Inhibitor as well as preparation method and application thereof
By preparing inhibitors containing specific structural units, the problem of single function of paraffin and asphaltenes inhibitors has been solved, achieving joint inhibition of paraffin and asphaltenes, reducing costs and simplifying the operation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-10-28
- Publication Date
- 2026-04-28
AI Technical Summary
Existing paraffin and asphaltenes inhibitors have limited functions and cannot effectively inhibit the deposition of both paraffin and asphaltenes simultaneously. Furthermore, traditional methods suffer from environmental hazards, high costs, and short effective periods.
An inhibitor is used, which is composed of monomers derived from Formula I, Formula II and 2-acrylamide-2-methylpropanesulfonic acid structural units, and is prepared by polymerization. The ester group interacts with paraffin, the amide group forms hydrogen bonds with paraffin, the carboxyl group reacts chemically with asphaltenes, and 2-acrylamide-2-methylpropanesulfonic acid provides emulsification and dispersing effects, thereby achieving the joint inhibition of paraffin and asphaltenes.
It achieves effective inhibition of paraffin and asphaltenes at low cost, maintains dynamic balance, avoids deposition, is easy to operate, and is suitable for the petrochemical industry.
Smart Images
Figure CN121930409A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of petrochemical technology, and more specifically, to an inhibitor, its preparation method, and its application. Background Technology
[0002] The deposition of paraffin and asphaltenes in crude oil can adversely affect crude oil extraction and transportation, and may even cause scaling and blockage in related equipment. Currently, there are many methods to remove paraffin and asphaltenes deposits or prevent their formation, such as solvent cleaning, physical removal, mechanical removal, ultrasonic removal, and the addition of inhibitors. However, solvent cleaning methods mostly use aromatic solvents such as benzene, toluene, and xylene, which pose significant hazards to the environment and operators. Mechanical methods have a short effective period and are limited in the areas they can clean, thus limiting their application. Ultrasonic removal utilizes the cavitation effect generated by ultrasound to break down the molecular structure of paraffin or asphaltenes, but its effective cleaning period is short, and its cost is high, also limiting its application.
[0003] To effectively reduce the hazards caused by the aggregation of paraffin or asphaltenes, adding inhibitors during the extraction process simplifies operations and lowers costs. Inhibitors allow paraffins and asphaltenes to be fully dispersed in crude oil, maintaining a dynamic equilibrium, thus preserving their stability and preventing or delaying their aggregation.
[0004] With the continuous exploitation of oil fields, the impact of paraffin or bituminous deposits in the oil reservoirs is becoming increasingly significant. Paraffin inhibitors (wax inhibitors) mainly include surfactant-type, polycyclic aromatic hydrocarbon-type, and polymer-type; bituminous inhibitors mainly fall into four categories: hydroxyl derivatives, alkylbenzene derivatives, high molecular weight polymers, and ionic liquids. Currently, domestic and international research institutions have conducted a series of in-depth studies on wax inhibitors and successfully developed a variety of wax inhibitor products. However, these products still have significant shortcomings, such as limited functionality and strong selectivity. Therefore, in future development, efforts should be made to address these shortcomings and develop wax inhibitors that meet specific needs. Summary of the Invention
[0005] The main objective of this invention is to provide an inhibitor, its preparation method, and its application, in order to solve the problem that existing paraffin and asphaltenes inhibitors have only one function, which makes it impossible to use the same inhibitor to simultaneously inhibit both paraffin and asphaltenes.
[0006] To achieve the above objective, according to a first aspect of the present invention, an inhibitor is provided, the inhibitor comprising structural units derived from the monomer shown in Formula I, structural units derived from the monomer shown in Formula II, and structural units derived from 2-acrylamide-2-methylpropanesulfonic acid:
[0007]
[0008] Where R1 and R2 are each independently C 12-22 Alkyl, C 12-22 One of the haloalkyl groups.
[0009] To further improve the inhibitory effect on paraffin and asphaltenes, the molar ratio of the structural units derived from the monomer shown in Formula I, the structural units derived from the monomer shown in Formula II, and the structural units derived from 2-acrylamide-2-methylpropanesulfonic acid in the above-mentioned inhibitor is (3-5):1:(1-4).
