Oil and gas field bactericide and preparation method thereof

Abstract

This invention relates to the field of chemical additives for oil and gas field development. It discloses an oil and gas field bactericide and its preparation method, comprising the following components by mass percentage: glutaraldehyde 8%-18%; quaternary ammonium salt 12%-22%; disodium ethylenediaminetetraacetate 2%-6%; polyethylene glycol 400 1%-3%; and the balance being water. The quaternary ammonium salt is a mixture of dodecyl dimethyl benzyl ammonium chloride and disedecyl dimethyl ammonium chloride in a mass ratio of 1.5:1-2.5:1. This invention, through synergistic compounding of multiple components, significantly improves the stability of the bactericide under high temperature, high mineralization, and weakly alkaline environments, achieving an active substance retention rate of ≥92% after 72 hours. This solves the problems of easy degradation of glutaraldehyde and poor stability of conventional formulations. The product has a broad bactericidal spectrum and good long-lasting effect, with low concentrations effective against three key types of bacteria, inhibiting microbial corrosion and blockage. The compounded system is less prone to drug resistance, and the preparation process is mild and simple, suitable for industrial production, and can meet the long-term stable bactericidal requirements of oil and gas fields.

Description

Technical Field

[0001] This invention relates to the field of chemical additives for oil and gas field development, specifically to an oil and gas field bactericide and its preparation method. Background Technology

[0002] During oil and gas field development, water injection systems and produced fluid treatment systems are highly susceptible to the growth of microorganisms such as sulfate-reducing bacteria, saprophytic bacteria, and iron bacteria, leading to pipeline corrosion, formation blockage, and equipment damage, severely impacting production efficiency and safety. Currently, commonly used bactericides in oil and gas fields mainly include glutaraldehyde and quaternary ammonium salts.

[0003] Glutaraldehyde has a broad bactericidal spectrum and rapid action, but it is prone to polymerization in the high-temperature (≥60℃), high-mineralization (≥20000 mg / L), and weakly alkaline (pH≥8.0) environments of oil and gas fields, leading to rapid degradation of the active ingredients and a significantly shortened effective period. Quaternary ammonium salt bactericides have good surface activity and bactericidal properties, but when used alone, they are easily ineffective due to interference from metal ions and organic matter in the system, and long-term use alone can easily lead to microbial resistance.

[0004] To overcome the shortcomings of single-component formulations, there are existing reports of using glutaraldehyde in combination with quaternary ammonium salts. However, existing compound bactericides still suffer from insufficient stability and low retention rate of bactericidal active substances in highly mineralized and weakly alkaline environments, making it difficult to meet the long-term bactericidal requirements of oil and gas fields. Therefore, we propose an oil and gas field bactericide and its preparation method to solve the above-mentioned problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an oil and gas field bactericide and its preparation method, solving the problems of existing glutaraldehyde bactericides being prone to polymerization and degradation in high-temperature, high-mineralization, and weakly alkaline environments, quaternary ammonium salts being easily affected by water quality, poor stability of compound products, low activity retention rate, weak long-term bactericidal effect, and easy development of drug resistance.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an oil and gas field bactericide and its preparation method, comprising the following components by mass percentage:

[0007] Glutaraldehyde 8%-18%;

[0008] Quaternary ammonium salts: 12%-22%;

[0009] Disodium ethylenediaminetetraacetate 2%-6%;

[0010] Polyethylene glycol 400 1%-3%;

[0011] The remainder is water;

[0012] The quaternary ammonium salt is a mixture of dodecyl dimethyl benzyl ammonium chloride and disedecyl dimethyl ammonium chloride in a mass ratio of 1.5:1 to 2.5:1;

[0013] The oil and gas field bactericide, after being sealed and placed for 72 hours in a highly mineralized weakly alkaline environment at 60℃, pH 8.0, and a mineralization of 20000 mg / L, retains ≥92% of the bactericidal active substances and has a minimum bactericidal concentration of ≤15 mg / L against sulfate-reducing bacteria over 120 hours.

[0014] Preferably, the mass ratio of glutaraldehyde to quaternary ammonium salt is 1:0.8-1:1.5.

[0015] Preferably, the minimum bactericidal concentration of the oil and gas field bactericide against saprophytic bacteria and iron bacteria over 120 hours is ≤20mg / L.

[0016] Preferably, the mass percentage of each component is: glutaraldehyde 10%-15%, quaternary ammonium salt 15%-20%, disodium ethylenediaminetetraacetate 3%-5%, and polyethylene glycol 400 1.5%-2.5%.

[0017] Preferably, the mass ratio of dodecyl dimethyl benzyl ammonium chloride to decyl dimethyl ammonium chloride is 2:1.

