Terpolymer scale inhibitors and methods for their preparation
A terpolymer scale inhibitor was prepared by free radical copolymerization of aconitic acid, N,N-dimethylacrylamide and p-aminobenzoic acid in aqueous solution, which solved the scaling problem in oil fields and achieved the effect of high-efficiency scale inhibition and green environmental protection.
Patent Information
- Application Number
- CN202411443362.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2044-10-16
AI Technical Summary
In existing technologies, scaling occurs during oilfield production, leading to pipeline blockage and equipment damage. Furthermore, traditional scale inhibitors cause serious environmental pollution, and there is a lack of efficient and environmentally friendly solutions.
A terpolymer scale inhibitor was prepared by using aconitic acid, N,N-dimethylacrylamide and p-aminobenzoic acid as raw materials and aqueous solution free radical copolymerization with ammonium persulfate initiator. The scale inhibition performance was improved and environmental pollution was reduced by utilizing carboxylic acid groups and amide groups.
The prepared terpolymer scale inhibitor exhibits a scale inhibition rate of up to 99.6% for calcium carbonate at low concentrations. It is environmentally friendly, uses readily available raw materials, is simple to prepare, and is suitable for industrial applications.
Smart Images
Figure CN119331168B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of polymer macromolecules and water treatment, and particularly relates to a terpolymer scale inhibitor and a preparation method thereof. BACKGROUND
[0002] At present, major oilfields in China have entered the middle and late development stage. In order to maintain the formation pressure and improve the oilfield development efficiency, water injection development is needed. In order to save water resources, oilfield produced water is usually used, which is complex in composition and contains calcium, magnesium, barium, strontium and other scale-forming ions. The deposition of these inorganic salts on the inside of the pipeline and mechanical equipment leads to problems such as pipeline blockage and equipment damage, especially when injected into the formation, which leads to formation scaling and plugging, resulting in a decrease in production and directly affecting the development benefit of the oilfield.
[0003] At present, the method for solving the problem of scaling in the production process of oilfields is mainly to add scale inhibitors and other chemical agents. With the development of science and technology and the needs of production, there are various scale inhibitors on the market. For a long time, the application of phosphorus-containing scale inhibitors is the most widespread, but their pollution to the environment is very serious. Green scale inhibitors are green in raw materials, production methods and production reactions. With the increasing environmental problems, the government has gradually increased its attention to environmental protection, so it is very important to develop a high-efficiency and green scale inhibitor. How to efficiently prevent scale formation and be green and environmentally friendly is a technical problem to be solved in the prior art. SUMMARY
[0004] The purpose of the present application is to overcome the above technical deficiencies and provide a terpolymer scale inhibitor and a preparation method thereof, which solve the technical problem of how to efficiently prevent scale formation and be green and environmentally friendly in the prior art.
[0005] To achieve the above technical purpose, the technical scheme of the present application provides a terpolymer scale inhibitor, which has the following general structure:
[0006]
[0007] In the formula, x, y, and n are each any integer from 1 to 10.
[0008] In addition, the present application also provides a preparation method of the terpolymer scale inhibitor, which comprises the following steps:
[0009] The aconitic acid and water are mixed and stirred to dissolve at 50-55 DEG C, then N,N-dimethyl acrylamide and p-aminobenzoic acid are added, then the temperature is raised to 65-85 DEG C and an initiator is added dropwise, and then the terpolymer scale inhibitor is obtained by reacting at 65-90 DEG C.
[0010] In any embodiment, the molar ratio of the aconitic acid to the N,N-dimethyl acrylamide is (1-3):1.
[0011] In any embodiment, the molar ratio of the aconitic acid to the p-aminobenzoic acid is (1-4):1.
[0012] In any embodiment, the initiator is ammonium persulfate.
[0013] In any embodiment, the amount of the ammonium persulfate added is 8% to 15% of the total mass of the aconitic acid, the N,N-dimethylacrylamide and the p-aminobenzoic acid.
[0014] In any embodiment, the reaction time is 0.5h to 2h.
[0015] In any embodiment, the time required for dropping the initiator is 1h to 2h.
