Slow-release, scale-inhibiting and corrosion-preventing multifunctional integrated agent as well as preparation method and application thereof

Abstract

The invention discloses a slow-release, scale-inhibition and corrosion-prevention multifunctional integrated agent and a preparation method and application thereof.The structural formula of the slow-release, scale-inhibition and corrosion-prevention multifunctional integrated agent is # imgabs0 #. Aromatic rings and N and O heteroatoms with air-pair electrons are introduced into molecules, so that the interaction between the molecules and the metal surface is enhanced, the corrosion inhibition performance of a product is improved, and the corrosion resistance of the product is improved; the introduction of a sulfonic acid group further improves the corrosion inhibition and temperature resistance; hydroxyl, phosphonic acid or sulfonic acid and other hydrophilic groups can well prevent chelation of metal ions and inhibit formation of scales. Meanwhile, the quaternary ammonium salt has a certain bactericidal effect, and after the medicament with the integrated function is made into a solid product, long-term effective anti-corrosion and anti-scaling effects can be provided.

Description

Technical Field

[0001] The present invention belongs to the field of oilfield application chemicals, and specifically relates to a slow-release scale and corrosion inhibitor with multifunctional integration, a preparation method thereof, and an application thereof. Background Art

[0002] At present, most oilfields at home and abroad have gradually entered the middle and late development stages with high water cut. Usually, injection water, CO 2 and other methods are used to supplement formation energy to achieve the purpose of improving the recovery rate. However, with the continuous increase in the injection volume of water, the problems such as unqualified injection water quality and the increase in the service life of pipelines exist. The scale formation phenomenon inside the injection wells becomes more and more serious. In addition, during the process of CO 2 flooding, part of the CO 2 will enter and dissolve in the formation water, forming precipitates with metal cations such as Ca 2+ , Mg 2+ in the water. At the same time, the dissolved CO 2 has extremely high corrosiveness. Especially under high temperature and high pressure conditions, it is easy to cause serious corrosion inside the wellbore pipe wall, resulting in a decrease in the pipeline flow cross-section and blocking the tubing, generating potential production safety hazards. At present, scale formation and corrosion generally exist in all aspects of oil and gas development, with great harm and increasing occurrence frequency. It has become a chronic problem affecting domestic oil and gas development and normal production. Therefore, anti-scale and anti-corrosion of pipelines are of great significance.

[0003] In the chemical industry, although the scale and corrosion inhibitors are widely used because of the methods with low cost, strong practicability, convenient operation and simple process, there are also certain deficiencies, such as being easily carried away by the water flow, resulting in unsatisfactory corrosion inhibition or scale inhibition efficiency. Therefore, it is imperative to research and develop new long-acting scale and corrosion inhibitors, but at the same time, it also faces great challenges, such as the need to consider factors such as high efficiency and cost.

[0004] The prior art, such as the invention patent with the publication (announcement) number: CN113403052A, provides an anti-corrosion and scale inhibitor slow-release granule for oil wells and a preparation method thereof. The raw material components of the anti-corrosion and scale inhibitor slow-release granule for oil wells include an adsorbent, a composite scale inhibitor and a curing agent. After the high-purity scale and corrosion inhibitor liquid is adsorbed and wrapped with the curing agent polyvinyl alcohol, it can be mixed with proppant sand and added to the oil well without adding additional dosing procedures. It utilizes the adsorption principle of molecular sieve to fully absorb the scale and corrosion inhibitor. After being wrapped, it is carried into the formation with the proppant sand, thereby solving the scale formation and corrosion phenomena in the pipeline. The preparation method provided by the invention can achieve the purpose of slow release, but still needs to compound a variety of existing agents to achieve the purpose of corrosion inhibition and scale inhibition. Summary of the Invention

[0005] To solve the problems in the prior art such as poor compatibility of corrosion inhibitors and scale inhibitors, resulting in low anti-corrosion and anti-scale efficiency and the need to improve the service life, the present invention provides a slow-release scale and corrosion inhibitor multifunctional agent, its preparation method and application, aiming to achieve multiple effects with one agent while also achieving the purpose of slow drug release, effectively reducing the problem of poor compatibility of multiple drugs.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] The present invention first discloses a slow-release scale and corrosion inhibitor multifunctional agent, and its structural formula is:

[0008]

[0009] Wherein R 1 is a straight-chain or branched-chain alkyl chain, aromatic group, cycloalkyl group or straight-chain amino group;

[0010] R 2 is a sulfonic acid group or a phosphonic acid group;

[0011] R 2 ′ is a sulfonic acid group or a phosphonic acid group;

[0012] R3 is an alkyl group, a hydroxyl group or an alkoxy group.

