Bactericidal corrosion inhibitor, its preparation method and application

Abstract

The application discloses a bactericidal corrosion inhibitor and a preparation method and application thereof. The bactericidal corrosion inhibitor comprises the following components in percentage by weight: 10-90% of a compound of formula (I), 10-90% of an organic polar solvent, 0-20% of an additive, and the balance of water; the bactericidal corrosion inhibitor can be quickly adsorbed on the metal surface and the bacterial surface, has good corrosion inhibition, bactericidal and bacteriostatic capacities, can control the corrosion rate mainly caused by hydrogen sulfide corrosion or carbon dioxide corrosion to be below 0.076 mm / a, and can effectively kill sulfate-reducing bacteria (SRB) with a bactericidal rate of more than 99%.

Description

Technical Field

[0001] The present invention relates to the field of petroleum and natural gas, and in particular to a bactericidal corrosion inhibitor and a preparation method and application thereof. Background Art

[0002] Industrial water systems in the oil and gas sector, in general, and industrial water from oil and gas field wells in particular, serve many different purposes. Any water system, including its equipment and water, is susceptible to microbial contamination and scaling. Metal surfaces in any water system are susceptible to corrosion, partly due to microbial contamination and "microbiologically influenced corrosion." This refers to corrosion of metal surfaces caused directly or indirectly by the corrosion of the metal itself. This corrosion is also caused by bacteria and their byproducts and metabolites on metal surfaces, particularly bacteria that grow on metal surfaces in biofilms. Biocorrosion, or bioinduced corrosion, is often associated with surface pitting, which leads to more rapid corrosion damage than uniform corrosion.

[0003] Biological corrosion or biologically induced chemical corrosion is usually caused by "sulfate-reducing bacteria" (sulfate-reducingbacteria SRB), which is considered to be one of the main culprits of biological corrosion under anaerobic conditions. It includes a group of bacteria, including at least 40 genera and 137 species of bacteria that produce H2S and use sulfate as the terminal electron acceptor. Many SRB are considered to be obligate anaerobes, which means that they can temporarily tolerate low levels of oxygen, but the cells cannot metabolize and / or replicate normally in the presence of oxygen. In addition, due to the microenvironment created within the bacterial biofilm / corrosion product layer, anaerobic conditions that can support the growth of SRB can be created in the entire aerobic environment. In addition, the biological corrosion or biologically induced chemical corrosion also includes biological corrosion or chemical corrosion caused by saprophytes and iron bacteria.

[0004] Typically, biological corrosion caused by SRB or chemical corrosion caused by H2S and CO2 produced by SRB metabolism is sterilized or controlled using quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt, tetrabutylammonium salt, tetrahexylammonium salt, and tetraoctylammonium salt. However, since ammonium salts are cationic surfactants, they will react with produced water under the influence of airflow during use to produce a large amount of foam that is difficult to eliminate. These foams will not only cause air blockage in the gathering and transportation process, but will also affect production due to incomplete separation in the separator.

[0005] Hydrogen sulfide and carbon dioxide are produced when organic matter is decomposed by bacteria during the formation of oil and natural gas. They are associated gases of oil and natural gas. Many oil and gas fields at home and abroad face H2S / CO2 chemical corrosion and microbial corrosion during development and production, posing serious challenges to safe production.

