Thickening agent for improving recovery efficiency and preparation method thereof

Abstract

The invention relates to the technical field of petrochemical engineering, and discloses a thickening agent capable of improving the recovery efficiency and a preparation method thereof.Dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, N, N-dimethylethylenediamine, fatty amine and sodium 3-chloro-2-hydroxypropanesulfonate serve as raw materials, and the prepared thickening agent contains sulfonic acid quaternary ammonium salt betaine groups, is high in surface activity and can improve the recovery efficiency. The tackifying effect is good, meanwhile, alkyl long chains contained in the tackifying agent can form a cross-linked network through the hydrophobic association effect, the good tackifying effect and anti-shearing effect are achieved, and the tackifying agent has the excellent temperature resistance and anti-shearing performance. The thickening agent contains hydrophobic long-chain alkane, hydrophilic amido bonds and betaine zwitterionic groups, has amphipathy and higher surface activity, and can reduce the oil-water interfacial tension, so that crude oil escapes from pores in a core, and the recovery rate of the crude oil is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical engineering, and particularly to a thickening agent for improving oil recovery and a preparation method thereof. Background Art

[0002] The performance of fracturing fluid has many effects on the fracturing operation technology of oil and gas fields and the increase of oil and gas production. Among them, the thickening agent plays a key role in the performance of fracturing fluid. Common thickening agents mainly include guar gum, polyacrylamide, surfactants, etc. Betaine zwitterionic surfactant has good surface properties, can reduce the interfacial tension between oil and water, and has good viscosity-increasing performance, and has good practical applications in the aspect of fracturing fluid thickening agent. Traditional betaine zwitterionic surfactants have problems such as poor temperature resistance and shear resistance, which are not conducive to their practical applications in fracturing fluid thickening agents.

[0003] Rosin is a natural oil resin, which is cheap and easily available, contains a hydrogenated phenanthrene ring structure, has good high-temperature resistance performance, and has extensive practical applications in the fields of surfactants, petrochemical engineering, etc. Chinese patent application document CN111944013A discloses a viscoelastic solution and a preparation method thereof, which uses rosin acid to react with multiple amino acids to obtain a rosin acid-based amino acid surfactant, which can be applied to petrochemical fields such as oilfield fracturing fluid and drag reducer. However, this rosin acid-based amino acid surfactant does not show good viscosity-increasing, temperature resistance, shear resistance and other performances, and cannot meet the practical applications in fracturing fluid thickening agents. Summary of the Invention

[0004] The present invention solves the problems of poor viscosity-increasing effect of the rosin acid surfactant used as a thickening agent and low crude oil recovery rate.

[0005] Technical Solution: A preparation method of a thickening agent for improving oil recovery: (1) Add dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, and an acid-binding agent to toluene, stir and react, then filter, distill the filtrate under reduced pressure, and recrystallize the product from dichloromethane to obtain a phthalic anhydride rosin intermediate. The preparation reaction formula is: .

[0006] (2) Add the phthalic anhydride rosin intermediate and N,N-dimethylethylenediamine to N,N-dimethylformamide. After the first reaction, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, and fatty amine. After the second reaction, add deionized water, extract with dichloromethane, dry and remove water from the dichloromethane organic phase with anhydrous sodium sulfate, filter, distill the filtrate under reduced pressure, wash with petroleum ether, and recrystallize the product from dichloromethane to obtain an alkyl tertiary amine rosin intermediate. The preparation reaction formula is: .

[0007] (3) Add alkyl tertiary amine rosin intermediate and sodium 3-chloro-2-hydroxypropanesulfonate to isopropanol, stir and react, then distill under reduced pressure, wash with petroleum ether, and recrystallize the product in an ethanol aqueous solution to obtain a thickening agent for enhancing oil recovery. The reaction formula is: .

[0008] Among them, the mass ratio of dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, and acid-binding agent in (1) is 100:(72 - 104):(32 - 38). The acid-binding agent is triethylamine or pyridine.

[0009] Among them, the reaction temperature in (1) is 20 - 35 °C, and the reaction time is 3 - 6 h.

[0010] Among them, in (2), the mass ratio of phthalic anhydride rosin intermediate, N,N-dimethylethylenediamine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, and fatty amine is 100:20.5:(45 - 63):(27 - 37):(43 - 69). The molecular formula of the fatty amine is NH2-C a H 2a+1 , and a is any integer from 12 to 18.

