CN116200179B - A surfactant preparation for reducing sulfate-reducing bacterial corrosion - Google Patents

Abstract

The invention discloses a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation and a preparation method thereof, and belongs to the technical field of oil production anti-corrosion. The surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation comprises the following raw materials in mass percentage: 0.5-3% of laurylamine dipropylene diamine, 2-10% of protective agent, 0.03-0.8% of complexing agent, and water balance. The present invention further develops a surfactant preparation with good compatibility with chemical flooding fluid containing anionic surfactant, low cost, strong bactericidal activity against sulfate-reducing bacteria, and the ability to freely regulate the viscoelasticity of chemical flooding fluid by adding a special protective agent (cocoamidopropyl betaine and/or isomeric tridecyl alcohol polyoxyethylene ether) to regulate the self-assembly behavior of surfactant micelles in aqueous solution.

Description

A surfactant preparation for reducing sulfate-reducing bacterial corrosion

Technical Field

The invention relates to the technical field of oil production anti-corrosion, in particular to a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation and a preparation method thereof.

Background technique

In the oil production industry, anaerobic microbial corrosion can cause equipment damage and pipeline perforation, which further leads to serious safety hazards and environmental pollution problems such as short circuits and leakage. Among them, the most representative anaerobic microorganisms are sulfate-reducing bacteria (SRB). SRB has the ability to reduce sulfate to hydrogen sulfide and is widely present in low-oxygen environments such as oil reservoirs and oceans. In order to kill such harmful microorganisms, people use a variety of antibiotics in the process of oil production, including quaternary ammonium surfactants and chlorine dioxide. However, due to the influence of many complex factors in the oil production process, the use of these antibiotics is not ideal. For example, chlorine dioxide has poor stability in high-temperature reservoirs, and cationic quaternary ammonium surfactants lose their bactericidal effect after mixing with anionic surfactants (commonly used as chemical flooding fluids) due to the interaction of Coulomb forces. This antagonistic effect greatly limits the application of cationic biocides for biological control in the presence of anionic surfactants. In addition, the frequent use of quaternary ammonium salts will cause an increase in bacterial resistance and may lead to bacterial biofilm rebound. Therefore, to achieve the same bactericidal effect, the amount of bactericide must be increased, which will cause a heavier environmental burden. Therefore, these antibiotics are only suitable for relatively simple environments such as water supply stations. In addition, the bactericide BDA (laurylamine dipropylene diamine) in the prior art has poor compatibility with anionic surfactants, and will produce white precipitates when mixed above the critical micelle concentration, thus having no bactericidal effect. Other methods against SRB, such as Zhao Feng et al. proposed a method of adding recombinant Pseudomonas to form a biological competition relationship with SRB to remove hydrogen sulfide and simultaneously produce rhamnolipids to increase oil recovery, which has excellent application prospects, but because the number of recombinant Pseudomonas needs to be precisely controlled, the technology is not yet mature; Cai Haoyuan et al. prepared a new metal-phenol supramolecular film coating that has the ability to enhance the corrosion resistance of steel surfaces. It is considered to be an effective method, but the cost of protecting pipelines through coatings is too high to achieve full coverage; Zeng Lingda et al. synthesized a charge reversal antibacterial cationic surfactant for reducing microbial corrosion during oil production and transportation, which has good application prospects, but under the negative influence of anionic surfactants in chemical flooding fluids, it is unclear whether the quaternary ammonium salt that has a bactericidal effect after hydrolysis can still play a role in SRB. In recent years, many new SRB antibiotics have been reported, such as some new quaternary ammonium surfactants based on Schiff bases, green antibiotics extracted from garlic or green plants, etc. Although they have strong bactericidal activity against SRB, the compatibility of these materials with chemical flooding fluids and complex geological conditions in the oil production process is unknown. The high price and complex extraction process also limit the application of the above antibiotics. Based on this, it is necessary to find a low-cost, easy-to-operate, and efficient biological control method that can be used under complex environmental conditions such as the oil production process. The development of a multi-surfactant preparation with strong bactericidal activity against SRB and tolerance to anionic surfactants is of great significance to the development of the oil production industry.

Summary of the invention

The purpose of the present invention is to provide a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation and a preparation method thereof to solve the problems existing in the above-mentioned prior art. The surfactant preparation of the present invention can significantly inhibit the number and activity of SRB, effectively kill SRB in oil reservoirs and pipelines, thereby reducing corrosion caused by SRB and the harm of hydrogen sulfide.