[0006] Currently, adding biocides and corrosion inhibitors has become the mainstream method for inhibiting corrosion and ensuring pipeline safety. Biocides are used to kill and control microorganisms, while corrosion inhibitors mainly play a role in inhibiting electrochemical corrosion. Patent application CN106719681A discloses an oilfield biocidal corrosion inhibitor and its preparation method. Patent application CN110273157A discloses a corrosion inhibitor with bactericidal and scale-inhibiting functions and its preparation method. Patent application CN104628097A discloses a composition for a biocidal corrosion inhibitor. Patent application CN109971447A discloses a biocidal corrosion inhibitor for oil well gathering and sewage treatment systems and its preparation method. Patent application JP2006348079A discloses a diamine alkoxy compound with bactericidal, low-foaming, and corrosion-inhibiting properties. Patent application RU2255141C1 discloses a patent for a bactericidal corrosion inhibitor for use in hydrogen sulfide-mineralized water media in oilfields. This inhibitor is produced by reacting a C8-C18 primary fatty amine with a phosphorus-containing acid derivative, particularly a product of phosphoric acid and a polyol. Patent application RU2259393C2 discloses a bactericidal corrosion inhibitor for use as an industrial detergent component with both antiseptic and bactericidal properties. This bactericidal corrosion inhibitor is produced by reacting N,N-methylmethanediamine with alkyl or alkenyl chlorides. This cleaning agent can be used in all industrial applications where organic oils, including oil and gas, lubricants, latex, asphalt, tar, and paraffin, adhere to metal surfaces. Patent application US9802908B2 discloses an ethylbenzyl quaternary ammonium salt of an aminoamide with bactericidal properties, which can be used as a soap clay cleaning agent and corrosion inhibitor for oilfield cleaning. These technologies all have a certain degree of bactericidal and corrosion-inhibiting effect.

[0007] However, existing technologies face at least the following problems: 1) Existing biocidal corrosion inhibitor products are mostly composites, meaning a mixture of corrosion inhibitor and biocide. This makes it difficult to improve the performance of these products over the existing corrosion inhibitor and biocide alone. 2) The majority of commercially available and widely used biocidal corrosion inhibitors are based on quaternary ammonium salts, which are cationic surfactants. During use, quaternary ammonium salts react with produced water under the influence of airflow to produce large amounts of difficult-to-eliminate foam. This foam not only causes air blockage during the gathering and transportation process, but also impacts production due to incomplete separation in the separator. Summary of the Invention

[0008] To address at least one of the above technical problems, the present invention provides a bactericidal corrosion inhibitor, its preparation method, and its application. The bactericidal corrosion inhibitor of the present invention has a novel structure and combines corrosion inhibition and bactericidal functions. Compared with single aldehyde bactericides, the bactericidal corrosion inhibitor of the present invention can effectively reduce the tolerance of various bacterial species; compared with quaternary ammonium salt bactericides, it can significantly reduce foaming and maintain high bactericidal efficacy even with long-term use.

[0009] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0010] In one aspect, the present invention provides a bactericidal corrosion inhibitor, comprising the following components in weight percentage: 10-90% of a compound of formula (I), 10-90% of an organic polar solvent, 0-20% of an auxiliary agent, and the balance water;

[0011]

[0012] wherein R1 is selected from a substituted or unsubstituted C1-C20 straight or branched alkyl group, a C1-C20 alkoxy group, a substituted or unsubstituted C1-C20 straight or branched alkenyl group, a C1-C20 alkylthio group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C2-C30 heteroaryl group;

[0013] R2 is selected from one of H, substituted or unsubstituted C1-C20 straight or branched alkyl, C1-C20 alkoxy, substituted or unsubstituted C1-C20 straight or branched alkenyl, C1-C20 alkylthio, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C2-C30 heteroaryl;

[0014] X - Selected from COO - 、SO3 - 、H2PO4 - or HSO4 - .

[0015] According to the bactericidal corrosion inhibitor of the present invention, preferably, the R1 is selected from substituted or unsubstituted C1-C20 straight chain or branched chain alkyl, substituted or unsubstituted C1-C20 straight chain or branched chain alkenyl.

[0016] According to the bactericidal corrosion inhibitor of the present invention, preferably, the R1 is selected from substituted or unsubstituted C1-C20 straight-chain or branched alkyl groups.

[0017] According to the bactericidal corrosion inhibitor of the present invention, preferably, R1 is selected from substituted or unsubstituted C6-C15 straight-chain alkyl groups. More preferably, R1 is selected from substituted or unsubstituted C6, C7, C8, C9, C10, C11, C12, C13, C14, and C15 straight-chain alkyl groups.