[0011] Among them, in (2), the temperature of the first reaction is 20 - 30 °C, and the reaction time is 2 - 4 h; the temperature of the second reaction is 20 - 35 °C, and the reaction time is 12 - 18 h.

[0012] Among them, in (3), the mass ratio of alkyl tertiary amine rosin intermediate and sodium 3-chloro-2-hydroxypropanesulfonate is 100:(29 - 42).

[0013] Among them, in (3), the reaction temperature is 80 - 85 °C, and the reaction time is 18 - 24 h.

[0014] The beneficial technical effects of the present invention: The present invention uses dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, N,N-dimethylethylenediamine, fatty amine, and sodium 3-chloro-2-hydroxypropanesulfonate as raw materials. The thickening agent prepared contains sulfonic acid quaternary ammonium betaine groups, has high surface activity and good thickening effect. At the same time, the alkyl long chains contained can form a cross-linked network through hydrophobic association, playing a good thickening role and shear resistance. And the thickening agent contains a heat-resistant rosin condensed ring structure and multiple benzene ring structures, making the thickening agent have good temperature resistance and not easily decompose by thermal aging, so that the thickening agent has excellent temperature and shear resistance.

[0015] The thickening agent of the present invention contains hydrophobic long-chain alkanes, hydrophilic amide bonds and betaine zwitterionic groups, has amphiphilicity and high surface activity, can reduce the oil-water interfacial tension, and cause crude oil to escape from the pores in the core, thereby improving the crude oil recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the infrared spectrum of the phthalic anhydride rosin intermediate prepared in Example 1.

[0017] Figure 2 It is the infrared spectrum of the alkyl tertiary amine rosin intermediate prepared in Example 1.

[0018] Figure 3 It is the infrared spectrum of the thickening agent for enhancing oil recovery prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0019] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0020] Prepare dehydroabietic acid acyl chloride according to the method in the journal "China Surfactant Detergent & Cosmetics", June 2007, Vol. 37, No. 3, the literature "Synthesis of Betaine-Type Amphoteric Surfactants Containing Rosin Skeleton": Add 30 g of dehydroabietic acid to 50 mL of toluene, then stir and heat to 80 °C, dropwise add 17.85 g of thionyl chloride, and then stir and react at 30 °C for 10 h. Distill off toluene and excess thionyl chloride under reduced pressure to obtain dehydroabietic acid acyl chloride. The structural formula is .

[0021] Example 1 (1) Add 5 g of dehydroabietic acid acyl chloride, 3.6 g of 4-hydroxyphthalic anhydride, and 1.8 g of triethylamine to 20 mL of toluene, stir and react at 25 °C for 5 h, filter, distill the filtrate under reduced pressure, and recrystallize the product from dichloromethane to obtain the phthalic anhydride rosin intermediate with a yield of 6.13 g. Figure 1 In the infrared spectrum of, the absorption peak at 1725 cm -1 is the absorption peak of C=O in the ester group, and the absorption peak at 953 cm -1 is the characteristic absorption peak of the five-membered ring of the acid anhydride, and the absorption peak at 1247 cm -1 is the absorption peak of C-O-C in the five-membered ring of the acid anhydride, indicating that the acyl chloride group of dehydroabietic acid acyl chloride and the hydroxyl group of 4-hydroxyphthalic anhydride have undergone an esterification reaction.

[0022] (2) 10 g of phthalic anhydride rosin intermediate, 2.05 g of N,N-dimethylethylenediamine were added to 80 mL of N,N-dimethylformamide, and the mixture was stirred and reacted at 20 °C for 4 h. Then, 5.2 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 3 g of N-hydroxysuccinimide, and 4.3 g of dodecylamine were added, and the mixture was stirred and reacted at 25 °C for 18 h. Deionized water was added, and the mixture was extracted with dichloromethane. The dichloromethane organic phase was dried with anhydrous sodium sulfate to remove water. After filtration, the filtrate was distilled under reduced pressure, washed with petroleum ether, and the product was recrystallized from dichloromethane to obtain an alkyl tertiary amine rosin intermediate with a yield of 9.27 g. Figure 2 In the infrared spectrum at 1723 cm -1 is the absorption peak of C=O in the ester group, and at 1658 cm -1 is the absorption peak of C=O in the amide bond, and at 1202 cm -1 is the absorption peak of the C-N bond in the tertiary amine bond, and at 2925 cm -1 and 2853 cm -1 are the absorption peaks of -CH3 and -CH2- in the fatty amine. At 953 cm -1 is the characteristic absorption peak of the anhydride five-membered ring, and at 1247 cm -1 The absorption peak of C-O-C in the anhydride five-membered ring disappeared, indicating that the anhydride group reacted with N,N-dimethylethylenediamine.

