Polymer synthesized by free radical polymerization, asphalt dispersant and preparation method and application thereof

Abstract

The invention discloses a polymer synthesized by free radical polymerization, an asphalt dispersant and a preparation method and application thereof, and belongs to the field of heavy oil asphalt dispersants. The asphalt dispersant comprises a main agent and a solvent, the main agent is a polymer synthesized by free radical polymerization. The solvent is selected from at least one of 100 # solvent oil, 150 # solvent oil, 180 # solvent oil and 260 # solvent oil. The mass ratio of the main agent to the solvent is 1: (1-30). According to the asphalt dispersing agent provided by the invention, the polymer synthesized by free radical polymerization is used as a main agent, so that the asphalt dispersing effect can be greatly improved, and the efficiency is higher. The use cost can be reduced due to low use amount of the asphalt dispersant; the temperature-resistant effect is achieved, the temperature can be resisted by 150 DEG C, and the method can be used for thermal production wells.

Description

Technical Field

[0001] This application relates to a free radical polymer, an asphalt dispersant, its preparation method and application, and belongs to the field of heavy oil asphalt dispersants. Background Technology

[0002] my country possesses abundant heavy oil reserves, but with continuous and in-depth extraction, it faces increasing challenges. Heavy oil typically contains high levels of gum and asphaltenes, resulting in high viscosity and density. To improve oil recovery, methods such as miscible flooding, CO2 injection, and steam injection are commonly used to reduce crude oil viscosity. As extraction progresses, the viscosity of the remaining oil in the reservoir increases, with heavy components like gum and asphaltenes remaining. Simultaneously, large amounts of external fluids enter the reservoir, significantly altering the composition of the reservoir fluids and the thermodynamic conditions (temperature, pressure, etc.) of the system. This disrupts the phase equilibrium of the crude oil system, making the organic solid components such as asphaltenes and gums unstable, leading to asphalt precipitation and deposition. Asphalt deposition in the wellbore increases lift resistance, requiring regular scraping to remove it; otherwise, the deposited asphalt gradually clogs the tubing and annulus, causing well shutdowns. Asphalt deposition in the reservoir also blocks seepage channels, reducing reservoir permeability and impacting well productivity.

[0003] Currently, mechanical removal, solvent dissolution, and dispersant injection are commonly used methods to address asphaltene deposition. Mechanical removal methods suffer from short treatment cycles and high labor costs, while solvent dissolution involves large quantities of chemicals and can cause environmental pollution. Dispersant injection is an effective method for stabilizing asphaltene within the crude oil system, requiring smaller amounts of the agent, ensuring safer application, and providing better treatment results.

[0004] To address the problem of asphalt deposition during heavy oil extraction, dispersants are typically added to the crude oil. These dispersants coat the asphalt particles, stabilizing the asphalt aggregates within the heavy oil system. However, currently available dispersants exhibit poor high-temperature stability, easily leading to secondary asphalt aggregation. Therefore, developing a high-temperature resistant asphalt dispersant is essential. Summary of the Invention

[0005] Therefore, this invention provides a high-temperature resistant asphalt dispersant, which mainly consists of a main agent and a solvent. The main agent is a polymer synthesized by free radical polymerization, and the solvent is mainly at least one selected from solvent oil No. 100, solvent oil No. 150, solvent oil No. 180, and solvent oil No. 260. The addition of the main agent can significantly improve the effect of the asphalt dispersant, reduce the dosage, control costs, and the polymer has good temperature resistance, withstanding temperatures up to 150°C.

[0006] According to a first aspect of this application, a polymer synthesized by free radical polymerization is provided.

[0007] A polymer synthesized by free radical polymerization has the following structural formula:

[0008] Among them, R1, R2, and R3 are independently selected from H, CH3-, or CH3CH2-; n1 represents the number of methylene groups, ranging from 0 to 15; n2 represents the number of ethoxy groups in the polyoxyethylene ether segment, ranging from 12 to 20. a represents the mass percentage of R1 and R2 substituted acrylic structural units, b represents the mass percentage of phenylene structural units, and c represents the mass percentage of R3 substituted allyl alcohol polyoxyethylene ether; a:b:c = (20~40):(30~50):(10~50), a+b+c = 100%.