[0018] This invention provides a method for preparing an oil and gas field bactericide, comprising the following steps performed sequentially:

[0019] S1. Add the prescribed amount of polyethylene glycol 400 to water with a conductivity ≤5μS / cm, and dissolve it under stirring conditions of 25-30℃ and 100-150r / min to obtain a stabilizer solution.

[0020] S2. Add the prescribed amount of glutaraldehyde to the stabilizer solution and continue stirring for 20-25 minutes.

[0021] S3. Add the quaternary ammonium salt mixture of the formula amount under stirring conditions of 120-150r / min, and stir for 10-15min;

[0022] S4. Finally, add the prescribed amount of disodium ethylenediaminetetraacetate and stir until completely dissolved to obtain the oil and gas field bactericide.

[0023] Preferably, the temperature of the entire system from S2 to S4 is controlled between 20-35℃.

[0024] Beneficial effects

[0025] This invention provides an oil and gas field bactericide and its preparation method. Compared with the prior art, it has the following advantages:

[0026] This oil and gas field bactericide and its preparation method significantly improve the stability of the bactericide under high temperature, high mineralization, and weakly alkaline conditions through the synergistic compounding of glutaraldehyde, compound quaternary ammonium salts, disodium ethylenediaminetetraacetate, and polyethylene glycol 400. After being sealed and placed in an environment of 60℃, pH 8.0, and a mineralization of 20000 mg / L for 72 hours, the retention rate of bactericidal active substances is ≥92%, effectively solving the problems of easy polymerization and degradation of glutaraldehyde, poor stability of conventional compound formulations, and rapid attenuation of active ingredients. Simultaneously, disodium ethylenediaminetetraacetate can chelate metal ions in water, reducing the interference of complex water quality on the bactericidal components and greatly improving the adaptability of the agent in produced fluids and injection water.

[0027] With a broad bactericidal spectrum and outstanding long-lasting effect, it has a minimum bactericidal concentration of ≤15mg / L against sulfate-reducing bacteria and ≤20mg / L against saprophytic bacteria and iron bacteria within 120 hours, effectively inhibiting microbial growth and preventing pipeline corrosion and formation blockage. The complementary mechanisms of action of the compound quaternary ammonium salt and glutaraldehyde effectively reduce the risk of microbial resistance and ensure stable long-term efficacy. The preparation process is mild, simple to operate, requires no special equipment, and can be controlled at ambient temperature and pressure throughout, making it suitable for large-scale industrial production. It can meet the long-term, stable, and efficient bactericidal needs of oil and gas fields, demonstrating outstanding practicality and economy. Attached Figure Description

[0028] Figure 1 This invention relates to a method for preparing an oil and gas field bactericide. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1 As shown:

[0031] Example 1:

[0032] An oil and gas field bactericide, by mass percentage, comprises: 10% glutaraldehyde, 10% dodecyl dimethyl benzyl ammonium chloride, 5% decyl dimethyl ammonium chloride, 3% disodium ethylenediaminetetraacetate, 1.5% polyethylene glycol 400, and the balance being deionized water.

[0033] The preparation method is as follows:

[0034] S1. Add polyethylene glycol 400 to deionized water and stir at 25°C and 120 r / min to dissolve it, thus obtaining a stabilizer solution.

[0035] S2. Add glutaraldehyde and continue stirring for 20 minutes;

[0036] S3. Add the quaternary ammonium salt mixture and stir at 120 r / min for 10 min.

[0037] S4. Add disodium ethylenediaminetetraacetate and stir until completely dissolved to obtain the product;

[0038] The temperature was controlled between 20-30℃ throughout the S2 to S4 process.

[0039] Performance testing: After being sealed for 72 hours at 60℃, pH 8.0, and a mineralization of 20000 mg / L, the retention rate of bactericidal active substances was 94.2%; the minimum bactericidal concentration for sulfate-reducing bacteria was 12 mg / L after 120 hours, the minimum bactericidal concentration for saprophytic bacteria was 18 mg / L after 120 hours, and the minimum bactericidal concentration for iron bacteria was 18 mg / L after 120 hours.

[0040] Example 2:

[0041] An oil and gas field bactericide, by mass percentage, comprises: 15% glutaraldehyde, 13.3% dodecyl dimethyl benzyl ammonium chloride, 6.7% decyl dimethyl ammonium chloride, 5% disodium ethylenediaminetetraacetate, 2.5% polyethylene glycol 400, with the balance being deionized water.

[0042] The preparation method is as follows:

[0043] S1. Add polyethylene glycol 400 to deionized water and stir at 30°C and 150 r / min to dissolve it.