[0010] Further, the monomer shown in Formula I is at least one of hexadecyl acrylate, octadecyl acrylate, and dibutyl acrylate; the monomer shown in Formula II is at least one of maleidoyl dodecylamine, maleidoyl hexadecylamine, maleidoyl octadecylamine, and maleidoyl dibutylamine.
[0011] Furthermore, the monomer shown in Formula I is docosahexadecyl acrylate, and the monomer shown in Formula II is maleic anhydride.
[0012] According to a second aspect of the present invention, a method for preparing an inhibitor is provided, the method comprising the following steps:
[0013] S1, at least one monomer of Formula I, at least one monomer of Formula II, and 2-acrylamide-2-methylpropanesulfonic acid are dispersed in a solvent to obtain a mixture;
[0014] S2, an initiator is added to the above mixture to induce a polymerization reaction and obtain an inhibitor;
[0015]
[0016] Where R1 and R2 are each independently C 12-22 Alkyl, C 12-22 One of the haloalkyl groups.
[0017] Furthermore, based on a mass fraction of 100% for the mixture, the total mass fraction of the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid is 20%-40%; based on a total mass fraction of 100% for the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid, the mass fraction of the initiator is 0.1%-1%.
[0018] Furthermore, in S1 above, the molar ratio of the monomer shown in Formula I, the monomer shown in Formula II, and 2-acrylamide-2-methylpropanesulfonic acid is (3-5):1:(1-4).
[0019] Furthermore, the solvent in S1 is water.
[0020] Furthermore, the initiator in S2 is persulfate.
[0021] Furthermore, the initiator is added after the mixture is heated to 48-52℃; the polymerization reaction is completed by stirring at 70-90℃ for 4-8 hours.
[0022] According to a third aspect of the present invention, an application is provided of the above-described inhibitor or the inhibitor prepared by the above-described preparation method in the field of inhibiting the formation of paraffin and / or asphaltenes precipitation, such as in the petrochemical field.
[0023] By applying the technical solution of this invention, the structure of the inhibitor is controlled. When the inhibitor contains structural units derived from the monomer shown in Formula I, the ester groups in its structure have high lipophilicity and molecular polarity, which can interact with paraffin to prevent its crystallization. Furthermore, when the inhibitor contains structural units derived from the monomer shown in Formula II, the amide groups in its structure can form hydrogen bonds with the fatty acids in paraffin, thereby preventing crystallization. Additionally, the carboxyl groups can react chemically with asphaltenes to form a stable dispersion system, preventing asphaltenes from agglomerating and depositing on the surfaces of pipes and equipment. When the inhibitor contains structural units derived from 2-acrylamido-2-methylpropanesulfonic acid, it has good emulsifying and dispersing effects, which can inhibit the deposition of asphaltenes in crude oil and prevent paraffin crystallization. The inhibitor disclosed in this invention has the ability to inhibit the formation of both paraffin and asphaltenes precipitation. It eliminates the need for multiple inhibitors during crude oil extraction, achieving good inhibition effects with a small dosage. The composite inhibitor of this invention has low viscosity, high temperature resistance, is safe and easy to store, and is convenient to use. Moreover, its raw materials are readily available and widely sourced, making it suitable for industrial applications. Attached Figure Description
[0024] Figure 1 The image shows the infrared spectrum of the inhibitor in Example 1. Detailed Implementation
[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.
[0026] Paraffin wax and bitumen are common deposits in crude oil. Paraffin wax is a mixture of hydrocarbons, mainly composed of solid alkanes, and usually exists in crude oil in solid or waxy form. It often causes blockage problems in oil wells and pipelines. Asphaltenes are a complex mixture composed of various complex high-molecular hydrocarbons and their non-metallic derivatives. They are relatively viscous. In crude oil, asphaltenes deposits usually affect the viscosity and flow properties of crude oil. Therefore, the treatment of paraffin wax and bitumen deposits in crude oil is a crucial part of the crude oil extraction process.
[0027] As described in the background section of this invention, existing technologies suffer from limitations in the inhibitory effects of inhibitors on paraffin and asphaltenes, and the inhibitors are limited in their ability to target only one substance in either paraffin or asphaltenes. To address these issues, in a typical embodiment of this invention, an inhibitor is provided that comprises structural units derived from the monomer shown in Formula I, structural units derived from the monomer shown in Formula II, and structural units derived from 2-acrylamido-2-methylpropanesulfonic acid.
[0028]
[0029] Where R1 and R2 are each independently C 12-22 Alkyl, C 12-22 One of the haloalkyl groups.
