluid is used for the outer wall of the oil pipe or the inner wall of the casing, the volume of the anti-corrosion treatment fluid V required for the repair of the outer wall of the oil pipe or the inner wall of the casing 2 = length of the oil pipe to be repaired × (3.14 × inner radius of the casing 2 -3.14×outer radius of the tubing 2 ), unit is m 3 ;

[0233] S22, replace the anti-corrosion treatment liquid with the amount of anti-corrosion treatment liquid obtained in step S21, shut down the well for reaction for 48 hours, and the oil pipe repair is completed; backwash the well for 4 weeks, and then inject water normally.

[0234] Furthermore, the acidic liquid in step S1 consists of the following components:

[0235] 10% acidic substance, 5% corrosion inhibitor, 5% non-ionic surfactant, and the balance is water.

[0236] Furthermore, the acidic substance is citric acid.

[0237] In another embodiment, the acidic substance is malic acid.

[0238] Furthermore, the corrosion inhibitor is a purchased commercial pickling corrosion inhibitor (a commercial pickling corrosion inhibitor whose main component is benzotriazole (content greater than 98wt%)). When cleaning metal pipes with acidic substances, adding the pickling corrosion inhibitor can inhibit the corrosion of the metal material by the acidic substances. After addition, the corrosion rate of the pipe column meets the requirements of the SY / T5405-1996 "Performance Test Method and Evaluation Index of Corrosion Inhibitors for Acidification".

[0239] Furthermore, the nonionic surfactant is polyoxyethylene fatty acid ester.

[0240] In another embodiment, the nonionic surfactant is polyoxyethylene alkylamine.

[0241] In yet another embodiment, the nonionic surfactant is polyoxyethylene alkylamide.

[0242] In another embodiment, the nonionic surfactant is a polyether.

[0243] Example 4

[0244] It is substantially the same as Example 1, except that the proportion of components of the anticorrosive treatment liquid is different:

[0245] An anticorrosive treatment liquid, calculated by mass percentage, consists of the following components:

[0246] Betaine modified waterborne epoxy resin 40;

[0247] Triethanolamine 0.5%;

[0248] Curing agent 4%;

[0249] The balance is water.

[0250] Example 5

[0251] It is substantially the same as Example 1, except that the proportion of components of the anticorrosive treatment liquid is different:

[0252] An anticorrosive treatment liquid, calculated by mass percentage, consists of the following components:

[0253] Betaine modified waterborne epoxy resin 50%;

[0254] Triethanolamine 3%;

[0255] Curing agent 15%;

[0256] The balance is water.

[0257] Example 6

[0258] It is substantially the same as Example 1, except that the proportion of components of the anticorrosive treatment liquid is different:

[0259] An anticorrosive treatment liquid, calculated by mass percentage, consists of the following components:

[0260] Betaine modified waterborne epoxy resin 42%;

[0261] Triethanolamine 1%;

[0262] Curing agent 6%;

[0263] The balance is water.

[0264] Example 7-21

[0265] It is similar to Example 1, except that the curing agent is different:

[0266]

[0267]

[0268] Embodiment 22

[0269] It is similar to Example 1, except that the curing agent is different:

[0270] The curing agent is a mixture of polyethylene polyamine, 1-methyl-2,4-cyclohexanediamine and boron trifluoride ethylamine, and the mass ratio thereof is 1:0.1:0.1.

[0271] Embodiment 23

[0272] It is similar to Example 1, except that the curing agent is different:

[0273] The curing agent is a mixture of polyethylene polyamine, 1-methyl-2,4-cyclohexanediamine and boron trifluoride ethylamine, and the mass ratio thereof is 1:10:15.

[0274] Embodiment 24

[0275] It is similar to Example 1, except that the curing agent is different:

[0276] The curing agent is a mixture of polyethylene polyamine, 1-methyl-2,4-cyclohexanediamine and boron trifluoride ethylamine, and the mass ratio thereof is 1:5:10.

[0277] Embodiment 25

[0278] It is substantially the same as Example 1, except that:

[0279] The general formula of unsaturated acids is CH 2 =CH-C n H 2n -COOH, wherein n is an integer and n=3, C n H 2n A C3 straight chain alkylene

[0280] Embodiment 26

[0281] It is substantially the same as Example 1, except that:

[0282] The general formula of unsaturated acids is CH 2 =CH-C n H 2n -COOH, wherein n is an integer and n=6, C n H 2n It is a C6 branched alkylene group.