[0018] The substituents in the above substituted groups may be hydroxyl, mercapto, amino, carbonyl, alkenyl, alkynyl, alkyl, and the like.

[0019] According to the bactericidal corrosion inhibitor of the present invention, preferably, the R1 is a straight-chain undecyl group.

[0020] According to the bactericidal corrosion inhibitor of the present invention, preferably, R2 is selected from one of H, substituted or unsubstituted C1-C20 straight-chain or branched alkyl, and substituted or unsubstituted C6-C30 aryl.

[0021] According to the bactericidal corrosion inhibitor of the present invention, preferably, R2 is selected from one of H, C1-C20 straight-chain or branched alkyl, C1-C20 straight-chain or branched alkyl substituted with mercapto, and C6-C30 aryl substituted with alkyl.

[0022] According to the bactericidal corrosion inhibitor of the present invention, preferably, R2 is H, methyl, mercaptomethyl or p-tolyl.

[0023] According to the bactericidal corrosion inhibitor of the present invention, preferably, the organic polar solvent includes one or a combination of two or more of alcohols, amides, nitriles, pyridines, ketones, ethers and aromatic compounds.

[0024] According to the bactericidal corrosion inhibitor of the present invention, preferably, the alcohols include methanol, ethanol, propanol, isopropanol, butanol, methyl ethyl alcohol, isobutanol, pentanol, isopentanol, ethylene glycol, and 2-methyl-1-butanol.

[0025] According to the bactericidal corrosion inhibitor of the present invention, preferably, the auxiliary agent comprises one or a combination of two or more of thiourea, thiazole, silicone and its derivatives, halogenated alkanes, halogenated olefins and halogenated aromatics.

[0026] According to the bactericidal corrosion inhibitor of the present invention, preferably, the auxiliary agent is methyl iodide or allyl chloride.

[0027] According to the bactericidal corrosion inhibitor of the present invention, preferably, the mass percentage of the compound of formula (I) is 20-25%, the mass percentage of the organic polar solvent is 20-30%, and the mass percentage of the auxiliary agent is 0-10%, more preferably 5-10%.

[0028] Another aspect of the present invention provides a method for preparing one or more bactericidal corrosion inhibitors, the preparation method comprising the following steps:

[0029] After the imidazole compound corresponding to R1 reacts with the organic acid R2-X in an organic polar solvent, an auxiliary agent is added to continue the reaction, and then water is added to obtain the bactericidal corrosion inhibitor.

[0030] According to the preparation method of the present invention, preferably, the acid is selected from an organic acid or an inorganic acid, and the organic acid includes acetic acid (CH3COOH, R2 is CH3, X - COO - ), thioglycolic acid ( R2 is SHCH2, X - COO - ) and p-toluenesulfonic acid ( R2 is p-tolyl, X - SO3 - ); the inorganic acid includes phosphoric acid (H3PO4, R2 is H, X - H2PO4 - ) and sulfuric acid (H2SO4, R2 is H, X - HSO4 - ).

[0031] According to the preparation method of the present invention, preferably, the temperature for reacting the imidazole compound with the organic acid is 10-100°C, more preferably 40°C.

[0032] According to the preparation method of the present invention, preferably, the time for reacting the imidazole compound with the acid R2-X is 0.5-24 hours.

[0033] According to the preparation method of the present invention, preferably, the temperature for reacting the imidazole compound with the acid R2-X is 20-80° C., and the time is 0.5-24 hours.

[0034] According to the preparation method of the present invention, preferably, the temperature for continuing the reaction after adding the auxiliary agent is 40 to 80° C. for 2 to 8 hours, more preferably, the temperature is 60° C. for 4 hours.

[0035] According to the preparation method of the present invention, preferably, the molar ratio of the imidazole compound to the acid R2-X is 1:(1-6), more preferably 1:(2-5), further preferably 1:(3-4), for example 1:1.