[0013] As a preferred scheme, the slow-release scale and corrosion inhibitor multifunctional agent includes a halogenated hydrocarbon derivative, 4-dimethylaminopyridine, a halogenated salt and intermediate I. The mass ratio of the halogenated hydrocarbon derivative to 4-dimethylaminopyridine is (5-8):1, and the mass ratio of the halogenated salt to 4-dimethylaminopyridine is (0.8-1):(0.8-1). Moreover, the total mass of the halogenated salt and 4-dimethylaminopyridine accounts for 0.06%-0.08% of the total mass of the halogenated hydrocarbon derivative and intermediate I.

[0014] A further preferred scheme is that the intermediate I is prepared by mixing diamine, pyridyl-substituted ketone and formaldehyde according to the mass ratio of (0.8-1):(2.1-2.5):(1.2-1.5).

[0015] As another preferred scheme of the present invention, the preparation method of the intermediate I is as follows: Take diamine and pyridyl-substituted ketone according to the ratio of (0.8-1):(2.1-2.5), add a certain amount of solvent, stir until evenly mixed, adjust the pH value of the system to 2-4, add Lewis acid as a catalyst, then add formaldehyde solution, and react at a temperature of 80-85°C for 6-8 hours. After the reaction is completed, spin-dry the solvent to obtain intermediate I.

[0016] Preferably, the mass of the Lewis acid is 0.06%-0.08% of the total mass of diamine, pyridyl-substituted ketone and formaldehyde.

[0017] Preferably, the halogenated hydrocarbon derivative is any one of sodium 3-chloro-2-hydroxypropanesulfonate, sodium 3-chloro-2-hydroxypropyl phosphate, and sodium 3-bromopropanesulfonate;

[0018] Preferably, the halogenated salt is any one of sodium iodide and potassium iodide.

[0019] Preferably, the diamine is any one of 1,3-propanediamine, 1,2-propanediamine, 1,6-hexanediamine, 1,8-octanediamine, 2,2-dimethyl-1,3-propanediamine, 1,4-benzenedimethanamine, 1,4-cyclohexanebis(methylamine), and o-xylenediamine.

[0020] Preferably, the pyridyl-substituted ketone is any one of 1-(3-methyl-2-pyridyl)ethanone, 1-(3-methoxy-2-pyridyl)ethanone, and 1-(3-ethyl-2-pyridyl)ethanone.

[0021] Preferably, the Lewis acid is one of aluminum chloride and aluminum p-aminobenzenesulfonate.

[0022] The present invention further discloses a preparation method of a slow-release scale and corrosion inhibitor multifunctional agent, comprising the following steps:

[0023] S1. Preparation of intermediate product I

[0024] First, place the diamine, pyridyl-substituted ketone, and solvent in a reaction vessel, stir until evenly mixed, then adjust the pH value of the system to 2-4, then add Lewis acid as a catalyst, and then add formaldehyde solution, and react at a temperature of 80-85 °C for 6-8 h. After the reaction is completed, spin-dry the solvent to obtain intermediate product I;

[0025] Wherein, the mass ratio of the diamine, pyridyl-substituted ketone, and formaldehyde is (0.8-1):(2.1-2.5):(1.2-1.5), and the mass of the Lewis acid is 0.06%-0.08% of the total mass of the diamine, pyridyl-substituted ketone, and formaldehyde;

[0026] S2. Preparation of the powdery multifunctional agent

[0027] First, place the halogenated hydrocarbon derivative, intermediate product I, 4-dimethylaminopyridine, halogenated salt, and solvent in a reaction vessel, stir until evenly mixed, then pass nitrogen into the solution until the air in the container is exhausted, and finally react at a temperature of 85-90 °C for 48-50 h. After the reaction is completed, spin-dry the solvent and recrystallize to obtain the powdery multifunctional agent;

[0028] Among them, the mass ratio of the halogenated hydrocarbon derivative to 4-dimethylaminopyridine is (5-8):1, the mass ratio of the halogenated salt to 4-dimethylaminopyridine is (0.8-1):(0.8-1), and the total mass of the halogenated salt and 4-dimethylaminopyridine accounts for 0.06%-0.08% of the total mass of the halogenated hydrocarbon derivative and intermediate I.