[0283] Embodiment 27

[0284] It is substantially the same as Example 1, except that:

[0285] The general formula of unsaturated acids is CH 2 =CH-C n H 2n-COOH, wherein n is an integer and n=9, C n H 2n It is a C9 straight chain alkylene group.

[0286] Embodiment 28

[0287] The method is similar to Example 1, except that the method for preparing the anticorrosive treatment liquid is different:

[0288] A method for preparing an anticorrosive treatment liquid, the specific steps are as follows:

[0289] (1) Preparation of betaine with double bonds;

[0290] (2) preparing betaine modified waterborne epoxy resin;

[0291] (3) Evenly stir the formulated amount of betaine-modified water-based epoxy resin, the formulated amount of triethanolamine, the formulated amount of curing agent, and the formulated amount of water to obtain an anti-corrosion treatment liquid.

[0292] Further, in parts by mass, step (1) comprises the following steps:

[0293] (11), taking 10 parts of an unsaturated tertiary amine and 12 parts of a first organic solvent, placing them in a reaction container and mixing them evenly to obtain a mixed solution;

[0294] (12) 10 parts of an unsaturated acid and 10 parts of a second organic solvent are mixed uniformly to obtain an unsaturated acid second organic solvent solution, and then the unsaturated acid second organic solvent solution is added dropwise to the mixed solution obtained in step (11) while stirring, to obtain a mixed solution after the addition is completed.

[0295] (13) The mixed solution obtained in step (12) is heated to 40° C., reacted for 8 hours, and then cooled to room temperature to precipitate a white solid, which is then washed three times with a third organic solvent to obtain betaine with a double bond.

[0296] Furthermore, in step (11), no more than 4 parts of an inhibitor are added and mixed evenly to obtain a mixed solution.

[0297] Furthermore, the polymerization inhibitor is benzaldehyde.

[0298] Furthermore, the unsaturated tertiary amine is dimethylallylamine.

[0299] Furthermore, the first organic solvent is carbon tetrachloride.

[0300] Furthermore, the unsaturated acid is acrylic acid.

[0301] Furthermore, the second organic solvent is benzene.

[0302] Furthermore, in step (12), the dropping speed is controlled to be 1 drop / 3s.

[0303] Furthermore, the third organic solvent is acetone.

[0304] Further, in parts by mass, step (2) comprises the following steps:

[0305] (21) Take 5 parts of sodium hydroxide and add 4 parts of water to dissolve to obtain a sodium hydroxide aqueous solution;

[0306] (22) adding 20 parts of betaine with double bonds obtained in step (1), adding appropriate amount of water to make the mass fraction of betaine with double bonds reach 50%, stirring and reacting for half an hour to obtain a reaction solution;

[0307] (23) Take 60 to 130 parts of waterborne epoxy resin in a colorless and transparent reaction container (such as glass), stir at a low speed, then add 5 parts of photoinitiator, and then add the reaction solution obtained in step (22) while stirring, and react under natural light for 1 hour to obtain betaine modified waterborne epoxy resin.

[0308] Furthermore, the water-based epoxy resin in step (23) is bisphenol A epoxy resin.

[0309] Furthermore, the photoinitiator in step (23) is diphenyltitanium fluoride.

[0310] Furthermore, the stirring speed of the low-speed stirring in step (23) is 200 rpm.

[0311] The synthetic route of the present embodiment is as follows:

[0312] 1. Take acrylic acid and dimethylallylamine as an example to synthesize betaine with double bonds:

[0313] acrylic acid:

[0314]

[0315] Dimethylallylamine:

[0316]

[0317] The synthetic route of betaine compounds with double bond structure is as follows:

[0318]

[0319] 2. Taking bisphenol A epoxy resin as an example, the structural formula of bisphenol A epoxy resin is:

[0320]

[0321] 3. The synthetic route of betaine modified waterborne epoxy resin is:

[0322]

[0323] Performance characterization:

[0324] 1. Evaluation of bacterial adhesion performance on the surface of anti-corrosion layer

[0325] Take the anticorrosion treatment liquids prepared in Example 1, Example 25, Example 26, and Example 27, and pour them into different culture dishes with a diameter of 63 mm and a depth of 20 mm. The height of the anticorrosion treatment liquid is 10 mm. Then add steel pipes of the same size into the culture dishes. The diameter of the steel pipes is 20 mm and the height is 5 mm. The steel pipes are immersed in the anticorrosion treatment liquid. After the anticorrosion treatment liquid solidifies, add sewage with a SRB quantity of 50 to 6000 / mL. After standing for 7 days, shake gently and pour out the sewage. During this period, a group of experiments without adding any anticorrosion treatment liquid is used as a blank control group.

