Crude oil asphaltene solid inhibitor as well as preparation method and application thereof

Abstract

The invention discloses a crude oil asphaltene solid inhibitor and a preparation method and application thereof, the preparation method comprises the following steps: reacting palmitoleic acid, aluminum oxide and diethylenetriamine, then reacting with ethidene diamine under the action of ethanol, and dissolving the obtained reactant and clay in water to obtain a mixture; and adding vinyl acetate into the mixture, uniformly stirring, adding cyclohexane, vinyl alcohol polyether and an initiator, uniformly mixing, and carrying out polymerization reaction to obtain the crude oil asphaltene solid inhibitor. The prepared crude oil asphaltene solid inhibitor can reduce the crude oil asphaltene precipitation temperature by 7-13 DEG C, and still has a good asphaltene precipitation inhibition function under the condition that the use concentration is reduced.

Description

Technical Field

[0001] This invention belongs to the field of petroleum extraction and relates to a crude oil asphaltene solid inhibitor, its preparation method, and its application. Background Technology

[0002] As oil temperature decreases, asphaltene-containing crude oil reaches its critical precipitation point, causing asphaltene deposits to form on the surface and adhere to the pipe walls, significantly reducing oil production and transportation capacity. In severe cases, this can lead to blockages, becoming a primary problem that must be solved in oil extraction. Domestically and internationally, the addition of chemical asphaltene inhibitors is widely used to address this challenge. Using asphaltene precipitation inhibitors is an ideal method to mitigate asphaltene precipitation during crude oil transportation. Among these, polymer-based inhibitors are widely used due to their advantages such as low dosage, high efficiency, and ease of modification.

[0003] Currently, there are numerous types and quantities of crude oil asphaltene inhibitors reported in domestic and international literature and patents. Commonly used crude oil asphaltene inhibitors mainly fall into the following categories: hydroxyl-containing asphaltene inhibitors, primarily alkylphenols, alkylphenol polyoxyethylene ethers, polyether polyols, and polyol fatty acid esters; alkylbenzene derivative inhibitors, mainly dodecylbenzenesulfonic acid, benzoic acid, dodecylphenol, and salicylic acid; and polymeric asphaltene inhibitors, primarily composed of amine organic compounds and polymers containing nitrogen-oxygen organic compounds, represent a new research direction in asphaltene inhibitors in recent years, mainly focusing on polyisobutylene succinimide, polyisobutylene succinate, nonylphenol aldehyde resin-modified polyamines, and rapeseed oil amide inhibitors. Hydroxyl nonionic inhibitors exert their inhibitory effect by forming hydrogen bonds with heteroatomic nitrogen or hydroxyl groups and adsorbing onto asphaltene molecules. However, because they can achieve self-association through hydrogen bonds and adsorb onto the side of the asphaltene, their inhibitory effect is significantly affected. The reason for the inhibitory effect of alkylbenzene derivative inhibitors on asphaltene deposition is that they form π-π interactions with asphaltene molecules, weakening the π-π interactions between asphaltene molecules. Furthermore, the head functional group of benzenesulfonic acid is highly acidic, capable of reacting with asphaltenes molecules through acid-base interactions and resulting in large-scale adsorption. This forms a strong dipole interaction, disrupting the intermolecular interactions of asphaltenes and thus inhibiting their polymerization and sedimentation. However, this asphaltenes inhibitor is also adsorbed on the side of the asphaltenes, which somewhat affects its inhibitory effect. In addition to acid-base adsorption, polymeric inhibitors can increase the thickness of the polymer adsorption layer to increase steric hindrance, thereby hindering asphaltenes aggregation and deposition and increasing the inhibitor's solubility in oil. With the continuous development of oil fields, asphaltenes deposition has caused serious damage to oilfield production. Currently, asphaltenes inhibitors are widely used in oil fields in Iran, Kuwait, Sudan, and domestically in fields such as Dagang and Tarim. Therefore, research on asphaltenes inhibitors is increasing both domestically and internationally. However, existing asphaltenes inhibitors are less effective at lower temperatures and require concentrations of 1000-5000 ppm, resulting in high costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a crude oil asphaltene solid inhibitor, its preparation method and application. The crude oil asphaltene solid inhibitor can reduce the precipitation temperature of crude oil asphaltene by 7-13°C, and still has a good function of inhibiting asphaltene precipitation even when the concentration is reduced.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A method for preparing a crude oil asphaltenes solid inhibitor includes the following steps:

[0007] After reacting palmitoleic acid, aluminum oxide and diethylenetriamine, the mixture is reacted with ethylenediamine in the presence of ethanol. The resulting reactants are dissolved in water with clay to obtain a mixture.

[0008] After adding vinyl acetate to the mixture and stirring it evenly, cyclohexane, vinyl alcohol polyether and initiator are added and mixed evenly. After polymerization reaction, crude oil asphalt solid inhibitor is obtained.

[0009] The mass ratio of palmitoleic acid, diethylenetriamine, and ethylenediamine is (1.5-2):1:0.9; the mass ratio of alumina and palmitoleic acid is (0.05-0.1):1; the mass ratio of reactants to clay is (0.3-0.5):(4-6); the mass ratio of vinyl acetate to vinyl alcohol polyether is (9-11):(0.2-0.4); and the mass ratio of vinyl acetate, water, cyclohexane, and initiator is (9-11):(80-100):(110-120):(0.01-0.03).

[0010] Preferably, the clay contains 80%-98% montmorillonite by mass.

[0011] Preferably, the initiator is azobisisobutyronitrile.

[0012] Preferably, palmitoleic acid, aluminum oxide, and diethylenetriamine are reacted at a temperature of 190-210℃ for 1-3 hours.

[0013] Furthermore, after palmitoleic acid, aluminum oxide and diethylene react, the mixture is cooled and then mixed with ethanol. Ethylenediamine is added when the temperature is raised to 30-40℃ to carry out the reaction. At the same time as adding ethylenediamine, the temperature is raised to 70-80℃ and the reaction is carried out for 2-4 hours.

[0014] Preferably, when vinyl acetate is added to the mixture and stirred evenly, the stirring speed is 10000-15000 r / min and the stirring time is 20-40 min.

[0015] Preferably, after adding cyclohexane, vinyl alcohol polyether and initiator, the mixture is stirred for 20-40 minutes at a stirring speed of 10000-15000 r / min until it is mixed.

[0016] Preferably, in the polymerization reaction, the stirring speed is 500-1000 r / min; the reaction temperature is 50-70℃; and the reaction time is 120-150 min.

[0017] A crude oil asphaltene solid inhibitor prepared by the above preparation method.

[0018] An application of the above-mentioned crude oil asphaltenes solids inhibitor in suppressing asphaltenes segregation, wherein the concentration of the crude oil asphaltenes solids inhibitor is 100-1000 ppm.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention relates to an organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor formed by compounding vinyl acetate with inorganic clay and performing a reverse emulsion polymerization reaction under the action of ethylene glycol polyether. The preparation process is simple, easy to operate, and has low production cost. It has a good function of inhibiting asphaltenes precipitation. The shelf life of the crude oil asphaltenes solid inhibitor is longer than that of liquid asphaltenes inhibitor and is not affected by evaporation or volatilization. The production cost of the crude oil asphaltenes solid inhibitor is lower than that of the liquid asphaltenes inhibitor, and no solvent or diluent is required. The crude oil asphaltenes solid inhibitor can be stored and transported at room temperature, while the liquid asphaltenes inhibitor needs to be stored and transported under specific temperature and pressure conditions.