To achieve the above object, the present invention provides the following solutions:

One of the technical solutions of the present invention is a surfactant preparation for reducing sulfate-reducing bacterial corrosion in oil production and pipeline transportation, which comprises the following raw materials in mass percentage: 0.5-3% of laurylamine dipropylene diamine (BDA), 2-10% of a protective agent, 0.03-0.8% of a complexing agent, and the remainder of water.

Furthermore, the surfactant preparation comprises the following raw materials in percentage by mass: 1% of laurylamine dipropylene diamine, 5% of protective agent, 3% of chemical flooding fluid, 0.5% of complexing agent, and the balance of water.

Furthermore, the protective agent includes a zwitterionic surfactant (betaine-type surfactant) and/or a nonionic surfactant.

Furthermore, the zwitterionic surfactant includes any one of cocamidopropyl betaine, dodecyl betaine and N-long chain thiocarboxylic acid type betaine.

Furthermore, the zwitterionic surfactant is cocamidopropyl betaine.

Cocamidopropyl betaine can be used as a "sacrificial agent" for the fungicide BDA in the surfactant preparation system, and combines with the anionic surfactant, the main active ingredient in the chemical flooding fluid, to form worm-like micelles, and finally obtain a highly viscoelastic surfactant antibacterial system. Users can choose which protective agent to use according to the type of oil reservoir and chemical flooding fluid.

Furthermore, the nonionic surfactant includes any one of isomeric tridecanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

Furthermore, the zwitterionic surfactant is isomeric tridecanol polyoxyethylene ether.

The protective agent isomeric tridecanol polyoxyethylene ether can effectively weaken the interaction between laurylamine dipropylene diamine and the main active ingredient anionic surfactant in chemical flooding fluid due to its branched structure and protonation in water, and finally generate spherical micelles to obtain a low-viscoelastic surfactant antibacterial system. Users can choose which protective agent to use according to the type of oil reservoir and chemical flooding fluid.

Furthermore, the complexing agent includes any one of tetrasodium glutamate diacetate, EDTA-2Na, EDTA-4Na and methylglycine diacetic acid.

Furthermore, the complexing agent is tetrasodium glutamate diacetate.

The role of tetrasodium glutamate diacetate is to complex the calcium and magnesium ions in the oil reservoir, ensuring the bactericidal activity of the bactericide and avoiding precipitation.

Furthermore, the main component of the chemical flooding fluid (chemical flooding fluid containing anionic surfactant) includes any one of fatty alcohol polyoxyethylene ether sodium sulfate or sodium dodecyl sulfate.

Laurylamine dipropylene diamine has excellent performance when mixed with sulfate surfactants commonly used in low-temperature and high-salinity reservoirs, such as sodium dodecyl sulfate and sodium fatty alcohol polyoxyethylene ether sulfate. However, when mixed with sulfonate surfactants, the concentration of sulfonate surfactants should not be too high and should be less than twice the molar concentration of BDA.

The second technical solution of the present invention is a method for preparing the above-mentioned surfactant preparation, comprising the following steps:

Weigh each raw material according to mass percentage, add laurylamine dipropylene diamine into water to dissolve, then add complexing agent and protective agent, stir evenly, add chemical flooding fluid after standing, mix evenly, and obtain the surfactant preparation.

Furthermore, the standing time is 12 hours.

Furthermore, the dissolution temperature of the laurylamine dipropylene diamine in water is 50-80°C.

The dissolving temperature should not exceed 90°C, and the heating time should not be too long, otherwise it will turn yellow and affect the appearance of the product.

Amine-containing surfactant preparations may turn yellow at high temperatures, but this does not affect their use. If BDA dissolves slowly at room temperature, an appropriate amount of dilute hydrochloric acid can be added to accelerate the protonation process of BDA to increase its water solubility.

The order of adding raw materials in the preparation method of the present invention cannot be changed at will. The protective agent must be added first and stirred into a single-phase uniform system and allowed to stand for 12 hours before further mixing with the chemical flooding liquid.

The third technical solution of the present invention: an application of the above surfactant preparation in oil production anti-corrosion.

When the surfactant preparation of the present invention is used for oil recovery and corrosion protection, it must be prepared and used immediately.

The present invention discloses the following technical effects:

(1) The surfactant preparation of the present invention can significantly inhibit the number and activity of SRB, effectively kill SRB in oil reservoirs and pipelines, and thus reduce the corrosion caused by SRB and the harm of hydrogen sulfide.

