Preparation method of degradable bactericide for oil field

Abstract

The invention relates to the technical field of organic high-molecular compounds, and discloses a preparation method of a degradable bactericide for oil fields, which comprises the following steps: carrying out anhydride ring-opening reaction on succinic anhydride and 1, 8-diamino-3, 6-dioxaoctane, then carrying out esterification polymerization reaction with N-Boc-serinol, and removing Boc protecting group to obtain the degradable bactericide for oil fields. And finally, reacting with an epoxy group of epoxy propyl dimethyl dodecyl ammonium chloride to obtain the degradable bactericide for the oil field. A side chain of the bactericide contains a large number of quaternary ammonium salt antibacterial groups, so that the bactericide has very strong bactericidal performance and good hydrophilicity and water solubility, and is beneficial to improving the dispersibility and surface activity of the bactericide in oil field water and enhancing the adsorption effect of the bactericide and bacteria, so that the bactericide is in full contact with the bacteria, and the antibacterial effect of the bactericide is improved. And the sterilization performance of the bactericide is better exerted. The heat resistance and the degradability are excellent.

Description

Technical Field

[0001] The invention relates to the technical field of organic polymer compounds, in particular to a method for preparing a degradable fungicide for oil fields. Background Art

[0002] The oilfield water injection system contains a large number of bacterial microorganisms such as sulfate-reducing bacteria, iron bacteria, saprophytes, and heterotrophic bacteria. During the growth, metabolism, and reproduction of these bacteria, they will corrode drilling and production equipment, water injection pipelines, and other equipment, block pipelines and injection wells, and reduce oil production and oil and gas quality. At present, the main bacterial control measures in the oilfield water injection system include cleaning the water injection system, microbial control method, ultraviolet irradiation sterilization treatment, and chemical sterilization treatment. Among them, the chemical sterilization treatment method is the most widely used because it is convenient, fast, and has a significant sterilization effect. The development of high-performance fungicides for oil fields is a research hotspot.

[0003] At present, the main fungicides used in oil fields are urea-based fungicides, isothiazolinone fungicides, quaternary ammonium salt fungicides, etc. Compared with small molecule fungicides, macromolecular polymer fungicides have strong structural stability and good heat resistance, and are suitable for the complex and harsh environment of high temperature and high salt in oil field water injection systems. However, the water solubility of macromolecular polymers is poor, which will affect their bactericidal performance. The patent with publication number CN114957525A discloses a bactericide and synthesis method for oilfield wastewater treatment, and its classification number is C08. The synthesis method is as follows: 2-cyclohexene-1-one is added to a four-necked flask protected by nitrogen, dibutylphosphine is slowly added dropwise, and then ethanol and 1,4-dichloro-2-butene are added, stirred, heated and refluxed for reaction, and distilled under reduced pressure; then ethyl acetate is added to the above crude product, heated to dissolve, filtered, and the filtrate is cooled to below 10°C to precipitate crystals; in another flask, the above monomers and water are added, an initiator is added dropwise, the temperature is raised to 60-70°C, the reaction is continued for 15-30 minutes, and a 20wt% sodium bisulfite solution is added to obtain a light yellow solid, which is then crushed into 30-60 mesh particles using a pulverizer to obtain a bactericide; the bactericide has the advantages of a wide source of raw materials and a simple synthesis process; it has a broad-spectrum bactericidal effect; it has the advantages of a small amount and a high bactericidal efficiency. Another invention patent with announcement number CN114751498B and classification number C08 discloses a flocculant for sterilizing and degreasing oil-containing wastewater in oilfields, and a preparation method and application thereof. The preparation method is as follows: tributylphosphine, allyl chloride, solvent, and cupric chloride are added to the first reactor, nitrogen is introduced, the temperature is raised by stirring, and the solution is refluxed and kept warm to obtain a solution; the solution is distilled to dryness under reduced pressure, dissolved by raising the temperature with ethyl acetate, filtered, cooled, recrystallized, and dried to obtain a solid; the solid, 3-[(3-acrylamidopropyl)dimethylammonium]propionate, acrylamide, 4-vinylpyridine, OP-10, sodium dodecyl sulfate, and water are added to the second reactor, and stirred to obtain a mixture solution; an initiator is added to the first high-level tank, and a reducing agent is added to the second high-level tank; the initiator and the reducing agent are added dropwise to the second reactor, the initiator and the reducing agent are added dropwise, the temperature is raised at the same time, and granulation is performed to obtain the product. The invention patent with publication number CN118496488A and classification number C08 discloses a method for preparing a water-based polyester with antibacterial function. The preparation method comprises the following steps: S1. Under nitrogen conditions, diethylene glycol and 1,6-hexanediol are added to a reactor, stirred and heated to 60-80°C, and then terephthalic acid and catalyst di-n-butyltin oxide are added, and the temperature is gradually increased to react until the solid acid value is less than 2; S2-S5; S6. Nitrogen is passed through the dilution kettle, ethylene glycol butyl ether and propylene glycol methyl ether are added, preheated to 60-80°C, stirred at 55-60r / min, and the materials in the reactor are transferred to the dilution kettle. The dilution temperature is maintained at 80-100°C during the dilution process. After the dilution is completed and the solid content and viscosity are tested to be qualified, the temperature is reduced to 50-55°C and the materials are discharged to obtain a water-based polyester with antibacterial function.

