RU2489469C1 - Chemical agent for suppression of growth of sulphate reducing bacteria - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: chemical agent for suppression of growth of sulphate reducing bacteria, which includes formaldehyde reaction product, contains hemiformals of aliphatic alcohols C₁-C₆, and mainly methanol and/or ethanol as reaction product, and in addition quaternary ammonium chlorous salt in commodity form at the following component ratio, wt %: the above salt 5-50; the above hemiformals are the rest.

EFFECT: enlarging the range of effective bactericides.

2 cl, 11 ex, 2 tbl

Description

The invention relates to chemicals that have the ability to suppress the vital activity of bacteria, and can be used in the oil and gas and oil and gas refining industries to prevent the growth of sulfate-reducing bacteria (SBB) in process fluids and a water-filled oil reservoir, as well as to protect equipment from hydrogen sulfide corrosion.

It is known to use quaternary ammonium salts as a biocidal reagent for suppressing the growth of SVB and hydrocarbon-oxidizing bacteria (BDS) (ed. Certificate of the USSR No. 1570999, RU 2122108, etc.).

The disadvantages of the known reagents are their relatively low biocidal activity and high specific consumption, as well as low manufacturability for use in the winter.

Known means for suppressing the growth of SVB, which is a substance from the class of dithiazines of the formula C ₅ H ₁₁ S ₂ ON and obtained by the interaction of an aqueous solution of formaldehyde (formalin) with monoethapolamine and hydrogen sulfide in stoichiometric proportions, followed by isolation of the target product from the reaction mixture (RU 2160233).

The disadvantages of this reagent are low biocidal activity and the difficulty of synthesis associated with the multicomponent composition of the reaction mixture and the use of highly toxic and corrosive hydrogen sulfide. In addition, the known tool and its aqueous solutions do not have the required adaptability for use in field conditions in the winter.

Known use as a biocidal reagent to inhibit the growth of SVB and inhibit corrosion of the product of the interaction of monoethapolamine with formaldehyde in a molar ratio of 1: (2.01-3.0). In an advantageous embodiment, the specified product is used in the form of an aqueous or aqueous-alcoholic solution, previously obtained by the interaction of monoethanolamine with a 30-40% formaldehyde solution - formalin (RU 2197605).

The disadvantages of this reagent are low efficiency, low thermochemical stability and a decrease in biocidal activity during storage.

Closest to the present invention is a means for suppressing the growth of SVB, which is a 71% aqueous solution of 1-hydroxy (1,3-oxazetidin-3-yl) ethane of the formula C ₄ H ₉ O ₂ N. The specified tool is obtained by the interaction paraformaldehyde and monoethanolamine in a molar ratio of 2: 1 with stirring, followed by exposure of the reaction mixture at 100 ° C for 10 minutes (RU 2173735).

The disadvantages of this reagent are not sufficiently high efficiency and manufacturability for use in winter due to the insufficient low pour point, as well as a decrease in biocidal activity during storage due to low thermochemical stability. In addition, it does not provide a high degree of protection against hydrogen sulfide corrosion.

In connection with the development of large oil fields in the Far North with harsh climatic conditions, the creation of a new, more efficient and technologically advanced biocidal reagent with a low pour point (not higher than minus 50 ° C) and high stability of biocidal activity during long-term storage (at least six months) is required )

The basis of the present invention is the creation of a reagent to inhibit the growth of SVB, which is highly effective at low specific costs and the required low pour point, as well as high stability of bactericidal activity during long-term storage. The objective of the invention is the creation of a biocidal composition having both an effective bactericidal and protective anticorrosive effect.

The invention also solves the problem of expanding the range of effective bactericides, which is important in connection with the rapid adaptation of microorganisms to them.

The problem is solved in that the reagent for suppressing the growth of sulfate-reducing bacteria, including the product of the interaction of formaldehyde, as the reaction product contains hemiformals of aliphatic alcohols C ₁ -C ₆ , mainly methanol and / or ethanol, and additionally contains quaternary ammonium chloride salt in the commodity form when the following ratio of components, wt.%:

Quaternary ammonium chloride salt 5-50 Hemiformy of methanol and / or ethanol rest

In an advantageous embodiment, the proposed reagent further comprises a bactericidal preparation of bacteriostatic action, preferably of the brand Bactid, and optionally a nonionic surfactant (nonionic surfactant), mainly hydroxyalkylated alkyl phenols or higher alcohols, in the following ratio, wt.%:

Quaternary ammonium chloride salt 5-45 Bactericidal drug 5-20 Oxyalkylated alkyl phenols or higher alcohols 0-10 Hemiformy of methanol and / or ethanol rest

At the same time, in order to intensify the synthesis process and increase the yield of the target product, predominantly used hemiformals are obtained by the interaction of paraformaldehyde (or gaseous formaldehyde) and a monohydric alcohol, mainly methanol and / or ethanol, in the presence of an alkaline catalyst at a pH of the reaction medium of at least 7.5.

