Corrosion and scale inhibitor and preparation method thereof

Abstract

The invention discloses a corrosion and scale inhibitor and a preparation method thereof, and belongs to the technical field of oilfield chemical industry. The corrosion and scale inhibitor has the following structural general formula: # imgabs0 #, and in the formula, x, y and n are respectively any integer in the range of 1-10. The invention also provides a preparation method of the corrosion and scale inhibitor, which comprises the following steps: dissolving aconitic acid in water, then adding sodium p-styrenesulfonate and 3-aminopyrazole, dissolving, then heating to 65-85 DEG C, and continuing to add the initiator for reaction to obtain the corrosion and scale inhibitor. The corrosion and scale inhibitor provided by the invention has excellent corrosion and scale inhibition performance.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield chemical industry, and in particular to a corrosion and scale inhibitor and a preparation method thereof. Background Art

[0002] Reinjection of produced water from oil fields is an important way to develop oil fields with water drive. Simply treating the produced wastewater and then reinjecting it into the formation not only reduces environmental pollution but also saves fresh water resources. It is an important way to improve the economic benefits of oil fields and ensure the sustainable development of oil fields. Although this can significantly increase the recovery rate of crude oil, it also makes the fluid components more complex, which is easy to cause equipment scaling and corrosion problems, resulting in serious economic losses and even production suspension. In most areas of oil fields, produced fluids have a serious scaling tendency, which can cause under-scale corrosion and even pipeline perforation.

[0003] At present, the method to solve the problem of corrosion and scaling in the oil field production process is mainly to add chemical agents such as corrosion inhibitors and scale inhibitors. Due to the large differences in water quality and working conditions in different blocks, in some harsh environments such as high temperature, high salt, and high CO2, a single scale inhibitor or corrosion inhibitor is difficult to effectively inhibit the scaling and corrosion of oil pipes. Therefore, different types of corrosion inhibitors and scale inhibitors need to be compounded for use. However, the problem with compound use is that the physical and chemical properties of different chemical agents are quite different. The injection of scale inhibitors and corrosion inhibitors at the same time may cause incompatibility between the two and cause the problem of reagent failure. Adding them in batches will make the injection process cumbersome. Therefore, the "anti-scaling + anti-corrosion" integrated inhibitor has significant advantages, but how to obtain corrosion inhibitors and scale inhibitors with excellent corrosion and scale inhibition performance is a problem that the existing technology needs to solve. Summary of the invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies, provide a corrosion and scale inhibitor and a preparation method thereof, and solve the technical problem of how to obtain a corrosion and scale inhibitor with excellent corrosion and scale inhibition performance in the prior art.

[0005] In order to achieve the above technical purpose, the technical solution of the present invention provides a corrosion and scale inhibitor having the following general structural formula:

[0006]

[0007] Wherein, x, y, and n are any integers between 1 and 10.

[0008] In addition, the present invention also provides a method for preparing a corrosion and scale inhibitor, comprising the following steps:

[0009] Aconitic acid is dissolved in water, then sodium p-styrene sulfonate and 3-aminopyrazole are added and dissolved, then the temperature is raised to 65-85° C., an initiator is continuously added to react to obtain the corrosion and scale inhibitor.

[0010] In any embodiment, dissolving aconitic acid in water comprises: mixing aconitic acid with water, then heating to 50-55° C. and stirring until dissolved.

[0011] In any embodiment, the molar ratio of the aconitic acid to the sodium p-styrene sulfonate is (1-3):1.

[0012] In any embodiment, the molar ratio of the aconitic acid to the 3-aminopyrazole is (1-4):1.

[0013] In any embodiment, the added amount of the initiator is 8%-15% of the total mass of the aconitic acid, the sodium p-styrenesulfonate and the 3-aminopyrazole.

[0014] In any embodiment, the initiator is added continuously for a reaction time of 0.5-2 hours.

[0015] In any embodiment, the initiator is added dropwise, and the time required to complete the dropwise addition is 1-2 hours.

[0016] In any embodiment, the initiator is one or both of ammonium persulfate and ammonium ferrous sulfate.

[0017] In any embodiment, the molar ratio of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole is 4:2:1, the amount of the initiator added is 10% of the total mass of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole, the temperature is raised to 75°C and the initiator is continued to be added at 75°C, and the reaction time is 1.5h.