[0030] In this invention, "monomer" refers to a single molecule or atom that constitutes a polymer.
[0031] In this invention, "structural unit" refers to a repeating chemical unit in a polymer.
[0032] In this invention, "derived from" means that the structural unit is obtained from the above monomers through a polymerization reaction.
[0033] In this invention, "C" 12-22 "Alkyl" refers to alkyl groups with 12 to 22 carbon atoms. They can be straight-chain alkyl groups or isomeric alkyl groups, such as dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, and docosyl.
[0034] In this invention, "C" 12-22 "Halogenated alkyl" refers to the above "C 12-22 A group in which one or more hydrogen atoms in an alkyl group are replaced by halogen atoms, wherein a halogen atom refers to at least one of fluorine, chlorine, bromine, iodine, and astatine.
[0035] Ester groups possess high lipophilicity and molecular polarity, enabling them to interact with paraffin wax and prevent its crystallization. Furthermore, ester groups can form a protective film on the surface of paraffin wax particles, hindering their attraction and crystallization process, thus inhibiting crystallization. Amide groups can form hydrogen bonds with fatty acids in paraffin wax, thereby preventing crystallization. Amide groups can also react chemically with asphaltenes to form a stable dispersion system, preventing asphaltenes from agglomerating and depositing on pipe and equipment surfaces, thus inhibiting asphaltenes deposition. Compounds containing carboxyl groups can also inhibit paraffin wax crystallization to some extent and can react chemically with asphaltenes to form highly soluble products, thereby reducing deposition problems. 2-Acrylamido-2-methylpropanesulfonic acid is a compound with surfactant properties that can inhibit asphaltenes deposition in crude oil to some extent. Additionally, 2-acrylamido-2-methylpropanesulfonic acid can emulsify and disperse in crude oil, helping to prevent paraffin wax crystallization.
[0036] In order to further improve the inhibitory effect on paraffin and asphaltene, as a preferred embodiment of the present invention, the molar ratio of the structural unit derived from the monomer shown in Formula I, the structural unit derived from the monomer shown in Formula II, and the structural unit derived from 2-acrylamide-2-methylpropanesulfonic acid in the above-mentioned inhibitor is (3-5):1:(1-4).
[0037] By limiting the amount of the three structural units as described above, the inhibition rate of paraffin and asphaltenes in crude oil can be effectively improved, achieving the effect of inhibiting both materials simultaneously with a single inhibitor. Moreover, compared with existing methods, it is simpler to operate and lower in cost.
[0038] In a preferred embodiment of the present invention, the monomer shown in Formula I is at least one of hexadecyl acrylate, octadecyl acrylate, and dibutyl acrylate; the monomer shown in Formula II is at least one of maleico-dodecylamine, maleico-hexadecylamine, maleico-octadecylamine, and maleico-dibutylamine.
[0039] In a preferred embodiment of the present invention, the monomer shown in Formula I is docosahexadecyl acrylate, and the monomer shown in Formula II is maleic anhydride.
[0040] Although compounds containing ester groups, carboxyl groups, and amide groups have a certain inhibitory effect on paraffin crystallization, their specific effects are greatly affected by the structure of the compound containing the ester, carboxyl, and amide groups. By optimizing the types of monomers shown in Formula I and Formula II as described above, the inhibition rate of the inhibitor on the paraffin crystallization process can be effectively improved.
[0041] In another typical embodiment of the present invention, a method for preparing an inhibitor is provided, the method comprising the following steps:
[0042] S1, at least one monomer of Formula I, at least one monomer of Formula II, and 2-acrylamide-2-methylpropanesulfonic acid are dispersed in a solvent to obtain a mixture;
[0043] S2, an initiator is added to the above mixture to induce a polymerization reaction and obtain an inhibitor;
[0044]
[0045] Where R1 and R2 are each independently C 12-22 Alkyl, C 12-22 One of the haloalkyl groups.
[0046] The preparation method of the above-mentioned inhibitor is simple; it only requires mixing the raw materials to induce a polymerization reaction, and the resulting polymer is the inhibitor. As described above, the inhibitor prepared using the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid has good effects in inhibiting paraffin crystallization and asphaltenes deposition.
