Temperature-resistant oil-displacing discharge aiding agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of oilfield chemical engineering, and discloses a temperature-resistant oil-displacing discharge aiding agent, a preparation method and application, dimethylaminoethyl-4-phenyl-2-pyrrolidone and 3-chloro-2-hydroxypropyl glucoside are subjected to a reaction, a product is added into deionized water, and the temperature-resistant oil-displacing discharge aiding agent is prepared. An amphiphilic structure of a hydrophilic quaternary ammonium salt cation group and a hydrophobic benzene ring is introduced into alkyl glycoside, high surface activity is achieved, the surface tension of a prepared cleanup additive aqueous solution is low, the surface tension of flow-back liquid is reduced, flow-back of the liquid is promoted, and the cleanup performance is excellent. And through high-temperature heat treatment, the discharge aiding agent solution still has very low surface tension, and the discharge aiding and flowback performance cannot be influenced.

Description

Technical Field

[0001] This invention relates to the field of oilfield chemical technology, specifically to a temperature-resistant oil displacement and drainage aid, its preparation method, and its application. Background Technology

[0002] Oil displacement and drainage aids are common oil extraction additives. They reduce the interfacial tension between oil and water, making it easier for residual fracturing fluid and other liquids to flow back to the surface, thus reducing damage to the formation. Furthermore, these aids can disrupt oil films and emulsion structures, enhancing crude oil fluidity and improving oil recovery. Developing novel and efficient oil displacement and drainage aids is a key research focus; for example, cationic, anionic, and amphoteric surfactants have important applications in this field.

[0003] Alkyl glycosides are environmentally friendly surfactants widely used in oil and gas well development and oilfield chemicals as flowback aids, oil displacement agents, anti-collapse inhibitors, and drilling fluid additives. However, traditional alkyl glycosides have low surface activity, high surface tension in solutions, poor flowback and drainage performance, and poor high-temperature resistance, making them unsuitable for high-temperature oil and gas reservoir development. Patent CN114426838B discloses a compounding of dodecyltrimethylammonium chloride and alkyl glycosides to obtain an enhanced flowback aid that reduces the interfacial tension of fracturing fluids in oil and gas fields. However, this patent does not address the problem of poor high-temperature resistance in alkyl glycoside flowback aids. Summary of the Invention

[0004] This invention provides a temperature-resistant oil displacement agent, its preparation method, and its application, which solves the problems of high surface tension, poor displacement effect, and poor temperature resistance of glycoside surfactants.

[0005] The technical solution of this invention: A method for preparing a temperature-resistant oil displacement and drainage aid: Step (1): Add 4-phenyl-2-pyrrolidone to N,N-dimethylformamide, add mineral oil containing sodium hydride, stir to activate, then add 2-dimethylaminobromoethane, controlling the ratio of 4-phenyl-2-pyrrolidone, sodium hydride, and 2-dimethylaminobromoethane to be 100g:(15-18)g:(113-132)g; after stirring the reaction, dilute with ethyl acetate, extract with sodium bicarbonate aqueous solution, separate, dry the organic layer with anhydrous sodium sulfate, and recrystallize the crude product in ethanol after rotary evaporation to obtain dimethylaminoethyl-4-phenyl-2-pyrrolidone. The preparation reaction formula is: .

[0006] Step (2): Add dimethylaminoethyl-4-phenyl-2-pyrrolidone and 3-chloro-2-hydroxypropyl glycoside in a ratio of 100g:(18-45) to N,N-dimethylformamide, stir the reaction, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.05-0.4%, which is the temperature-resistant oil displacement aid. The preparation reaction formula is: .

[0007] Furthermore, the temperature for stirring and activating in step (1) is 65-75℃, and the activation time is 1-1.5h.

[0008] Furthermore, in step (1), the temperature of the stirring reaction is 90-110℃, and the reaction time is 7-12h.

[0009] Furthermore, in step (2), the temperature of the stirring reaction is 80-110℃, and the reaction time is 12-24h.

[0010] Furthermore, temperature-resistant oil displacement aids are applied in oil reservoir development.

[0011] The beneficial technical effects of this invention are as follows: This invention involves a quaternization reaction of dimethylaminoethyl-4-phenyl-2-pyrrolidone and 3-chloro-2-hydroxypropyl glycoside to obtain a glycoside containing phenylpyrrolidone and a quaternary ammonium salt. This glycoside has an amphiphilic structure containing a hydrophilic quaternary ammonium salt cationic group and a hydrophobic benzene ring, exhibiting high surface activity. The prepared drainage aid aqueous solution has low surface tension, which is beneficial for reducing the surface tension of the backflow liquid, promoting liquid backflow, and demonstrating excellent drainage aid performance.