[0036] The mass percentage of the polar solvent in the reaction system is 10-90%, such as 80-90%, 70-90%, 60-90%, or 50-90%.

[0037] According to the preparation method of the present invention, preferably, the mass percentage of the auxiliary agent in the reaction system is 0-20%, more preferably 0-10%, and further preferably 5-10%.

[0038] In another aspect, the present invention provides the use of the above bactericidal corrosion inhibitor in microbial corrosion protection or chemical corrosion protection in oil and gas fields.

[0039] The microorganisms in the microbial corrosion include one or more of sulfate-reducing bacteria, saprophytic bacteria and iron bacteria. The chemical corrosion includes corrosion caused by H2S and CO2.

[0040] The compound of formula (I) of the present invention and the bactericidal corrosion inhibitor prepared therefrom can be rapidly adsorbed on metal surfaces and bacterial surfaces, and have good corrosion inhibition, bactericidal and antibacterial abilities. As shown in the embodiments of the present invention, the compound can control the corrosion rate mainly caused by hydrogen sulfide corrosion or carbon dioxide corrosion to below 0.076 mm / a, and can effectively kill sulfate-reducing bacteria (SRB), with a bactericidal rate of over 99%.

[0041] From the perspective of bactericidal mechanism, effective bactericidal molecules generally contain hydrophilic cationic groups and hydrophobic alkyl chains. The mechanism is mainly that the antibacterial polymer first adheres to the bacterial surface through electrostatic interaction, and then the substituted alkyl groups on the molecule penetrate the cell membrane through hydrophobic interaction, causing bacterial death. Therefore, an effective polymer bactericide should contain three elements: ① It must be in full contact with the cell; ② It must have sufficient cationic charge to promote adhesion to the microbial cell membrane; ③ It must have a portion of the hydrophobic chain that can be adsorbed and integrated into the porous cell membrane. Because the bacterial cell membrane surface is negatively charged, the compound of formula (I) of the present invention is a positively charged ionic compound that can be adsorbed on the bacterial cell membrane surface through electrostatic interaction. The hydrophobic group of the compound partially penetrates the cell membrane and enters the cell interior to exert a bactericidal effect. Imidazole derivatives are a class of broad-spectrum bactericides, but due to their poor water solubility, they are not widely used in practice. 2-Undecyl imidazole itself has a weak alkalinity and can react with organic acids to form positively charged ionic compounds, which enhances its water solubility while playing an adsorption and bactericidal role. In addition, the S and P in the organic acid can enhance the corrosion inhibition performance. DETAILED DESCRIPTION

[0042] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0043] All numerical specifications herein (e.g., temperatures, times, concentrations, and weights, including ranges for each thereof) are generally approximate and may be modified (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are to be understood as being preceded by the term "about."

[0044] Example 1

[0045] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0046] 2-Undecyl imidazole (0.1 mol, 22.2 g), acetic acid (0.1 mol, 6.1 g) and 28.0 g of butanol were mixed and stirred at 40° C. until homogeneous, and then 56.3 g of water was added to obtain the final agent 1.

[0047] Example 2

[0048] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0049] 2-Undecyl imidazole (0.1 mol, 22.2 g), thioglycolic acid (0.1 mol, 9.2 g) and 32.0 g of ethylene glycol were mixed and stirred at 40° C. until homogeneous, and then 63.0 g of water was added to obtain the final agent 2.

[0050] Example 3

[0051] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0052] 2-Undecyl imidazole (0.1 mol, 22.2 g), p-toluenesulfonic acid (0.1 mol, 17.2 g) and 40.0 g of isopropyl alcohol were mixed and stirred at 40° C. until homogeneous, and then 80.0 g of water was added to obtain the final agent 3.

[0053] Example 4

[0054] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0055] 2-Ethylimidazole (0.1 mol, 9.6 g), thioglycolic acid (0.1 mol, 9.2 g) and 18.8 g of butanol were mixed and stirred at 40° C. until homogeneous, and then 37.6 g of water was added to obtain the final agent 4.