[0047] In a preferred embodiment of the present invention, the total mass fraction of the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid is 20%-40% based on a 100% mass fraction of the mixture; and the mass fraction of the initiator is 0.1%-1% based on a 100% mass fraction of the total mass fraction of the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid. The present invention uses emulsion polymerization to prepare the inhibitor. Under the above conditions, each monomer can undergo a polymer reaction to generate an inhibitor with the desired structure.
[0048] In a preferred embodiment of the present invention, in S1 above, the molar ratio of the monomer shown in Formula I, the monomer shown in Formula II, and 2-acrylamide-2-methylpropanesulfonic acid is (3-5):1:(1-4). The inhibitor prepared with the above ratio exhibits synergistic effects among its functional groups, effectively enhancing its inhibitory effect.
[0049] Typically, and not limitingly, the inhibitor of this invention is prepared by an emulsion polymer, therefore water is used as the solvent in S1; the initiator in S2 is a persulfate, such as ammonium persulfate or potassium persulfate.
[0050] In a preferred embodiment of the present invention, in step S2, the mixture is heated to 50°C before the initiator is added; the polymerization reaction is completed by stirring at 70-90°C for 4-8 hours. Under the above conditions, efficient polymerization can be achieved to prepare the inhibitor.
[0051] In another typical embodiment of the present invention, the application of the above-mentioned inhibitor or the inhibitor prepared by the above-mentioned preparation method in the field of inhibiting the formation of paraffin and / or asphaltenes precipitation is provided.
[0052] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.
[0053] Example 1
[0054] An embodiment of the inhibitor of the present invention is prepared by the following method, and the types and proportions of monomers used are shown in Table 1:
[0055] S1. Add 2-acrylamide, maleic hexadecylamine and 2-acrylamide-2-methylpropanesulfonic acid to a three-necked flask to disperse the three monomers in deionized water to obtain a mixture.
[0056] S2, when the temperature of the mixture rises to 50°C, add the initiator ammonium persulfate, and the inhibitor is obtained after the reaction.
[0057] The molar ratio of 2-diethyl acrylate, maleic hexadecylamine, and 2-acrylamide-2-methylpropanesulfonic acid is 3:1:4; the total mass fraction of monomers in the mixture is 20% based on a mass fraction of 100%; the mass fraction of initiator is 0.1% based on a mass fraction of all monomers in the mixture; and the inhibitor is obtained by reacting at 70°C for 4 hours.
[0058] Figure 1 The image shows the infrared spectrum of the inhibitor in Example 1. As can be seen from the image, at 2925 cm⁻¹... -1 2852cm -1 The presence of a double absorption peak nearby indicates the presence of a methyl structure, 1729 cm⁻¹ -1 1187cm -1 The presence of an absorption peak, located at 1454 cm⁻¹, indicates the presence of an ester group. -1 The absorption peaks indicate the presence of an amide structure in the polymer, and the spectrum suggests that the synthesis of the inhibitor was successful.
[0059] Examples 2-5
[0060] The embodiments of the inhibitor of the present invention differ from those of Embodiment 1 only in that the molar ratio of each monomer is different, as shown in Table 1.
[0061] Examples 6-9
[0062] The embodiments of the inhibitors of the present invention differ from those of Embodiment 1 only in that the monomers shown in Formula I and / or Formula II are of different types, as shown in Table 1.
[0063] Example 10
[0064] The embodiment of the inhibitor of the present invention differs from that of Example 1 in that, based on a mass fraction of 100% of the mixture, the total mass fraction of the monomer is 40%; based on a total mass fraction of 100% of the monomer, the mass fraction of the initiator is 1%, and the polymerization reaction is completed at 80°C for 8 hours.
[0065] Example 11
[0066] The embodiment of the inhibitor of the present invention differs from that of Example 1 in that, based on a mass fraction of 100% of the mixture, the total mass fraction of the monomer is 30%; based on a total mass fraction of 100% of the monomer, the mass fraction of the initiator is 0.5%, and the polymerization reaction is completed at 70°C for 6 hours.
[0067] Comparative Example 1
[0068] An inhibitor that differs from Example 1 in that it does not contain the monomer maleic hexadecylamine, and the molar ratio of dodecyl acrylate and 2-acrylamide-2-methylpropanesulfonic acid is 3:4.
[0069] Comparative Example 2
[0070] An inhibitor that differs from Example 1 in that the monomer 2-acrylamide-2-methylpropanesulfonic acid is not added, and the molar ratio of dodecyl acrylate to maleic hexadecylamine is 3:1.