[0021] Furthermore, the prepared organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor, when used at a concentration of 100-1000 ppm, can reduce the precipitation temperature of crude oil asphaltenes by 7-13℃, demonstrating excellent asphaltenes precipitation inhibition function. Detailed Implementation

[0022] The embodiments of the present invention are described in detail below. In this description, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientation or positional relationships, are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terms “installation,” “connection,” and “linkage” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; a mechanical connection, an electrical connection, or a connection that allows communication; a direct connection or an indirect connection via an intermediate medium; or a connection within two elements or an interaction between two elements. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0026] This embodiment provides a method for preparing a crude oil asphaltene solid inhibitor, including the following steps:

[0027] After reacting palmitoleic acid, aluminum oxide, and polyethylene polyamine, the mixture reacts with aliphatic diamine under the action of alcohol compounds. The resulting reactants are dissolved in water with clay to obtain a mixture.

[0028] After adding vinyl acetate to the mixture and stirring it evenly, cycloalkanes, ethylene alcohol polyether and an initiator are added and mixed evenly to obtain a stable water-in-oil emulsion. After polymerization, a crude oil asphalt solid inhibitor is obtained.

[0029] The clay used is ordinary clay, with a montmorillonite content of 80%-98% by mass.

[0030] The mass ratio of vinyl acetate to vinyl alcohol polyether is (9-11):(0.2-0.4).

[0031] The mass ratio of vinyl acetate to water, cycloalkanes, and initiator is (9-11):(80-100):(110-120):(0.01-0.03).

[0032] In this process, vinyl acetate is added to the mixture and stirred uniformly at a speed of 10,000-15,000 r / min for 20-40 min to obtain an aqueous solution containing water-soluble monomers and clay.

[0033] Add cycloalkanes, vinyl alcohol polyethers, and an initiator to the aqueous solution, and stir for 20-40 minutes at a stirring speed of 10000-15000 r / min until mixed to obtain a stable water-in-oil emulsion.

[0034] In the polymerization reaction, the stirring speed of the water-in-oil microemulsion is 500-1000 r / min; the reaction temperature is 50-70℃; and the reaction time is 120-150 min.

[0035] The step of reacting palmitoleic acid, aluminum oxide, and ethylene polyamine, followed by reacting them with aliphatic diamines under the action of alcohol compounds, and then dissolving the resulting reactants with clay in water to obtain a mixture, includes:

[0036] Palmitoleic acid, aluminum oxide, and ethylene polyamine are reacted at 190-210℃ for 1-3 hours. After cooling, they are mixed with alcohol compounds, and when the temperature is raised to 30-40℃, aliphatic diamine is added. At the same time, the temperature is raised to 70-80℃ and the reaction is carried out for 2-4 hours. The resulting reactants are dissolved in water with clay to obtain a mixture.

[0037] The mass ratio of the reactant to clay is (0.3-0.5):(4-6).

[0038] The mass ratio of palmitoleic acid, diethylenetriamine, and fatty diamine is (1.5-2):1:0.9; the mass ratio of aluminum oxide and palmitoleic acid is (0.05-0.1):1.

[0039] Among them, the ethylene polyamine is one or more of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; the initiator is one or two of azobisisobutyronitrile and azobisisoheptanenitrile; the alcohol compound is one or more of methanol, ethanol, propanol, and butanol; the aliphatic diamine is one or more of ethylenediamine, propylenediamine, and butanediamine; and the cycloalkanes are one or more of tetrahydrofuran, cyclohexane, cyclopentane, and cycloheptane.

[0040] The crude oil asphaltene solid inhibitor described in this embodiment was prepared using the above-described preparation method.

[0041] The crude oil asphaltenes solids inhibitor described in this embodiment can be used to inhibit asphaltenes precipitation. The concentration of the crude oil asphaltenes solids inhibitor is 100-1000 ppm.

