Zwitterionic bactericide and method for its preparation

Abstract

The present application relates to the technical field of bactericides for treating oilfield produced water, and particularly relates to a zwitterionic bactericide and a preparation method thereof, the zwitterionic bactericide comprises a compound SS, a structure of which is shown in formula I, and has the advantages of excellent bactericidal performance, difficulty in producing drug resistance and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of bactericides for treating produced water in oil fields, specifically to an amphoteric bactericide and its preparation method. Background Technology

[0002] As oilfields enter the mid-to-late stages of development, extraction becomes increasingly difficult, often requiring secondary and tertiary recovery methods to further increase crude oil production. However, this also leads to the entry into the medium-to-high water-cut phase. Produced water contains a large number of sulfate-reducing bacteria (SRB), iron bacteria (TGB), saprophytic bacteria (FB), yeasts, and other harmful bacteria. These bacteria cause severe corrosion to oilfield pipelines and equipment through oxygen concentration cells (electrochemical reactions). Furthermore, these harmful bacteria easily adhere to the inner walls of oilfield pipelines and equipment, as well as to the surfaces of other corrosion products, further causing blockages and ultimately affecting safe oilfield production. Therefore, providing a highly efficient and environmentally friendly bactericide for oilfield produced water is essential.

[0003] Currently, bactericides commonly used in oil fields can be broadly classified into three categories based on their function and composition: oxidizing bactericides, non-oxidizing bactericides, and compound bactericides.

[0004] Oxidative bactericides kill bacteria through oxidation. The agent reacts with metabolic enzymes within bacteria, completely decomposing them into carbon dioxide and water, thus achieving sterilization. Examples of this type of bactericide include chlorine, bromine, sodium hypochlorite, and halogenated hydantoin. However, long-term practical experience has shown that oxidative bactericides have drawbacks such as susceptibility to pH fluctuations, the tendency for reducing substances in water to react with the bactericide itself, unstable efficacy, and the potential for resistance with long-term use.

[0005] Non-oxidizing fungicides primarily work by penetrating into organisms and forming complexes with amino acids within the bacteria. These fungicides can be further divided into non-ionic and ionic fungicides.

[0006] Nonionic bactericides include organic aldehydes, cyanide compounds, organotin compounds, etc. For example, Chinese patent application CN201610621006.X discloses a bactericide, its preparation method and application. This bactericide is a nonionic bactericide and includes the following components by mass percentage: bromonitroethanol 5%-8%, sodium dichloroisocyanurate 10%-15%, dithiocyanomethane 1%-4%, glutaraldehyde 20%-35%, dispersant 2%-4%, and the balance being water.

[0007] Ionic bactericides include: cationic bactericides, anionic bactericides, and amphoteric bactericides.

[0008] Among them, cationic bactericides include quaternary ammonium salts, quaternary phosphine salts, and alkyl guanidines, such as Chinese patent application CN201410118918.6 which discloses a method for preparing a gemini bis-quaternary ammonium salt bromide bactericide, Chinese patent application CN95116434.1 which discloses a quaternary ammonium salt bactericide and its preparation method, and Chinese patent application CN201410685477.8 which discloses a water treatment dodecyl guanidine acetate bactericide and its preparation method.

[0009] Amphoteric bactericides include phosphate betaine type, such as Chinese patent application CN201710252049.X, which discloses a phosphate betaine type high-efficiency bactericide for oilfield polymer-containing wastewater and its preparation method.

[0010] However, most anionic bactericides have poor water solubility and compatibility, resulting in low bactericidal performance. Therefore, there is little research and few reports on them in related fields.

[0011] Compound bactericides are mainly formulated by combining two or more bactericides with other excipients. Through the synergistic effect between the components, the bactericidal efficiency is improved. For example, Chinese patent application CN201711048235.8 discloses an environmentally friendly bactericide and its preparation method. The environmentally friendly bactericide is obtained by compounding multiple bactericidal components.

[0012] Currently, cationic bactericides (such as quaternary ammonium salts and quaternary phosphine salts) are widely used due to their advantages of high efficiency, ease of use, low cost, and wide applicability. Cationic bactericides mainly work by adsorbing cations onto the cell walls of microorganisms, disrupting enzymes within the cell walls, thereby affecting microbial metabolism and ultimately achieving sterilization. Quaternary ammonium salt bactericides are most widely used in oilfield production. However, practical experience has shown that cationic bactericides have disadvantages such as reduced bactericidal performance in highly salinized media, easy foaming, and easy adsorption loss. Furthermore, long-term use in produced water from the same oilfield block can easily lead to drug resistance.