[0071] Table 1
[0072]
[0073]
[0074] Performance testing
[0075] The performance of the inhibitors in the examples and comparative examples was tested. The paraffin inhibition rate was tested according to the standard SYT 6300-2009 "Technical Conditions for Dewaxing and Inhibiting Agents for Oil Production". The asphaltene inhibition rate was tested by ultraviolet spectrophotometry. The test results are shown in Table 2-3.
[0076] Table 2 Paraffin Inhibition Rate / %
[0077]
[0078] Table 3 Asphaltene Inhibition Rate (%)
[0079]
[0080]
[0081] As can be seen from the above test results, the inhibitor in the embodiments of the present invention has a good inhibitory effect on paraffin and asphaltenes. Under the condition of a concentration of 200 ppm, it has an inhibition rate of more than 55% for paraffin and asphaltenes, and is suitable for widespread industrial application.
[0082] Furthermore, comparing the test results of Examples 1-5, it can be found that when the molar ratio of the structural unit derived from the monomer shown in Formula I, the structural unit derived from the monomer shown in Formula II, and the structural unit derived from 2-acrylamide-2-methylpropanesulfonic acid in the structure of the inhibitor is (3-5):1:(1-4), and its concentration is 200ppm, the inhibition rate of paraffin and asphaltenes can reach more than 65%.
[0083] Comparing the test structures of Examples 1 and 6-9, it can be found that when the monomer shown in Formula I is at least one of hexadecyl acrylate, octadecyl acrylate, and dodecyl acrylate, and the monomer shown in Formula II is at least one of maleidoyl dodecylamine, maleidoyl hexadecylamine, maleidoyl octadecylamine, and maleidoyl dodecylamine, the inhibition rate is higher; furthermore, when the monomer shown in Formula I is dodecyl acrylate and the monomer shown in Formula II is maleidoyl hexadecylamine, the inhibition rate is the highest.
[0084] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An inhibitor, characterized in that, It includes structural units derived from the monomer shown in Formula I, structural units derived from the monomer shown in Formula II, and structural units derived from 2-acrylamide-2-methylpropanesulfonic acid: Where R1 and R2 are each independently C 12-22 Alkyl, C 12-22 One of the haloalkyl groups.
2. The inhibitor according to claim 1, characterized in that, In the inhibitor, the molar ratio of the structural unit derived from the monomer shown in Formula I, the structural unit derived from the monomer shown in Formula II, and the structural unit derived from 2-acrylamide-2-methylpropanesulfonic acid is (3-5):1:(1-4).
3. The inhibitor according to claim 1 or 2, characterized in that, The monomer represented by Formula I is at least one of hexadecyl acrylate, octadecyl acrylate, and dibutyl acrylate; the monomer represented by Formula II is at least one of maleic dodecylamine, maleic hexadecylamine, maleic octadecylamine, and maleic dibutylamine.
4. The inhibitor according to claim 3, characterized in that, The monomer represented by Formula I is docosahexadecyl acrylate, and the monomer represented by Formula II is maleic anhydride.
5. A method for preparing the inhibitor according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1, at least one monomer of Formula I, at least one monomer of Formula II, and 2-acrylamide-2-methylpropanesulfonic acid are dispersed in a solvent to obtain a mixture; S2, an initiator is added to the mixture to induce a polymerization reaction and obtain the inhibitor.
6. The method for preparing the inhibitor according to claim 5, characterized in that, Based on a mass fraction of 100% for the mixture, the total mass fraction of the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid is 20%-40%; based on a total mass fraction of 100% for the monomers shown in Formula I, Formula II, and 2-acrylamide-2-methylpropanesulfonic acid, the mass fraction of the initiator is 0.1%-1%.
7. The method for preparing the inhibitor according to claim 5 or 6, characterized in that, The solvent is water.
8. The method for preparing the inhibitor according to claim 5 or 6, characterized in that, The initiator is persulfate.
9. The method for preparing the inhibitor according to claim 5 or 6, characterized in that, In step S2, the initiator is added after the mixture is heated to 48-52°C; the polymerization reaction is completed by stirring at 70-90°C for 4-8 hours.
10. The use of an inhibitor according to any one of claims 1 to 4 or an inhibitor prepared by any one of claims 5 to 9 in the field of inhibiting the formation of paraffin and / or asphaltenes deposits.