[0029] As a further preferred embodiment, in step S1, the formaldehyde solution is slowly added dropwise at a rate of 2-3 drops per second.

[0030] The present invention further discloses the application of any one of the above-mentioned slow-release scale and corrosion inhibitor multifunctional agents or the slow-release scale and corrosion inhibitor multifunctional agent prepared by the above-mentioned preparation method in oil and gas exploitation. Preferably, the application method is to add auxiliary materials to the powdery multifunctional agent to prepare a medicament, which is applied to the anti-corrosion and scale inhibition of pipelines in the process of oilfield produced fluid.

[0031] As a further preferred embodiment, the preparation method of the medicament is as follows:

[0032] At 95-100°C, melt polyvinyl alcohol and then successively add deionized water, sodium alginate, and the powdery multifunctional agent, stir until evenly mixed, and then cast and cool to room temperature to form a mold, thus obtaining the medicament for anti-corrosion and scale inhibition of oilfield pipelines; in this preparation method, the mass ratio of polyvinyl alcohol, deionized water, sodium alginate, and the powdery multifunctional agent is (65-85):(5-8):(5-10):(5-20).

[0033] The reaction mechanism of the present invention is as follows:

[0034] First, a ketone containing active α-hydrogen reacts with an amine and another aldehyde through a condensation reaction to form an α-position alkylated intermediate, and then the intermediate undergoes a nucleophilic substitution and quaternization reaction with a halogenated hydrocarbon derivative under the action of a catalyst to form a final product.

[0035] Adopting the above technical solutions, the present invention has the following beneficial effects:

[0036] 1. Through molecular design, the present invention introduces functional groups such as hydroxyl, phosphoric acid or sulfonic acid groups into the structure, which can chelate and solubilize scale-forming ions, enabling scale crystals to be better dispersed in water; at the same time, the molecule can interact with metals through functional groups such as N and O heteroatoms and aromatic rings, firmly adsorb on the surface of metal substances to form a dense hydrophobic film, thereby preventing direct corrosion of the metal surface by corrosive media. In addition, sulfonic acid groups or aromatic ring groups have good temperature resistance, so under high-temperature conditions, the medicament (i.e., the slow-release scale and corrosion inhibitor multifunctional agent) can still provide good anti-corrosion effects, and the introduction of quaternary ammonium salts also endows the medicament with bactericidal effects, further reducing bacterial corrosion or scale formation caused by bacteria.

[0037] 2. Sodium alginate and polyvinyl alcohol are excellent drug sustained-release carriers. Therefore, after the slow-release scale and corrosion inhibitor multifunctional agent is compounded with them, it can play a role in slow release and achieve the purpose of long-term use.

[0038] 3. The raw materials used in the present invention are easily available and can be directly purchased on the market. The preparation method can be completed by using conventional synthesis equipment, which can effectively reduce the cost of the product; and each step of the preparation method is simple to operate and suitable for large-scale industrial production.

[0039] The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the content of the specification, the following takes the preferred embodiments of the present invention and combines the accompanying drawings to describe in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other design solutions and accompanying drawings can be obtained based on these drawings.

[0041] Figure 1 It is the infrared spectrum diagram of the slow-release scale and corrosion inhibitor multifunctional agent L1.

[0042] Figure 2 It is the change curve of the corrosion inhibition rate of the slow-release scale and corrosion inhibitor multifunctional agent L2.

[0043] Figure 3 It is the curve of the release rate of the slow-release scale and corrosion inhibitor multifunctional agent L1 changing with time after casting.

[0044] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The content of the present invention can be further understood by combining the following detailed description of the preferred implementation methods of the present invention and the included embodiments. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. If the definitions of specific terms disclosed in the prior art are inconsistent with any definitions provided in the present invention, the definitions provided in the present invention shall prevail.

[0046] In a typical implementation manner of the present application, a slow-release scale and corrosion inhibitor multifunctional agent is provided, and its structural formula is:

[0047]

[0048] wherein R 1 is a straight-chain or branched alkyl chain, aryl group, cycloalkyl group or straight-chain amino group;

[0049] R 2 is a sulfonic acid group or a phosphonic acid group;

[0050] R 2 ' is a sulfonic acid group or a phosphonic acid group;

[0051] R3 is an alkyl group, a hydroxyl group or an alkoxy group.