[0013] Amphoteric bactericides have both positive and negative charges in their molecular structure, giving them advantages such as wide applicability, good compatibility, low toxicity, and minimal adsorption loss. They combine the bactericidal properties of both anionic and cationic bactericides, thus making them promising for widespread application.

[0014] In response to the above problems and to meet the actual needs of oilfield production, this invention proposes an amphoteric bactericide for oilfield produced water and its preparation method. Summary of the Invention

[0015] Currently, bactericides used in oilfield produced water are prone to problems such as drug resistance, narrow applicability, and poor environmental performance. The purpose of this invention is to overcome the shortcomings of the existing technology and provide an amphoteric bactericide with excellent bactericidal performance and environmental protection for oilfield produced water, as well as its preparation method.

[0016] This invention is achieved through the following technical solutions:

[0017] A compound SS, the structure of which is shown in Formula I:

[0018]

[0019] Preferably, X in Formula I - It is a halide ion.

[0020] More preferably, X in Formula I - It can be chloride ion, bromide ion or fluoride ion.

[0021] Preferably, Y in Formula I + It is at least one of hydrogen ions, ammonium ions, and alkali metal ions.

[0022] Preferably, the compound SS does not contain X. - and Y + Specifically, the structural formula is shown in Formula II:

[0023]

[0024] This invention also relates to a method for preparing the above-mentioned compound SS, comprising the following steps:

[0025] (1) Under acidic conditions, diallyl thiosulfinate is oxidized to give product SO;

[0026] (2) Take product SO and quaternary ammonium salt catalyst, add haloepoxide to obtain product SC;

[0027] (3) Mix product SC with an aliphatic tertiary amine and an alcohol catalyst to obtain product SN;

[0028] (4) Take the product SN and react it with halosulfonic acid to obtain the product SS.

[0029] Preferably, step (1) includes the following steps: mixing the oxidant with water, adjusting the pH to 3-5, stirring thoroughly, slowly adding diallyl thiosulfinate under nitrogen protection, heating to 35-45°C, continuing to stir for 1-3 hours, removing water, and obtaining product SO.

[0030] More preferably, the acid used to adjust the pH in step (1) is sulfuric acid.

[0031] Preferably, the oxidant used in step (1) includes potassium permanganate.

[0032] More preferably, the mass molar ratio of potassium permanganate to diallyl thiosulfinate in step (1) is 1-1.5 g: 0.2 mol.

[0033] Preferably, the quaternary ammonium salt catalyst in step (2) includes at least one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate and benzyltriethylammonium chloride.

[0034] Preferably, the haloepoxide in step (2) includes at least one of epichlorohydrin, epibromopropane and epichlorohydrin.

[0035] Preferably, step (2) includes the following steps: take product SO, add water and quaternary ammonium salt catalyst, add haloepoxide dropwise under nitrogen protection, heat to 45-55℃ and react for 2-4 hours, distill under reduced pressure to obtain product SC.

[0036] Preferably, the molar ratio of SO, haloepoxide and quaternary ammonium salt catalyst in step (2) is 1:2.1-2.4:0.2-0.5.

[0037] Preferably, the aliphatic tertiary amine in step (3) includes at least one of N,N-dimethyl-ethylamine, N,N-dimethyl-propylamine and N,N-dimethyl-methylamine.

[0038] Preferably, the alcohol catalyst in step (3) includes at least one of isopropanol, 2-butanol and cyclohexanol.

[0039] Preferably, step (3) includes the following steps: take product SC, add water, add aliphatic tertiary amine and alcohol catalyst in sequence under nitrogen protection, heat to 45-55℃, reflux for 7-9h, remove isopropanol, and obtain product SN.

[0040] Preferably, the molar ratio of SC, aliphatic tertiary amine and alcohol catalyst in step (3) is 1:2.1-2.4:0.7-0.9.

[0041] Preferably, the halosulfonic acid in step (4) is at least one of chlorosulfonic acid, bromosulfonic acid and fluorosulfonic acid.

[0042] Preferably, step (4) includes the following steps: take product SN, add water, heat to 55-65°C under nitrogen protection, add halosulfonic acid dropwise and stir for 3-5 hours, adjust pH to 8-10, continue stirring for 1-3 hours to obtain product SS.

