A thickening agent for improving oil recovery and its preparation method

Abstract

The present invention relates to the technical field of petrochemical engineering, and discloses a thickening agent for enhancing oil recovery and a preparation method thereof. The thickening agent of the present invention is prepared from dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, N,N-dimethylethylenediamine, fatty amine, and 3-chloro-2-hydroxypropanesulfonate sodium. The prepared thickening agent contains sulfobetaine groups of quaternary ammonium salts, has high surface activity and good viscosity increasing effect. At the same time, the alkyl long chains contained can form a cross-linked network through hydrophobic association, playing a good role in viscosity increasing and shear resistance, and having excellent temperature and shear resistance performance. The thickening agent 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 enable crude oil to escape from the pore channels in the core, thereby enhancing the crude oil recovery rate.

Description

Technical Field

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

[0002] The performance of fracturing fluids has many effects on the fracturing operation technology of oil and gas fields and the increase of oil and gas production. Among them, thickening agents play a key role in the performance of fracturing fluids. Common thickening agents mainly include guar gum, polyacrylamide, surfactants, etc. Betaine zwitterionic surfactants have good surface properties, can reduce the interfacial tension between oil and water, and have good viscosity-increasing properties, and have good practical applications in fracturing fluid thickening agents. 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 fields such as surfactants and petrochemical engineering. Chinese patent application document CN111944013A discloses a viscoelastic solution and a preparation method thereof. By reacting rosin acid with multiple amino acids, a rosin acid-based amino acid surfactant is obtained, which can be applied to petrochemical fields such as oilfield fracturing fluids and drag reducers. However, this rosin acid-based amino acid surfactant does not show good viscosity-increasing, temperature-resistant, shear-resistant and other properties, and cannot meet the actual 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 enhancing oil recovery:

[0006] (1) Add dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, and an acid-binding agent to toluene, stir and react, then filter. The filtrate is distilled under reduced pressure, and the product is recrystallized in dichloromethane to obtain a phthalic anhydride rosin intermediate. The preparation reaction formula is:

[0007] 。

[0008] (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. The dichloromethane organic phase is dried with anhydrous sodium sulfate to remove water, filtered, and the filtrate is distilled under reduced pressure, washed with petroleum ether, and the product is recrystallized in dichloromethane to obtain an alkyl tertiary amine rosin intermediate. The preparation reaction formula is:

[0009] .

[0010] (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 as follows:

[0011] .

[0012] Among them, in (1), the mass ratio of dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, and acid-binding agent is 100:(72 - 104):(32 - 38). The acid-binding agent is triethylamine or pyridine.

[0013] Among them, in (1), the reaction temperature is 20 - 35 °C, and the reaction time is 3 - 6 h.

[0014] 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.

[0015] 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.

[0016] Among them, in (3), the mass ratio of alkyl tertiary amine rosin intermediate and sodium 3-chloro-2-hydroxypropanesulfonate is 100:(29 - 42).

[0017] Among them, in (3), the reaction temperature is 80 - 85 °C, and the reaction time is 18 - 24 h.

[0018] 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 salt 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.

[0019] 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 enable crude oil to escape from the pores in the core, thereby improving the crude oil recovery rate. Description of the Drawings

[0020] Figure 1 It is the infrared spectrum of the phthalic anhydride rosin intermediate prepared in Example 1.

[0021] Figure 2 It is the infrared spectrum of the alkyl tertiary amine rosin intermediate prepared in Example 1.

[0022] Figure 3 It is the infrared spectrum of the thickening agent for enhancing oil recovery prepared in Example 1. Detailed Embodiments

[0023] 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 clearly and completely described below. Apparently, 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.

[0024] Prepare dehydroabietic acid acyl chloride according to the method in the literature "Synthesis of Betaine-Type Amphoteric Surfactants Containing Rosin Skeleton" in the 3rd issue of the 37th volume of the journal "China Surfactant Detergent & Cosmetics" in June 2007: 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 .

[0025] Example 1

[0026] (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.

[0027] (2) Add 10 g of phthalic anhydride rosin intermediate and 2.05 g of N,N-dimethylformamide to 80 mL of N,N-dimethylformamide, stir and react at 20 °C for 4 h, then add 5.2 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 3 g of N-hydroxysuccinimide, and 4.3 g of dodecylamine, stir and react at 25 °C for 18 h, add deionized water, extract with dichloromethane, dry the dichloromethane organic phase with anhydrous sodium sulfate to remove water, filter, and distill the filtrate under reduced pressure, wash with petroleum ether, and recrystallize the product from dichloromethane to obtain alkyl tertiary amine rosin intermediate with a yield of 9.27 g. Figure 2 In the infrared spectrum, 1723 cm -1 It is the absorption peak of C=O in the ester group, 1658cm -1 It is the absorption peak of C=O in the amide bond, 1202 cm -1 It is the absorption peak of tertiary amine bond CN bond, 2925cm -1 and 2853cm -1 It is the absorption peak of -CH3 and -CH2- in fatty amines. 953cm -1 The characteristic absorption peak of the five-membered ring of anhydride and 1247 cm -1 The absorption peak of COC in the five-membered ring of the anhydride disappeared, indicating that the anhydride group reacted with N,N-dimethylethylenediamine.