[0052] In a preferred embodiment, the slow-release scale and corrosion inhibitor multifunctional agent includes a halogenated hydrocarbon derivative, 4-dimethylaminopyridine, a halogenated salt and intermediate I. The mass ratio of the halogenated hydrocarbon derivative to 4-dimethylaminopyridine is (5-8):1, the mass ratio of the halogenated salt to 4-dimethylaminopyridine is (0.8-1):(0.8-1), and the total mass of the halogenated salt and 4-dimethylaminopyridine accounts for 0.06%-0.08% of the total mass of the halogenated hydrocarbon derivative and intermediate I.

[0053] Preferably, the halogenated hydrocarbon derivative is any one of sodium 3-chloro-2-hydroxypropanesulfonate, sodium 3-chloro-2-hydroxypropylphosphate, sodium 3-bromopropanesulfonate;

[0054] Preferably, the halogenated salt is any one of sodium iodide and potassium iodide.

[0055] In a preferred embodiment, intermediate I is prepared from diamine, pyridyl-substituted ketone and formaldehyde in a mass ratio of (0.8-1):(2.1-2.5):(1.2-1.5).

[0056] In another preferred embodiment, the preparation method of intermediate I is as follows: Take diamine and pyridyl-substituted ketone in a mass ratio of (0.8-1):(2.1-2.5), add a solvent, stir until evenly mixed, adjust the pH value of the system to 2-4, add a Lewis acid as a catalyst, and then slowly dropwise add a formaldehyde solution at a dropping rate of 2-3 drops / second. React at a temperature of 80-85°C for 6-8h. After the reaction is completed, spin-dry the solvent to obtain intermediate I. Preferably, the mass of the Lewis acid is 0.06%-0.08% of the total mass of diamine, pyridyl-substituted ketone and formaldehyde.

[0057] Preferably, the diamine is any one of 1,3-propanediamine, 1,2-propanediamine, 1,6-hexanediamine, 1,8-octanediamine, 2,2-dimethyl-1,3-propanediamine, 1,4-benzenedimethanamine, 1,4-cyclohexanebis(methylamine), o-xylenediamine.

[0058] Preferably, the pyridyl-substituted ketone is any one of 1-(3-methyl-2-pyridyl)ethanone, 1-(3-methoxy-2-pyridyl)ethanone, and 1-(3-ethyl-2-pyridyl)ethanone.

[0059] Preferably, the Lewis acid is one of aluminum chloride and aluminum p-aminobenzenesulfonate.

[0060] Through molecular design, functional groups such as hydroxyl, phosphoric acid, or sulfonic acid groups are introduced into the structure of the present invention, which can chelate and solubilize scale-forming ions, enabling scale crystals to be better dispersed in water; at the same time, the molecule can interact with metals through functional groups such as N and O heteroatoms and aromatic rings, firmly adsorb on the surface of metal substances to form a dense hydrophobic film, thereby preventing direct corrosion of the metal surface by corrosive media. In addition, sulfonic acid groups or aromatic ring groups have good temperature resistance. Therefore, under high-temperature conditions, this agent can still provide good anti-corrosion effects, and the introduction of quaternary ammonium salts also enables this agent to have a bactericidal effect, further reducing bacterial corrosion or scale formation caused by bacteria.

[0061] In the second typical embodiment of the present invention, a preparation method of a slow-release scale and corrosion inhibitor multifunctional agent is provided, including the following steps:

[0062] S1. Prepare intermediate product I

[0063] First, place diamine, pyridyl-substituted ketone, and a solvent in a reaction vessel, stir magnetically until evenly mixed, then adjust the pH value of the system to 2-4, then add Lewis acid as a catalyst, and then add formaldehyde solution, and react at a temperature of 80-85°C for 6-8 hours. After the reaction is completed, spin-dry the solvent to obtain intermediate product I;

[0064] Among them, the mass ratio of diamine, pyridyl-substituted ketone, and formaldehyde is (0.8-1):(2.1-2.5):(1.2-1.5), and the mass of Lewis acid is 0.06%-0.08% of the total mass of diamine, pyridyl-substituted ketone, and formaldehyde;