[0043] Preferably, the molar ratio of SN to halosulfonic acid in step (4) is 1:1.2 to 1.5.

[0044] The present invention also relates to an amphoteric bactericide, comprising the above-mentioned compound SS or the compound SS or its salt prepared by the above-mentioned preparation method.

[0045] The present invention also relates to the application of the above-mentioned compound SS or the compound SS or its salt prepared by the above-mentioned preparation method as a bactericide.

[0046] The zwitterionic bactericide of this invention for oilfield produced water contains both anions and cations in its molecular structure, thus possessing the advantages of both anionic and cationic bactericides. It also has multiple hydrophilic and lipophilic groups, resulting in excellent water solubility and water-oil miscibility. The synthesized bactericide SS contains sulfur and oxygen atoms in its molecular structure, and the synergistic effect of the quaternary ammonium salt cation further enhances its bactericidal performance.

[0047] The bactericide SS of this invention is synthesized using diallyl thiosulfinate (allicin) as a base reagent. Due to its molecular structure, diallyl thiosulfinate (allicin) has inhibitory or bactericidal effects on a variety of bacteria. By designing and introducing specific functional groups to optimize its molecular structure, and targeting the mechanisms of action of sulfate-reducing bacteria (SRB), iron bacteria (FB), and saprophytic bacteria (TGB) in oilfield produced water, a highly efficient and environmentally friendly bactericide for oilfield produced water is synthesized. This bactericide is suitable for use in oilfield produced water of various water qualities (wide pH range) and has excellent bactericidal effect.

[0048] The beneficial effects of this invention are:

[0049] A bactericide for oilfield produced water was synthesized through molecular structure design, as detailed below:

[0050] (1) The bactericide prepared by the present invention is easily soluble in oilfield produced water of various water qualities (wide pH range 4.5-9.5), and has low foaming power, is environmentally friendly and low toxicity, and is highly efficient.

[0051] (2) The bactericide prepared in this invention can effectively kill and inhibit sulfate-reducing bacteria (SRB), iron bacteria (FB), saprophytic bacteria (TGB) and other bacteria in oilfield produced water. Detailed Implementation

[0052] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0053] Example 1

[0054] 50 mL of distilled water and 20 mL of 5% potassium permanganate aqueous solution were added to a three-necked flask equipped with a mechanical stirrer. 2% sulfuric acid aqueous solution was added to adjust the pH to 4. The mixture was stirred thoroughly for 10 min. Under nitrogen protection, 0.2 mol of diallyl thiosulfinate was slowly added. The temperature was raised to 40 °C and stirring was continued for 2 h. The water was removed by rotary evaporation to obtain SO product.

[0055] Take 1.0 mol of SO product into a three-necked flask, add 50 mL of distilled water and an aqueous solution containing 0.2 mol of tetrabutylammonium bromide, stir for 10 min, add 2.1 mol of epichlorohydrin dropwise under nitrogen protection, heat to 50 °C and react for 3 h, then distill under reduced pressure to obtain product SC.

[0056] Take 1.0 mol of the above SC product into a three-necked flask, add 50 mL of distilled water and stir thoroughly for 10 min. Under nitrogen protection, add 2.1 mol of N,N-dimethyl-ethylamine and 0.7 mol of isopropanol in sequence, heat to 50 °C, and reflux for 8 h with stirring. Remove isopropanol by rotary evaporation to obtain product SN.

[0057] Take 1.0 mol of the above SN product into a three-necked flask, add 50 mL of distilled water and stir for 10 min. Under nitrogen protection, heat to 60 °C, add 1.2 mol of chlorosulfonic acid dropwise and continue stirring for 4 h. Then add 5% NaOH aqueous solution to adjust the pH to 9 and continue stirring for 2 h to obtain the product SS.

[0058] The main molecular reaction formulas of the products involved are as follows:

[0059]

[0060] Example 2

[0061] 50 mL of distilled water and 20 mL of 5% potassium permanganate aqueous solution were added to a three-necked flask equipped with a mechanical stirrer. 2% sulfuric acid aqueous solution was added to adjust the pH to 4. The mixture was stirred thoroughly for 10 min. Under nitrogen protection, 0.2 mol of diallyl thiosulfinate was slowly added. The temperature was raised to 40 °C and stirring was continued for 2 h. The water was removed by rotary evaporation to obtain SO product.