[0023] (3) 6 g of alkyl tertiary amine rosin intermediate and 2.15 g of 3-chloro-2-hydroxypropanesulfonate were added to 80 mL of isopropanol, and the mixture was stirred and reacted at 85 °C for 18 h. During the reaction, it was refluxed under condensation, distilled under reduced pressure, washed with petroleum ether, and the product was recrystallized from an ethanol aqueous solution to obtain a thickening agent for enhancing oil recovery with a yield of 4.53 g. Figure 2 In the infrared spectrum at 1721 cm -1 is the absorption peak of C=O in the ester group, and at 1655 cm -1 is the absorption peak of C=O in the amide bond, and at 2926 cm -1 and 2855 cm -1 are the absorption peaks of -CH3 and -CH2- in the fatty amine, and at 1336 cm -1 is the + absorption peak of the N-C bond in the quaternary ammonium salt, and at 1052 cm -1 is the - absorption peak of -SO3 -1 At the same time, the absorption peak of the C-N bond in the tertiary amine bond disappeared, indicating that the tertiary amine group of the alkyl tertiary amine rosin intermediate reacted with 3-chloro-2-hydroxypropanesulfonate to form a sulfonic acid quaternary ammonium salt betaine structure.

[0024] Example 2 (1) Add 5 g of dehydroabietic acid acyl chloride, 5.2 g of 4-hydroxyphthalic anhydride, and 1.6 g of pyridine to 30 mL of toluene. Stir and react at 20 °C for 6 h. Filter, and distill the filtrate under reduced pressure. Recrystallize the product from dichloromethane to obtain the phthalic anhydride rosin intermediate, with a yield of 5.64 g.

[0025] (2) Add 10 g of the phthalic anhydride rosin intermediate and 2.05 g of N,N-dimethylethylenediamine to 100 mL of N,N-dimethylformamide. Stir and react at 20 °C for 4 h. Then add 6.3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 3.7 g of N-hydroxysuccinimide, and 6.9 g of hexadecylamine. Stir and react at 35 °C for 12 h. Add deionized water, extract with dichloromethane. Dry the dichloromethane organic phase with anhydrous sodium sulfate to remove water. Filter, distill the filtrate under reduced pressure, wash with petroleum ether, and recrystallize the product from dichloromethane to obtain the alkyl tertiary amine rosin intermediate, with a yield of 11.18 g.

[0026] (3) Add 6 g of the alkyl tertiary amine rosin intermediate and 2.52 g of 3-chloro-2-hydroxypropanesulfonate to 100 mL of isopropanol. Stir and react at 85 °C for 18 h, with reflux during the reaction. Distill under reduced pressure, wash with petroleum ether, and recrystallize the product from an ethanol aqueous solution to obtain the thickening agent for enhanced oil recovery, with a yield of 4.82 g.

[0027] Example 3 (1) Add 5 g of dehydroabietic acid acyl chloride, 4.8 g of 4-hydroxyphthalic anhydride, and 1.9 g of triethylamine to 30 mL of toluene. Stir and react at 35 °C for 3 h. Filter, and distill the filtrate under reduced pressure. Recrystallize the product from dichloromethane to obtain the phthalic anhydride rosin intermediate, with a yield of 5.90 g.

[0028] (2) Add 10 g of the phthalic anhydride rosin intermediate and 2.05 g of N,N-dimethylethylenediamine to 120 mL of N,N-dimethylformamide. Stir and react at 30 °C for 2 h. Then add 4.5 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 2.7 g of N-hydroxysuccinimide, and 6.2 g of octadecylamine. Stir and react at 20 °C for 18 h. Add deionized water, extract with dichloromethane. Dry the dichloromethane organic phase with anhydrous sodium sulfate to remove water. Filter, distill the filtrate under reduced pressure, wash with petroleum ether, and recrystallize the product from dichloromethane to obtain the alkyl tertiary amine rosin intermediate, with a yield of 10.49 g.