[0065] S2. Prepare the powdery multifunctional agent

[0066] First, place the halogenated hydrocarbon derivative, intermediate product I, 4-dimethylaminopyridine, halogenated salt, and a solvent in a reaction vessel, stir magnetically until evenly mixed, then pass nitrogen into the solution until the air in the container is exhausted, and finally react at a temperature of 85-90°C for 48-50 hours. After the reaction is completed, spin-dry the solvent and recrystallize to obtain the powdery multifunctional agent;

[0067] The mass ratio of the halogenated hydrocarbon derivative to 4-dimethylaminopyridine is (5-8):1, the mass ratio of the halogenated salt to 4-dimethylaminopyridine is (0.8-1):(0.8-1), and the total mass of the halogenated salt and 4-dimethylaminopyridine accounts for 0.06% to 0.08% of the total mass of the halogenated hydrocarbon derivative and the intermediate product I.

[0068] In a further preferred embodiment, in step S1, the formaldehyde solution is slowly added at a rate of 2 to 3 drops per second.

[0069] In a third typical embodiment of the present invention, the present invention further discloses the use of any of the above-mentioned slow-release anti-scaling and anti-corrosion multifunctional integrated agents or the slow-release anti-scaling and anti-corrosion multifunctional integrated agents prepared by the above-mentioned preparation method in oil and gas production. The preferred application method is to add auxiliary materials to the powdered multifunctional integrated agent to prepare a medicine, and apply it to the anti-corrosion and anti-scaling of pipelines in the process of oilfield production fluid.

[0070] In a preferred embodiment, the preparation method of the medicament is:

[0071] At 95-100°C, melt polyvinyl alcohol and add deionized water, sodium alginate and powdered multifunctional agent in sequence, stir magnetically until the mixture is evenly mixed, and then cool the mold to room temperature to form an anti-corrosion and anti-scaling agent for oilfield pipelines. It is worth mentioning that the agent can be made into flakes, particles or rods according to needs. In the preparation method, as a preferred method, the mass ratio of polyvinyl alcohol, deionized water, sodium alginate and powdered multifunctional agent is (65-85): (5-8): (5-10): (5-20).

[0072] Sodium alginate and polyvinyl alcohol are excellent drug sustained-release carriers, so the powdered multifunctional all-in-one agent can be slowly released after being compounded with them to achieve the purpose of long-term use.

[0073] The present invention is further described below in conjunction with the embodiments:

[0074] In the following examples, the data are obtained from laboratory-prepared pharmaceutical tests. The main reagents used are as follows:

[0075] Diamine (analytical grade, Aladdin reagent);

[0076] Pyridyl substituted ketone (analytical grade, Aladdin reagent);

[0077] Formaldehyde solution (36%wt, analytical grade, Aladdin reagent);

[0078] Hydrochloric acid (36%wt, analytical grade, Chengdu Kelong Chemical Reagent);

[0079] Halogenated hydrocarbon derivatives (analytical grade, Aladdin reagent);

[0080] Lewis acid (analytical grade, Aladdin reagent);

[0081] 4-Dimethylaminopyridine (analytical grade, Aladdin reagent);

[0082] Halide salt (analytical grade, Aladdin reagent);

[0083] Polyvinyl alcohol (molecular weight 80000-98000, analytical grade, Chengdu Kelong Chemical Reagent);

[0084] Sodium alginate (analytical grade, Chengdu Kelong Chemical Reagent).

[0085] To facilitate the description of this scheme, in the following embodiments, 1,3-propylenediamine, 1,4-phenylenediamine, and 1,4-cyclohexanebis(methylamine) are used as examples of diamines; 1-(3-methyl-2-pyridyl)ethanone and 1-(3-ethyl-2-pyridyl)ethanone are used as examples of pyridyl substituted ketones; 3-chloro-2-hydroxypropane sodium phosphate and 3-chloro-2-hydroxypropane sodium sulfonate are used as examples of halogenated hydrocarbon derivatives; sodium iodide is used as an example of a halide salt; and AlCl is used as an example of a Lewis acid. 3 Take ethanol as an example, and further explain this scheme.