[0042] It is worth noting that the addition of vinyl acetate and ethylene alcohol polyether significantly affects the pour point depressant effect of the obtained crude oil asphaltene solid inhibitor. The mechanism is as follows: when vinyl acetate and ethylene alcohol polyether undergo physical adsorption with asphaltene, they are adsorbed onto the asphaltene surface using van der Waals forces, electrostatic interactions, and hydrogen bonds. This interaction alters the solubility and dispersion state of asphaltene, allowing it to be uniformly dispersed in crude oil and preventing asphaltene aggregation and precipitation. Furthermore, the crude oil asphaltene solid inhibitor provided in this application has the following advantages compared to liquid asphaltene inhibitors: longer shelf life (the shelf life of the crude oil asphaltene solid inhibitor is longer than that of the liquid asphaltene inhibitor and is not affected by evaporation or volatilization); lower cost (the production cost of the crude oil asphaltene solid inhibitor is lower than that of the liquid asphaltene inhibitor and does not require the use of solvents or diluents); and easier storage and transportation (the crude oil asphaltene solid inhibitor can be stored and transported at room temperature, while the liquid asphaltene inhibitor requires storage and transportation under specific temperature and pressure conditions). The concentration of crude oil asphaltenes solid inhibitor used downhole with crude oil is 100-1000 ppm, which can reduce the precipitation temperature of crude oil asphaltenes by 7-13℃. Even with the reduced concentration, it still has a good function of inhibiting asphaltenes precipitation.

[0043] The technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the preparation method of the crude oil asphaltene solid inhibitor of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0044] Additionally, it should be noted that the values ​​given in the following embodiments are as accurate as possible. However, those skilled in the art will understand that due to unavoidable measurement errors and experimental issues, each number should be understood as an approximation rather than an absolutely accurate value.

[0045] Example 1

[0046] 1) Add 30g of palmitoleic acid to 1.5g of aluminum oxide and 15g of diethylenetriamine, heat to 200℃ and react for 2h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of ethanol. Heat to 35℃ and add 18g of ethylenediamine dropwise to the reaction system using a dropping funnel. At the same time, raise the temperature to 75℃ and stir the reaction for 3h. Dissolve 0.3g of the resulting reactant and 4g of clay in 100g of water and mix well to obtain a mixed solution of clay.

[0047] 2) Add 9g of vinyl acetate to the above clay mixture solution and stir at 10000r / min for 20min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0048] 3) Add 110g cyclohexane, 0.3g ethylene glycol polyether and 0.01g azobisisobutyronitrile to the aqueous solution, and stir for 20min at a stirring speed of 10000r / min until mixed to obtain a stable water-in-oil emulsion.

[0049] 4) The above stable water-in-oil microemulsion was heated to 55°C and reacted for 120 min under stirring at 500 r / min to obtain an organic-inorganic composite hybrid crude oil asphaltene solid inhibitor.

[0050] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 1 reduced the crude oil asphaltenes precipitation temperature from 31°C to 24°C.

[0051] Example 2

[0052] 1) Add 30g of palmitoleic acid to 2g of aluminum oxide and 18g of triethylenetetramine, heat to 190℃ and react for 2h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of ethanol. Heat to 32℃, add 16g of ethylenediamine dropwise to the reaction system using a dropping funnel, and simultaneously raise the temperature to 70℃ and stir for 3h. Dissolve 0.5g of the resulting reactant and 6g of clay in 80g of water, mix well, and obtain a mixed solution of clay.

[0053] 2) Add 11g of vinyl acetate to the above clay mixture solution and stir at 15000r / min for 40min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0054] 3) Add 120g cyclohexane, 0.3g ethylene glycol polyether and 0.03g azobisisobutyronitrile to the aqueous solution, and stir for 40min at a stirring speed of 15000r / min until mixed to obtain a stable water-in-oil emulsion.

[0055] 4) The above stable water-in-oil microemulsion was heated to 50°C and reacted for 150 min under stirring at 1000 r / min to obtain an organic-inorganic composite hybrid crude oil asphaltene solid inhibitor.

[0056] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 2 reduced the crude oil asphaltenes precipitation temperature from 31°C to 24°C.

[0057] Example 3

[0058] 1) Add 30g of palmitoleic acid to 1.01g of aluminum oxide and 16g of tetraethylenepentamine, heat to 200℃ and react for 1h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of methanol. Heat to 40℃ and add 14g of butanediamine dropwise to the reaction system using a dropping funnel. At the same time, raise the temperature to 80℃ and stir the reaction for 3h. Dissolve 0.4g of the resulting reactant and 3.2g of clay in 90g of water and mix well to obtain a mixed solution of clay.