[0009] According to a second aspect of this application, a method for preparing a polymer synthesized by free radical polymerization is provided. Acrylic acid and phenylene substituted with R1 and R2, and allyl alcohol polyoxyethylene ether substituted with R3 are mixed uniformly in a certain proportion, and the main product is obtained by free radical copolymerization. The free radical copolymerization reaction uses ethylene glycol methyl ether or propylene glycol methyl ether as solvent; the initiator for the free radical copolymerization reaction is selected from azobisisobutyronitrile (AIBN) or benzoyl peroxide, and the amount of initiator is 0.5% to 3% of the total mass of the monomers; the reaction temperature is 60℃ to 80℃ (AIBN initiation) and 80℃ to 100℃ (benzoyl peroxide initiation) during the initiation stage, and 80℃ to 120℃ during the complete monomer conversion stage; the reaction time is 3 to 6 hours; the reaction requires nitrogen protection.

[0010] The method for preparing the polymer synthesized by free radical polymerization described above includes: The R1 and R2 substituted acrylic acid, phenylene, and R3 substituted allyl alcohol polyoxyethylene ether were placed in a solvent, mixed evenly, and a free radical copolymerization initiator was added. The reaction was carried out under an inactive atmosphere. After the reaction was completed, the solvent was removed to obtain the polymer. The definitions of R1, R2, and R3 are the same as in claim 1; The number of alkyl groups in a benzene is n1, as defined in claim 1; The number of ethoxy groups in allyl alcohol polyoxyethylene ether is n2, as defined in claim 1.

[0011] Optionally, the amount of the initiator is 0.5% to 3% of the total mass of the monomer.

[0012] Optionally, the initiator is selected from azobisisobutyronitrile or benzoyl peroxide; When the initiator is azobisisobutyronitrile, the temperature during dropwise addition is 60~80℃; When benzoyl peroxide is used, the temperature during initiator addition is 80~100℃.

[0013] Optionally, the solvent is ethylene glycol methyl ether and / or propylene glycol methyl ether.

[0014] Optionally, the reaction temperature is 80~120℃ and the reaction time is 3~6h.

[0015] Optionally, the inactive atmosphere is nitrogen.

[0016] According to a third aspect of this application, an asphalt dispersant is provided. The synthetic main agent in this asphalt dispersant can greatly improve the asphalt dispersion effect, making it more efficient. This asphalt dispersant also has temperature resistance, withstanding temperatures up to 150°C.

[0017] An asphalt dispersant comprising a main agent and a solvent; the main agent is a polymer synthesized by free radical polymerization as described above.

[0018] Optionally, the solvent is selected from at least one of solvent oil No. 100, solvent oil No. 150, solvent oil No. 180, and solvent oil No. 260.

[0019] Optionally, the mass ratio of the main agent to the solvent is 1:1 to 30.

[0020] Preferably, the mass ratio of the main agent to the solvent is 1:1 to 20.

[0021] According to a fourth aspect of this application, an application of an asphalt dispersant is provided.

[0022] The application of the aforementioned asphalt dispersant in heavy oil extraction.

[0023] The beneficial effects that this application can produce include: The asphalt dispersant provided in this application uses a polymer synthesized by free radical polymerization as the main agent, which can significantly improve the asphalt dispersion effect and make it more efficient. The asphalt dispersant requires a low dosage, reducing usage costs; it also has temperature resistance, withstanding temperatures up to 150℃, making it suitable for use in thermal recovery wells. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of asphalt dispersant adsorbing and dispersing asphalt. Detailed Implementation

[0025] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0026] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0027] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.