[0004] However, the above-mentioned macromolecular polymer type fungicides are not biodegradable and will cause serious pollution if they exist in the oil field water injection system for a long time. Summary of the invention

[0005] The invention solves the problem that the conventional polymer-type fungicides (especially polyester-based fungicides) used in oil fields have low water solubility and are not biodegradable.

[0006] The technical solution of the present invention is: a method for preparing a degradable fungicide for oil fields: Step A: Add N,N-dimethylformamide, N-Boc-serinol, 1,8-di(butyramic acid)-3,6-dioxaoctane, and p-toluenesulfonic acid into a reaction vessel, stir and react at 75-90°C for 8-12 hours, distill the solution under reduced pressure, wash with ethanol, and dry to obtain Boc amino polyester. The reaction formula is as follows:

[0007] Step B: Add ethyl acetate solution of hydrochloric acid and Boc amino polyester to a reaction vessel, stir and react at 20-30°C for 5-8h, distill the solution under reduced pressure, wash with saturated sodium bicarbonate and ethanol in turn, and dry to obtain amino polyester. The reaction formula is:

[0008] Step C: Add water, amino polyester and glycidyl dimethyl dodecyl ammonium chloride to a reaction vessel, stir to react, heat the solution to evaporate, precipitate a large amount of precipitate, filter, wash with ethanol, and dry to obtain a degradable fungicide for oil fields. The reaction formula is:

[0009] Preferably, in step A, the ratio of N-Boc-serinol, 1,8-di(butyramic acid)-3,6-dioxaoctane, and p-toluenesulfonic acid is 1 mol: (0.9-1.1) mol: (0.04-0.05) mol.

[0010] Preferably, in step C, the ratio of amino polyester to glycidyl dimethyl dodecyl ammonium chloride is 1 g: (0.6-0.9) g.

[0011] Preferably, in step C, the reaction temperature is 55-70° C. and the reaction time is 18-24 h.

[0012] Preferably, in step C, the preparation method of 1,8-di(butyric acid)-3,6-dioxooctane is as follows: add N,N-dimethylformamide solvent, succinic anhydride, then add 1,8-diamino-3,6-dioxooctane, ethyl acetate cosolvent to the reaction container, stir and react for 6-10h at 30-45°C, add saturated sodium chloride solution, extract with ethyl acetate 3 times, combine the organic phases, dry with anhydrous sodium sulfate, filter, distill the filtrate under reduced pressure, wash with petroleum ether, and dry to obtain 1,8-di(butyric acid)-3,6-dioxooctane. The reaction formula is:

[0013] Preferably, the ratio of succinic anhydride to 1,8-diamino-3,6-dioxaoctane is (2.6-3.2) mol:1 mol.

[0014] Preferably, the ratio of N,N-dimethylformamide solvent to ethyl acetate co-solvent is 1L:(0.2-0.3)L.