[0012] This method grafts heat-resistant benzene and pyrrolidone ring structures onto glycosides, which improves the high-temperature resistance of the excretion aid and makes it less prone to thermal decomposition. Even after high-temperature heat treatment, the excretion aid solution still has very low surface tension and will not affect the excretion aid and excretion return performance. Detailed Implementation

[0013] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0014] 3-Chloro-2-hydroxypropyl glycoside was prepared according to the method described in the literature "Quercing Reaction in the Synthesis of Cationic Alkyl Glucosides" published in the June 2014 issue of the journal *Applied Chemical Industry*, Vol. 43, No. 6. The reaction was carried out by adding 0.4 mol epichlorohydrin and 4.66 g dodecylbenzenesulfonic acid to 65 mL of water, heating to 80 °C, stirring, adding 0.4 mol dodecyl glucoside, heating to 100 °C, refluxing for 3 h, diluting with saturated sodium chloride solution, extracting with dichloromethane, separating, drying the organic layer with anhydrous sodium sulfate, rotary evaporating, and drying to obtain 3-chloro-2-hydroxypropyl glycoside, with the structural formula [insert structural formula here]. .

[0015] Example 1 (1) Add 1g of 4-phenyl-2-pyrrolidone to 10mL of N,N-dimethylformamide, add 0.3g of mineral oil containing 0.18g of sodium hydride, heat to 75℃, stir and activate for 1h, then add 1.13g of 2-dimethylaminobromoethane, heat to 90℃, stir and react for 12h, add ethyl acetate to dilute, extract with sodium bicarbonate aqueous solution, separate, dry the organic layer with anhydrous sodium sulfate, and after rotary evaporation, recrystallize the crude product in ethanol to obtain dimethylaminoethyl-4-phenyl-2-pyrrolidone.

[0016] (2) Add 0.48g of dimethylaminoethyl-4-phenyl-2-pyrrolidone and 2g of 3-chloro-2-hydroxypropyl glycoside to 20mL of N,N-dimethylformamide, heat to 80℃, stir and react for 18h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.05%, which is the temperature-resistant oil displacement aid.

[0017] Example 2 (1) Add 1g of 4-phenyl-2-pyrrolidone to 15mL of N,N-dimethylformamide, add 0.25g of mineral oil containing 0.15g of sodium hydride, heat to 65℃, stir and activate for 1.5h, then add 1.32g of 2-dimethylaminobromoethane, heat to 110℃, stir and react for 7h, add ethyl acetate to dilute, extract with sodium bicarbonate aqueous solution, separate, dry the organic layer with anhydrous sodium sulfate, and recrystallize the crude product in ethanol after rotary evaporation to obtain dimethylaminoethyl-4-phenyl-2-pyrrolidone.

[0018] (2) Add 0.8g of dimethylaminoethyl-4-phenyl-2-pyrrolidone and 2g of 3-chloro-2-hydroxypropyl glycoside to 30mL of N,N-dimethylformamide, heat to 80℃, stir and react for 24h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.1%, which is the heat-resistant oil displacement aid.

[0019] Example 3 (1) Add 0.36g of dimethylaminoethyl-4-phenyl-2-pyrrolidone (prepared according to the method of Example 1) and 2g of 3-chloro-2-hydroxypropyl glycoside to 20mL of N,N-dimethylformamide, heat to 90℃, stir and react for 12h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.2%, which is the heat-resistant oil displacement aid.

[0020] Example 4 (1) Add 0.9g of dimethylaminoethyl-4-phenyl-2-pyrrolidone (prepared according to the method of Example 1) and 2g of 3-chloro-2-hydroxypropyl glycoside to 30mL of N,N-dimethylformamide, heat to 90℃, stir and react for 24h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.3%, which is the heat-resistant oil displacement aid.

[0021] Example 5 (1) Add 0.64 g of dimethylaminoethyl-4-phenyl-2-pyrrolidone (prepared according to the method of Example 1) and 2 g of 3-chloro-2-hydroxypropyl glycoside to 25 mL of N,N-dimethylformamide, heat to 110 °C, stir and react for 18 h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.4%, which is the heat-resistant oil displacement aid.

[0022] Comparative Example 1: 3-chloro-2-hydroxypropyl glycoside was added to deionized water to prepare a solution with a mass fraction of 0.05%, which is the oil displacement and drainage aid.

[0023] Comparative Example 2 (1) Add 0.48g N,N-dimethyldecylamine and 2g 3-chloro-2-hydroxypropyl glycoside to 20mL N,N-dimethylformamide, heat to 80℃, stir and react for 18h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a solution with a mass fraction of 0.05%, which is the oil displacement aid.

[0024] Comparative Example 3 (1) Add 0.48g of 4-phenyl-2-pyrrolidone to 20mL of N,N-dimethylformamide, add 0.12g of mineral oil containing 0.072g of sodium hydride, heat to 75℃, stir and activate for 1h, then add 2g of 3-chloro-2-hydroxypropyl glycoside, heat to 80℃, stir and react for 18h, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, then add the product to deionized water to prepare a solution with a mass fraction of 0.05%, which is the oil displacement aid.