[0028] like Figure 1 The diagram illustrates the adsorption and dispersion of asphalt by an asphalt dispersant. The main causes of asphalt sedimentation are the dipole interactions, charge transfer interactions, and hydrogen bonds between asphalt molecules. Dipole interactions arise from the localized charge imbalance within asphalt molecules due to the presence of heteroatoms, leading to the formation of permanent dipoles and subsequent electrostatic interactions between them. Charge transfer interactions are primarily manifested in the π-π charge transfer interactions between aromatic molecules. Hydrogen bonds are the interactions between hydrogen atoms bonded to electronegative atoms such as O, S, and N, and other electronegative atoms or electron-rich centers. These dipole interactions, charge transfer interactions, and hydrogen bonds are the main causes of asphalt molecule self-association and even aggregation and precipitation. Asphalt dispersants can adsorb onto these interaction sites on asphalt molecules, thus preventing mutual adsorption between asphalt molecules and inhibiting their aggregation and precipitation.

[0029] Example 1 Add 100g of ethylene glycol methyl ether and 0.5g of sodium bicarbonate to a four-necked flask, stir until the sodium bicarbonate is completely dissolved, and purge with nitrogen for 30 minutes. In a beaker, add 40g of acrylic acid, 50g of styrene, and 10g of allyl alcohol polyoxyethylene ether sequentially, stir for 10 minutes until homogeneous, and transfer to a constant-pressure dropping funnel. Weigh 1.2g of azobisisobutyronitrile (AIBN), dissolve it in 10g of ethylene glycol methyl ether, and transfer it to the constant-pressure dropping funnel. Heat the system in the four-necked flask to 75°C using a constant-temperature water bath. After the system stabilizes, begin simultaneously adding the monomer mixture and initiator solution, with a total adding time of 3 hours. Maintain nitrogen protection during the adding process, and control the stirring speed at 250 rpm. After the addition is complete, the temperature is raised to 90℃, and the reaction continues for 2 hours. After the reaction is complete, heating and nitrogen gas are stopped, and the mixture is allowed to cool naturally to below 40℃. The reaction solution is then transferred to a vacuum distillation apparatus, and ethylene glycol methyl ether is removed by distillation at 60℃~70℃ and 0.08MPa, yielding a yellow viscous polymer, which is the main agent 1. In the structural formula corresponding to the main agent, R1 is H, R2 is H, R3 is CH3, n1 is 0, n2 is 6, a is 40%, b is 50%, and c is 10%.

[0030] Dissolve 10g of the main agent in 200g of No. 100 solvent oil to obtain asphalt dispersant 1. # .

[0031] Example 2 The preparation process of the main agent is the same as in Example 1. 10g of the main agent is dissolved in 200g of No. 150 solvent oil to obtain asphalt dispersant 2. # .

[0032] Example 3 The preparation process of the main agent is the same as in Example 1. 10g of the main agent is dissolved in 200g of No. 180 solvent oil to obtain asphalt dispersant 3. # .

[0033] Example 4 The preparation process of the main agent is the same as in Example 1. Take 10g of the main agent and dissolve it in 200g of No. 260 solvent oil to obtain asphalt dispersant 4#.

[0034] Example 5 Add 100g of ethylene glycol methyl ether and 0.5g of sodium bicarbonate to a four-necked flask, stir until the sodium bicarbonate is completely dissolved, and purge with nitrogen for 30 minutes. In a beaker, add 30g of acrylic acid, 40g of styrene, and 30g of allyl alcohol polyoxyethylene ether sequentially, stir for 10 minutes until homogeneous, and transfer to a constant-pressure dropping funnel. Weigh 1.2g of azobisisobutyronitrile (AIBN), dissolve it in 10g of ethylene glycol methyl ether, and transfer it to the constant-pressure dropping funnel. Heat the system in the four-necked flask to 75°C using a constant-temperature water bath. After the system stabilizes, begin simultaneously adding the monomer mixture and initiator solution, with a total adding time of 3 hours. Maintain nitrogen protection during the adding process, and control the stirring speed at 250 rpm. After the addition was complete, the temperature was raised to 90℃, and the reaction continued for 2 hours. After the reaction was completed, heating and nitrogen gas were stopped, and the mixture was allowed to cool naturally to below 40℃. The reaction solution was transferred to a vacuum distillation apparatus, and ethylene glycol methyl ether was removed by distillation at 60℃~70℃ and 0.08MPa to obtain a yellow viscous polymer, which is the main agent 2. In the structural formula corresponding to the main agent, R1 is H, R2 is H, R3 is CH3, n1 is 0, n2 is 6, a is 30%, b is 40%, and c is 30%.