[0015] The technical effect of the present invention is as follows: the present invention conducts an anhydride ring-opening reaction between succinic anhydride and 1,8-diamino-3,6-dioxooctane to obtain 1,8-di(succinamide acid)-3,6-dioxooctane, then conducts an esterification polymerization reaction with N-Boc-serinol, and removes the Boc protecting group to obtain amino polyester, and finally the amino group of the side chain reacts with the epoxy group of glycidyl dimethyl dodecyl ammonium chloride to obtain a degradable fungicide for oil fields.

[0016] The side chain of the bactericide of the present invention contains a large number of quaternary ammonium salt antibacterial groups and has strong bactericidal performance. At the same time, the main chain contains hydrophilic ether bonds and multiple hydrophilic amide bonds, which significantly improves the hydrophilicity and water solubility of the polyester-based bactericide, is beneficial to improving the dispersibility and surface activity of the bactericide in oilfield water, enhances the adsorption effect between the bactericide and bacterial cells, makes the bactericide fully contact with the bacterial cells, and better exerts the bactericidal performance of the bactericide.

[0017] The oil field degradable fungicide of the present invention is a macromolecular polymer with better heat resistance. After high-temperature heat treatment, it still maintains the structural stability of the molecular chain, is not easy to be thermally decomposed, and still shows a good sterilization rate. In addition, the polymer main chain contains a large number of ester groups and has strong hydrolysis, so that the fungicide shows good degradability and is green and environmentally friendly with little pollution. DETAILED DESCRIPTION

[0018] The technical scheme of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention. Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products, or can be prepared by known methods.

[0019] Example 1 (1) Add 1500 mL of N,N-dimethylformamide solvent, 140 mmol of succinic anhydride, and then add 50 mmol of 1,8-diamino-3,6-dioxooctane and 400 mL of ethyl acetate as a cosolvent to a reaction vessel, stir and react at 30°C for 10 h, add saturated sodium chloride solution, and extract with ethyl acetate three times. Combine the organic phases, dry with anhydrous sodium sulfate, filter, and distill the filtrate under reduced pressure, wash with petroleum ether, and dry to obtain 1,8-di(succinamic acid)-3,6-dioxooctane.

[0020] (2) Add 300 mL of N,N-dimethylformamide, 20 mmol of N-Boc-serinol, 20 mmol of 1,8-di(butyramic acid)-3,6-dioxaoctane, and 0.8 mmol of p-toluenesulfonic acid into a reaction vessel, stir and react at 80°C for 8 h, distill the solution under reduced pressure, wash with ethanol, and dry to obtain Boc amino polyester.

[0021] (3) Add 800 mL of 4 mol / L hydrochloric acid in ethyl acetate and 40 g of Boc amino polyester to a reaction vessel, stir and react at 30°C for 5 h, distill the solution under reduced pressure, wash with saturated sodium bicarbonate and ethanol in turn, and dry to obtain amino polyester.

[0022] (4) Add 2L of water, 40g of amino polyester and 24g of epoxypropyl dimethyl dodecyl ammonium chloride into a reaction container, stir and react at 55°C for 18h, heat the solution to evaporate, and a large amount of precipitate is precipitated. After filtering, wash with ethanol and dry to obtain a biodegradable fungicide for oil fields.

[0023] Example 2 (1) Add 1500 mL of N,N-dimethylformamide solvent, 130 mmol of succinic anhydride, and then add 50 mmol of 1,8-diamino-3,6-dioxooctane and 300 mL of ethyl acetate as a cosolvent to a reaction vessel, stir and react at 45°C for 8 h, add saturated sodium chloride solution, and extract with ethyl acetate three times. Combine the organic phases, dry with anhydrous sodium sulfate, filter, and distill the filtrate under reduced pressure, wash with petroleum ether, and dry to obtain 1,8-di(succinamic acid)-3,6-dioxooctane.

[0024] (2) Add 400 mL of N,N-dimethylformamide, 20 mmol of N-Boc-serinol, 22 mmol of 1,8-di(butyramic acid)-3,6-dioxaoctane, and 1 mmol of p-toluenesulfonic acid into a reaction vessel, stir and react at 75°C for 12 h, distill the solution under reduced pressure, wash with ethanol, and dry to obtain Boc amino polyester.