[0018] Compared with the prior art, the beneficial effects of the present invention include: the preparation method of the corrosion and scale inhibitor proposed by the present invention uses aconitic acid as a polymerization monomer, so that the polymer molecule has a large number of carboxylic acid groups, which are the most important groups for inhibiting the formation of calcium scale. At the same time, the carboxyl group and the adjacent hydroxyl group synergistically enhance the complexation of calcium ions and increase the diffusion and permeability of the molecule; sodium p-styrene sulfonate and 3-aminopyrazole are introduced to make the polymer molecule contain phenyl and nitrogen-containing five-membered heterocyclic rings, which enhances the adsorption capacity of the polymer molecule on the metal surface and forms a protective layer to achieve a good corrosion inhibition effect. In addition, the amide group and phenyl group in the polymer molecule can improve the solubility of the polymer, enhance the stability and durability of the polymer molecule, and thus the obtained corrosion and scale inhibitor has excellent corrosion and scale inhibition performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the infrared spectrum of the corrosion and scale inhibitor prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0020] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0021] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0022] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0023] This specific embodiment provides a corrosion and scale inhibitor having the following general structural formula:

[0024]

[0025] In the formula, x, y, and n are any integers from 1 to 10 respectively.

[0026] The copolymer corrosion and scale inhibitor of the present invention introduces a large number of carboxyl groups, phenyl groups and nitrogen-containing five-membered heterocyclic rings. The large π bond in the phenyl group forms coordination bonds and feedback bonds with the empty d orbital on the metal surface through charge transfer, thereby achieving stable adsorption of the corrosion inhibitor molecules on the metal surface, effectively improving the corrosion inhibition performance. At the same time, the nitrogen-containing heterocyclic ring can be adsorbed on the metal surface and form a stable chelate therewith, forming hydrogen bonds between or within the molecules to form a protective layer to protect the metal from being destroyed by corrosive ions. The five-membered heterocyclic ring structure has multiple adsorption centers and is easy to use, low cost and high efficiency. At the same time, a large number of carboxyl groups can chelate with metal ions to form complexes, which are effective scale inhibition groups and play an important role in scale inhibition.

[0027] This specific embodiment also proposes a method for preparing the above-mentioned corrosion and scale inhibitor, comprising the following steps:

[0028] Aconitic acid is dissolved in water, and then sodium p-styrene sulfonate and 3-aminopyrazole are added and dissolved, and then the temperature is raised to 65-85°C and an initiator is continuously added to react for 0.5-2h to obtain the corrosion and scale inhibitor; the molar ratio of the aconitic acid to the sodium p-styrene sulfonate is (1-3):1; the molar ratio of the aconitic acid to the 3-aminopyrazole is (1-4):1; the amount of the initiator added is 8% to 15% of the total mass of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole; the initiator is one or both of ammonium persulfate and ammonium ferrous sulfate.

[0029] In some embodiments, dissolving aconitic acid in water comprises: mixing aconitic acid with water, then heating to 50-55° C. and stirring until dissolved.

[0030] In some embodiments, the initiator is added dropwise, and the time required to complete the addition is 1-2 hours.

[0031] In some embodiments, the molar ratio of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole is 4:2:1, the amount of the initiator added is 10% of the total mass of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole, the temperature is raised to 75°C and the initiator is continued to be added at 75°C, and the reaction time is 1.5h.

[0032] The present invention adopts a redox initiation system to obtain a terpolymer by free radical copolymerization in aqueous solution. The reaction mechanism involved is:

[0033] During the reaction, the carbon-carbon double bonds of aconitic acid and p-styrenesulfonic acid are broken, and then chain polymerization occurs. Ammonium persulfate and ammonium ferrous sulfate act as initiators and become active centers, which react with the monomers. The amino group in 3-aminopyrazole reacts with the carboxylic acid group in aconitic acid to form an amidation reaction. The reaction formula is as follows:

[0034]

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] In the present invention, reference is made to “some embodiments”, “this embodiment”, examples, etc., which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0037] If similar descriptions of "first / second" appear in the application documents, the following instructions are added. In the following description, the terms "first\second\third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0038] In this embodiment, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, object A and / or object B may represent three situations: object A exists alone, object A and object B exist at the same time, and object B exists alone.