[0029] (3) 6 g of alkyl tertiary amine rosin intermediate and 1.74 g of sodium 3-chloro-2-hydroxypropanesulfonate were added to 100 mL of isopropanol, and the mixture was stirred and reacted at 80 °C for 24 h. During the reaction, condensation reflux was carried out, followed by vacuum distillation and washing with petroleum ether. The product was recrystallized from an ethanol aqueous solution to obtain a thickening agent for enhanced oil recovery, with a yield of 4.92 g.

[0030] In Comparative Example 1, the alkyl tertiary amine rosin intermediate (prepared in Example 1) was used as the thickening agent.

[0031] Comparative Example 2 (1) 3.44 g of phthalic anhydride (structural formula is ) and 2.05 g of N,N-dimethylethylenediamine were added to 80 mL of N,N-dimethylformamide, and the mixture was stirred and reacted at 20 °C for 4 h. Then, 5.2 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 3 g of N-hydroxysuccinimide, and 4.3 g of dodecylamine were added, and the mixture was stirred and reacted at 25 °C for 18 h. Deionized water was added, and the mixture was extracted with dichloromethane. The dichloromethane organic phase was dried over anhydrous sodium sulfate to remove water, and after filtration, the filtrate was subjected to vacuum distillation and washed with petroleum ether. The product was recrystallized from dichloromethane to obtain intermediate d.

[0032] (2) 6 g of intermediate d and 2.15 g of sodium 3-chloro-2-hydroxypropanesulfonate were added to 80 mL of isopropanol, and the mixture was stirred and reacted at 85 °C for 12 h. During the reaction, condensation reflux was carried out, followed by vacuum distillation and washing with petroleum ether. The product was recrystallized from an ethanol aqueous solution to obtain a thickening agent.

[0033] In Comparative Example 3, sulfopropyl betaine was prepared according to the method described in the literature "Synthesis of Rosin-based Betaine Amphoteric Surfactants" in the 37th volume, issue 3 of the journal "China Surfactant Detergent & Cosmetics" in June 2007.

[0034] (1) 15.9 g of dehydroabietic acid acyl chloride was added to 15 mL of toluene, and a benzene solution containing 8.9 g of N,N-dimethylethanolamine was added dropwise. The mixture was stirred and reacted at 30 °C for 3 h. Saturated sodium chloride solution was added, and after standing and separating layers, the toluene organic phase was taken and dried over anhydrous sodium sulfate to remove water. After filtration, the filtrate was subjected to vacuum distillation to obtain (2-dehydroabietoyloxy)ethyl dimethyl tertiary amine. The structural formula is .

[0035] (2) 20 g of (2-dehydroabietoyloxy)ethyl dimethyl tertiary amine was added to 150 mL of 95% ethanol aqueous solution, and an aqueous solution containing 9.83 g of sodium 3-chloro-2-hydroxypropanesulfonate in 50 mL was added. The mixture was stirred and reacted at 80 °C for 8 h. During the reaction, condensation reflux was carried out, and ethanol and water were removed by vacuum distillation. The product was added to ethanol, and after filtration, the filtrate was subjected to vacuum distillation. The product was recrystallized from a petroleum ether and ethanol solution with a volume ratio of 1:3 to obtain sulfopropyl betaine, which was used as the thickening agent. The structural formula is 。

[0036] Add a thickening agent to deionized water to prepare a thickening agent solution with a concentration of 4 g / L, shear it at room temperature for 2 - 30 min, and the shear rate is 170 s -1 , and measure the apparent viscosity through a viscometer.

[0037] Place guar gum in an oven at 140 °C for thermal aging for 72 h, cool it to room temperature, add it to deionized water to prepare a solution with a mass concentration of 4 g / L, shear it for 2 min, and the shear rate is 170 s -1 , and measure the apparent viscosity through a viscometer.

[0038] Table 1 Test of the shear resistance performance of the thickening agent

[0039] Table 2 Test of the temperature resistance performance of the thickening agent

[0040] After testing, the thickening agents prepared in Examples 1 - 3 have higher apparent viscosities. And after long - term shearing and high - temperature thermal aging, the thickening agents still have very high apparent viscosities and large retention rates. This is mainly because the thickening agents contain sulfonic acid quaternary ammonium salt betaine groups, which have high surface activity and good thickening effects. At the same time, the alkyl long chains contained can form cross - linked networks through hydrophobic association, playing a good thickening role and shear - resistance role. And the thickening agents contain heat - resistant rosin condensed ring structures and multiple benzene ring structures, enabling the thickening agents to have good temperature resistance, not being easily thermally aged and decomposed, so that the thickening agents have excellent temperature - resistance and shear - resistance performance.