[0062] Take 1.0 mol of SO product into a three-necked flask, add 50 mL of distilled water and an aqueous solution containing 0.3 mol of tetrabutylammonium bromide, stir for 10 min, add 2.2 mol of epichlorohydrin dropwise under nitrogen protection, heat to 50 °C and react for 3 h, then distill under reduced pressure to obtain product SC.

[0063] Take 1.0 mol of the above SC product into a three-necked flask, add 50 mL of distilled water and stir thoroughly for 10 min. Under nitrogen protection, add 2.2 mol of N,N-dimethyl-propylamine and 0.8 mol of cyclohexanol in sequence, heat to 50 °C, and reflux under stirring for 8 h. Remove isopropanol by rotary evaporation to obtain product SN.

[0064] Take 1.0 mol of the above SN product into a three-necked flask, add 50 mL of distilled water and stir for 10 min. Under nitrogen protection, heat to 60 °C, add 1.3 mol of chlorosulfonic acid dropwise and continue stirring for 4 h. Then add 5% NaOH aqueous solution to adjust the pH to 9 and continue stirring for 2 h to obtain the product SS.

[0065] Example 3

[0066] 50 mL of distilled water and 20 mL of 5% potassium permanganate aqueous solution were added to a three-necked flask equipped with a mechanical stirrer. 2% sulfuric acid aqueous solution was added to adjust the pH to 4. The mixture was stirred thoroughly for 10 min. Under nitrogen protection, 0.2 mol of diallyl thiosulfinate was slowly added. The temperature was raised to 40 °C and stirring was continued for 2 h. The water was removed by rotary evaporation to obtain SO product.

[0067] Take 1.0 mol of SO product into a three-necked flask, add 50 mL of distilled water and an aqueous solution containing 0.4 mol of benzyltriethylammonium chloride, stir for 10 min, add 2.3 mol of epichlorohydrin dropwise under nitrogen protection, heat to 50 °C and react for 3 h, then distill under reduced pressure to obtain product SC.

[0068] Take 1.0 mol of the above SC product into a three-necked flask, add 50 mL of distilled water and stir thoroughly for 10 min. Under nitrogen protection, add 2.3 mol of N,N-dimethyl-ethylamine and 0.9 mol of 2-butanol in sequence, heat to 50 °C, and reflux under stirring for 8 h. Remove isopropanol by rotary evaporation to obtain product SN.

[0069] Take 1.0 mol of the above SN product into a three-necked flask, add 50 mL of distilled water and stir for 10 min. Under nitrogen protection, heat to 60 °C, add 1.4 mol of fluorosulfonic acid dropwise and continue stirring for 4 h. Then add 5% NaOH aqueous solution dropwise to adjust the pH to 9 and continue stirring for 2 h to obtain the product SS.

[0070] Example 4

[0071] 50 mL of distilled water and 20 mL of 5% potassium permanganate aqueous solution were added to a three-necked flask equipped with a mechanical stirrer. 2% sulfuric acid aqueous solution was added to adjust the pH to 4. The mixture was stirred thoroughly for 10 min. Under nitrogen protection, 0.2 mol of diallyl thiosulfinate was slowly added. The temperature was raised to 40 °C and stirring was continued for 2 h. The water was removed by rotary evaporation to obtain SO product.

[0072] Take 1.0 mol of SO product into a three-necked flask, add 50 mL of distilled water and an aqueous solution containing 0.5 mol of tetrabutylammonium hydrogen sulfate, stir for 10 min, add 2.4 mol of epichlorohydrin dropwise under nitrogen protection, heat to 50 °C and react for 3 h, then distill under reduced pressure to obtain product SC.

[0073] Take 1.0 mol of the above SC product into a three-necked flask, add 50 mL of distilled water and stir thoroughly for 10 min. Under nitrogen protection, add 2.4 mol of N,N-dimethyl-methylamine and 0.9 mol of 2-butanol in sequence, heat to 50 °C, and reflux under stirring for 8 h. Remove isopropanol by rotary evaporation to obtain product SN.

[0074] Take 1.0 mol of the above SN product into a three-necked flask, add 50 mL of distilled water and stir for 10 min. Under nitrogen protection, heat to 60 °C, add 1.5 mol of bromosulfonic acid dropwise and continue stirring for 4 h. Then add 5% NaOH aqueous solution to adjust the pH to 9 and continue stirring for 2 h to obtain the product SS.