[0039] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0040] Example 1

[0041] This embodiment provides a method for preparing a corrosion inhibitor, comprising the following steps:

[0042] Under air conditions, a certain amount of aconitic acid and pure water were added to the reactor, the temperature was raised to 55°C, sodium p-styrene sulfonate and 3-aminopyrazole were added after stirring at a uniform speed until completely dissolved, the molar ratio of aconitic acid to sodium p-styrene sulfonate was 1:1, and the molar ratio of aconitic acid to 3-aminopyrazole was 1:1. After sodium p-styrene sulfonate and 3-aminopyrazole were completely dissolved, the temperature was raised to 70°C, and the initiator ammonium persulfate was added dropwise at a uniform speed. The addition was completed within 1 hour. The amount of initiator added was 15% of the total mass of aconitic acid, sodium p-styrene sulfonate and 3-aminopyrazole. The reaction temperature was controlled to 70°C, the reaction was carried out for 1 hour, and the reaction was cooled after the reaction was completed to obtain a reaction product solution. The product was purified by dialysis to remove unreacted small molecular monomers, and a polymer corrosion and scale inhibitor was obtained after freeze drying.

[0043] Example 2

[0044] This embodiment provides a method for preparing a corrosion inhibitor, comprising the following steps:

[0045] Under air conditions, a certain amount of aconitic acid and pure water were added to the reactor, the temperature was raised to 55°C, sodium p-styrene sulfonate and 3-aminopyrazole were added after stirring at a uniform speed until completely dissolved, the molar ratio of aconitic acid to sodium p-styrene sulfonate was 2:1, and the molar ratio of aconitic acid to 3-aminopyrazole was 2:1. After sodium p-styrene sulfonate and 3-aminopyrazole were completely dissolved, the temperature was raised to 80°C, and the initiator ammonium ferrous sulfate was added dropwise at a uniform speed. The addition was completed within 1 hour. The amount of initiator added was 12% of the total mass of aconitic acid, sodium p-styrene sulfonate and 3-aminopyrazole. The reaction temperature was controlled to 80°C, the reaction was carried out for 1.5 hours, and the reaction was cooled after the reaction was completed to obtain a reaction product solution. The product was purified by dialysis to remove unreacted small molecular monomers, and a polymer corrosion and scale inhibitor was obtained after freeze drying.

[0046] Example 3

[0047] This embodiment provides a method for preparing a corrosion inhibitor, comprising the following steps:

[0048] Under air conditions, add a certain amount of aconitic acid and pure water to the reactor, raise the temperature to 55°C, stir at a uniform speed until completely dissolved, then add sodium p-styrene sulfonate and 3-aminopyrazole, the molar ratio of aconitic acid to sodium p-styrene sulfonate is 2:1, and the molar ratio of aconitic acid to 3-aminopyrazole is 4:1. After sodium p-styrene sulfonate and 3-aminopyrazole are completely dissolved, raise the temperature to 75°C, uniformly add initiator ammonium ferrous sulfate, and complete the addition within 1 hour. The amount of initiator added is 10% of the total mass of aconitic acid, sodium p-styrene sulfonate and 3-aminopyrazole. Control the reaction temperature to 75°C, react for 1.5 hours, cool after the reaction is completed, and obtain a reaction product solution. The product is purified by dialysis to remove unreacted small molecular monomers, and a polymer corrosion and scale inhibitor is obtained after freeze drying.

[0049] Figure 1 This is the infrared spectrum of the scale inhibitor prepared in this example. Figure 1 Found 3436.8cm -1 、2926.5cm -1 、1732.1cm -1 、1637.6cm -1 、1424.8cm -1 、1123.6cm -1 、1021.5cm -1 、685.2cm -1 and 571.8cm -1 The characteristic absorption peaks of 3436.8cm -1 and 1637.6cm -1 They are the NH stretching vibration absorption peak in the amide group and the stretching vibration absorption peak of C=O. -1 It is the stretching vibration absorption peak of methylene. 1732.1cm -1 and 1123.6cm -1 The vibrations are caused by the stretching vibration peaks of C=O and CO in the carboxylic acid group, 1429.8cm -1 It is the characteristic absorption peak of CN stretching vibration. 685.2cm -1 and 571.8cm -1 The characteristic absorption peak is caused by CS stretching vibration. At the same time, no 1620-1640cm -1 The C=C absorption peak shows that the monomers have been copolymerized to obtain the target product, corrosion inhibitor and scale inhibitor.