[0025] (3) Add 800 mL of 4 mol / L hydrochloric acid in ethyl acetate and 40 g of Boc amino polyester to a reaction vessel, stir and react at 25°C for 8 h, distill the solution under reduced pressure, wash with saturated sodium bicarbonate and ethanol in turn, and dry to obtain amino polyester.

[0026] (4) Add 2L of water, 40g of amino polyester and 36g of epoxypropyl dimethyl dodecyl ammonium chloride into a reaction container, stir and react at 70°C for 18h, heat the solution to evaporate, and a large amount of precipitate is precipitated. After filtering, wash with ethanol and dry to obtain a biodegradable fungicide for oil fields.

[0027] Example 3 (1) Add 1500 mL of N,N-dimethylformamide solvent, 160 mmol of succinic anhydride, and then add 50 mmol of 1,8-diamino-3,6-dioxooctane and 450 mL of ethyl acetate as a co-solvent to a reaction vessel, stir and react at 45°C for 6 h, add saturated sodium chloride solution, and extract with ethyl acetate for 3 times. Combine the organic phases, dry with anhydrous sodium sulfate, filter, and distill the filtrate under reduced pressure, wash with petroleum ether, and dry to obtain 1,8-di(succinamic acid)-3,6-dioxooctane.

[0028] (2) Add 400 mL of N,N-dimethylformamide, 20 mmol of N-Boc-serinol, 18 mmol of 1,8-di(butyric acid)-3,6-dioxaoctane, and 0.8 mmol of p-toluenesulfonic acid into a reaction vessel, stir and react at 90°C for 8 h, distill the solution under reduced pressure, wash with ethanol, and dry to obtain Boc amino polyester.

[0029] (3) Add 800 mL of 4 mol / L hydrochloric acid in ethyl acetate and 40 g of Boc amino polyester to a reaction vessel, stir and react at 20°C for 8 h, distill the solution under reduced pressure, wash with saturated sodium bicarbonate and ethanol in turn, and dry to obtain amino polyester.

[0030] (4) Add 2L of water, 40g of amino polyester and 30g of epoxypropyl dimethyl dodecyl ammonium chloride into a reaction container, stir and react at 60°C for 24h, heat the solution to evaporate, and a large amount of precipitate is precipitated. After filtering, wash with ethanol and dry to obtain a biodegradable fungicide for oil fields.

[0031] Comparative Example 1 (1) Add 300 mL of N,N-dimethylformamide, 20 mmol of N-Boc-serinol, 20 mmol of adipic acid, and 0.8 mmol of p-toluenesulfonic acid into a reaction vessel, stir and react at 80°C for 8 h, distill the solution under reduced pressure, wash with ethanol, and dry to obtain Boc amino polyester.

[0032] (2) Add 4 mol / L hydrochloric acid in ethyl acetate and 40 g of Boc amino polyester to a reaction vessel, stir and react at 30°C for 5 h, distill the solution under reduced pressure, wash with saturated sodium bicarbonate and ethanol in turn, and dry to obtain amino polyester.

[0033] (3) Add 2L of water, 40g of amino polyester and 24g of epoxypropyl dimethyl dodecyl ammonium chloride into a reaction container, stir and react at 55°C for 18h, heat the solution to evaporate, and a large amount of precipitate is precipitated. After filtering, wash with ethanol and dry to obtain a biodegradable fungicide for oil fields.

[0034] Comparative Example 2 (1) Add 300 mL of N,N-dimethylformamide, 20 mmol of 1,3-propylene glycol, 20 mmol of 1,8-di(butyramic acid)-3,6-dioxaoctane (prepared in the same manner as in Example 1), and 0.8 mmol of p-toluenesulfonic acid into a reaction container, stir and react at 80° C. for 8 h, distill the solution under reduced pressure, wash with ethanol, and dry to obtain polyester.

[0035] (2) Add 2L of water, 40g of polyester and 24g of epoxypropyl dimethyl dodecyl ammonium chloride into a reaction container, stir and react at 55°C for 18h, heat the solution to evaporate, and a large amount of precipitate is precipitated. After filtering, wash with ethanol and dry to obtain a biodegradable fungicide for oil fields.

