CN119331168B

CN119331168B - Terpolymer scale inhibitor and preparation method thereof

Info

Publication number: CN119331168B
Application number: CN202411443362.8A
Authority: CN
Inventors: 张煜; 陈文心; 沈俊辰
Original assignee: Hubei University for Nationalities
Current assignee: Hubei University for Nationalities
Priority date: 2024-10-16
Filing date: 2024-10-16
Publication date: 2025-11-07
Anticipated expiration: 2044-10-16
Also published as: CN119331168A

Abstract

This invention discloses a ternary copolymer scale inhibitor and its preparation method, belonging to the field of polymer and water treatment technology. The ternary copolymer scale inhibitor has the following general structural formula: In the formula, x, y, and n are any integers from 1 to 10. Furthermore, this invention also proposes a method for preparing a ternary copolymer scale inhibitor, comprising the following steps: mixing aconitine and water and stirring to dissolve at 50-55°C; then adding N,N-dimethylacrylamide and p-aminobenzoic acid; then heating to 65-85°C and adding an initiator dropwise; and finally reacting at 65-90°C to obtain the ternary copolymer scale inhibitor. The scale inhibitor proposed in this invention is environmentally friendly and exhibits excellent scale inhibition performance.

Description

Terpolymer scale inhibitor and preparation method thereof

Technical Field

The invention relates to the technical field of polymer macromolecules and water treatment, in particular to a terpolymer scale inhibitor and a preparation method thereof.

Background

At present, each large oil field in China enters a middle-late development stage, and water injection exploitation is needed to maintain formation pressure and improve oil field exploitation efficiency. In order to save water resources, oilfield produced water is usually used, and the oilfield produced water has complex components and contains scale-forming ions such as calcium, magnesium, barium, strontium and the like. These inorganic salts deposit and adhere to the inside of the pipeline and on the mechanical equipment, causing problems such as pipeline blockage, equipment damage, etc., especially injecting into the stratum, causing formation scale blockage, reducing the yield, and directly affecting the exploitation benefits of the oil field.

At present, the method for solving the scaling phenomenon problem in the oilfield production process mainly comprises the steps of adding chemical agents such as scale inhibitors, and along with technological development and production requirements, the scale inhibitors on the market are various, and the phosphorus-containing scale inhibitors are most widely applied for a long time, but have serious environmental pollution. The green scale inhibitor is prepared from the green production raw materials, the green production mode and the green production reaction. With the increasing emphasis of environmental problems, the national importance of environmental protection is gradually increased, so that the development of an efficient and environment-friendly scale inhibitor is very important. How to efficiently inhibit scale and is environment-friendly is a technical problem to be solved in the prior art.

Disclosure of Invention

The invention aims to overcome the technical defects, and provides a terpolymer scale inhibitor and a preparation method thereof, which solve the technical problems of high scale inhibition efficiency and environmental protection in the prior art.

In order to achieve the technical purpose, the technical scheme of the invention provides a terpolymer scale inhibitor, which has the following structural general formula:

wherein x, y and n are each an integer of 1 to 10.

In addition, the invention also provides a preparation method of the terpolymer scale inhibitor, which comprises the following steps:

Mixing aconitic acid and water, stirring and dissolving at 50-55 ℃, adding N, N-dimethylacrylamide and p-aminobenzoic acid, heating to 65-85 ℃, dripping an initiator, and reacting at 65-90 ℃ to obtain the terpolymer scale inhibitor.

In any embodiment, the molar ratio of aconitic acid to N, N-dimethylacrylamide is (1-3): 1.

In any embodiment, the molar ratio of aconitic acid to para-aminobenzoic acid is (1-4): 1.

In any embodiment, the initiator is ammonium persulfate.

In any embodiment, the addition amount of the ammonium persulfate is 8% -15% of the total mass of the aconitic acid, the N, N-dimethylacrylamide and the para-aminobenzoic acid.

In any embodiment, the reaction time is from 0.5h to 2h.

In any embodiment, the time required for the dropwise addition of the initiator is from 1h to 2h.