[0041] The thickening agent of Comparative Example 1 does not contain zwitterionic betaine groups, and its hydrophilicity and water solubility are poor, resulting in a very low apparent viscosity.

[0042] Taking phthalic anhydride as the raw material, the thickening agent prepared in Comparative Example 2 does not contain heat - resistant rosin condensed ring structures, resulting in poor heat resistance of the thickening agent, being easily thermally aged and decomposed. After high - temperature thermal aging, the decline amplitude of the apparent viscosity is relatively large and the retention rate is low.

[0043] Taking conventional sulfopropyl betaine as the thickening agent in Comparative Example 3, it does not contain alkyl long chains and cannot form cross - linked networks through hydrophobic association, resulting in a lower thickening effect and poor shear - resistance performance. After long - term shearing, the decline amplitude of the apparent viscosity is relatively large. And the benzene ring content is less, and the heat resistance is not good. After high - temperature thermal aging, the decline amplitude of the apparent viscosity is greater than that of each example.

[0044] Add thickening agent to deionized water to prepare a dialysis solution with a concentration of 4 g / L; first saturate the natural core with formation water (salinity 21,476 mg / L), then saturate it with crude oil at 50 °C, then place the natural core in a imbibition bottle, add the dialysis solution for the imbibition process. During the imbibition process, the crude oil droplets will float and precipitate. Read the volume V1 of the precipitated oil and calculate the recovery rate Q. Q = (V1 / V2) × 100%. V2 is the volume of saturated crude oil.

[0045] Table 3 Recovery Rate Test Recovery rate (%) Example 1 14.7 Example 2 15.6 Example 3 14.0 Comparative Example 1 0.73 Comparative Example 2 15.3 Comparative Example 3 8.4 After testing, compared with the thickening agents of Comparative Example 1 and Comparative Example 3, the dialysis recovery rates of the thickening agents of Examples 1-3 reached 14.7-15.6%. This is mainly because the thickening agent contains hydrophobic long-chain alkanes, hydrophilic amide bonds and betaine zwitterionic groups, has amphiphilicity and a high surface activity effect, can reduce the oil-water interfacial tension, and make the crude oil escape from the pores of the core, thereby improving the crude oil recovery rate.

Claims

1. A method for preparing a thickener for improving oil recovery, characterized in that: The preparation method comprises: (1) adding dehydroabietic acid chloride, 4-hydroxyphthalic anhydride and an acid binding agent in a mass ratio of 100:(72-104):(32-38) to toluene, stirring for reaction and filtering, distilling the filtrate under reduced pressure, and recrystallizing the product to obtain a phthalic anhydride rosin intermediate; The acid binding agent is triethylamine or pyridine; (2) Add phthalic anhydride rosin intermediate and N,N-dimethylethylenediamine to N,N-dimethylformamide, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide and fatty amine after a primary reaction, extract after a secondary reaction, and recrystallize the product to obtain an alkyl tertiary amine rosin intermediate; the mass ratio of the phthalic anhydride rosin intermediate, N,N-dimethylethylenediamine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide and fatty amine is 100:20.5:(45-63):(27-37):(43-69); The molecular formula of the fatty amine is NH2-C a H 2a+1 , a is any integer between 12 and 18; (3) Adding an alkyl tertiary amine rosin intermediate and sodium 3-chloro-2-hydroxypropanesulfonate in a mass ratio of 100:(29-42) to isopropanol, stirring the reaction, distilling under reduced pressure, washing, and recrystallizing the product to obtain a thickener for improving oil recovery.

2. The method for preparing a thickener for enhancing oil recovery according to claim 1, characterized in that: The reaction temperature in (1) is 20-35°C and the reaction time is 3-6h.

3. The method for preparing a thickener for enhancing oil recovery according to claim 1, characterized in that: In the step (2), the temperature of the first reaction is 20-30°C, and the reaction time is 2-4h; the temperature of the second reaction is 20-35°C, and the reaction time is 12-18h.

4. The method for preparing a thickener for enhancing oil recovery according to claim 1, characterized in that: In the above (3), the reaction temperature is 80-85°C and the reaction time is 18-24h.

5. A thickener for improving oil recovery obtained by the preparation method according to any one of claims 1 to 4, characterized in that: The structural formula of the thickener is: ; R1= , R2= , a is any integer between 12 and 18; or R2= , R1= , a is any integer between 12 and 18.

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