Oil removal agent for oil field sewage treatment and preparation method of oil removal agent

Abstract

The invention relates to the technical field of oilfield treatment agents, in particular to an oilfield sewage treatment degreaser and a preparation method thereof.The oilfield sewage treatment degreaser is obtained through the following steps that 1-ethyl-4-vinyl benzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, absolute ethyl alcohol and water are stirred and mixed to be uniform, and then a mixed solution is obtained; and adding acrylamide and a catalyst into the mixed solution, and reacting to obtain the water-soluble polymer. The raw materials are easy to obtain, the process is simple, and the oil removal agent for oil field sewage treatment obtained through the preparation method is high in oil removal capacity, high in oil removal rate and suitable for oil-water separation of oil field sewage. The oil removal agent for oil field sewage treatment is effective in a wide pH range, does not contain metal ions, avoids secondary pollution, and also has the effects of demulsification, sterilization, flocculation and slow release.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield treatment agents, in particular to an oilfield sewage treatment degreasing agent and a preparation method thereof. Background Art

[0002] Since many solids in sewage are difficult to dissolve in water, when one or more of these solids exist in large quantities in oil and water, under the agitation of hydraulic or external power, these solids and crude oil can exist in the water in an emulsified state, forming an emulsion, which makes the emulsification state very serious and even difficult to separate the two phases.

[0003] A deoiler is a water-miscible wastewater treatment product that can break oil-in-water emulsions, shortening oil-water separation time. Deoilers are often called reverse demulsifiers. Cationic reverse demulsifiers are particularly important for O / W emulsions. Their demulsification mechanism is achieved by combining the positive charge in the reverse demulsifier with the negative charge in the oil droplets, thereby achieving the desired oil removal effect.

[0004] Currently, a large amount of research has been conducted abroad on reverse demulsifiers, and a series of reverse demulsifiers have been developed. They are used to break the emulsions of O / W emulsions and remove oil from oily wastewater. Most of these reverse demulsifiers use cationic polymers for demulsification and oil removal, but existing conventional deoilers often have unsatisfactory oil removal effects. Summary of the Invention

[0005] The present invention provides an oilfield wastewater treatment degreasing agent and a preparation method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem of poor degreasing effect of existing conventional degreasing agents.

[0006] One of the technical solutions of the present invention is achieved through the following measures: an oilfield wastewater treatment degreasing agent, the raw materials of which include 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and a catalyst in a molar concentration ratio of (0.2 to 1.0): (0.5 to 1.5): (0.3 to 2.0): (0.4 to 3.0): (0.1 to 0.2): (0.0002 to 0.0004).

[0007] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The catalyst consists of ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:1.

[0008] The above-mentioned oilfield wastewater treatment degreasing agent is obtained by the following method: In the first step, under a nitrogen atmosphere, required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol and water are stirred and mixed to obtain a mixed solution; In the second step, a required amount of acrylamide and a catalyst are added to the mixed solution for reaction to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent.

[0009] The amount of anhydrous ethanol added is 10% to 20% of the total weight of the raw materials.

[0010] The amount of water added is 60% to 70% of the total weight of the raw materials.

[0011] In the first step, the stirring time is 30 to 40 minutes, the stirring temperature is 30° C. to 40° C., and the stirring speed is 600 to 700 rpm.

[0012] In the second step, the reaction temperature is 45° C. to 80° C., and the reaction time is 30 minutes to 40 minutes.

[0013] The mass concentration of the above oilfield wastewater treatment degreaser is 10% to 20%.

[0014] The second technical solution of the present invention is achieved by the following measures: a method for preparing an oil field wastewater treatment degreasing agent is carried out as follows: In the first step, under a nitrogen atmosphere, required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol and water are stirred and mixed to obtain a mixed solution; In the second step, a required amount of acrylamide and a catalyst are added to the mixed solution for reaction to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent.

[0015] The oilfield wastewater treatment deoiler produced by the present invention utilizes readily available raw materials and a simple process. The deoiler has a strong deoiling capability and a high oil removal rate, making it suitable for oil-water separation in oilfield wastewater while requiring minimal usage. The deoiler is effective over a wide pH range, contains no metal ions, and avoids secondary contamination. Furthermore, it possesses demulsification, sterilization, flocculation, and sustained-release properties, effectively addressing the poor deoiling effectiveness of existing deoilers. DETAILED DESCRIPTION

[0016] The present invention is not limited to the following embodiments; specific implementation methods may be determined based on the technical solutions and actual conditions of the present invention. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art; and percentages in the present invention are all by mass unless otherwise specified.

[0017] The present invention will be further described below in conjunction with the embodiments: Example 1: The oilfield wastewater treatment deoiling agent comprises raw materials including 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and a catalyst in a molar concentration ratio of (0.2 to 1.0): (0.5 to 1.5): (0.3 to 2.0): (0.4 to 3.0): (0.1 to 0.2): (0.0002 to 0.0004).

[0018] Example 2: As an optimization of the above example, the catalyst consists of ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:1.