[0044] S2. Add glutaraldehyde and continue stirring for 25 minutes;

[0045] S3. Add the quaternary ammonium salt mixture and stir at 150 r / min for 15 min.

[0046] S4. Add disodium ethylenediaminetetraacetate and stir until completely dissolved to obtain the product; the temperature is controlled at 25-35℃ throughout the process.

[0047] Performance testing: After being sealed for 72 hours at 60℃, pH 8.0, and a mineralization of 20000 mg / L, the retention rate of bactericidal active substances was 95.6%; the minimum bactericidal concentration against sulfate-reducing bacteria was 10 mg / L after 120 hours, and the minimum bactericidal concentration against saprophytic bacteria and iron bacteria was 16 mg / L after 120 hours.

[0048] Example 3

[0049] An oil and gas field bactericide, by mass percentage, comprises: glutaraldehyde 8%, dodecyl dimethyl benzyl ammonium chloride 7.2%, decyl dimethyl ammonium chloride 4.8%, disodium ethylenediaminetetraacetate 2%, polyethylene glycol 400 1%, and the balance being deionized water.

[0050] The preparation method is as follows:

[0051] S1. Add polyethylene glycol 400 to deionized water and stir at 25°C and 100r / min to dissolve it.

[0052] S2. Add glutaraldehyde and continue stirring for 20 minutes;

[0053] S3. Add the quaternary ammonium salt mixture and stir at 120 r / min for 12 min.

[0054] S4. Add disodium ethylenediaminetetraacetate and stir until completely dissolved to obtain the product; the temperature is controlled at 20-30℃ throughout the process.

[0055] Performance testing: After being sealed for 72 hours at 60℃, pH 8.0, and a mineralization of 20000 mg / L, the retention rate of bactericidal active substances was 92.1%; the minimum bactericidal concentration against sulfate-reducing bacteria was 14 mg / L after 120 hours, and the minimum bactericidal concentration against saprophytic bacteria and iron bacteria was 19 mg / L after 120 hours.

[0056] Example 4

[0057] An oil and gas field bactericide, by mass percentage, comprises: 12% glutaraldehyde, 12% dodecyl dimethyl benzyl ammonium chloride, 6% didecyl dimethyl ammonium chloride, 4% disodium ethylenediaminetetraacetate, 400% polyethylene glycol, and the balance being deionized water.

[0058] The preparation method is as follows:

[0059] S1. Weigh out each raw material according to the formula and set aside; add the formula amount of polyethylene glycol 400 to deionized water with conductivity ≤5μS / cm, stir at 25–30℃ and 100–150r / min until completely dissolved to obtain a stabilizer solution.

[0060] S2. Add the prescribed amount of glutaraldehyde to the stabilizer solution and continue stirring for 20–25 minutes.

[0061] S3. Add the formulated amount of compound quaternary ammonium salt under stirring conditions of 120–150 r / min, and stir for 10–15 min until the mixture is uniform.

[0062] S4. Add the prescribed amount of disodium ethylenediaminetetraacetate and stir until completely dissolved. Maintain the temperature at 20–35℃ throughout the process. The finished product is obtained by discharging the material.

[0063] Performance testing: After being sealed for 72 hours at 60℃, pH 8.0, and a mineralization of 20000 mg / L, the retention rate of bactericidal active substances was 96.3%; the minimum bactericidal concentration against sulfate-reducing bacteria was 9 mg / L after 120 hours, and the minimum bactericidal concentration against saprophytic bacteria and iron bacteria was 15 mg / L after 120 hours.

[0064] Comparative Example 1

[0065] The formula is a conventional compound formulation, without the addition of disodium ethylenediaminetetraacetate and polyethylene glycol 400. By mass percentage: glutaraldehyde 10%, dodecyl dimethyl benzyl ammonium chloride 15%, and the balance being deionized water. Mix thoroughly at room temperature.

[0066] Performance testing: After being sealed for 72 hours at 60℃, pH 8.0, and a mineralization of 20000 mg / L, the retention rate of bactericidal active substances was only 68.3%; the minimum bactericidal concentration against sulfate-reducing bacteria was 32 mg / L after 120 hours, and the bactericidal effect was significantly inferior to that of the present invention.

[0067] Comparative Example 2

[0068] The mixture was prepared using a single component, dodecyl dimethyl benzyl ammonium chloride, with a mass concentration of 15%, and the remainder was deionized water, mixed at room temperature.