[0086] In this scheme, the preparation method of the slow-release scale inhibition and anticorrosion multifunctional integrated agent specifically includes the following steps:

[0087] S1: Place diamine, pyridyl substituted ketone and ethanol in a container, stir until uniformly mixed, adjust the pH of the system to 2-4 with hydrochloric acid, add Lewis acid as a catalyst, and then slowly add formaldehyde solution at a drop rate of 2-3 drops / second, react at 80-85℃ for 6-8h, and spin dry the solvent after the reaction to obtain intermediate product I;

[0088] S2: Place the halogenated hydrocarbon derivative, intermediate product I, 4-dimethylaminopyridine, halogenated salt and ethanol in a container, stir until uniformly mixed, introduce nitrogen into the solution to exhaust air for 10 to 20 minutes, react at 85 to 90°C for 48 to 50 hours, and after the reaction, spin dry the solvent and recrystallize to obtain a powdered multifunctional all-in-one agent.

[0089] S3: After the polyvinyl alcohol is melted at 95-100°C, deionized water, sodium alginate and powdered multifunctional agent are added in sequence, stirred until the mixture is evenly mixed, and then the mold is cooled to room temperature to form the medicine.

[0090] Example 1

[0091] The raw materials and raw material components for preparing the multifunctional all-in-one slow-release scale and corrosion inhibitor in this embodiment are shown in Table 1, and the multifunctional all-in-one slow-release scale and corrosion inhibitor L1 is obtained.

[0092] Table 1​

[0093]

[0094] Example 2

[0095] The raw materials and their components for preparing the slow-release scale and corrosion inhibitor multifunctional agent in this example are shown in Table 2 below, and the slow-release scale and corrosion inhibitor multifunctional agent L2 is obtained.

[0096] Table 2

[0097]

[0098] Example 3

[0099] The raw materials and their components for preparing the slow-release scale and corrosion inhibitor multifunctional agent in this example are shown in Table 3 below, and the slow-release scale and corrosion inhibitor multifunctional agent L3 is obtained.

[0100] Table 3

[0101]

[0102] Example 4

[0103] The raw materials and their components for preparing the slow-release scale and corrosion inhibitor multifunctional agent in this example are shown in Table 4 below, and the slow-release scale and corrosion inhibitor multifunctional agent L4 is obtained.

[0104] Table 4

[0105]

[0106] Example 5

[0107] The raw materials and their components for preparing the slow-release scale and corrosion inhibitor multifunctional agent in this example are shown in Table 5 below, and the slow-release scale and corrosion inhibitor multifunctional agent L5 is obtained.

[0108] Table 5

[0109]

[0110]

[0111] Example 6

[0112] The raw materials and their components for preparing the slow-release scale and corrosion inhibitor multifunctional agent in this example are shown in Table 6 below, and the slow-release scale and corrosion inhibitor multifunctional agent L6 is obtained.

[0113] Table 6

[0114]

[0115] Example 7

[0116] The raw materials and their components for preparing the slow-release scale and corrosion inhibitor multifunctional agent in this example are shown in Table 7 below, and the slow-release scale and corrosion inhibitor multifunctional agent L7 is obtained.

[0117] Table 7

[0118]

[0119]

[0120] The infrared spectrum of the slow-release scale and corrosion inhibitor multifunctional agent L1 prepared in Example 1 is as Figure 1 shown. Referring to Figure 1 , the 3500 cm -1 in the spectrum is the characteristic signal peak of -OH in the molecule, the 2800 - 2900 cm -1 is the C-H characteristic peak in methyl and methylene, the 1680 cm -1 is the C=O characteristic peak. At the same time, the characteristic peak of the absorption band on the aromatic ring appears at 2000 - 1700 cm -1 , and the characteristic peaks of the sulfonic acid functional group appear at 1200, 1060, 650, 500 cm -1 . The characteristic signal peaks of the above functional groups indicate that the designed molecule has been successfully prepared.

[0121] The corrosion inhibition rate change curve of the slow-release scale and corrosion inhibitor multifunctional agent L2 prepared in Example 2 is as Figure 2 shown. The performance of the corrosion inhibitor is evaluated according to the method in the Petroleum and Natural Gas Industry Standard of the People's Republic of China (SY / T5273 - 2014). Among them, the corrosion medium is a saturated CO 2 solution of 3% NaCl.