[0050] Example 4

[0051] This embodiment provides a method for preparing a corrosion inhibitor, comprising the following steps:

[0052] Under air conditions, add a certain amount of aconitic acid and pure water to the reactor, raise the temperature to 55°C, stir at a uniform speed until completely dissolved, then add sodium p-styrene sulfonate and 3-aminopyrazole, the molar ratio of aconitic acid to sodium p-styrene sulfonate is 2:1, and the molar ratio of aconitic acid to 3-aminopyrazole is 4:1. After sodium p-styrene sulfonate and 3-aminopyrazole are completely dissolved, raise the temperature to 85°C, uniformly add initiator ammonium persulfate, and complete the addition within 1 hour. The amount of initiator added is 8% of the total mass of aconitic acid, sodium p-styrene sulfonate and 3-aminopyrazole. Control the reaction temperature to 85°C, react for 1 hour, cool after the reaction is completed, and obtain a reaction product solution. The product is purified by dialysis to remove unreacted small molecular monomers, and a polymer corrosion and scale inhibitor is obtained after freeze drying.

[0053] Comparative Example 1

[0054] This comparative example proposes a method for preparing a corrosion inhibitor and scale inhibitor, which differs from Example 3 only in that 3-aminopyrazole is not added, and comprises the following steps:

[0055] Under air conditions, add a certain amount of aconitic acid and pure water to the reactor, raise the temperature to 55°C, stir at a uniform speed until completely dissolved, and then add sodium p-styrene sulfonate. The amount of aconitic acid is the same as that in Example 3, and the amount of sodium p-styrene sulfonate is the total amount of sodium p-styrene sulfonate and 3-aminopyrazole in Example 3. After the sodium p-styrene sulfonate is completely dissolved, raise the temperature to 75°C, uniformly add the initiator ammonium ferrous sulfate, and complete the addition within 1 hour. The amount of the initiator added is 10% of the total mass of aconitic acid and sodium p-styrene sulfonate. Control the reaction temperature to 75°C, react for 1.5 hours, and cool after the reaction to obtain a reaction product solution. The product is purified by dialysis to remove unreacted small molecular monomers, and a polymer corrosion inhibitor is obtained after freeze drying.

[0056] Comparative Example 2

[0057] This comparative example proposes a method for preparing a corrosion inhibitor and scale inhibitor, which differs from Example 3 only in that sodium p-styrene sulfonate is not added, and comprises the following steps:

[0058] Under air conditions, add a certain amount of aconitic acid and pure water to the reactor, raise the temperature to 55°C, stir at a uniform speed until completely dissolved, and then add 3-aminopyrazole. The amount of aconitic acid is the same as that in Example 3, and the amount of 3-aminopyrazole is the total amount of sodium p-styrene sulfonate and 3-aminopyrazole in Example 3. After 3-aminopyrazole is completely dissolved, raise the temperature to 75°C, uniformly add the initiator ammonium ferrous sulfate, and complete the addition within 1 hour. The amount of initiator added is 10% of the total mass of aconitic acid and 3-aminopyrazole. Control the reaction temperature to 75°C, react for 1.5 hours, and cool after the reaction to obtain a reaction product solution. The product is purified by dialysis to remove unreacted small molecular monomers, and a polymer corrosion inhibitor is obtained after freeze drying.

[0059] Corrosion inhibition performance test

[0060] The medium used in the test is a sample of produced water from a block of Changqing Oilfield. The test method is a rotating coupon corrosion test, and the material used in the test is carbon steel, specifically:

[0061] Use a vernier caliper to measure the size of the test piece, accurate to 0.02mm, and calculate the area of ​​the test piece. Wipe the test piece with filter paper, put it in a container filled with petroleum ether with a boiling range of 60-90℃, remove the surface grease with absorbent cotton, and then soak it in anhydrous ethanol for 5 minutes for further degreasing and dehydration. Take out the test piece and place it on the filter paper, blow it dry with cold air, then wrap the test piece with filter paper, store it in a desiccator, and weigh it accurately to 0.01mg after leaving it for 1 hour.

[0062] Add the corrosion inhibitor to the experimental container. The corrosion inhibitor content in the water sample is 100 mg / L. The amount of water sample is 1 cm 2 The surface area of ​​the test piece is not less than 20mL (test piece area 50mm*13mm*1.5mm). Nitrogen is purged into the test container to remove air, and then oilfield water is introduced through a rubber tube. At the same time, a blank sample without corrosion inhibitor is made. Place it in a constant temperature box at 70℃ for 7 days. The test results are recorded in Table 1.