[0028] (3) 6 g of alkyl tertiary amine rosin intermediate and 2.15 g of sodium 3-chloro-2-hydroxypropanesulfonate were added to 80 mL of isopropanol, and the mixture was stirred at 85 °C for 18 h. During the reaction, the mixture was condensed and refluxed, and distilled under reduced pressure. The product was washed with petroleum ether and recrystallized from ethanol aqueous solution to obtain a thickening agent for improving oil recovery. The yield was 4.53 g. Figure 2 In the infrared spectrum, 1721 cm -1 It is the absorption peak of C=O in the ester group, 1655cm -1 It is the absorption peak of C=O in the amide bond, 2926cm -1 and 2855cm -1 It is the absorption peak of -CH3 and -CH2- in fatty amines, 1336cm -1 It is a quaternary ammonium salt + Absorption peak of NC bond, 1052 cm -1 Yes-SO3 - The absorption peak at 1202 cm -1 The absorption peak of the CN bond of the tertiary amine bond disappears, indicating that the tertiary amine group of the alkyl tertiary amine rosin intermediate reacts with sodium 3-chloro-2-hydroxypropanesulfonate to form a sulfonic acid quaternary ammonium salt betaine structure.

[0029] Example 2

[0030] (1) 5 g of dehydroabietic acid acyl chloride, 5.2 g of 4-hydroxyphthalic anhydride, and 1.6 g of pyridine were added to 30 mL of toluene, and the mixture was stirred at 20 °C for 6 h. After filtration, the filtrate was distilled under reduced pressure, and the product was recrystallized from dichloromethane to obtain a phthalic anhydride rosin intermediate with a yield of 5.64 g.

[0031] (2) 10 g of the phthalic anhydride rosin intermediate and 2.05 g of N,N-dimethylethylenediamine were added to 100 mL of N,N-dimethylformamide, and the mixture was stirred at 20 °C for 4 h. Then, 6.3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 3.7 g of N-hydroxysuccinimide, and 6.9 g of hexadecylamine were added, and the mixture was stirred at 35 °C for 12 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 distilled under reduced pressure and washed with petroleum ether. The product was recrystallized from dichloromethane to obtain an alkyl tertiary amine rosin intermediate with a yield of 11.18 g.

[0032] (3) 6 g of the alkyl tertiary amine rosin intermediate and 2.52 g of 3-chloro-2-hydroxypropanesulfonate were added to 100 mL of isopropanol, and the mixture was stirred at 85 °C for 18 h with reflux condensation during the reaction. After distillation under reduced pressure 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 4.82 g.

[0033] Example 3

[0034] (1) 5 g of dehydroabietic acid acyl chloride, 4.8 g of 4-hydroxyphthalic anhydride, and 1.9 g of triethylamine were added to 30 mL of toluene, and the mixture was stirred at 35 °C for 3 h. After filtration, the filtrate was distilled under reduced pressure, and the product was recrystallized from dichloromethane to obtain a phthalic anhydride rosin intermediate with a yield of 5.90 g.

[0035] (2) 10 g of the phthalic anhydride rosin intermediate and 2.05 g of N,N-dimethylethylenediamine were added to 120 mL of N,N-dimethylformamide, and the mixture was stirred at 30 °C for 2 h. Then, 4.5 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 2.7 g of N-hydroxysuccinimide, and 6.2 g of octadecylamine were added, and the mixture was stirred at 20 °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 distilled under reduced pressure and washed with petroleum ether. The product was recrystallized from dichloromethane to obtain an alkyl tertiary amine rosin intermediate with a yield of 10.49 g.

[0036] (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, washing with petroleum ether, and recrystallization of the product in an ethanol aqueous solution to obtain a thickening agent for enhanced oil recovery, with a yield of 4.92 g.

[0037] Comparative Example 1 used alkyl tertiary amine rosin intermediate (prepared in Example 1) as the thickening agent.

[0038] Comparative Example 2

[0039] (1) 3.44 g of phthalic anhydride (structural formula ) 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 in dichloromethane to obtain intermediate d.

[0040] (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, washing with petroleum ether, and recrystallization of the product in an ethanol aqueous solution to obtain a thickening agent.

[0041] Comparative Example 3 prepared sulfopropyl betaine according to the method in the journal "China Surfactant Detergent & Cosmetics", June 2007, Vol. 37, No. 3, the literature "Synthesis of Rosin-based Betaine Amphoteric Surfactants".