[0035] Dissolve 10g of the main agent 2 in 200g of No. 100 solvent oil to obtain asphalt dispersant 5. # .

[0036] Example 6 Add 100g of ethylene glycol methyl ether and 0.5g of sodium bicarbonate to a four-necked flask, stir until the sodium bicarbonate is completely dissolved, and purge with nitrogen for 30 minutes. In a beaker, add 20g of acrylic acid, 30g of styrene, and 50g of allyl alcohol polyoxyethylene ether sequentially, stir for 10 minutes until homogeneous, and transfer to a constant-pressure dropping funnel. Weigh 1.2g of azobisisobutyronitrile (AIBN), dissolve it in 10g of ethylene glycol methyl ether, and transfer it to the constant-pressure dropping funnel. Heat the system in the four-necked flask to 75°C using a constant-temperature water bath. After the system stabilizes, begin simultaneously adding the monomer mixture and initiator solution, with a total adding time of 3 hours. Maintain nitrogen protection during the adding process, and control the stirring speed at 250 rpm. After the addition was complete, the temperature was raised to 90℃, and the reaction continued for 2 hours. After the reaction was completed, heating and nitrogen gas were stopped, and the mixture was allowed to cool naturally to below 40℃. The reaction solution was transferred to a vacuum distillation apparatus, and ethylene glycol methyl ether was removed by distillation at 60℃~70℃ and 0.08MPa to obtain a yellow viscous polymer, which is the main agent 3. In the structural formula corresponding to the main agent, R1 is H, R2 is H, R3 is CH3, n1 is 0, n2 is 6, a is 20%, b is 30%, and c is 50%.

[0037] Dissolve 10g of the main agent 3 in 200g of No. 100 solvent oil to obtain asphalt dispersant 6. # .

[0038] Comparative Examples 1-4 These are solvent oils of grades 100, 150, 180, and 260, respectively.

[0039] Comparative Example 5 10g of alkylphenol polyoxyethylene ether carboxylic acid was dissolved in 200g of No. 100 solvent oil to obtain asphalt dispersant. The preparation method of alkylphenol polyoxyethylene ether carboxylic acid is referenced in: Huang Zhankai, Zhao Yingqiu, An Feng, Jin Zhengzheng. Synthesis and evaluation of polyether carboxylic acid type asphalt dispersant for residual fuel oil [J]. Fine Petrochemicals, 2021, 38(6):56-61. Specifically, the designed amount of alkylphenol polyoxyethylene ether (NP-4) was added to a three-necked flask, and sodium hydroxide was added and alkalized for 2h under stirring at 45~50℃. A certain amount of acetone was added, and chloroacetic acid (CEA) with a certain molar ratio to alkylphenol polyether was added under uniform stirring, wherein n(NP-4):n(CEA):n(NaOH)=1:2:3, n(acetone):n(NP-4)=6:1, and the reaction was carried out at 45℃ for 4h. The reaction was stopped, and the temperature was raised to 58℃ to distill off the acetone, and a light yellow viscous alkylphenol polyether carboxylic acid salt was obtained. The organic phase was acid-washed with dilute hydrochloric acid solution and heated to promote the separation of the organic phase and the aqueous phase. The organic phase containing alkylphenol polyether carboxylic acid was collected and then washed with distilled water to obtain the target product alkylphenol polyoxyethylene ether carboxylic acid.