[0019] Example 3: As an optimization of the above example, an oilfield wastewater treatment degreasing agent is obtained by the following method: In the first step, under a nitrogen atmosphere, required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol and water are stirred and mixed to obtain a mixed solution; In the second step, a required amount of acrylamide and a catalyst are added to the mixed solution for reaction to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent.

[0020] Example 4: As an optimization of the above example, the amount of anhydrous ethanol added is 10% to 20% of the total weight of the raw materials.

[0021] Example 5: As an optimization of the above example, the amount of water added is 60% to 70% of the total weight of the raw materials.

[0022] Example 6: As an optimization of the above example, in the first step, the stirring time is 30 minutes to 40 minutes, the stirring temperature is 30°C to 40°C, and the stirring rate is 600 rpm to 700 rpm.

[0023] Example 7: As an optimization of the above example, in the second step, the reaction temperature is 45°C to 80°C, and the reaction time is 30 minutes to 40 minutes.

[0024] Example 8: As an optimization of the above example, the mass concentration of the oilfield wastewater treatment deoiling agent is 10% to 20%.

[0025] Example 9: The oilfield wastewater treatment degreasing agent comprises raw materials including 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst (ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:1) in a molar concentration ratio of 0.2:0.5:0.3:0.4:0.1:0.0002, and is prepared according to the following method: The first step is to stir the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere at a stirring speed of 600 rpm and a stirring temperature of 30° C. for 30 minutes to obtain a mixed solution; wherein the amount of anhydrous ethanol added is 10% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 60% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst); In the second step, the required amount of acrylamide and catalyst (ammonium persulfate and sodium sulfite with a molar concentration ratio of 1:1) were added to the mixed solution, and the reaction was carried out at 45°C for 30 minutes to obtain a reaction product. The reaction product was diluted with water to obtain an oilfield wastewater treatment deoiling agent with a mass concentration of 10%.

[0026] The chemical structural formula of the oilfield wastewater treatment degreasing agent prepared in Example 9 of the present invention is as follows: Wherein, R1 and R2 are alkyl groups, and the alkyl group is methyl or ethyl, etc.; a=5 to 180, b=20 to 450, c=10 to 300, d=10 to 350.

[0027] Example 10: The oilfield wastewater treatment degreasing agent comprises raw materials including 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst (ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:1) in a molar concentration ratio of 1.0:1.5:2.0:3.0:0.2:0.0004, and is obtained by the following method: The first step is to stir the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere at a stirring speed of 700 rpm and a stirring temperature of 40° C. for 40 minutes to obtain a mixed solution; wherein the amount of anhydrous ethanol added is 20% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 70% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst); In the second step, the required amount of acrylamide and a catalyst (ammonium persulfate and sodium sulfite with a molar concentration ratio of 1:1) were added to the mixed solution, and the mixture was reacted at 80°C for 40 minutes to obtain a reaction product. The reaction product was diluted with water to obtain an oilfield wastewater treatment deoiling agent with a mass concentration of 20%.

[0028] Example 11: The oilfield wastewater treatment degreasing agent comprises raw materials including 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst (ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:1) in a molar concentration ratio of 0.6:1.0:1.0:1.5:0.15:0.0003, and is obtained by the following method: The first step is to stir the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere at a stirring speed of 650 rpm and a stirring temperature of 35° C. for 35 minutes to obtain a mixed solution; wherein the amount of anhydrous ethanol added is 15% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 65% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst); In the second step, the required amount of acrylamide and catalyst (ammonium persulfate and sodium sulfite with a molar concentration ratio of 1:1) were added to the mixed solution, and the reaction was carried out at 60°C for 35 minutes to obtain a reaction product. The reaction product was diluted with water to obtain an oilfield wastewater treatment deoiling agent with a mass concentration of 15%.

[0029] Example 12: The oilfield wastewater treatment degreasing agent is obtained by the following method: In the first step, nitrogen was introduced into a reactor equipped with a stirrer, a thermometer, and a reflux condenser, and 0.2 mol / L of 1-ethyl-4-vinylbenzene, 0.8 mol / L of methacrylate, 1.2 mol / L of long-chain alkyldimethylallylammonium chloride, and 0.1 mol / L of urea were added in sequence. Anhydrous ethanol and water were then added to the reactor. The reactor was heated to 35° C. and stirred at 650 rpm for 30 minutes to obtain a mixed solution. In the second step, 1.5 mol / L acrylamide, 0.15 mmol / L ammonium persulfate and 0.15 mmol / L sodium sulfite are added to the reactor containing the mixed solution, the temperature is slowly raised to 45°C, and the reaction is carried out for 30 minutes (the reaction is exothermic, when the temperature rises to about 95°C), to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent with a mass concentration of 15; wherein the amount of anhydrous ethanol added is 15% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and catalyst), and the amount of water added is 60% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and catalyst).