[0063] Table 1 Corrosion inhibition performance test results of corrosion and scale inhibitors

[0064]

[0065] Note: Medium blank mass loss Δm0 = 0.0375 g; annual uniform corrosion rate is 0.167 mm / year.

[0066] It can be seen from Table 1 that the corrosion and scale inhibitor provided by the present invention has good corrosion inhibition performance. When the dosage is 100 mg / L, the corrosion inhibition efficiency can reach 82.93%, and the corrosion rate can be as low as 0.029 mm / year.

[0067] Calcium carbonate scale inhibition performance test

[0068] The static scale inhibition evaluation method was used to test the calcium carbonate scale inhibition performance of the polymer prepared in the example. The test results are recorded in Table 2.

[0069] Accurately weigh 0.50g of scale inhibitor, dissolve it in a small amount of pure water, transfer it to a 250mL volumetric flask and dilute to the mark to obtain a scale inhibitor solution. Take 200mL of pure water in a 250mL volumetric flask, add the pre-prepared CaCl2 solution, and prepare CaCl2. 2+ Content: 96.00mg·L -1 Calcium chloride solution. Add 3.75 ml of scale inhibitor solution to the calcium chloride solution, let it stand for 10 minutes, and then add the pre-prepared Na2CO3 solution while shaking to make CO3 2- Content: 150.72 mg·L -1 Then add pure water to dilute to the scale and put it into a ground-mouth triangle bottle, put it into a water bath at 50℃±1℃ for half an hour and then let it stand for 16 hours.

[0070] When the reaction is complete, the solution is cooled to room temperature and filtered with quantitative filter paper. The filtrate of CaCO3 is titrated with ethylenediaminetetraacetic acid (EDTA) standard solution to determine Ca 2+ The concentration of the blank test was carried out at the same time, and the scale inhibition rate was calculated according to the following formula:

[0071]

[0072] Where η(100%) is the scale inhibition rate, V blank2 V is the volume of EDTA consumed by all calcium ions in the solution; blank1 V is the volume of EDTA consumed by calcium ions in the solution without adding antiscalant; final It is the volume of EDTA consumed by the calcium ions present in the solution after adding the antiscalant.

[0073] Table 2 Scale inhibition performance test results of corrosion and scale inhibitors

[0074] Serial number Antiscalant dosage (mg / L) Calcium carbonate scale inhibition rate (%) Example 1 30 88.2 Example 2 30 90.2 Example 3 30 93.7 Example 4 30 87.7 Comparative Example 1 30 55.5 Comparative Example 2 30 45.8

[0075] It can be seen from Table 2 that the corrosion inhibitor and scale inhibitor proposed in the present invention has good inhibitory performance on calcium carbonate, and the scale inhibition efficiency can reach 93.7% when the scale inhibitor is used at a concentration of 30 mg / L.

[0076] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A corrosion and scale inhibitor, characterized in that: It has the following general structural formula: In the formula, x, y, and n are any integers from 1 to 10 respectively.

2. A method for preparing a corrosion and scale inhibitor, characterized in that: The following steps are involved: Aconitic acid is dissolved in water, then sodium p-styrene sulfonate and 3-aminopyrazole are added and dissolved, then the temperature is raised to 65-85° C., an initiator is continuously added to react to obtain the corrosion and scale inhibitor.

3. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The dissolving of aconitic acid in water comprises: mixing aconitic acid with water, then heating to 50-55° C. and stirring until dissolved.

4. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The molar ratio of the aconitic acid to the sodium p-styrene sulfonate is (1-3):

1.

5. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The molar ratio of the aconitic acid to the 3-aminopyrazole is (1-4):

1.

6. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The added amount of the initiator is 8%-15% of the total mass of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole.

7. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The initiator is continuously added for a reaction time of 0.5-2 hours.

8. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The initiator is added dropwise, and the time required to complete the addition is 1-2 hours.

9. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The initiator is one or both of ammonium persulfate and ammonium ferrous sulfate.

10. The method for preparing the corrosion and scale inhibitor according to claim 2, characterized in that: The molar ratio of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole is 4:2:1, the amount of the initiator added is 10% of the total mass of the aconitic acid, the sodium p-styrene sulfonate and the 3-aminopyrazole, the temperature is raised to 75°C and the initiator is continued to be added at 75°C, and the reaction time is 1.5h.

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