In any embodiment, the molar ratio of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid is 4:2:1, and the addition amount of the initiator is 12% of the total mass of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid.

In any embodiment, the temperature of the reaction is 75 ℃ and the time of the reaction is 1h.

Compared with the prior art, the invention has the beneficial effects that aconitic acid is used as a polymerization monomer, so that polymer molecules have a large number of carboxylic acid groups, and the carboxylic acid groups are the most main groups for inhibiting calcium scale formation. Meanwhile, due to the introduction of N, N-dimethylacrylamide and p-aminobenzoic acid, polymer molecules have amide groups, so that the solubility of the polymer is improved, and the stability and durability of the polymer molecules are enhanced. The monomer raw materials used in the preparation method do not contain phosphorus groups, are nontoxic and harmless to the environment, meet the requirements of green scale inhibitor production raw materials, production modes and production reaction greenization, and the obtained scale inhibitor is green and environment-friendly and has excellent scale inhibition performance. In addition, the scale inhibitor has the advantages of easily available raw materials, safety, environmental protection, simple preparation operation and easy industrialized application.

Drawings

FIG. 1 is an infrared spectrum of a ternary copolymer scale inhibitor prepared in example 3 of the present invention.

Detailed Description

The "range" disclosed herein is defined in terms of lower and upper limits, with the given range being defined by the selection of a lower and an upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges that are defined in this way can be inclusive or exclusive of the endpoints, and any combination can be made, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if minimum range values 1 and 2 are listed, and if maximum range values 3,4, and 5 are listed, the following ranges are all contemplated as 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise indicated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed throughout, and "0-5" is a shorthand representation of only a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is disclosed that the parameter is, for example, an integer of 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12 or the like.

The terms "comprising" and "including" as used herein mean open ended or closed ended, unless otherwise noted. For example, the terms "comprising" and "comprises" may mean that other components not listed may be included or included, or that only listed components may be included or included.

The term "or" is inclusive in this application, unless otherwise specified. For example, the phrase "a or B" means "a, B, or both a and B. More specifically, either condition satisfies the condition "A or B" that A is true (or present) and B is false (or absent), that A is false (or absent) and B is true (or present), or that both A and B are true (or present).

The specific embodiment provides a terpolymer scale inhibitor, which is characterized by having the following structural general formula:

wherein x, y and n are each an integer of 1 to 10.

The specific embodiment also provides a preparation method of the terpolymer scale inhibitor, which comprises the following steps:

Mixing aconitic acid and water, stirring and dissolving at 50-55 ℃, adding N, N-dimethylacrylamide and para-aminobenzoic acid, heating to 65-85 ℃ and dripping an initiator, finishing dripping of the initiator at 1-2 h, and reacting for 0.5-2 h at 65-90 ℃ to obtain the terpolymer scale inhibitor, wherein the mol ratio of aconitic acid to N, N-dimethylacrylamide is (1-3): 1, the mol ratio of aconitic acid to para-aminobenzoic acid is (1-4): 1, the initiator is ammonium persulfate, and the adding amount of the ammonium persulfate is 8% -15% of the total mass of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid.

In some embodiments, the molar ratio of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid is 4:2:1, the initiator is added in an amount of 12% of the total mass of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid, the temperature of the reaction is 75 ℃, and the time of the reaction is 1h.

The invention adopts an ammonium persulfate redox initiation system, and obtains a green terpolymer through aqueous solution free radical copolymerization, and the related reaction mechanism is as follows:

In the reaction process, the carbon-carbon double bonds of aconitic acid and N, N-dimethyl acrylamide are broken, chain polymerization is carried out, ammonium persulfate is used as an initiator to be changed into an active center, and an addition reaction is carried out with a monomer. The amidation reaction of the carboxylic acid group in the para aminobenzoic acid and aconitic acid. The reaction formula is as follows:

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In this disclosure reference is made to "some embodiments," "this embodiment," and examples, etc., which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with one another without conflict.