[0326] The steel pipes were taken out and then the number of bacteria on the surface of the steel pipes was observed with an electron microscope. The number of bacteria adsorbed on the blank surface was relatively large, reaching 520, while the number of bacteria adsorbed on the surface of the steel pipes in the anti-corrosion treatment fluid was relatively small, reduced by about 98%. The injected water was in a flowing state underground, which can be used to show that the anti-bacterial adsorption ability of the anti-corrosion treatment fluid is better.

[0327] Table 1 Evaluation of bacterial adhesion performance on the surface of anticorrosive layer

[0328]

[0329] 2. Evaluation of the solidification performance of anti-corrosion treatment fluid

[0330] According to the technical scheme of Example 28, the amounts and order of addition of acrylic acid, dimethylallylamine and inhibitor were fixed, the reaction time was fixed at 8 h, the reaction temperature was changed (the reaction temperatures were 40°C, 45°C, 50°C, 55°C, 60°C, 75°C and 90°C, respectively), and the other process parameters remained unchanged, to prepare different betaine-modified water-based epoxy resins, and then prepare different anticorrosive treatment solutions under the same conditions.

[0331] Figure 1 The results show that the strength of different anti-corrosion treatment liquids after solidification changes with the synthesis temperature of betaine-modified waterborne epoxy resin. Figure 1 It can be seen that with the increase of the synthesis temperature of betaine modified waterborne epoxy resin, the strength of the anti-corrosion treatment liquid first increases and then decreases after solidification, and the optimal reaction temperature is 50-60℃.

[0332] 3. Evaluation of the solidification performance of anti-corrosion treatment fluid 2

[0333] According to the technical scheme of Example 28, the dosage and addition order of acrylic acid, dimethylallylamine and inhibitor were fixed, the reaction time was fixed at 8h and the reaction temperature was fixed at 55°C, betaine with double bonds was prepared, and then the anti-corrosion treatment liquid was prepared under the same conditions to investigate the effect of different solidification temperatures on the solidification strength of the anti-corrosion treatment liquid.

[0334] Figure 2 The variation of the strength after consolidation with the solidification reaction temperature of the anti-corrosion treatment liquid is shown. Figure 2 It can be seen that with the increase of the consolidation reaction temperature, the reaction strength of the anti-corrosion treatment liquid after solidification first increases, then remains stable, and then decreases. There is a relatively wide temperature window between 45 and 125°C, so that the post-solidification strength of the anti-corrosion treatment liquid can meet the use requirements.

[0335] 4. Adhesion strength test of anticorrosion treatment fluid

[0336] The adhesion strength test method and index requirements of the anti-corrosion treatment liquid refer to "SY / T 0315-2013 Technical Specifications for Steel Pipeline Fusion Epoxy Powder External Coating".

[0337] 4.1 Specimen preparation

[0338] The bottom plate is a steel test plate with a size of 100 mm in length and width and a thickness of 6 mm. After drying at 50°C for 24 hours, it is cooled in a dryer to room temperature. After being taken out, the surface is rusted according to regulations. The anti-corrosion treatment liquid prepared in Example 28 is sprayed on one side of the steel plate test piece by a thermal spraying method to form a single-sided coating with a coating thickness of (0.35±0.05) mm. It is naturally cooled to room temperature. The number of test pieces in each group should be 3.

[0339] 4.2 Evaluation method:

[0340] Refer to the relevant requirements in Appendix G of SY / T 0315-2013 "Technical Specifications for External Coatings of Fusion-bonded Epoxy Powder for Steel Pipes". After soaking, take out the test piece and wipe it dry. When the test piece is still warm, immediately use a knife to scratch a rectangle of about 30mm×15mm on the coating, through the coating to the base plate, and then cool naturally to 20℃±3℃ in the air. Within 1 hour after taking out the test piece, insert the tip of the knife under the coating from any corner of the rectangle, pry off the coating with horizontal force, and continue to push the tip of the knife until the coating in the rectangle is completely pried off or the coating shows obvious anti-pry performance. Evaluate the adhesion level of the coating inside the rectangle according to the following grading standards.

[0341] 4.3 Testing process:

[0342] The anti-corrosion coating was immersed in sewage to test the effect of different factors in sewage on the adhesion strength of the anti-corrosion coating. The test results are shown in Table 2 and Table 3: The adhesion strength of the anti-corrosion coating did not change significantly after being immersed in sewage with different mineralization and different bacterial content for 28 days.