(2) The bactericide BDA has poor solubility with anionic surfactants. When mixed above the critical micelle concentration, white precipitate will be produced and the bactericidal effect will be lost. However, the two protective agents provided by the present invention can effectively weaken the interaction between BDA and anionic surfactants, effectively protect the bactericidal activity of BDA, and enhance the anionic surfactant resistance of BDA, so that BDA can still exert excellent bactericidal performance when it contains anionic surfactants and its concentration is much greater than the critical micelle concentration.

(3) The present invention can freely select different protective agents (cocamidopropyl betaine and/or isomeric tridecyl alcohol polyoxyethylene ether) according to oil recovery requirements to further regulate the self-assembly behavior of surfactant micelles, thereby achieving free regulation of the viscoelasticity of the chemical flooding fluid, and the appropriate viscoelasticity of the chemical flooding fluid is helpful to improve the oil recovery rate (when other conditions remain unchanged, the appropriate viscoelasticity of the chemical flooding fluid is helpful to improve the oil recovery rate).

(4) The present invention applies BDA to the oil recovery process for the first time, expanding the application of BDA in petrochemical industry. Compared with other anti-corrosion methods such as coatings and bactericidal materials with complicated synthesis steps, it has significant advantages of low cost and easy operation.

(5) The present invention further develops a surfactant preparation having good compatibility with chemical flooding fluids containing anionic surfactants, low cost, strong bactericidal activity against sulfate-reducing bacteria, and the ability to freely regulate the viscoelasticity of chemical flooding fluids by adding a special protective agent (cocamidopropyl betaine and/or isomeric tridecyl alcohol polyoxyethylene ether) to regulate the self-assembly behavior of surfactant micelles in aqueous solution.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and/or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

The “parts” described in the following examples are all “parts by mass”.

The chemical flooding fluid A used in the following examples and comparative examples of the present invention mainly comprises sodium sulfate of fatty alcohol polyoxyethylene ether, sodium carbonate and polyacrylamide polymer. The specific formula of the chemical flooding fluid A is: 3 parts of anionic surfactant (sodium sulfate of fatty alcohol polyoxyethylene ether), 1 part of sodium carbonate, 0.5 parts of polyacrylamide, and the balance is 95.5 parts of water.

The chemical flooding fluid B used in the following examples and comparative examples of the present invention mainly comprises sodium dodecyl sulfate, sodium carbonate and polyacrylamide polymer. The specific formula of the chemical flooding fluid B is: 3 parts of anionic surfactant (sodium dodecyl sulfate), 1 part of sodium carbonate, 0.5 parts of polyacrylamide, and the balance is 95.5 parts of water.

The isomeric tridecanol polyoxyethylene ether used in the following examples and comparative examples of the present invention has a hydroxyl value of 120.

Example 1

A method for preparing a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of laurylamine dipropylene diamine (BDA), 5 parts of a protective agent (cocamidopropyl betaine), 3 parts of a chemical flooding fluid A (containing sodium fatty alcohol polyoxyethylene ether sulfate), 0.5 parts of a complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Laurylamine dipropylene diamine (BDA) was added into 80°C water to fully dissolve, a complexing agent was added, and then a protective agent was added, stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 2

A method for preparing a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of laurylamine dipropylene diamine (BDA), 5 parts of protective agent (isomeric tridecanol polyoxyethylene ether), 3 parts of chemical flooding fluid A (containing sodium fatty alcohol polyoxyethylene ether sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Laurylamine dipropylene diamine (BDA) was added into 80°C water to fully dissolve, a complexing agent was added, and then a protective agent was added, stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 3

A method for preparing a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of laurylamine dipropylene diamine (BDA), 5 parts of a protective agent (cocamidopropyl betaine), 3 parts of a chemical flooding fluid B (containing sodium lauryl sulfate), 0.5 parts of a complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Laurylamine dipropylene diamine (BDA) was added into 80°C water to fully dissolve, a complexing agent was added, and then a protective agent was added, stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 4

A method for preparing a surfactant preparation for reducing sulfate-reducing bacteria corrosion in oil production and pipeline transportation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of laurylamine dipropylene diamine (BDA), 5 parts of protective agent (isomeric tridecanol polyoxyethylene ether), chemical flooding fluid B (containing sodium dodecyl sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Laurylamine dipropylene diamine (BDA) was added into 80°C water to fully dissolve, a complexing agent was added, and then a protective agent was added, stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 5

Preparation method of surfactant preparation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of benzalkonium chloride, 5 parts of protective agent (cocamidopropyl betaine), 3 parts of chemical flooding fluid A (containing sodium fatty alcohol polyoxyethylene ether sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Benzalkonium chloride is added into deionized water and fully dissolved, a complexing agent is added, and then a protective agent is added and stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 6