[0016] In any embodiment, the molar ratio of the aconitic acid, the N,N-dimethylacrylamide and the p-aminobenzoic acid is 4:2:1, and the amount of the initiator added is 12% of the total mass of the aconitic acid, the N,N-dimethylacrylamide and the p-aminobenzoic acid.
[0017] In any embodiment, the reaction temperature is 75℃, and the reaction time is 1h.
[0018] Compared with the prior art, the present application has the following advantages: the present application uses aconitic acid as a polymerization monomer, so that the polymer molecules have a large number of carboxylic acid groups, which are the main groups for inhibiting the formation of calcium scale. At the same time, the introduction of N,N-dimethylacrylamide and p-aminobenzoic acid makes the polymer molecules have amide groups, which improves the solubility of the polymer, and enhances the stability and durability of the polymer molecules. The monomer raw materials used in the preparation method of the present application do not contain phosphorus groups, and are non-toxic and harmless to the environment, which meets the requirements of green production of raw materials, production mode and production reaction of scale inhibitors, and the obtained scale inhibitor is green and environmentally friendly, and has excellent scale inhibition performance. In addition, the raw materials of the scale inhibitor of the present application are easy to obtain, safe and environmentally friendly, the preparation operation is simple, and the industrial application is easy to carry out. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 is the infrared spectrum of the terpolymer scale inhibitor prepared in Example 3 of the present application. DETAILED DESCRIPTION
[0020] "RANGES" disclosed herein are defined, for each range by endpoints, with the endpoint of the lower limit being included and the endpoint of the upper limit being excluded. Ranges can be expressed as from about one particular value and / or to about another; for example, from about 60 to about 120. Unless otherwise stated, the use of approximation such as "about" and "substantially" can refer to ranges within 10% or less, preferably within 1% or less, more preferably within 0.5% or less of a given value or range. Unless otherwise stated, the use of approximation such as "about" and "substantially" can refer to ranges within 10% or less, preferably within 1% or less, more preferably within 0.5% or less of a given value or range. For example, the numerical range "0-5" is intended to function the same as, inter alia, the discrete numerical values "0, 1, 2, 3, 4, 5," and "5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, and 1.0.
[0021] "COMPRISING" and "CONTAINING" are used in the broadest sense inclusive of open-ended and closed-ended claims unless otherwise specifically noted. For example, the terms "comprising" and "containing" can mean that other components can also be included or can mean that only the listed components are included.
[0022] "OR" is used in the broadest sense inclusive of exclusive or unless otherwise specifically noted. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following are satisfied by the condition "A or B": A is true (or present) and B is false (or not present); A is false (or not present) and B is true (or present); or both A and B are true (or present).
[0023] The present embodiment provides a terpolymer scale inhibitor, characterized by having the following general structure:
[0024]
[0025] wherein x, y, n are each an integer from 1 to 10.
[0026] The present embodiment also provides a method for preparing the terpolymer scale inhibitor, comprising the following steps:
[0027] The aconitic acid and water are mixed and dissolved under stirring at 50-55 DEG C, then N,N-dimethyl acrylamide and p-aminobenzoic acid are added, then the temperature is increased to 65-85 DEG C and the initiator is added dropwise, the dropping of the initiator is completed in 1h-2h, then the reaction is carried out at 65-90 DEG C for 0.5h-2h to obtain the terpolymer scale inhibitor; the molar ratio of the aconitic acid to the N,N-dimethyl acrylamide is (1-3):1; the molar ratio of the aconitic acid to the p-aminobenzoic acid is (1-4):1; the initiator is ammonium persulfate; the adding amount of the ammonium persulfate is 8%-15% of the total mass of the aconitic acid, the N,N-dimethyl acrylamide and the p-aminobenzoic acid.
[0028] In some embodiments, the molar ratio of the aconitic acid, the N,N-dimethyl acrylamide and the p-aminobenzoic acid is 4:2:1, the adding amount of the initiator is 12% of the total mass of the aconitic acid, the N,N-dimethyl acrylamide and the p-aminobenzoic acid, the reaction temperature is 75 DEG C, and the reaction time is 1h.
[0029] The present application adopts an ammonium persulfate redox type initiator system, and a green terpolymer is obtained through aqueous solution free radical copolymerization.