[0343] Table 2 Anti-corrosion coating adhesion strength test table

[0344]

[0345] Table 3 Effect of mineralization on adhesion strength of anti-corrosion coating

[0346]

[0347] The above describes the embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An anticorrosion treatment liquid, characterized in that: In terms of mass percentage, it is composed of the following components: Betaine modified waterborne epoxy resin 30% to 60%; Triethanolamine 0.3% to 8%; Curing agent 2% to 25%; The balance is water.

2. The anticorrosion treatment liquid according to claim 1, characterized in that: In terms of mass percentage, it is composed of the following components: Betaine modified waterborne epoxy resin 40% to 50%; Triethanolamine 0.5% to 3%; Curing agent 4% to 15%; The balance is water.

3. The anticorrosion treatment liquid according to claim 1, characterized in that: The curing agent is one or more of aliphatic amine, alicyclic amine and aromatic amine.

4. An anticorrosive treatment liquid as claimed in claim 3, characterized in that: The fatty amine is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, boron trifluoride ethylamine, hexamethylenediamine and polyethylene polyamine; The alicyclic amine is at least one of 4,4'-diaminodicyclohexylmethane alicyclic amine and 1-methyl-2,4-cyclohexanediamine; The aromatic amine is at least one of 1,3-phenylenediamine, m-phenylenediamine, 2-phenylimidazole, p-methylbenzyl chloride, 4,4-diaminophenylsulfone and 4,4-diaminodiphenylmethane.

5. An anti-corrosion treatment liquid as claimed in claim 4, characterized in that: The curing agent is a mixture of polyethylene polyamine, 1-methyl-2,4-cyclohexanediamine and trifluoroborane ethylamine, and the mass ratio thereof is 1: (0.1-10): (0.1-15).

6. A method for preparing the anticorrosion treatment liquid according to any one of claims 1 to 5, characterized in that: The specific steps are as follows: (1) Preparation of betaine with double bonds; (2) preparing betaine modified waterborne epoxy resin; (3) Evenly stir the formulated amount of betaine-modified water-based epoxy resin, the formulated amount of triethanolamine, the formulated amount of curing agent, and the formulated amount of water to obtain an anti-corrosion treatment liquid.

7. The method for preparing an anticorrosive treatment liquid according to claim 6, characterized in that: In parts by mass, step (1) comprises the following steps: (11), taking 8.5 to 23.9 parts of an unsaturated tertiary amine and 3.64 to 15.93 parts of a first organic solvent into a reaction container and mixing them uniformly to obtain a mixed solution; (12) 5.76 to 29.7 parts of an unsaturated acid and 2.47 to 19.8 parts of a second organic solvent are mixed uniformly to obtain an unsaturated acid second organic solvent solution, and then the unsaturated acid second organic solvent solution is added dropwise to the mixed solution obtained in step (11) while stirring, to obtain a mixed solution after the addition is completed. (13) The mixed solution obtained in step (12) is heated to 40-90° C. for reaction for 2-24 h, preferably heated to 50-60° C. for reaction for 6-10 h, then cooled to room temperature to precipitate a white solid, and then washed with a third organic solvent for at least 3 times to obtain betaine with a double bond.

8. The method for preparing an anticorrosive treatment liquid according to claim 7, characterized in that: In step (11), no more than 6 parts of polymerization inhibitor are added and mixed evenly to obtain a mixed solution.

9. The method for preparing an anticorrosive treatment liquid according to claim 8, characterized in that: The polymerization inhibitor is one of benzaldehyde, p-toluenesulfonamide, 2,6-di-tert-butyl-p-cresol, and tetrachlorobenzoquinone.

10. The method for preparing an anticorrosive treatment liquid according to claim 7, characterized in that: The molecular formula of the unsaturated tertiary amine is CH2=CH-C n H 2n -N(CH3)2, wherein n is a positive integer, and n=1 to 12, preferably n=1 to 3; C n H 2n It is a C1-C12 straight chain alkylene group or a C3-C12 branched chain alkylene group.

11. The method for preparing an anticorrosive treatment liquid according to claim 7, characterized in that: The first organic solvent is at least one of ethanol, isopropanol, and carbon tetrachloride; The second organic solvent is at least one of benzene, acetone, and carbon tetrachloride; The third organic solvent is one of acetone, ether and petroleum ether with a boiling point of 30° C.-60° C.