[0025] The surface tension of the drainage aid was tested using a surface tension meter at a temperature of 25°C.

[0026] The expulsion aid was placed in a reaction vessel and treated at a high temperature of 100-130℃ for 72 hours. After cooling to room temperature, the surface tension of the expulsion aid was tested at a temperature of 25℃.

[0027] Table 1 Surface tension test of drainage aids

[0028] Examples 1-4 involve quaternization of dimethylaminoethyl-4-phenyl-2-pyrrolidone and 3-chloro-2-hydroxypropyl glycoside to obtain glycosides containing phenylpyrrolidone and quaternary ammonium salts. These glycosides are then formulated into aqueous solutions as drainage aids. These solutions possess an amphiphilic structure, containing a hydrophilic quaternary ammonium salt cationic group and a hydrophobic benzene ring, exhibiting high surface activity and low surface tension. This facilitates the reduction of surface tension in the drainage liquid, promoting liquid drainage and demonstrating excellent drainage aid performance. Furthermore, the grafting of heat-resistant benzene and pyrrolidone ring structures into the glycosides significantly improves the high-temperature resistance of the drainage aid. Even after high-temperature heat treatment, the drainage aid retains a very low surface tension, without affecting its drainage aid and drainage performance.

[0029] Comparative Example 1 used a solution of 3-chloro-2-hydroxypropyl glycoside as an excretion aid, which had low surface activity and high surface tension, making it unfavorable for improving excretion and backflow performance.

[0030] In Comparative Example 2, N,N-dimethyldecylamine was quaternized with 3-chloro-2-hydroxypropyl glycoside. The resulting glycoside product did not contain heat-resistant benzene rings and pyrrolidone rings. After high-temperature heat treatment, the excretion aid was easily thermally decomposed, exhibiting poor high-temperature resistance. The surface tension of the solution increased significantly, which affected the excretion aid and excretion return performance.

[0031] In Comparative Example 3, the chlorine atom of 3-chloro-2-hydroxypropyl glycoside was substituted with the imino group of 4-phenyl-2-pyrrolidone. The resulting glycoside product did not contain a quaternary ammonium salt cationic group, had low surface activity, and had high surface tension, which was not conducive to improving the excretion and return performance.

[0032] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A method for preparing a temperature-resistant oil displacement and drainage aid, characterized in that, The preparation method includes the following steps: Step (1): Add 4-phenyl-2-pyrrolidone to N,N-dimethylformamide, add mineral oil containing sodium hydride, stir to activate, then add 2-dimethylaminobromoethane, stir to react, add ethyl acetate to dilute, extract with sodium bicarbonate aqueous solution, separate, dry the organic layer with anhydrous sodium sulfate, rotary evaporate, and recrystallize the crude product in ethanol to obtain dimethylaminoethyl-4-phenyl-2-pyrrolidone; Step (2): Add dimethylaminoethyl-4-phenyl-2-pyrrolidone and 3-chloro-2-hydroxypropyl glycoside to N,N-dimethylformamide, stir and react, add acetone to the solution to precipitate the precipitate, filter, wash with acetone, dry, and then add the product to deionized water to prepare a drainage aid solution, which is a temperature-resistant oil displacement aid.

2. The preparation method of the temperature-resistant oil displacement and drainage aid according to claim 1, characterized in that, In step (1), the ratio of 4-phenyl-2-pyrrolidone, sodium hydride, and 2-dimethylaminobromoethane is 100g:(15-18)g:(113-132)g.

3. The preparation method of the temperature-resistant oil displacement and drainage aid according to claim 1, characterized in that, The temperature for stirring and activating in step (1) is 65-75℃, and the activation time is 1-1.5h.

4. The preparation method of the temperature-resistant oil displacement and drainage aid according to claim 1, characterized in that, The temperature of the stirring reaction in step (1) is 90-110℃, and the reaction time is 7-12h.

5. The preparation method of the temperature-resistant oil displacement and drainage aid according to claim 1, characterized in that, In step (2), the ratio of 3-chloro-2-hydroxypropyl glycoside to dimethylaminoethyl-4-phenyl-2-pyrrolidone is 100g:(18-45).

6. The preparation method of the temperature-resistant oil displacement and drainage aid according to claim 1, characterized in that, The temperature of the stirring reaction in step (2) is 80-110℃, and the reaction time is 12-24h.

7. The preparation method of the temperature-resistant oil displacement and drainage aid according to claim 1, characterized in that, The mass fraction of the drainage aid solution in step (2) is 0.05-0.4%.

8. A heat-resistant oil displacement and drainage aid obtained by the preparation method according to any one of claims 1-7.

9. The application of the heat-resistant oil displacement aid as described in claim 8 in oil reservoir development.

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