[0075] To demonstrate the bactericidal performance of the bactericide of the present invention, the evaluation method for the bactericidal performance of the bactericide synthesized in the above embodiments is as follows:

[0076] The sterilization performance evaluation method is based on the erasure dilution method in section 5.6 of the standard SY / T 5329-2012 "Water Quality Indicators and Analysis Methods for Injection Water in Clastic Rock Reservoirs". The sterilization performance is evaluated by calculating the number of bacteria after sterilization according to SY / T 5757-2010.

[0077] Test temperature: 35℃; test time: 168h; dosage: 50mg / L. The results are shown in Table 1.

[0078] Table 1

[0079]

[0080]

[0081] As shown in Table 1, Examples 1 to 4 all exhibited excellent bactericidal performance in produced water from different oilfield blocks, with the number of the three types of bacteria remaining low or even zero after sterilization. This indicates that the bactericidal performance of the present invention is not easily affected by the pH value of the water. Example 2 showed the most significant bactericidal effect, with the number of the three types of bacteria remaining at zero after sterilization in produced water from different oilfield blocks.

[0082] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A compound SS, characterized in that, The structure of the compound SS is shown in Formula I: The X - The Y is a halide ion. + It can be hydrogen ions, ammonium ions, or alkali metal ions.

2. The compound SS according to claim 1, characterized in that, X does not exist - and Y + .

3. The method for preparing compound SS according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Under acidic conditions, diallyl thiosulfinate is oxidized to give product SO; (2) Take product SO and quaternary ammonium salt catalyst, add haloepoxide to obtain product SC; (3) Mix product SC with an aliphatic tertiary amine and an alcohol catalyst to obtain product SN; (4) Take product SN and react it with halosulfonic acid to obtain product SS; The structural formulas of products SO, SC, and SN are as follows:

4. The preparation method according to claim 3, characterized in that, The oxidant used in step (1) includes potassium permanganate.

5. The preparation method according to claim 3, characterized in that, The quaternary ammonium salt catalyst in step (2) includes at least one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate and benzyltriethylammonium chloride; the haloepoxide includes at least one of epichlorohydrin, epibromopropane and epichlorohydrin.

6. The preparation method according to claim 3, characterized in that, The aliphatic tertiary amine in step (3) includes at least one of N,N-dimethyl-ethylamine, N,N-dimethyl-propylamine and N,N-dimethyl-methylamine; the alcohol catalyst includes at least one of isopropanol, 2-butanol and cyclohexanol.

7. The preparation method according to claim 3, characterized in that, The halosulfonic acid mentioned in step (4) is at least one of chlorosulfonic acid, bromosulfonic acid and fluorosulfonic acid.

8. The preparation method according to claim 3, characterized in that, Step (1) includes the following steps: mix the oxidant with water, adjust the pH to 3-5, stir thoroughly, slowly add diallyl thiosulfinate under nitrogen protection, heat to 35-45℃, continue stirring for 1-3 hours, remove water, and obtain product SO.

9. The preparation method according to claim 3, characterized in that, Step (2) includes the following steps: Take product SO, add water and quaternary ammonium salt catalyst, add haloepoxide dropwise under nitrogen protection, heat to 45-55℃ and react for 2-4 hours, distill under reduced pressure to obtain product SC.

10. The preparation method according to claim 3, characterized in that, Step (3) includes the following steps: Take product SC, add water, and under nitrogen protection, add aliphatic tertiary amine and alcohol catalyst in sequence, heat to 45-55℃, reflux for 7-9h, remove isopropanol, and obtain product SN.

11. The preparation method according to claim 3, characterized in that, Step (4) includes the following steps: Take product SN, add water, heat to 55-65℃ under nitrogen protection, add halosulfonic acid dropwise and stir for 3-5 hours, adjust pH to 8-10, continue stirring for 1-3 hours to obtain product SS.

12. The preparation method according to claim 3, characterized in that, The molar ratio of SO, haloepoxide and quaternary ammonium salt catalyst is 1:2.1-2.4:0.2-0.5; the molar ratio of SC, aliphatic tertiary amine and alcohol catalyst is 1:2.1-2.4:0.7-0.9; and the molar ratio of SN to halosulfonic acid is 1:1.2-1.

5.

13. An amphoteric bactericide, characterized in that, The compound SS includes the compound SS described in any one of claims 1-2 or the compound SS prepared by the preparation method described in any one of claims 3-12.

14. The use of compound SS as described in any one of claims 1-2 or compound SS prepared by any one of the preparation methods described in claims 3-12 as a bactericide.

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