[0059] 2) Add 10g of vinyl acetate to the above clay mixture solution and stir at 12500r / min for 30min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0060] 3) Add 115g tetrahydrofuran, 0.3g vinyl alcohol polyether and 0.02g azobisisobutyronitrile to the aqueous solution, and stir for 30min at a stirring speed of 12500r / min until mixed to obtain a stable water-in-oil emulsion.

[0061] 4) The above stable water-in-oil microemulsion was heated to 60°C and reacted for 135 min under stirring at 750 r / min to obtain an organic-inorganic composite hybrid crude oil asphaltene solid inhibitor.

[0062] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 3 reduced the crude oil asphaltenes precipitation temperature from 31°C to 22°C.

[0063] Example 4

[0064] 1) Add 30g of palmitoleic acid to 3g of aluminum oxide and 20g of diethylenetriamine, heat to 210℃ and react for 3h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of propanol, heat to 30℃, and add 13.5g of propylenediamine dropwise to the reaction system using a dropping funnel. At the same time, raise the temperature to 70℃ and stir the reaction for 4h. Dissolve 0.3g of the resulting reactant and 3g of clay in 80g of water, mix well, and obtain a mixed solution of clay.

[0065] 2) Add 9g of vinyl acetate to the above clay mixture solution and stir at 15000r / min for 20min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0066] 3) Add 115g of cyclopentane, 0.2g of vinyl alcohol polyether and 0.02g of azobisisobutyronitrile to the aqueous solution, and stir for 30min at a stirring speed of 12500r / min until mixed to obtain a stable water-in-oil emulsion.

[0067] 4) The above stable water-in-oil microemulsion was heated to 60°C and reacted for 135 min under stirring at 750 r / min to obtain an organic-inorganic composite hybrid crude oil asphaltene solid inhibitor.

[0068] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 4 reduced the crude oil asphaltenes precipitation temperature from 31°C to 21°C.

[0069] Example 5

[0070] 1) Add 30g of palmitoleic acid to 2.5g of aluminum oxide and 20g of diethylenetriamine, heat to 210℃ and react for 2h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of butanol, heat to 40℃, and add 13.5g of ethylenediamine dropwise to the reaction system using a dropping funnel. At the same time, raise the temperature to 70℃ and stir the reaction for 4h. Dissolve 0.4g of the resulting reactant and 4.8g of clay in 100g of water, mix well, and obtain a mixed solution of clay.

[0071] 2) Add 11g of vinyl acetate to the above clay mixture solution and stir at 12500r / min for 30min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0072] 3) Add 120g of cycloheptane, 0.4g of vinyl alcohol polyether and 0.03g of azobisisobutyronitrile to the aqueous solution, and stir for 20min at a stirring speed of 15000r / min until mixed to obtain a stable water-in-oil emulsion.

[0073] 4) The above stable water-in-oil microemulsion was heated to 55°C and reacted for 120 min under stirring at 500 r / min to obtain an organic-inorganic composite hybrid crude oil asphaltene solid inhibitor.

[0074] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 5 reduced the crude oil asphaltenes precipitation temperature from 31°C to 18°C.

[0075] Example 6

[0076] 1) Add 30g of palmitoleic acid to 2g of aluminum oxide and 15g of diethylenetriamine, heat to 190℃ and react for 3h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of ethanol. Heat to 30℃ and add 18g of ethylenediamine dropwise to the reaction system using a dropping funnel. At the same time, raise the temperature to 80℃ and stir for 2h. Dissolve 0.3g of the resulting reactant and 6g of clay in 100g of water and mix well to obtain a mixed solution of clay.

[0077] 2) Add 11g of vinyl acetate to the above clay mixture solution and stir at 10000r / min for 40min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0078] 3) Add 110g cyclohexane, 0.2g ethylene glycol polyether and 0.03g azobisisobutyronitrile to the aqueous solution, and stir for 40min at a stirring speed of 10000r / min until mixed to obtain a stable water-in-oil emulsion.