[0036] Add oilfield degradable fungicide to distilled water to prepare solutions with different mass concentrations, stir for 10 minutes at 25°C, let stand for 1 hour, and observe the state of the solution. The results are shown in Table 1.

[0037] Table 1 Test of water solubility of fungicides

[0038] It can be seen from Table 1 that the degradable fungicide for oil field prepared in Examples 1-3 has good water solubility at a mass concentration of 0.05-10 g / L. This is because 1,8-di(butyramic acid)-3,6-dioxaoctane contains a hydrophilic ether bond and multiple hydrophilic amide bonds. After esterification and polymerization with N-Boc-serinol, the ether bond and amide bond are introduced into the main chain of the polyester, which significantly improves the hydrophilicity and water solubility of the polyester-based fungicide.

[0039] In Comparative Example 1, N-Boc-serinol and adipic acid are polymerized to obtain a polyester-based fungicide that does not contain hydrophilic ether bonds and amide bonds, has poor water solubility, and is prone to forming suspended matter and precipitation in water.

[0040] In Comparative Example 2, 1,3-propylene glycol and 1,8-di(butyramic acid)-3,6-dioxaoctane were polymerized to obtain a polyester-based fungicide whose main chain contained hydrophilic ether bonds and amide bonds and had good water solubility.

[0041] Weigh 10 g (denoted as m) of fungicide and add it to 1 L of PBS buffer solution, stir at 30°C for 7-28 days, freeze-dry to remove water, wash with ethanol, dry, weigh (denoted as m1), and calculate the weight loss rate W.

[0042] W = (m-m1) / m×100%. The greater the weight loss rate, the better the degradation performance. The results are shown in Table 2.

[0043] Table 2 Bactericide weight loss test

[0044] After testing, the fungicides of Examples 1-3 have a high weight loss rate and excellent degradability. This is mainly because the fungicides have good water solubility and good solubility in water, and contain a large number of ester groups in the polymer main chain, which has strong hydrolysis, so that the fungicides show good degradability.

[0045] The fungicide of Comparative Example 1 contains a large number of ester groups in its main chain and has strong hydrolysis properties, but its weight loss rate is lower than that of the embodiments. This is mainly because the fungicide has low water solubility, the polyester molecular chain cannot fully contact with water, and has poor hydrolysis properties.

[0046] Bactericidal performance test: Add bactericide to distilled water to prepare a bactericide solution with a mass concentration of 50 mg / L. According to the SY-T 5890-93 method, the bactericide solution was tested for sulfate-reducing bacteria SRB (concentration 6.2×10 5 / mL), iron bacteria FB (concentration 8.5×10 4 / mL) and heterotrophic bacteria TGB (concentration 1.4×10 7 / mL) sterilization rate.

[0047] The bactericide was placed in an oven, heat treated at 120°C for 48 hours, cooled, and then tested for bactericidal performance. The results are shown in Table 3.

[0048] Table 3 Bactericidal and heat resistance test of fungicides

[0049] In Comparative Example 3, epoxypropyl dimethyl dodecyl ammonium chloride was used as the fungicide.

[0050] As shown in Table 2, the side chains of the polyester-based fungicides of Examples 1-3 contain a large number of quaternary ammonium salt antibacterial groups, which show a high sterilization rate against sulfate-reducing bacteria, iron bacteria and heterotrophic bacteria, and the fungicide, as a macromolecular polymer, has better heat resistance, and after high-temperature heat treatment, still maintains the structural stability of the molecular chain, is not easy to be thermally decomposed, and still shows a good sterilization rate. At the same time, the polyester-based fungicide has good water solubility, which can improve the dispersibility and surface activity of the fungicide in oilfield water, enhance the adsorption of the fungicide and bacterial cells, make the fungicide fully contact with the bacterial cells, and better play the sterilization performance of the fungicide.