As a quaternary ammonium chloride salt (HOUR) in the commodity form, the proposed reagent mainly contains a cationic substance of the brand Catamine AB according to TU 9392-003-48482528-99 or KATAPAV according to TU 2482-008-04706205-2004, or KSINAL according to TU 9392-001- 76639615-06, which is an approximately 50% aqueous solution of alkyl dimethylbenzylammonium chlorides, or KATAPAV C according to TU 2482-003-04706205-2004, which is an alcohol solution of alkylbenzyl dimethylammonium chlorides, or ALKAPAV C according to TU 2482-004-04706205-2005 an alcohol solution of alkyltrimethylammonium chlorides, or C EPTAPAV XC according to TU 2482-021-04706205-2005, which is an alcoholic solution of didecyldimethylammonium chloride, or mixtures thereof, or their foreign analogues, for example, VKS brand 80%. The indicated HOUR solutions are intended to be used as raw materials (active base) in the production of detergents and disinfectants, textile auxiliary substances, household chemical goods, antiseptic preparations for preserving wood, processing leather, fur, etc.

The bactericidal preparation of bacteriostatic action of the Bactic brand, manufactured according to TU 2484-010-05744685-96, is a liquid product with a density of 1.1-1.2 g / cm ³ based on an ethanolamine trimer of the formula C ₉ H ₂₁ N ₃ O ₃ , and is intended for use as a long-acting bacteriostatic to protect against microbial damage to organic products, their solutions and emulsions.

As a nonionic surfactant, the proposed reagent mainly contains oxyalkylated mono- and / or dialkylphenols, preferably of the brand Neonol AF 9-12, AF 9-10 according to TU 2483-077-05766801-98 or OP-7, OP-10 according to GOST 8433, or hydroxyalkylated higher alcohols, for example, Sintanol ALM-10 grades according to TU 6-14-864-98. These nonionic surfactants are used as an oil-displacing additive for water during flooding of oil reservoirs and feedstock for the production of corrosion inhibitors (RU 2168561, RU 2405861, etc.).

Technical raw paraformaldehyde (TU 6-05-930-78 or TU 6-09-141-03-89) and lower aliphatic alcohol, mainly methanol (GOST 2222) or ethanol (GOST 17299, GOST 18300). The preparation of hemiformal formulas of alcohols of the general formula R-O- (CH ₂ O) _n H, where R is C ₁ -C ₁₀ alkyl, by reacting paraformaldehyde or gaseous monomeric formaldehyde with C ₁ -C ₁₀ alcohols is described in the literature (ZhPKh. 1979. T .52. No. 12. S. 2722-2730, Ogorodnikov S. K. Formaldehyde. L. Chemistry. 1984. S. 95-96 and others). It is also known the use of hemiformals of lower aliphatic alcohols as a reactive component of hydrogen sulfide neutralizers and mercaptans (RU 2348679, RU 2418036, etc.). It should be noted that in order to intensify the process of hemiformal synthesis and increase the yield of the target product, it is advisable to carry out the reaction of paraformaldehyde with alcohols in the presence of an alkaline catalyst. In this case, alkali metal hydroxide and / or tertiary amines, which, unlike primary and secondary amines, do not interact with formaldehyde, but serve only as a reaction catalyst, are mainly used as an alkaline catalyst. Thus, for the manufacture of the proposed biocidal reagent, it is proposed to use hemiformals obtained by the interaction of paraformaldehyde with C ₁ -C ₆ alcohols in the presence of an alkaline catalyst, without further purification of the contained catalyst.

The feasibility of using hemiformals as a biocidal reagent in a mixture with QAS is due to the occurrence of a synergistic effect of suppressing the growth of SVB. It was found that the addition of QAS to the obtained hemiformal leads to a sharp increase in bactericidal activity. In this case, a synergistic effect is observed in a wide range of ratios of the components of the mixture, and the greatest effect is when the concentration of the commercial form of HOUR in the reagent is from 10 to 50%. In addition, the addition of HOURs in amounts up to 50-60% also leads to an increase in the protective anticorrosive effect of the reagent in hydrogen sulfide-containing media, as well as its biocidal activity with respect to hydrocarbon-oxidizing bacteria. An additional introduction of a bactericidal preparation of bacteriostatic action, for example, Bacticide brand, into the reagent in an amount of up to 20% makes it possible to obtain a biocidal composition with an extended bactericidal action period suitable for protection against microbial damage to organic media, for example, drilling fluids on an organic basis.