[0030] Example 13: The oilfield wastewater treatment degreasing agent is obtained by the following method: The first step is to introduce nitrogen into a reactor equipped with a stirrer, a thermometer, and a reflux condenser, and sequentially add 0.5 mol / L of 1-ethyl-4-vinylbenzene, 1.2 mol / L of methacrylate, 1.5 mol / L of long-chain alkyl dimethyl allyl ammonium chloride, and 0.1 mol / L of urea, then add anhydrous ethanol and water to the reactor, heat the reactor to 30° C. to 40° C., and stir at 600 to 700 rpm for 30 minutes to obtain a mixed solution; In the second step, 2.0 mol / L acrylamide, 0.15 mmol / L ammonium persulfate and 0.15 mmol / L sodium sulfite are added to the reactor containing the mixed solution, the temperature is slowly raised to 45°C, and the reaction is carried out for 30 minutes (the reaction is exothermic, when the temperature rises to about 95°C), to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent with a mass concentration of 15%; wherein the amount of anhydrous ethanol added is 15% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and catalyst), and the amount of water added is 60% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and catalyst).

[0031] Comparative Example 1: Compared with Example 12, the raw material 1-ethyl-4-vinylbenzene is omitted, and the remaining steps are the same as the preparation method of Example 12.

[0032] Comparative Example 2: Compared with Example 13, the raw material long-chain alkyl dimethyl allyl ammonium chloride is omitted, and the remaining steps are the same as the preparation method of Example 12.

[0033] Example 14: The sewage in the sewage pool is heavy oil sewage with an oil content of 650 mg / L. The oil field sewage treatment deoiling agent prepared in Examples 11 and 12 of the present invention is added to the sewage pool at a dosage of 5 mg / L. At the same time, Comparative Examples 1 and 2 and existing deoiling agent models including SP169, CW-01 and BY01B are used as controls, and the method specified in Q / SY XJ0354-2022 "Technical Specifications for Deoiling Agents for Water Injection Treatment" is referred to.

[0034] The oil removal effect of the deoiling agent of the present invention is shown in Table 1. It can be seen from Table 1 that the oilfield wastewater treatment deoiling agent prepared in Examples 12 and 13 of the present invention is used to remove oil from the sewage in the sewage pool. The oil content of the sewage after adding the agent is reduced to between 15 mg / L and 18 mg / L, and the oil removal rate reaches 97.7%; the deoiling agent prepared in Comparative Examples 1 and 2 is used to remove oil from the sewage in the sewage pool. The oil content of the sewage after adding the agent is reduced to between 76 mg / L and 85 mg / L, and the oil removal rate is only between 86% and 88%; the existing deoiling agent is used to remove oil from the sewage. The oil content of the sewage after adding the agent is reduced to about 98 mg / L to 125 mg / L, and the oil removal rate is only between 60% and 84%.

[0035] In summary, the oilfield wastewater treatment deoiler produced by the present invention utilizes readily available raw materials and a simple process. The preparation method exhibits strong oil removal capabilities and a high oil removal rate, making it suitable for oil-water separation in oilfield wastewater. For oilfield wastewater with an oil content of less than 2000 mg / L, the deoiler can be used in small amounts, typically between 2 mg / L and 5 mg / L. The oilfield wastewater treatment deoiler is effective over a wide pH range, contains no metal ions, and avoids secondary contamination. Furthermore, it exhibits demulsification, sterilization, flocculation, and sustained-release properties, effectively addressing the poor deoiling effectiveness of existing deoilers.

[0036] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

Claims

1. A degreasing agent for oilfield wastewater treatment, characterized in that The raw materials include 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyldimethylallylammonium chloride, acrylamide, urea and a catalyst in a molar concentration ratio of 0.2 to 1.0: 0.5 to 1.5: 0.3 to 2.0: 0.4 to 3.0: 0.1 to 0.2: 0.0002 to 0.0004.

2. The oilfield wastewater treatment degreasing agent according to claim 1, characterized in that The catalyst consists of ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:

1.

3. The oil field wastewater treatment degreasing agent according to claim 1 or 2, characterized in that Obtained as follows: In the first step, under a nitrogen atmosphere, required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol and water are stirred and mixed to obtain a mixed solution; In the second step, a required amount of acrylamide and a catalyst are added to the mixed solution for reaction to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent.

4. The oilfield wastewater treatment degreasing agent according to claim 3, characterized in that The amount of anhydrous ethanol added is 10% to 20% of the total weight of the raw materials.

5. The oil field wastewater treatment degreasing agent according to claim 3 or 4, characterized in that The amount of water added is 60% to 70% of the total weight of the raw materials.

6. The oilfield wastewater treatment degreasing agent according to claim 3, 4 or 5, characterized in that In the first step, the stirring time is 30 to 40 minutes, the stirring temperature is 30° C. to 40° C., and the stirring speed is 600 to 700 rpm.

7. The oilfield wastewater treatment degreasing agent according to any one of claims 3 to 6, characterized in that In the second step, the reaction temperature is 45° C. to 80° C., and the reaction time is 30 minutes to 40 minutes.

8. A method for preparing an oil field wastewater treatment degreasing agent according to any one of claims 1 to 2 and 4 to 7, characterized in that Proceed as follows: In the first step, under a nitrogen atmosphere, required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol and water are stirred and mixed to obtain a mixed solution; In the second step, a required amount of acrylamide and a catalyst are added to the mixed solution for reaction to obtain a reaction product, and the reaction product is diluted with water to obtain an oilfield wastewater treatment degreasing agent.

Images