[0042] (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 the mixture was allowed to stand for liquid separation. The toluene organic phase was taken, and anhydrous sodium sulfate was added for drying to remove water. After filtration, the filtrate was subjected to vacuum distillation to obtain (2-dehydroabietoyloxy)ethyl dimethyl tertiary amine. The structural formula is .

[0043] (2) Add 20 g of (2-dehydroabietoyloxy)ethyl dimethyl tertiary amine to 150 mL of 95% ethanol aqueous solution, add 50 mL of aqueous solution containing 9.83 g of sodium 3-chloro-2-hydroxypropanesulfonate, stir and react at 80 °C for 8 h. During the reaction, carry out condensation reflux, distill off ethanol and water under reduced pressure. Add the product to ethanol, filter, and then distill the filtrate under reduced pressure. Recrystallize the product in a petroleum ether and ethanol solution with a volume ratio of 1:3 to obtain sulfopropyl betaine, which is used as a thickening agent. The structural formula is .

[0044] Add a thickening agent to deionized water to prepare a thickening agent solution with a concentration of 4 g / L, shear at room temperature for 2 - 30 min, and the shear rate is 170 s -1 , and measure the apparent viscosity through a viscometer.

[0045] Place guar gum in an oven and heat age at 140 °C for 72 h. Cool to room temperature, add it to deionized water, and prepare a solution with a mass concentration of 4 g / L. Shear for 2 min, and the shear rate is 170 s -1 , and measure the apparent viscosity through a viscometer.

[0046] Table 1 Test on the shear resistance performance of the thickening agent

[0047]

[0048] Table 2 Test on the temperature resistance performance of the thickening agent

[0049]

[0050] After testing, the thickening agents prepared in Examples 1 - 3 have higher apparent viscosities. And after long-term shearing and high-temperature heat 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, making the thickening agents have good temperature resistance and are not easily decomposed by heat aging, so that the thickening agents have excellent temperature and shear resistance performance.

[0051] The thickening agent of Comparative Example 1 does not contain amphoteric betaine groups, and its hydrophilicity and water solubility are poor, resulting in a very low apparent viscosity.

[0052] 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 and being easily decomposed by heat aging. After high-temperature heat aging, the decline amplitude of the apparent viscosity is large and the retention rate is low.

[0053] Comparative Example 3 uses a conventional sulfopropyl betaine as a thickening agent. It does not contain long alkyl chains and cannot form a cross-linked network through hydrophobic association, resulting in a low thickening effect and poor shear resistance. After long-term shearing, the apparent viscosity decreases significantly. Moreover, it has a small benzene ring content and poor heat resistance. After high-temperature thermal aging, the decrease in apparent viscosity is greater than that of each example.

[0054] Add a 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 21476 mg / L), then saturate it with crude oil at 50°C, and then place the natural core in an 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.

[0055] Table 3 Recovery Rate Test

[0056] 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

[0057] 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 reach 14.7-15.6%. This is mainly because the thickening agent contains hydrophobic long-chain alkanes, hydrophilic amide bonds, and betaine zwitterionic groups, which have amphiphilicity and a high surface activity effect, can reduce the oil-water interfacial tension, and enable the crude oil to escape from the pores of the core, thereby improving the crude oil recovery rate.

Claims

1. A preparation method of a thickening agent for enhancing oil recovery, characterized in that, The preparation method includes the following steps: (1) Add dehydroabietic acid acyl chloride, 4-hydroxyphthalic anhydride, and an acid-binding agent with a mass ratio of 100:(72 - 104):(32 - 38) to toluene. After stirring and reacting, filter, distill the filtrate under reduced pressure, and recrystallize the product to obtain a phthalic anhydride rosin intermediate; The acid-binding agent is triethylamine or pyridine; (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 a fatty amine. After the second reaction, perform extraction, 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 the 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 , where a is any integer from 12 to 18; (3) Add the alkyl tertiary amine rosin intermediate and sodium 3-chloro-2-hydroxypropylsulfonate with a mass ratio of 100:(29 - 42) to isopropanol. After stirring and reacting, distill under reduced pressure, wash, and recrystallize the product to obtain a thickening agent for enhancing oil recovery.

2. The preparation method of the thickening agent for enhanced oil recovery according to claim 1, characterized in that, The reaction temperature in (1) is 20 - 35°C, and the reaction time is 3 - 6 h.

3. The preparation method of the thickening agent for enhanced oil recovery according to claim 1, characterized in that, The temperature of the first reaction in (2) 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.

4. The preparation method of the thickening agent for enhanced oil recovery according to claim 1, characterized in that In (3), the reaction temperature is 80 - 85°C, and the reaction time is 18 - 24 h.

5. A thickening agent for enhanced oil recovery obtained by the preparation method according to any one of claims 1-4, characterized in that, The structural formula of the thickening agent is as follows: ; R1 = , R2 = , a is any integer from 12 to 18; or R2 = , R1 = , a is any integer from 12 to 18.

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