If a similar description of "first/second" appears in the application document, the following description is added, in which the terms "first/second/third" are merely distinguishing between similar objects and not representing a particular ordering of the objects, it being understood that the "first/second/third" may, where allowed, interchange a particular order or precedence order to enable embodiments described herein to be implemented in an order other than that illustrated or described herein.

The term "and/or" in this embodiment is merely an association relation describing the associated objects, and indicates that three kinds of relations may exist, for example, object a and/or object B may indicate that object a exists alone, object a and object B exist together, and object B exists alone.

Hereinafter, embodiments of the present application are described. The following examples are illustrative only and are not to be construed as limiting the application. The examples are not to be construed as limiting the specific techniques or conditions described in the literature in this field or as per the specifications of the product. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

Example 1

The embodiment provides a preparation method of a green terpolymer scale inhibitor, which comprises the following steps:

Under the air condition, adding a certain amount of aconitic acid and pure water into a reactor, raising the temperature to 55 ℃, uniformly stirring until the aconitic acid and the pure water are completely dissolved, and then adding N, N-dimethylacrylamide and para-aminobenzoic acid, wherein the molar ratio of the aconitic acid to the N, N-dimethylacrylamide is 1:1, and the molar ratio of the aconitic acid to the para-aminobenzoic acid is 2:1. After N, N-dimethyl acrylamide and p-aminobenzoic acid are completely dissolved, heating to 85 ℃, dropwise adding an ammonium persulfate initiator at a constant speed, and after the dropwise adding is completed within 1.5h, the adding amount of the ammonium persulfate is 10% of the total mass of aconitic acid, N-dimethyl acrylamide and p-aminobenzoic acid. The reaction temperature is controlled to be 90 ℃, the reaction is carried out for 1h, and the reaction product solution is obtained after the reaction is finished and cooled. And (3) purifying the product by dialysis to remove unreacted micromolecule monomers, and freeze-drying to obtain the copolymer scale inhibitor.

Example 2

Under the air condition, adding a certain amount of aconitic acid and pure water into a reactor, raising the temperature to 55 ℃, uniformly stirring until the aconitic acid and the pure water are completely dissolved, and then adding N, N-dimethylacrylamide and para-aminobenzoic acid, wherein the molar ratio of the aconitic acid to the N, N-dimethylacrylamide is 2:1, and the molar ratio of the aconitic acid to the para-aminobenzoic acid is 3:1. After N, N-dimethyl acrylamide and p-aminobenzoic acid are completely dissolved, heating to 80 ℃, dropwise adding an ammonium persulfate initiator at a constant speed, wherein the addition amount of ammonium persulfate is 8% of the total mass of aconitic acid, N-dimethyl acrylamide and p-aminobenzoic acid after the dropwise addition is completed within 1 h. The reaction temperature is controlled to be 85 ℃, the reaction is carried out for 1.5 hours, and the reaction product solution is obtained after the reaction is finished and cooled. And (3) purifying the product by dialysis to remove unreacted micromolecule monomers, and freeze-drying to obtain the copolymer scale inhibitor.

Example 3

Under the air condition, adding a certain amount of aconitic acid and pure water into a reactor, raising the temperature to 55 ℃, stirring at a constant speed until the aconitic acid and the pure water are completely dissolved, and then adding N, N-dimethylacrylamide and para-aminobenzoic acid, wherein the molar ratio of the aconitic acid to the N, N-dimethylacrylamide is 2:1, and the molar ratio of the aconitic acid to the para-aminobenzoic acid is 4:1. After N, N-dimethyl acrylamide and p-aminobenzoic acid are completely dissolved, heating to 70 ℃, dropwise adding an ammonium persulfate initiator at a constant speed, wherein the addition amount of the ammonium persulfate is 12% of the total mass of aconitic acid, N-dimethyl acrylamide and p-aminobenzoic acid after the dropwise addition is completed within 1 h. The reaction temperature is controlled to be 70 ℃, the reaction is carried out for 45min, and the reaction product solution is obtained after the reaction is finished. And (3) purifying the product by dialysis to remove unreacted micromolecule monomers, and freeze-drying to obtain the copolymer scale inhibitor.