[0079] 4) The above stable water-in-oil microemulsion was heated to 65°C and reacted for 120 min under stirring at 500 r / min to obtain a vinyl acetate-vinyl alcohol polyether-montmorillonite (VA-AEO-MMT) organic-inorganic composite hybrid crude oil asphaltene solid inhibitor.

[0080] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 6 reduced the crude oil asphaltenes precipitation temperature from 31°C to 16°C.

[0081] Example 7

[0082] 1) Add 30g of palmitoleic acid to 2.3g of aluminum oxide and 18g of diethylenetriamine, heat to 200℃ and react for 2h. After cooling the resulting 30g of product to room temperature, add it to the reactor along with 12mL of ethanol. Heat to 35℃ and add 15g of ethylenediamine dropwise to the reaction system using a dropping funnel. At the same time, raise the temperature to 75℃ and stir the reaction for 3h. Dissolve 0.4g of the resulting reactant and 4g of clay in 90g of water and mix well to obtain a mixed solution of clay.

[0083] 2) Add 10g of vinyl acetate to the above clay mixture solution and stir at 12500r / min for 30min until well mixed to obtain an aqueous solution containing water-soluble monomers and clay.

[0084] 3) Add 120g cyclohexane, 0.3g emulsifier ethylene alcohol polyether and 0.03% initiator azobisisobutyronitrile to the aqueous solution, and stir for 20min at a stirring speed of 10000r / min until mixed to obtain a stable water-in-oil emulsion.

[0085] 4) The above stable water-in-oil microemulsion was heated to 70°C and reacted for 150 min under stirring at 750 r / min to obtain an organic-inorganic composite hybrid crude oil asphalt solid inhibitor.

[0086] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Example 7 reduced the crude oil asphaltenes precipitation temperature from 31°C to 13°C.

[0087] Comparative Example 1

[0088] 1) Add 30g of palmitoleic acid to 1.5g of aluminum oxide and 15g of diethylenetriamine, heat to 200℃, cool the resulting 30g of product to room temperature and add it to the reactor along with 12mL of ethanol, heat to 35℃, add 18g of ethylenediamine dropwise to the reaction system using a dropping funnel, and simultaneously raise the temperature to 75℃ and stir for 3h. Dissolve 0.3g of the resulting reactant and 4g of clay in 100g of water, mix well, and obtain a mixed solution of clay.

[0089] 2) Add 4g acrylamide, 5g vinyl acetate and 7g perfluoroalkyl acrylate monomer to the above clay mixture solution, and stir at 10000r / min for 20min until well mixed to obtain an aqueous solution containing water-soluble monomer and clay.

[0090] 3) Add 110g cyclohexane, 0.3g vinyl alcohol polyether and 0.01g azobisisobutyronitrile to the aqueous solution, and stir for 20min at a stirring speed of 10000r / min until mixed to obtain a stable water-in-oil emulsion.

[0091] 4) The above stable water-in-oil microemulsion was heated to 55°C and reacted for 120 min under stirring at 5000 r / min to obtain an organic-inorganic composite hybrid crude oil asphalt solid inhibitor.

[0092] The organic-inorganic composite hybrid crude oil asphaltenes solid inhibitor prepared in Comparative Example 1 reduced the crude oil asphaltenes precipitation temperature from 31°C to 29°C. Compared with the results of Example 1, it is demonstrated that using vinyl acetate alone as the water-soluble monomer achieves better technical results than using a mixture of acrylamide, vinyl acetate and perfluoroalkyl acrylate monomers.