[0069] Performance testing: After being sealed for 72 hours at 60℃, pH 8.0, and a mineralization of 20000 mg / L, the retention rate of bactericidal active substances was 62.7%; the minimum bactericidal concentration against sulfate-reducing bacteria was >40 mg / L after 120 hours, indicating that the bactericidal effect was poor due to severe interference from water quality.

[0070] In summary, the bactericide obtained by this invention through specific component compounding and optimized preparation process exhibits high stability and good long-lasting bactericidal effect under high temperature, high mineralization, and weak alkaline environments. It can effectively solve the problem of microbial corrosion and blockage in oil and gas fields and is suitable for widespread application.

[0071] This formulation, through the synergistic compounding of glutaraldehyde, a compounded quaternary ammonium salt, disodium EDTA, and polyethylene glycol 400, significantly improves the stability of the bactericide under high temperature, high mineralization, and weakly alkaline conditions. After being sealed for 72 hours in an environment of 60℃, pH 8.0, and a mineralization of 20000 mg / L, the product exhibits a bactericidal active substance retention rate of ≥92%, effectively solving the problems of easy polymerization and degradation of glutaraldehyde, poor stability of conventional compound formulations, and rapid attenuation of active ingredients. Simultaneously, disodium EDTA can chelate metal ions in water, reducing the interference of complex water quality on the bactericidal components and significantly improving the adaptability of the agent in field-extracted and injected water.

[0072] With a broad bactericidal spectrum and outstanding long-lasting effect, it has a minimum bactericidal concentration of ≤15mg / L against sulfate-reducing bacteria and ≤20mg / L against saprophytic bacteria and iron bacteria within 120 hours, effectively inhibiting microbial growth and preventing pipeline corrosion and formation blockage. The complementary mechanisms of action of the compound quaternary ammonium salt and glutaraldehyde effectively reduce the risk of microbial resistance and ensure stable long-term efficacy. The preparation process is mild, simple to operate, requires no special equipment, and can be controlled at ambient temperature and pressure throughout, making it suitable for large-scale industrial production. It can meet the long-term, stable, and efficient bactericidal needs of oil and gas fields, demonstrating outstanding practicality and economy.

[0073] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil and gas field bactericide, characterized in that: It consists of the following components by mass percentage: Glutaraldehyde 8%-18%; Quaternary ammonium salts: 12%-22%; Disodium ethylenediaminetetraacetate 2%-6%; Polyethylene glycol 400 1%-3%; The remainder is water; The quaternary ammonium salt is a mixture of dodecyl dimethyl benzyl ammonium chloride and disedecyl dimethyl ammonium chloride in a mass ratio of 1.5:1 to 2.5:1; The oil and gas field bactericide, after being sealed and placed for 72 hours in a highly mineralized weakly alkaline environment at 60℃, pH 8.0, and a mineralization of 20000 mg / L, retains ≥92% of the bactericidal active substances and has a minimum bactericidal concentration of ≤15 mg / L against sulfate-reducing bacteria over 120 hours.

2. The oil and gas field bactericide according to claim 1, characterized in that: The mass ratio of glutaraldehyde to quaternary ammonium salt is 1:0.8-1:1.

5.

3. The oil and gas field bactericide according to claim 1, characterized in that: The minimum bactericidal concentration of the oil and gas field bactericide against saprophytic bacteria and iron bacteria is ≤20 mg / L over 120 hours.

4. The oil and gas field bactericide according to claim 1, characterized in that: The mass percentages of each component are as follows: glutaraldehyde 10%-15%, quaternary ammonium salt 15%-20%, disodium ethylenediaminetetraacetate 3%-5%, and polyethylene glycol 400 1.5%-2.5%.

5. The oil and gas field bactericide according to claim 1, characterized in that: The mass ratio of dodecyl dimethyl benzyl ammonium chloride to decyl dimethyl ammonium chloride is 2:

1.

6. A method for preparing an oil and gas field bactericide according to any one of claims 1-5, characterized in that, This includes the following steps performed sequentially: S1. Add the prescribed amount of polyethylene glycol 400 to water with a conductivity ≤5μS / cm, and dissolve it under stirring conditions of 25-30℃ and 100-150 r / min to obtain a stabilizer solution. S2. Add the prescribed amount of glutaraldehyde to the stabilizer solution and continue stirring for 20-25 minutes. S3. Add the quaternary ammonium salt mixture of the formula amount under stirring conditions of 120-150 r / min, and stir for 10-15 min; S4. Finally, add the prescribed amount of disodium ethylenediaminetetraacetate and stir until completely dissolved to obtain the oil and gas field bactericide.

7. The method for preparing the oil and gas field bactericide according to claim 6, characterized in that: The temperature of the entire system from S2 to S4 is controlled between 20-35℃.

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