12. The method for preparing an anticorrosive treatment liquid according to claim 7, characterized in that: The molecular formula of the unsaturated acid is CH2=CH-C n H 2n -COOH, wherein n is an integer, and n=0 to 9; When n=1~9, C n H 2n It is a C1-C9 straight chain alkylene group or a C3-C9 branched chain alkylene group.

13. The method for preparing an anticorrosive treatment liquid according to claim 7, characterized in that: In step (12), the dropping speed is controlled to be 1 drop / 3 to 5 seconds.

14. The method for preparing an anticorrosive treatment liquid according to claim 7, characterized in that: In parts by mass, step (2) comprises the following steps: (21) Take 4 to 6 parts of sodium hydroxide, add 3.6 to 5.5 parts of water to dissolve and obtain a sodium hydroxide aqueous solution; (22), adding 15.7 to 43.7 parts of the betaine with double bonds obtained in step (1), adding an appropriate amount of water until the mass fraction of the betaine with double bonds is 40% to 60%, and stirring the reaction for at least half an hour to obtain a reaction solution; (23) Take 60 to 130 parts of water-based epoxy resin in a colorless and transparent reaction container (such as glass), stir at a low speed, then add 0.005 to 10 parts of photoinitiator, and then add the reaction solution obtained in step (22) while stirring, and carry out photoreaction under natural light for at least 1 hour to obtain betaine-modified water-based epoxy resin.

15. The method for preparing an anticorrosive treatment liquid according to claim 14, characterized in that: The water-based epoxy resin in step (23) is one or more of bisphenol A epoxy resin, bisphenol S epoxy resin, and brominated epoxy resin.

16. The method for preparing an anticorrosive treatment liquid according to claim 14, characterized in that: The photoinitiator in step (23) is one of fluorinated diphenyl titanocene, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl) butanone, 2,4,6 (trimethylbenzoyl) diphenyl phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, bis (4-tert-butylbenzene) iodine hexafluorophosphate and ethyl 4-(N,N-dimethylamino) benzoate.

17. The method for preparing an anticorrosive treatment liquid according to claim 14, characterized in that: The light reaction time of step (23) is 1 to 9 hours, and the stirring speed of the low-speed stirring in step (23) is 100 to 500 rpm.

18. The anti-corrosion treatment liquid according to any one of claims 1 to 5 or the anti-corrosion treatment liquid prepared by the preparation method according to any one of claims 6 to 17 is used as an online repair liquid for downhole pipes in oil production.

19. The use according to claim 18, characterized in that The application comprises the following steps: S1. Use pretreatment liquid to pickle the wellbore to be treated: Inject low-concentration acidic liquid into the tubing and / or the annulus of the casing in a forward or reverse manner, and let it react for at least 30 minutes. After the reaction is complete, backwash the well with water. When the water quality at the inlet and outlet is consistent, the backwashing of the well is terminated, wherein: The water discharge capacity is at least 500L / min; S2, replace the anti-corrosion treatment liquid: S21. Calculate the amount of anti-corrosion treatment fluid When the anti-corrosion treatment fluid is used to repair the inner wall of the oil pipe, the volume of the anti-corrosion treatment fluid required for the inner wall of the oil pipe is V1 = the length of the oil pipe to be repaired × 3.14 × the inner radius of the oil pipe 2 , unit is m 3 ; When the anti-corrosion treatment liquid is used for the outer wall of the oil pipe or the inner wall of the casing, the volume of the anti-corrosion treatment liquid V2 required for the repair of the outer wall of the oil pipe or the inner wall of the casing = the length of the oil pipe to be repaired × (3.14 × the inner radius of the casing 2 -3.14×outer radius of the tubing 2 ), unit is m 3 ; S22, replace the anti-corrosion treatment liquid with the amount of anti-corrosion treatment liquid obtained in step S21, shut down the well for reaction for at least 24 hours, and the oil pipe repair is completed; backwash the well for at least 2 weeks, and then normal water injection can be performed.

20. The use according to claim 19, characterized in that The acidic liquid in step S1 consists of the following components: 5% to 10% of acidic substances, 1% to 5% of corrosion inhibitors, 1% to 5% of non-ionic surfactants, and the balance is water.

21. The use according to claim 20, characterized in that The acidic substance is one or more of hydrochloric acid, citric acid and malic acid.

22. The use according to claim 20, characterized in that The nonionic surfactant is one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide and polyether.

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