[0093] The asphaltene precipitation temperature test method is as follows: ① Prepare crude oil sample: Prepare 150 mL of crude oil with an asphaltene precipitation temperature of 31℃; ② Prepare asphaltene inhibitor: Based on experimental requirements and previous research, determine the amount of solid asphaltene inhibitor to be added to the crude oil asphaltene as 10 ppm; ③ Mix sample: Add 50 mL of crude oil sample and 10 ppm of asphaltene inhibitor to a sealed container and mix thoroughly; ④ Heating process: Place the sample container in a constant temperature bath or hot water bath and heat to 90℃ at a predetermined heating rate of 5 kJ / h. After reaching 90℃, maintain the temperature for 30 min, then decrease the temperature at a rate of 2 kJ / h, and record the temperature and time; ⑤ Observe asphaltene precipitation: Observe the changes in the sample using a microscope during the cooling process. When the precipitation of asphaltene into particles or precipitates is observed, record the temperature at this point, which is the asphaltene precipitation temperature.

[0094] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0095] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A method for preparing a crude oil asphaltene solids inhibitor, characterized by, The process comprises the following steps: After the reaction of palmitoleic acid, aluminum oxide and polyethylene polyamine, the reaction product is reacted with a fatty diamine in the presence of an alcohol compound, and the reaction product and clay are dissolved in water to obtain a mixture; After the addition of vinyl acetate to the mixture and uniform stirring, naphthene, ethylene glycol polyether and an initiator are added and uniformly mixed, and then a crude asphalt solid inhibitor is obtained through polymerization.

2. The method of claim 1, wherein the crude oil asphaltene solids inhibitor is prepared by the process of: When the mixture is uniformly stirred with the addition of vinyl acetate, the stirring speed is 10000-15000r / min, and the stirring time is 20-40min.

3. The method of claim 1, wherein the crude oil asphaitene solids inhibitor is prepared by the steps of: After the addition of naphthene, ethylene glycol polyether and initiator, the mixture is stirred at a speed of 10000-15000r / min for 20-40min.

4. The method of claim 1, wherein the crude oil asphaitene solids inhibitor is prepared by the steps of: The mass percentage of montmorillonite in the clay is 80%-98%.

5. The method of claim 1, wherein the crude oil asphaitene solids inhibitor is prepared by the steps of: The mass ratio of palmitoleic acid, ethylene polyamine and fatty diamine is (1.5-2):1:0.9; the mass ratio of aluminum oxide and palmitoleic acid is (0.05-0.1):1; the mass ratio of the reaction product and clay is (0.3-0.5):(4-6); the mass ratio of vinyl acetate and ethylene glycol polyether is (9-11):(0.2-0.4); the mass ratio of vinyl acetate, water, naphthene and initiator is (9-11):(80-100):(110-120):(0.01-0.03).

6. The method of claim 1, wherein the crude oil asphaitene solids inhibitor is prepared by the steps of: The ethylene polyamine is one or more of diethylene triamine, triethylene tetramine and tetraethylene pentamine; the initiator is one or both of azobisisobutyronitrile and azobisisoheptyl nitrile; the alcohol compound is one or more of methanol, ethanol, propanol and butanol; the fatty diamine is one or more of ethylenediamine, propylenediamine and butylenediamine; and the naphthene is one or more of tetrahydrofuran, cyclohexane, cyclopentane and cycloheptane.

7. The method of claim 1, wherein the crude oil asphaitene solids inhibitor is prepared by the steps of: After the reaction of palmitoleic acid, aluminum oxide and ethylene polyamine, the mixture is cooled, and then mixed with an alcohol compound; and when the temperature is raised to 30-40℃, the fatty diamine is added and reacted for 2-4h while the temperature is raised to 70-80℃.

8. The method of claim 1, wherein the crude oil asphaitene solids inhibitor is prepared by the steps of: In the polymerization reaction, the stirring speed is 500-1000r / min; the reaction temperature is 50-70℃; and the reaction time is 120-150min.

9. A crude oil asphaltene solids inhibitor characterized in that, The crude asphalt solid inhibitor is prepared based on the method of any one of claims 1-8.

10. Use of a crude oil asphaltene solid inhibitor as defined in claim 9 for inhibiting the precipitation of asphaltenes, characterized in that, The use concentration of the crude asphalt solid inhibitor is 100-1000ppm.