FIG. 1 is an infrared spectrum of the scale inhibitor prepared in this example. From FIG. 1, a characteristic absorption peak of 3443.8cm^-1、1723.1cm^-1、1643.1cm^-1、1403.4cm^-1、1219.1cm^-1、1117.6cm^-1 was found. Wherein 3443.8cm ^-1 and 1643.1cm ^-1 are the NH telescopic vibration absorption peak and the C=O telescopic vibration absorption peak in the amide group, respectively. Vibrations of 1723.1cm ^-1 and 1117.6cm ^-1 are caused by the c=o and C-O stretching vibration peaks in the carboxylic acid groups, respectively, 1403.4cm ^-1 and 1219.1cm ^-1 being C-N stretching vibration characteristic absorption peaks. Meanwhile, no C=C absorption peak of 1620-1640cm ^-1 is found in the infrared spectrum, which indicates that the monomer is copolymerized, and the scale inhibitor of the embodiment is prepared.

Example 4

Under the air condition, adding a certain amount of aconitic acid and pure water into a reactor, raising the temperature to 55 ℃, uniformly stirring until the aconitic acid and the pure water are completely dissolved, and then adding N, N-dimethylacrylamide and para-aminobenzoic acid, wherein the molar ratio of the aconitic acid to the N, N-dimethylacrylamide is 3:1, and the molar ratio of the aconitic acid to the para-aminobenzoic acid is 4:1. After N, N-dimethyl acrylamide and p-aminobenzoic acid are completely dissolved, heating to 70 ℃, dropwise adding an ammonium persulfate initiator at a constant speed, wherein the addition amount of the ammonium persulfate is 12% of the total mass of aconitic acid, N-dimethyl acrylamide and p-aminobenzoic acid after the dropwise addition is completed within 1 h. The reaction temperature is controlled to be 80 ℃, the reaction is carried out for 1h, and the reaction product solution is obtained after the reaction is finished and cooled. And (3) purifying the product by dialysis to remove unreacted micromolecule monomers, and freeze-drying to obtain the polymer scale inhibitor.

Comparative example 1

This comparative example proposes a method for preparing a scale inhibitor, which is different from example 3 in that p-aminobenzoic acid is not added, comprising the steps of:

Under the air condition, adding a certain amount of aconitic acid and pure water into a reactor, raising the temperature to 55 ℃, stirring at a constant speed until the aconitic acid and the pure water are completely dissolved, and then adding N, N-dimethylacrylamide, wherein the dosage of the aconitic acid is the same as that of the example 3, and the dosage of the N, N-dimethylacrylamide is the sum of the dosage of the N, N-dimethylacrylamide and the dosage of the para-aminobenzoic acid in the example 3. After the N, N-dimethylacrylamide is completely dissolved, heating to 70 ℃, dropwise adding an ammonium persulfate initiator at a constant speed, wherein the adding amount of the ammonium persulfate is 12% of the total mass of aconitic acid and the N, N-dimethylacrylamide after the dropwise adding is completed within 1 hour. The reaction temperature is controlled to be 70 ℃, the reaction is carried out for 45min, and the reaction product solution is obtained after the reaction is finished. And (3) purifying the product by dialysis to remove unreacted micromolecule monomers, and freeze-drying to obtain the scale inhibitor.

Comparative example 1

This comparative example proposes a method for preparing a scale inhibitor, which is different from example 3 in that no N, N-dimethylacrylamide is added, comprising the steps of:

Under the air condition, adding a certain amount of aconitic acid and pure water into a reactor, raising the temperature to 55 ℃, stirring at a constant speed until the aconitic acid and the pure water are completely dissolved, and then adding the para-aminobenzoic acid, wherein the dosage of the aconitic acid is the same as that of the example 3, and the dosage of the para-aminobenzoic acid is the sum of the dosage of N, N-dimethylacrylamide and the dosage of the para-aminobenzoic acid in the example 3. After the para aminobenzoic acid is completely dissolved, heating to 70 ℃, dropwise adding an ammonium persulfate initiator at a constant speed, wherein the addition amount of the ammonium persulfate is 12% of the total mass of the aconitic acid and the para aminobenzoic acid after the dropwise addition is completed within 1h. The reaction temperature is controlled to be 70 ℃, the reaction is carried out for 45min, and the reaction product solution is obtained after the reaction is finished. And (3) purifying the product by dialysis to remove unreacted micromolecule monomers, and freeze-drying to obtain the scale inhibitor.