Preparation method of surfactant preparation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of benzalkonium chloride, 5 parts of protective agent (isomeric tridecanol polyoxyethylene ether), 3 parts of chemical flooding fluid A (containing fatty alcohol polyoxyethylene ether sodium sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Benzalkonium chloride is added into deionized water and fully dissolved, a complexing agent is added, and then a protective agent is added and stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 7

Preparation method of surfactant preparation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of benzalkonium chloride, 5 parts of protective agent (cocamidopropyl betaine), 3 parts of chemical flooding fluid B (containing sodium lauryl sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Benzalkonium chloride is added into deionized water and fully dissolved, a complexing agent is added, and then a protective agent is added and stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 8

Preparation method of surfactant preparation:

The raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of benzalkonium chloride, 5 parts of protective agent (isomeric tridecanol polyoxyethylene ether), 3 parts of chemical flooding fluid B (containing sodium dodecyl sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Preparation method of surfactant preparation:

Benzalkonium chloride is added into deionized water and fully dissolved, a complexing agent is added, and then a protective agent is added and stirred into a single homogeneous phase, and then allowed to stand for 12 hours, and then mixed with a chemical flooding fluid to obtain a surfactant preparation.

Example 9

The same as Example 1, except that the raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 0.5 parts of laurylamine dipropylene diamine (BDA), 10 parts of a protective agent (cocamidopropyl betaine), 3 parts of a chemical flooding fluid A (sodium fatty alcohol polyoxyethylene ether sulfate), 0.5 parts of a complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Example 10

The same as Example 1, except that the raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 3 parts of laurylamine dipropylene diamine (BDA), 10 parts of a protective agent (cocamidopropyl betaine), 3 parts of a chemical flooding fluid B (sodium lauryl sulfate), 0.5 parts of a complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Embodiment 11

The same as Example 1, except that the raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 0.5 parts of laurylamine dipropylene diamine (BDA), 5 parts of protective agent (isomeric tridecanedioic ether), 3 parts of chemical flooding fluid A (fatty alcohol polyoxyethylene ether sodium sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Example 12

The same as Example 1, except that the raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 3 parts of laurylamine dipropylene diamine (BDA), 5 parts of protective agent (isomeric tridecanedioxyethylene ether), 3 parts of chemical flooding fluid B (sodium dodecyl sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Example 13

Same as Example 1, except that cocamidopropyl betaine (protective agent) is replaced by an equal mass portion of dodecyl betaine, and tetrasodium glutamate diacetate (complexing agent) is replaced by an equal mass portion of EDTA-2Na.

Embodiment 14

Same as Example 1, except that cocamidopropyl betaine (protective agent) is replaced by an equal mass portion of N-long-chain thiocarboxylic acid type betaine, and tetrasodium glutamate diacetate (complexing agent) is replaced by an equal mass portion of EDTA-4Na.

Embodiment 15

Same as Example 1, except that cocamidopropyl betaine (protective agent) is replaced by an equal mass portion of fatty alcohol polyoxyethylene ether, and tetrasodium glutamate diacetate (complexing agent) is replaced by an equal mass portion of methylglycine diacetic acid.

Example 16

The same as Example 1, except that cocamidopropyl betaine (protective agent) is replaced by an equal mass portion of alkylphenol polyoxyethylene ether.

Embodiment 17

The same as Example 1, except that the raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of laurylamine dipropylene diamine (BDA), 5 parts of protective agent (cocamidopropyl betaine), 5 parts of protective agent (isomeric tridecyl alcohol polyoxyethylene ether), 3 parts of chemical flooding fluid A (fatty alcohol polyoxyethylene ether sodium sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Embodiment 18

The same as Example 1, except that the raw materials for preparing the surfactant preparation are the following components: a total of 100 parts, 1 part of laurylamine dipropylene diamine (BDA), 5 parts of protective agent (cocamidopropyl betaine), 5 parts of protective agent (isomeric tridecyl alcohol polyoxyethylene ether), 3 parts of chemical flooding fluid B (sodium dodecyl sulfate), 0.5 parts of complexing agent (tetrasodium glutamate diacetate), and the balance of deionized water.

Comparative Example 1

The same as Example 1, except that the raw materials do not contain any protective agent.

Comparative Example 2

The same as Example 3, except that the raw materials do not contain any protective agent.

Comparative Example 3

The same as Example 5, except that the raw materials do not contain any protective agent.

Comparative Example 4

The same as Example 7, except that the raw materials do not contain any protective agent.

Comparative Example 5

The same as Example 1, except that the preparation method is: all raw materials are dissolved and then mixed in one step.