[0040] Asphalt dispersant dissolution rate determination Take 10 mL of asphalt dissolving and dispersing agent and place it in a 50 mL flat-bottomed glass sample bottle. Heat the bottle in a constant temperature water bath at 80℃. After the temperature stabilizes, weigh approximately 0.5 g (accurate to 0.001 g) of Experiment 70# asphalt and add it to the sample bottle. Shake the sample bottle once every 5 minutes and observe and record the time for complete dispersion and dissolution of the asphalt, accurate to 1 minute. Calculate the dissolution rate v using the following formula:

[0041] In the formula: v -- dissolution rate, in mg / (mL·min); V -- Volume of asphalt dispersant, in mL; m -- Mass of 70# asphalt, in mg; t -- Asphalt dispersion and dissolution time, in minutes.

[0042] Experimental results Table 1 Results of Asphalt Dispersant Dissolution Rate Measurement

[0043] Experimental conclusion: Adding the main agent to the solvent oil can greatly improve the dispersion and dissolution rate of asphalt, making it more efficient.

[0044] Evaluation of the temperature resistance of asphalt dispersants The asphalt dispersant was placed in a high-temperature, high-pressure reactor and kept at 150°C for 48 hours before being cooled to room temperature. The asphalt dispersion and dissolution rate was then tested again using the aged agent.

[0045] Table 2 Results of Asphalt Dispersion and Dissolution Rate Measurement After Aging

[0046] Experimental conclusion: The asphalt dispersant of this application does not affect its asphalt dispersion performance after aging. However, in Comparative Example 5, the asphalt dispersant using alkylphenol polyoxyethylene ether carboxylic acid as the main agent in the prior art showed a decrease in asphalt dispersion performance after aging at 150°C.

[0047] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A polymer synthesized by free radical polymerization, having the following structural formula: wherein R1, R2, and R3 are independently selected from H, CH3-, or CH3CH2-; n1 represents the number of methylene groups, ranging from 0 to 15; n2 represents the number of ethoxy groups in the polyoxyethylene ether segment, ranging from 12 to 20. a represents the mass percentage of R1 and R2 substituted acrylic structural units, b represents the mass percentage of phenylene structural units, and c represents the mass percentage of R3 substituted allyl alcohol polyoxyethylene ether; a:b:c = (20~40):(30~50):(10~50), a+b+c = 100%.

2. The method of claim 1, wherein the free-radical polymerization is initiated by a photoinitiator. The preparation method includes: The R1 and R2 substituted acrylic acid, phenylene, and R3 substituted allyl alcohol polyoxyethylene ether were placed in a solvent, mixed evenly, and a free radical copolymerization initiator was added. The reaction was carried out under an inactive atmosphere. After the reaction was completed, the solvent was removed to obtain the polymer. The definitions of R1, R2, and R3 are the same as in claim 1; The number of alkyl groups in a benzene is n1, as defined in claim 1; The number of ethoxy groups in allyl alcohol polyoxyethylene ether is n2, as defined in claim 1.

3. The method of claim 2, wherein, The amount of the initiator is 0.5% to 3% of the total mass of the monomer.

4. The preparation method according to claim 2, characterized in that, The initiator is selected from azobisisobutyronitrile or benzoyl peroxide; When the initiator is azobisisobutyronitrile, the temperature during dropwise addition is 60~80℃; When benzoyl peroxide is used, the temperature during initiator addition is 80~100℃.

5. The preparation method according to claim 2, characterized in that, The solvent is ethylene glycol methyl ether and / or propylene glycol methyl ether.

6. The preparation method according to claim 2, characterized in that, The reaction temperature is 80~120℃, and the reaction time is 3~6h.

7. An asphalt dispersant characterized by comprising: The asphalt dispersant comprises a main agent and a solvent; the main agent is the polymer synthesized by free radical polymerization as described in claim 1.

8. The asphalt dispersant of claim 7, wherein, The solvent is selected from at least one of No. 100 solvent oil, No. 150 solvent oil, No. 180 solvent oil, and No. 260 solvent oil.

9. The asphalt dispersant of claim 7, wherein, The mass ratio of the main agent to the solvent is 1:1~30; Preferably, the mass ratio of the main agent to the solvent is 1:1 to 20.

10. The application of the asphalt dispersant according to any one of claims 7 to 9 in heavy oil extraction.

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