Evaluation of Scale inhibition Property

The method adopts the standard of the national standard GBT 16632-2019 water treatment agent scale inhibition performance determination-calcium carbonate deposition method.

The water sample is oilfield produced water, and the water quality components are shown in Table 1.

TABLE 1 oilfield produced Water quality composition (unit: mg/L)

The scale inhibiting ability of the polymer scale inhibitors prepared in examples 1 to 4 and the scale inhibitors of comparative examples 1 to 2 to calcium carbonate was measured, and the test results are shown in Table 2.

TABLE 2 scale inhibition test results

Sequence number	Scale inhibitor metering (mg/L)	Scale inhibition rate of calcium carbonate
			Example 1	30	96.5%
Example 2	30	97.2%
			Example 3	30	99.6%
Example 4	30	98.6%
			Comparative example 1	30	56.8%
Comparative example 2	30	52.1%

As can be seen from Table 1, the green terpolymer obtained by using aconitic acid, N-dimethylacrylamide and p-aminobenzoic acid as raw materials and adopting an ammonium persulfate oxidation-reduction initiator through aqueous solution free radical copolymerization has good scale inhibition performance on calcium carbonate, and when the dosage of the scale inhibitor is 30mg/L, the scale inhibition rate on the calcium carbonate is up to 99.6%, so that the scale formation in water with high hardness and high carbonate is prevented under lower concentration.

In addition, as can be seen from the above results, the scale inhibition effect of the embodiment 3 of the present invention is better, which indicates that when the mole ratio of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid monomers is 4:2:1, the addition amount of ammonium persulfate is 12% of the total mass of aconitic acid, N-dimethylacrylamide and para-aminobenzoic acid, and the product has a higher scale inhibition rate.

The above-described embodiments of the present invention do not limit the scope of the present invention. Any other corresponding changes and modifications made in accordance with the technical idea of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a terpolymer scale inhibitor, characterized by comprising the following steps:

Aconitic acid and water are mixed and dissolved at 50-55°C with stirring. Then, N,N-dimethylacrylamide and p-aminobenzoic acid are added. The temperature is then raised to 65-85°C and an initiator is added dropwise. The reaction is then carried out at 65-90°C to obtain the terpolymer scale inhibitor. The molar ratio of aconitic acid to N,N-dimethylacrylamide is (1-3):1; the molar ratio of aconitic acid to p-aminobenzoic acid is (1-4):1; the initiator is ammonium persulfate; the amount of ammonium persulfate added is 8% to 15% of the total mass of aconitic acid, N,N-dimethylacrylamide, and p-aminobenzoic acid.

The ternary copolymer scale inhibitor has the following general structural formula:

In the formula, x, y, and n are any integers from 1 to 10;

The terpolymer scale inhibitor is used to inhibit calcium scale.

2. The method for preparing the terpolymer scale inhibitor according to claim 1, wherein the reaction time is 0.5h-2h.

3. The method for preparing the terpolymer scale inhibitor according to claim 1, characterized in that the time required for adding the initiator is 1h-2h.

4. The method for preparing the ternary copolymer scale inhibitor according to claim 1, characterized in that the molar ratio of aconitic acid, N,N-dimethylacrylamide and p-aminobenzoic acid is 4:2:1, and the amount of initiator added is 12% of the total mass of aconitic acid, N,N-dimethylacrylamide and p-aminobenzoic acid.

5. The method for preparing the terpolymer scale inhibitor according to claim 1, characterized in that the reaction temperature is 75°C and the reaction time is 1 hour.