Effect Example 1

The experimental operation steps for sulfate reducing bacteria (SRB) cell activity are as follows:

(1) First, prepare SRB culture medium and surfactant preparation (prepared in Examples and Comparative Examples, stock solution). The SRB culture medium is sterilized; the surfactant preparation is filtered using a sterilizing filter (physical sterilization).

Sulfate-reducing bacteria were inoculated into the culture medium, and after cultivation, a bacterial suspension with a concentration of 2.3×10 ⁵ CFU/mL was obtained.

The surfactant preparation (stock solution) and the SRB medium were mixed at a volume ratio of 1:1 to obtain a mixed solution.

(2) Take 2 mL of the mixed solution and put it into a 10 mL centrifuge tube, add 100 μL (2.3×10 ⁵ CFU/mL, determined by MPN counting method) of bacterial suspension, place all centrifuge tubes in anaerobic bags for 1 hour, and then culture in a shaker for 3 days. CCK-8 (CellCounting Kit) was used to determine the relative content of SRB. All samples were centrifuged, and 250 μL of the supernatant was carefully taken and 250 μL of PBS was added to the centrifuge tube. After centrifugation, 50 μL of CCK-8 was injected into each tube. After the operation, the centrifuge tube was incubated at 37°C for 10 minutes, then centrifuged at 6000 rpm for 3 minutes, and 200 μL of the supernatant was sampled. The absorbance of the supernatant at 450 nm was measured using an enzyme marker. The experiment was repeated three times, and the sterilization rate was calculated. The viscosity is the relative viscosity measured at a constant shear rate. The results are shown in Table 1.

The formula for calculating the sterilization rate is: sterilization rate (%) = 1-(absorbance of the experimental group-blank value) ÷ (absorbance of the control group-blank value)

Table 1 Effects of different surfactant preparations on SRB bactericidal rate and relative viscosity

As shown in Table 1, after adding the protective agent, the bactericidal rate of BDA to SRB is significantly improved (Examples 1-4), and the number of SRB is significantly lower than that of the control group (Comparative Example 1-2 group), proving that the protective agent enhances the anionic surfactant resistance of BDA. No bactericidal activity of benzalkonium chloride to SRB was observed in the positive control group (Examples 5-8 and Comparative Examples 3-4), but the use of the protective agent can significantly reduce the amount of white precipitate produced by the interaction between benzalkonium chloride and the anionic surfactant. As shown in Table 1 (Examples 17-18), adjusting the ratio of the two protective agents can achieve free regulation of the viscoelasticity of the system, that is, two protective agents can be added to the chemical flooding fluid at the same time, and the higher the proportion of cocamidopropyl betaine, the stronger the viscoelasticity, and vice versa.

The embodiments described above are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims (7)

1. A surfactant preparation for reducing sulfate-reducing bacterial corrosion in oil production and pipeline transportation, characterized in that it comprises the following raw materials in mass percentage: 0.5-3% of laurylamine dipropylene diamine, 2-10% of protective agent, 0.03-0.8% of complexing agent, and the balance of water; The protective agent includes a zwitterionic surfactant and/or a nonionic surfactant; The zwitterionic surfactant includes any one of cocamidopropyl betaine and dodecyl betaine; the nonionic surfactant includes any one of isomeric tridecanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether; The complexing agent includes any one of tetrasodium glutamate diacetate, EDTA-2Na, EDTA-4Na and methylglycine diacetate. 2. The surfactant preparation according to claim 1 is characterized in that it comprises the following raw materials in mass percentage: 1% of laurylamine dipropylene diamine, 5% of protective agent, 3% of chemical flooding fluid, 0.5% of complexing agent, and the balance of water. 3. The surfactant preparation according to claim 2 is characterized in that the main component of the chemical flooding fluid includes any one of fatty alcohol polyoxyethylene ether sodium sulfate or sodium lauryl sulfate. 4. A method for preparing the surfactant preparation according to any one of claims 2 to 3, characterized in that it comprises the following steps: Weigh each raw material according to mass percentage, add laurylamine dipropylene diamine into water to dissolve, then add complexing agent and protective agent, stir evenly, add chemical flooding fluid after standing, mix evenly, and obtain the surfactant preparation. 5. The preparation method according to claim 4, characterized in that the standing time is 12 hours. 6. The preparation method according to claim 4, characterized in that the dissolution temperature of the laurylamine dipropylene diamine in water is 50-80°C. 7. Use of the surfactant preparation according to any one of claims 1 to 3 in oil production corrosion prevention.