[0056] Example 5

[0057] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0058] Mix 2-undecylimidazole (0.1 mol, 22.2 g), thioglycolic acid (0.1 mol, 9.2 g) and 32.0 g of ethylene glycol, stir at 40°C until homogeneous, then add 14.2 g of iodomethane, stir at 60°C for 4 h, and then add 78.0 g of water to obtain the final agent 5.

[0059] Example 6

[0060] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0061] Mix 2-undecyl imidazole (0.1 mol, 22.2 g), phosphoric acid (0.1 mol, 9.8 g) and 32.0 g of ethylene glycol, stir at 40°C until homogeneous, then add 14.2 g of iodomethane, stir at 60°C for 4 h, and then add 78.0 g of water to obtain the final agent 6.

[0062] Example 7

[0063] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0064] Mix 2-undecylimidazole (0.1 mol, 22.2 g), sulfuric acid (0.1 mol, 9.8 g) and 32.0 g of ethylene glycol, stir at 40°C until homogeneous, add 7.7 g of allyl chloride, stir at 60°C for 4 h, and then add 72.0 g of water to obtain the final agent 7.

[0065] Example 8

[0066] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following method:

[0067] Mix 2-undecylimidazole (0.1 mol, 22.2 g), acetic acid (0.1 mol, 6.1 g) and 28.0 g of butanol, stir at 40°C until homogeneous, add 7.7 g of allyl chloride, stir at 60°C for 4 h, and then add 64.0 g of water to obtain the final agent 8.

[0068] Application Example 1

[0069] This application example evaluates the bactericidal corrosion inhibitors obtained in Examples 1 to 8. The specific evaluation process is as follows:

[0070] Bactericidal tests were conducted on water samples containing SRB bacteria using agents 1 to 8, respectively. The concentrations of the bactericidal corrosion inhibitors were 100 mg / L and 50 mg / L. After adding the bactericides, the water samples containing SRB bacteria were cultured at 25°C in an anaerobic environment for 24 hours. The bacterial content was determined according to the SY / T 0532 Oilfield Injection Water Bacteria Analysis Method (Extinction Dilution Method), and the bactericidal rate was calculated. The results are shown in Table 1. The bactericidal rate calculation formula is as follows:

[0071]

[0072] Where:

[0073] X-bactericidal rate, %;

[0074] a2-Number of bacteria after sterilization, cells / mL;

[0075] a1 - number of blank bacteria, cells / mL.

[0076] Table 1

[0077] Bactericidal corrosion inhibitor Test agent concentration, ppm SRB bacterial count, Sterilization rate, % blank - <![CDATA[2.5×10 2 ]]> - Potion 1 100 0 99.9 Potion 2 100 0 99.9 Potion 3 100 0 99.9 Potion 4 100 0 99.9 Potion 5 50 0 100.0 Potion 6 50 0 100.0 Potion 7 50 0 100.0 Potion 8 50 0 100.0

[0078] As shown in Table 1, the bactericidal rates of Agents 1 to 4 in the Examples are above 99.9%. Even when the concentrations of Agents 5 to 8, which contain additives, are halved, the bactericidal effect is improved, reaching a bactericidal rate of 100%. This indicates that the bactericidal corrosion inhibitors provided by the present invention have excellent bactericidal properties.

[0079] Application Example 2

[0080] This application example evaluates the bactericidal corrosion inhibitors obtained in Examples 1 to 8. The specific evaluation process is as follows:

[0081] Corrosion tests were conducted on 5% sodium chloride water samples containing 500ppm CO2 using reagents 1 to 8. The concentration of the bactericidal corrosion inhibitor was 100mg / L. The corroded material was L360N. After being placed in an anaerobic environment at 40°C for 72 hours, the corrosion rate was calculated in accordance with SY / T 7437 Technical Requirements and Evaluation Methods for Corrosion Inhibitors for Natural Gas Gathering and Transportation. The results are shown in Table 2. The corrosion rate calculation formula is as follows:

[0082]

[0083] Where:

[0084] Vc—uniform corrosion rate, in millimeters per year (mm / a);

[0085] m—weight loss of coupon, in grams (g);

[0086] s—Exposed area of ​​coupon, in square centimeters (cm 2 );

[0087] t—experimental time, in hours (h);

[0088] ρ—relative density of the coupon, in grams per cubic centimeter (g / cm 3 ).