[0030] In the reaction process, the carbon-carbon double bond of the aconitic acid and the N,N-dimethyl acrylamide is broken, then chain polymerization is carried out, the ammonium persulfate is changed into an active center as an initiator, and addition reaction occurs with monomers.
[0031]
[0032] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.
[0033] In the present application, "some embodiments", "the present embodiment" and examples and the like are described, which describe a subset of all possible embodiments, but it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.
[0034] If the application file contains similar descriptions of "first / second", the following description is added: in the following description, the terms "first / second / third" are only used to distinguish similar objects, and do not represent a specific order of the objects. Understandably, "first / second / third" can be interchanged in a specific order or sequence as allowed, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.
[0035] In this embodiment, the term "and / or" is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, object A and / or object B, which can represent three cases: object A exists alone, object A and object B exist together, and object B exists alone.
[0036] The following describes the embodiments of the present application. The embodiments described below are exemplary and are used only to explain the present application and cannot be understood as limiting the present application. If the specific technology or condition is not specified in the embodiments, it is performed according to the technology or condition described in the literature in the art or according to the product manual. If the reagent or instrument used is not specified by the manufacturer, it is a conventional product that can be obtained from the market.
[0037] Embodiment 1
[0038] The present embodiment proposes a preparation method of a green ternary copolymer scale inhibitor, comprising the following steps:
[0039] Under air condition, a certain amount of aconitic acid and pure water are added to the reactor, the temperature is raised to 55℃, and N,N-dimethyl acrylamide and p-aminobenzoic acid are added after uniform stirring until complete dissolution. The molar ratio of aconitic acid to N,N-dimethyl acrylamide is 1:1, and the molar ratio of aconitic acid to p-aminobenzoic acid is 2:1. After N,N-dimethyl acrylamide and p-aminobenzoic acid are completely dissolved, the temperature is raised to 85℃, and ammonium persulfate initiator is added at a uniform speed, and the addition is completed within 1.5h. The addition amount of ammonium persulfate is 10% of the total mass of aconitic acid, N,N-dimethyl acrylamide and p-aminobenzoic acid. The reaction temperature is controlled at 90℃, and the reaction is carried out for 1h. After the reaction is completed, the reaction product solution is obtained after cooling. The product is purified by dialysis to remove unreacted small molecule monomers, and the copolymer scale inhibitor is obtained after freeze-drying.
[0040] Embodiment 2
[0041] The present embodiment proposes a preparation method of a green ternary copolymer scale inhibitor, comprising the following steps:
[0042] Under air condition, a certain amount of aconitic acid and pure water were added into a reactor, the temperature was raised to 55℃, and N,N-dimethyl acrylamide and p-aminobenzoic acid were added after uniform stirring until complete dissolution. The molar ratio of aconitic acid to N,N-dimethyl acrylamide was 2:1, and the molar ratio of aconitic acid to p-aminobenzoic acid was 3:1. After complete dissolution of N,N-dimethyl acrylamide and p-aminobenzoic acid, the temperature was raised to 80℃, and ammonium persulfate initiator was added at a uniform speed, and the addition was completed within 1h. The addition amount of ammonium persulfate was 8% of the total mass of aconitic acid, N,N-dimethyl acrylamide and p-aminobenzoic acid. The reaction temperature was controlled at 85℃, and the reaction was carried out for 1.5h. After the reaction was completed, the reaction product solution was obtained after cooling. The product was purified by dialysis to remove unreacted small molecule monomers, and the copolymer scale inhibitor was obtained after freeze-drying.