[0122] It can be seen from Figure 2 that the prepared drug still has good protection effect on metals at 90 °C, and the corrosion inhibition rate can reach about 95%. The corrosion inhibition rate varies with the change of functional groups. In Example 2, R 1 is the aromatic ring functional group, which has large π electrons and can interact with the empty orbit of Fe on the metal surface. Therefore, it is easier to adsorb on the metal surface than methylene in Example 3, providing better protection. In Example 5, R 3 is the methoxy functional group, and the O heteroatom can also interact with the empty orbit of Fe. At the same time, in Examples 2 and 5, R 2 is the sulfonic acid group functional group, which also provides good temperature resistance.

[0123] The release rate change curve of the slow-release scale and corrosion inhibitor multifunctional agent after casting L1 in Example 1 is as Figure 3 shown. It can be seen from Figure 3It can be seen that the drug release time reaches 25 days at 30°C, and there is still a release time of 15 days at 60°C. The shorter release time at 90°C is mainly because PVA dissolves faster at 90°C, indicating that the use time of the drug can be effectively delayed and extended by changing the drug ratio and temperature.

[0124] The composition of the test water sample and the scale inhibition performance data of the slow-release scale and corrosion inhibitor multifunctional integrated agent product in Example 3 are shown in Table 8. The scale inhibition performance was evaluated according to the method in the Petroleum and Natural Gas Industry Standard of the People's Republic of China (SY / T5673-2020). The water sample is the produced water from the oilfield. The scale inhibition efficiency of this agent against calcium carbonate reaches 93.2%, which can effectively inhibit the formation of scale.

[0125] Table 8 shows the on-site water quality table (mg / L) and scale inhibition data

[0126]

[0127] Through molecular structure design, aromatic rings and N and O heteroatoms with lone pairs of electrons are introduced into the molecule in the present invention, which enhances the interaction between the molecule and the metal surface and improves the corrosion inhibition performance of the product. The introduction of sulfonic acid groups further improves the corrosion inhibition and temperature resistance; hydrophilic groups such as hydroxyl, phosphonic acid or sulfonic acid can effectively prevent the chelation of metal ions and inhibit the formation of scale; at the same time, quaternary ammonium salts have a certain bactericidal effect. After making this functional integrated agent into a solid product, it can provide long-term and effective anti-corrosion and anti-scaling effects. This agent is obtained through two-step reactions and has the value of potential industrial production.

[0128] The above are only the preferred embodiments of the present invention, which are illustrative of the present invention rather than limiting the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A multifunctional all-in-one slow-release scale and corrosion inhibitor, characterized in that: The structural formula of the slow-release scale-inhibiting and anti-corrosion multifunctional integrated agent is: Wherein R1 is a straight or branched alkyl chain, an aromatic group, a cycloalkyl group or a straight chain amine group; R2 is a sulfonic acid group or a phosphonic acid group; R2′ is a sulfonic acid group or a phosphonic acid group; R3 is an alkyl group, a hydroxy group or an alkoxy group.

2. The multifunctional all-in-one slow-release scale and corrosion inhibitor according to claim 1, characterized in that: The slow-release scale inhibition and anticorrosion multifunctional integrated agent comprises a halogenated hydrocarbon derivative, 4-dimethylaminopyridine, a halogenated salt and an intermediate product I, wherein the mass ratio of the halogenated hydrocarbon derivative to 4-dimethylaminopyridine is (5-8):1, the mass ratio of the halogenated salt to 4-dimethylaminopyridine is (0.8-1):(0.8-1), and the total mass of the halogenated salt and 4-dimethylaminopyridine accounts for 0.06% to 0.08% of the total mass of the halogenated hydrocarbon derivative and the intermediate product I; The intermediate product I is prepared from diamine, pyridyl substituted ketone and formaldehyde in a mass ratio of (0.8-1): (2.1-2.5): (1.2-1.5).

3. The multifunctional all-in-one slow-release scale and corrosion inhibitor according to claim 2, characterized in that: The preparation method of the intermediate product I is as follows: taking diamine and pyridyl substituted ketone according to a ratio, adding a solvent, stirring until the mixture is uniform, adjusting the pH value of the system to 2-4, adding Lewis acid as a catalyst, and then adding formaldehyde solution, reacting at a temperature of 80-85° C. for 6-8 hours, and after the reaction is completed, drying the solvent to obtain the intermediate product I.