[0089] Table 2

[0090] Bactericidal corrosion inhibitor provided by the embodiment Test agent concentration, ppm Corrosion rate, mm / a blank - 0.3890 Potion 1 100 0.0646 Potion 2 100 0.0514 Potion 3 100 0.0580 Potion 4 100 0.0554 Potion 5 100 0.0488 Potion 6 100 0.0660 Potion 7 100 0.0673 Potion 8 100 0.0422

[0091] As shown in Table 2, the corrosion rates of Agents 1 to 8 are below 0.076 mm / a. It can be seen that the bactericidal corrosion inhibitor provided by the embodiment of the present invention has good corrosion inhibition performance.

[0092] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A bactericidal corrosion inhibitor, characterized in that: The bactericidal corrosion inhibitor comprises the following components in weight percentage: 10-90% of the compound of formula (I), 10-90% of an organic polar solvent, 5-10% of an auxiliary agent and the balance water; Formula (I) wherein R1 is selected from one of unsubstituted C1 to C20 straight-chain alkyl groups; R2-X - is a monovalent anion of acetic acid, thioglycolic acid, p-toluenesulfonic acid, phosphoric acid or sulfuric acid; The organic polar solvent is selected from one or a combination of two or more alcohols; The auxiliary agent is methyl iodide or allyl chloride.

2. The bactericidal corrosion inhibitor according to claim 1, characterized in that The R1 is selected from unsubstituted C6-C15 straight-chain alkyl groups.

3. The bactericidal corrosion inhibitor according to claim 2, characterized in that The R1 is a straight-chain undecyl group.

4. The bactericidal corrosion inhibitor according to claim 1, characterized in that The alcohols include methanol, ethanol, propanol, isopropanol, butanol, methyl ethyl alcohol, isobutanol, amyl alcohol, isopentanol, ethylene glycol, and 2-methyl-1-butanol.

5. The bactericidal corrosion inhibitor according to claim 1, characterized in that The mass percentage of the compound of formula (I) is 20-25%, and the mass percentage of the organic polar solvent is 20-30%.

6. A method for preparing the bactericidal corrosion inhibitor according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: After reacting the imidazole compound corresponding to R1 with the acid R2-X in an organic polar solvent, an auxiliary agent is added to continue the reaction, and then water is added to obtain the bactericidal corrosion inhibitor; The acid R2-X is acetic acid, thioglycolic acid, p-toluenesulfonic acid, phosphoric acid or sulfuric acid.

7. The preparation method according to claim 6, characterized in that The temperature for reacting the imidazole compound with the acid R2-X is 10-100°C.

8. The preparation method according to claim 6, characterized in that The time for reacting the imidazole compound with the acid R2-X is 0.5-24 hours.

9. The preparation method according to claim 6, characterized in that The temperature for reacting the imidazole compound with the acid R2-X is 20-80° C. and the time is 0.5-24 hours.

10. The preparation method according to claim 6, characterized in that The temperature after adding the auxiliary agent and continuing the reaction is 40~80℃ and the time is 2~8 hours.

11. The preparation method according to claim 6, characterized in that The molar ratio of the imidazole compound to the acid R2-X is 1:(1-6).

12. The preparation method according to claim 6, characterized in that The mass percentage of the organic polar solvent in the reaction system is 10-90%.

13. Use of the bactericidal corrosion inhibitor according to any one of claims 1 to 5 in microbial corrosion protection or chemical corrosion protection in oil and gas fields.

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