[0043] Example 3
[0044] The present example proposes a preparation method of a green ternary copolymer scale inhibitor, comprising the following steps:
[0045] Under air condition, a certain amount of aconitic acid and pure water were added into a reactor, the temperature was raised to 55℃, and N,N-dimethyl acrylamide and p-aminobenzoic acid were added after uniform stirring until complete dissolution. The molar ratio of aconitic acid to N,N-dimethyl acrylamide was 2:1, and the molar ratio of aconitic acid to p-aminobenzoic acid was 3:1. After complete dissolution of N,N-dimethyl acrylamide and p-aminobenzoic acid, the temperature was raised to 80℃, and ammonium persulfate initiator was added at a uniform speed, and the addition was completed within 1h. The addition amount of ammonium persulfate was 8% of the total mass of aconitic acid, N,N-dimethyl acrylamide and p-aminobenzoic acid. The reaction temperature was controlled at 85℃, and the reaction was carried out for 1.5h. After the reaction was completed, the reaction product solution was obtained after cooling. The product was purified by dialysis to remove unreacted small molecule monomers, and the copolymer scale inhibitor was obtained after freeze-drying.
[0046] Figure 1 The infrared spectrum of the scale inhibitor prepared in the present example is shown in Figure 1 characteristic absorption peaks of 3443.8cm -1 , 1723.1cm -1 , 1643.1cm -1 , 1403.4cm -1 , 1219.1cm -1 , 1117.6cm -1 were found. Among them, 3443.8cm -1 and 1643.1cm -1 are the NH stretching vibration absorption peak and C=O stretching vibration absorption peak in amide group, respectively. 1723.1cm -1 and 1117.6cm -1vibration peaks of C=O and C-O in carboxylic acid group, 1403.4 cm -1 and 1219.1 cm -1 are characteristic absorption peaks of C-N stretching vibration. Meanwhile, no C=C absorption peak in 1620-1640 cm -1 was found in the infrared spectrum, which indicates that the monomers have been copolymerized and the scale inhibitor of the present example has been prepared.
[0047] Example 4
[0048] The present example proposes a preparation method of a green terpolymer scale inhibitor, comprising the following steps:
[0049] Under air condition, a certain amount of aconitic acid and pure water are added into a reactor, the temperature is raised to 55℃, and N,N-dimethylacrylamide and p-aminobenzoic acid are added after uniform stirring until complete dissolution. The molar ratio of aconitic acid to N,N-dimethylacrylamide is 3:1, and the molar ratio of aconitic acid to p-aminobenzoic acid is 4:1. After complete dissolution of N,N-dimethylacrylamide and p-aminobenzoic acid, the temperature is raised to 70℃, and ammonium persulfate initiator is added at a uniform speed, and the addition is completed within 1h. The addition amount of ammonium persulfate is 12% of the total mass of aconitic acid, N,N-dimethylacrylamide and p-aminobenzoic acid. The reaction temperature is controlled at 80℃, and the reaction is carried out for 1h. After the reaction is completed, the reaction product solution is obtained after cooling. The product is purified by dialysis to remove unreacted small molecule monomers, and the polymer scale inhibitor is obtained after freeze-drying.
[0050] Comparative Example 1
[0051] The present comparative example proposes a preparation method of a scale inhibitor, which is different from Example 3 in that p-aminobenzoic acid is not added, comprising the following steps:
[0052] Under air condition, a certain amount of aconitic acid and pure water are added into a reactor, the temperature is raised to 55℃, and N,N-dimethylacrylamide is added after uniform stirring until complete dissolution. The amount of aconitic acid is the same as that in Example 3, and the amount of N,N-dimethylacrylamide is the sum of the amounts of N,N-dimethylacrylamide and p-aminobenzoic acid in Example 3. After complete dissolution of N,N-dimethylacrylamide, the temperature is raised to 70℃, and ammonium persulfate initiator is added at a uniform speed, and the addition is completed within 1h. The addition amount of ammonium persulfate is 12% of the total mass of aconitic acid and N,N-dimethylacrylamide. The reaction temperature is controlled at 70℃, and the reaction is carried out for 45min. After the reaction is completed, the reaction product solution is obtained after cooling. The product is purified by dialysis to remove unreacted small molecule monomers, and the scale inhibitor is obtained after freeze-drying.