4. The multifunctional all-in-one slow-release scale and corrosion inhibitor according to claim 3, characterized in that: The mass of the Lewis acid is 0.06% to 0.08% of the total mass of the diamine, the pyridyl substituted ketone and the formaldehyde.

5. The multifunctional all-in-one slow-release scale and corrosion inhibitor according to claim 2, characterized in that: The halogenated hydrocarbon derivative is any one of sodium 3-chloro-2-hydroxypropanesulfonate, sodium 3-chloro-2-hydroxypropanephosphate, and sodium 3-bromopropanesulfonate; The halide salt is any one of sodium iodide and potassium iodide.

6. The multifunctional all-in-one slow-release scale and corrosion inhibitor according to claim 2 or 3, characterized in that: The diamine is any one of 1,3-propylenediamine, 1,2-propylenediamine, 1,6-hexanediamine, 1,8-octanediamine, 2,2-dimethyl-1,3-propylenediamine, 1,4-phenylenediamine, 1,4-cyclohexanebis(methylamine), and o-xylylenediamine; The pyridyl-substituted ketone is any one of 1-(3-methyl-2-pyridyl)ethanone, 1-(3-methoxy-2-pyridyl)ethanone, and 1-(3-ethyl-2-pyridyl)ethanone; The Lewis acid is one of aluminum chloride and aluminum p-aminobenzenesulfonate.

7. A method for preparing a multifunctional all-in-one slow-release scale and corrosion inhibitor, characterized in that: The following steps are involved: S1. Preparation of intermediate product I Firstly, a diamine, a pyridyl substituted ketone and a solvent are placed in a reaction container, stirred until uniformly mixed, and then the pH value of the system is adjusted to 2-4, and then Lewis acid is added as a catalyst, and then a formaldehyde solution is added, and the reaction is carried out at a temperature of 80-85°C for 6-8h. After the reaction is completed, the solvent is dried by spin drying to obtain an intermediate product I; The mass ratio of the diamine, the pyridyl substituted ketone and the formaldehyde is (0.8-1): (2.1-2.5): (1.2-1.5), and the mass of the Lewis acid is 0.06%-0.08% of the total mass of the diamine, the pyridyl substituted ketone and the formaldehyde; S2. Preparation of powdered multifunctional all-in-one agent First, a halogenated hydrocarbon derivative, an intermediate product I, 4-dimethylaminopyridine, a halogenated salt and a solvent are placed in a reaction container, stirred until the mixture is uniformly mixed, and then nitrogen is introduced into the solution until the air in the container is exhausted, and finally the mixture is reacted at a temperature of 85 to 90° C. for 48 to 50 hours. After the reaction is completed, the solvent is dried and recrystallized to obtain a powdered multifunctional all-in-one agent; Among them, the mass ratio of the halogenated hydrocarbon derivative and 4-dimethylaminopyridine is (5-8):1, the mass ratio of the halide salt and 4-dimethylaminopyridine is (0.8-1):(0.8-1), and the total mass of the halide salt and 4-dimethylaminopyridine accounts for 0.06% to 0.08% of the total mass of the halogenated hydrocarbon derivative and the intermediate product I.

8. The method for preparing the slow-release scale inhibition and anticorrosion multifunctional integrated agent according to claim 1, characterized in that: In the step S1, the formaldehyde solution is slowly added dropwise at a speed of 2 to 3 drops per second.

9. Use of the multifunctional all-in-one slow-release scale and corrosion inhibitor according to any one of claims 1 to 6 or the multifunctional all-in-one slow-release scale and corrosion inhibitor prepared by the preparation method according to any one of claims 7 to 8 in oil and gas production, characterized in that: The powdered multifunctional all-in-one agent is added with auxiliary materials to form a medicine, which is used for corrosion and scale prevention of pipelines in the process of oil field production.

10. The use of the slow-release scale and corrosion inhibitor multifunctional all-in-one agent as claimed in claim 9, characterized in that: The preparation method of the medicament is: At 95-100°C, after the polyvinyl alcohol is melted, deionized water, sodium alginate and powdered multifunctional agent are added in sequence, stirred until the mixture is uniform, and then the mold is cooled to room temperature to form a corrosion and scale inhibitor for oil field pipelines. The mass ratio of polyvinyl alcohol, deionized water, sodium alginate and powdered multifunctional all-in-one agent is (65-85):(5-8):(5-10):(5-20).

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