[0051] The polyester-based fungicide of Comparative Example 1 has poor water solubility, easily forms suspended matter and precipitation in water, has low adsorption effect on bacterial cells, cannot fully contact with bacterial cells, and has a sterilization rate significantly lower than that of Example 1. However, as a macromolecular polymer, the polyester-based fungicide has better heat resistance, and after high-temperature heat treatment, the sterilization rate decreases very little.

[0052] In Comparative Example 2, 1,3-propylene glycol and 1,8-di(butyramic acid)-3,6-dioxaoctane were used for polymerization reaction. The obtained polyester did not contain amino groups and could not react with the epoxy groups of epoxypropyl dimethyl dodecyl ammonium chloride. The obtained fungicide did not contain quaternary ammonium salt antibacterial groups and showed no bactericidal rate against bacteria such as sulfate-reducing bacteria.

[0053] Comparative Example 3 uses epoxypropyl dimethyl dodecyl ammonium chloride as a bactericide, and shows a good bactericidal rate against sulfate-reducing bacteria and other bacteria. However, epoxypropyl dimethyl dodecyl ammonium chloride, as a small molecule compound, has a low thermal decomposition temperature and poor heat resistance. After high-temperature heat treatment, it is easy to produce thermal decomposition, which seriously affects its bactericidal performance and the bactericidal rate drops significantly.

[0054] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A method for preparing a degradable fungicide for oil fields, characterized in that: The preparation method is as follows: Step A, adding N,N-dimethylformamide, N-Boc-serinol, 1,8-di(butyramic acid)-3,6-dioxaoctane, and p-toluenesulfonic acid into a reaction container, stirring for reaction, distilling the solution under reduced pressure, washing with ethanol, and drying to obtain Boc amino polyester; The structural formula of the 1,8-di(butyramic acid)-3,6-dioxaoctane is as follows: ； Step B, adding a hydrochloric acid ethyl acetate solution and Boc amino polyester into a reaction vessel, stirring and reacting at 20-30° C. for 5-8 hours, distilling the solution under reduced pressure, washing, and drying to obtain amino polyester; Step C, adding water, amino polyester and glycidyl dimethyl dodecyl ammonium chloride into a reaction container, stirring for reaction, heating the solution for evaporation, separating out the precipitate, filtering, washing and drying to obtain a degradable fungicide for oil fields.

2. The method for preparing a degradable fungicide for oil fields according to claim 1, characterized in that: In the step A, the ratio of N-Boc-serinol, 1,8-di(butyramic acid)-3,6-dioxaoctane, and p-toluenesulfonic acid is 1 mol: (0.9-1.1) mol: (0.04-0.05) mol.

3. The method for preparing a degradable fungicide for oil fields according to claim 1, characterized in that: In the step A, the reaction temperature is 75-90° C. and the reaction time is 8-12 h.

4. The method for preparing a degradable fungicide for oil fields according to claim 1, characterized in that: In the step C, the ratio of amino polyester to glycidyl dimethyl dodecyl ammonium chloride is 1 g: (0.6-0.9) g.

5. The method for preparing a degradable fungicide for oil fields according to claim 1, characterized in that: In the step C, the reaction temperature is 55-70° C. and the reaction time is 18-24 hours.

6. The method for preparing a degradable fungicide for oil fields according to claim 2, characterized in that: In the step C, the preparation method of 1,8-di(butyramic acid)-3,6-dioxooctane is as follows: N,N-dimethylformamide solvent and succinic anhydride are added to a reaction container, and then 1,8-diamino-3,6-dioxooctane and ethyl acetate as a co-solvent are added. After the reaction, extraction, washing and drying are performed to obtain 1,8-di(butyramic acid)-3,6-dioxooctane.

7. The method for preparing a degradable fungicide for oil fields according to claim 6, characterized in that: The ratio of succinic anhydride to 1,8-diamino-3,6-dioxaoctane is (2.6-3.2) mol:1 mol.

8. The method for preparing a degradable fungicide for oil fields according to claim 6, characterized in that: The ratio of the N,N-dimethylformamide solvent to the ethyl acetate co-solvent is 1L:(0.2-0.3)L.

9. The method for preparing a degradable fungicide for oil fields according to claim 6, characterized in that: The reaction temperature is 30-45°C and the reaction time is 6-10h.

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