[0053] Comparative Example 1
[0054] A preparation method of a scale inhibitor is provided in the comparative example, which is different from example 3 in that N,N-dimethylacrylamide is not added, and includes the following steps:
[0055] Under air condition, a certain amount of aconitic acid and pure water are added to the reactor, the temperature is raised to 55℃, and p-aminobenzoic acid is added after uniform stirring until complete dissolution. The amount of aconitic acid is the same as that in example 3, and the amount of p-aminobenzoic acid is the sum of the amounts of N,N-dimethylacrylamide and p-aminobenzoic acid in example 3. After the complete dissolution of p-aminobenzoic acid, the temperature is raised to 70℃, and ammonium persulfate initiator is added at a uniform speed, and the addition is completed within 1h. The addition amount of ammonium persulfate is 12% of the total mass of aconitic acid and p-aminobenzoic acid. The reaction temperature is controlled at 70℃, and the reaction is carried out for 45min. After the reaction is completed, the product solution is obtained after cooling. The product is purified by dialysis to remove unreacted small molecule monomers, and the scale inhibitor is obtained after freeze-drying.
[0056] Scale inhibition performance evaluation
[0057] The standard adopted is the national standard “GBT 16632-2019 Determination of scale inhibition performance of water treatment agent - Calcium carbonate deposition method”.
[0058] Water sample: oilfield produced water, and the water quality composition is shown in table 1.
[0059] Table 1 Water quality composition of oilfield produced water sample (unit: mg / L)
[0060]
[0061] The scale inhibition ability of the scale inhibitors prepared in examples 1-4 and comparative examples 1-2 on calcium carbonate is determined, and the test results are shown in table 2.
[0062] Table 2 Test results of scale inhibition performance
[0063] Serial number Dosing of scale inhibitor (mg / L) Calcium carbonate scale inhibition rate 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％
[0064] As shown in table 1, the green ternary copolymer obtained by using aconitic acid, N,N-dimethylacrylamide and p-aminobenzoic acid as raw materials, and using ammonium persulfate redox initiator, has good scale inhibition performance on calcium carbonate. When the amount of the scale inhibitor is 30mg / L, the scale inhibition rate on calcium carbonate is as high as 99.6%, which realizes the prevention of scale formation in high-hardness and high-carbonate water quality at a low concentration.
[0065] In addition, it can be seen from the above results that the scale inhibition effect of Example 3 of the present application is better, indicating that when the molar ratio of aconitic acid, N,N-dimethyl acrylamide and p-aminobenzoic acid monomers is 4:2:1, and the addition amount of ammonium persulfate is 12% of the total mass of aconitic acid, N,N-dimethyl acrylamide and p-aminobenzoic acid, the product has a higher scale inhibition rate.
[0066] The specific embodiments of the application described above do not constitute a limitation of the protection scope of the application. Any various other corresponding changes and modifications made according to the technical concept of the application should be included in the protection scope of the claims of the application.
Claims
1. A process for the preparation of a terpolymer scale inhibitor, characterized in that, The method comprises the following steps: aconitic acid and water are mixed and dissolved under stirring at 50-55℃, then N,N-dimethyl acrylamide and p-aminobenzoic acid are added, then the temperature is raised to 65-85℃ and an initiator is added dropwise, then the reaction is carried out at 65-90℃ to obtain the terpolymer scale inhibitor; the molar ratio of the aconitic acid to the N,N-dimethyl acrylamide is (1-3):1; the molar ratio of the aconitic acid to the p-aminobenzoic acid is (1-4):1; the initiator is ammonium persulfate; the addition amount of the ammonium persulfate is 8% to 15% of the total mass of the aconitic acid, the N,N-dimethyl acrylamide and the p-aminobenzoic acid; The terpolymer scale inhibitor has the following general structure: In the formula, x, y, n are any integer from 1 to 10, respectively. The terpolymer scale inhibitor is used for calcium scale inhibition.
2. The method for preparing the terpolymer scale inhibitor according to claim 1, characterized in that, 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 dropwise addition of the initiator is 1h-2h.
4. The method for preparing the terpolymer scale inhibitor according to claim 1, characterized in that, The molar ratio of the aconitic acid, the N,N-dimethyl acrylamide and the p-aminobenzoic acid is 4:2:1, and the addition amount of the initiator is 12% of the total mass of the aconitic acid, the N,N-dimethyl acrylamide and the p-aminobenzoic acid.
5. The method for preparing the terpolymer scale inhibitor according to claim 1, characterized in that, The reaction temperature is 75℃, and the reaction time is 1h.