An analysis of the known technical solutions selected in the search process showed that in science and technology in this area there is no object similar in terms of the claimed combination of features and the presence of the above properties and advantages, which allows us to conclude that its criteria are “novelty” and “inventive step”.

The invention is illustrated by the following specific, but not limiting examples of obtaining the proposed biocidal reagent and testing it for effectiveness.

Example 1. Obtaining a biocidal reagent. 24 g of methanol are charged into a reaction flask equipped with a stirrer, thermometer and reflux condenser and 26 g of crystalline paraformaldehyde (paraform) are introduced with stirring. The resulting suspension is stirred at a temperature of 55-60 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. The molar ratio of formaldehyde: methanol in the reaction mixture is 1.1: 1 and the pH of the reaction mixture is 6. According to published NMR spectroscopy data (HPLC. 1979. No. 12. P.2725-2730), in the interaction of formaldehyde with methanol in such a molar a mixture of mono-, di-, tri- and tetrahemoformals of methanol of the general formula CH ₃ —O— (CH ₂ O) _n H, where n = 1-4, is formed. Moreover, the content of mono-hemiformal methanol (methoxymethanol) of the formula CH ₃ —O — CH ₂ —OH in the reaction mixture is more than 50%. Then, 50 g of Quaternary ammonium salt (HOUR) in the marketable form of KATAPAV C.50 brand is added to the resulting reaction mixture and stirred until a homogeneous product is obtained. Thus obtained product, which is a mixture of methanol hemiformals and QAS, is used as a biocidal reagent.

Example 2. In the reaction flask of Example 1, 53 g of ethanol were charged and 0.3 g of sodium hydroxide as catalyst and 42 g of paraform were added with stirring. The resulting suspension is stirred at a temperature of 65-70 ° C until the paraform is completely dissolved with the formation of ethanol hemiformals. The molar ratio of formaldehyde: ethanol in the reaction mixture is 1.2: 1, the pH of the reaction mixture is 10.2. Then, 5 g of HOUR is introduced into the resulting reaction mass in the marketable form of KATAPAV C.80 brand and mixed until a homogeneous product is obtained. The resulting product, which is a mixture of hemoformals of ethanol and HOUR, is used as a biocidal reagent.

Example 3. In the reaction flask of Example 1, 24 g of methanol were charged and 1 g of potassium hydroxide was added as a catalyst with stirring, and 30 g of paraform was added. The resulting suspension is stirred at a temperature of 45-50 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. The molar ratio of formaldehyde: methanol in the reaction mixture is 1.3: 1, the pH value of the reaction mixture is 12. Then, 45 g HOUR in the marketable form of KATAPAV C.50 brand is added to the resulting reaction mixture and stirred until a homogeneous product is obtained. The product thus obtained, which is a mixture of hemiformals of methanol, HOUR and potassium hydroxide and having an alkaline reaction of the medium, is used as a biocidal reagent.

Example 4. To the reaction flask of Example 1, 41 g of methanol are charged and 4.5 g of triethanolamine are added as a catalyst and 44.5 g of paraform with stirring. The resulting suspension is stirred at a temperature of 50-55 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. The molar ratio of formaldehyde: methanol in the reaction mixture is 1.1: 1, the pH of the reaction mixture is 8.5. Then, 10 g HOUR is introduced in the marketable form of KATAPAV C.80 brand and mixed until a homogeneous product is obtained.

Examples 5-8. Biocidal compositions No. 5-8 are obtained in the same manner and in the conditions of example 4, using other brands of HOURs in the commodity form and changing the ratio of components. Moreover, in example 8, a bactericidal preparation of the brand Baktsid in an amount of 5% is additionally introduced into the reagent.

Example 9. In the reaction flask of Example 1, 39 g of ethanol was charged and 0.2 g of sodium hydroxide and 3.3 g of C ₈ -C ₁₄ dimethylalkylamines were added as a catalyst, and then 27.5 g of paraform. The resulting suspension is stirred at a temperature of 55-60 ° C until complete dissolution of the paraform with the formation of ethanol hemiformals. Then, 12 g of the bactericidal preparation Bactid, 16 g of HOUR in the trademark form of the XINAL brand, 2 g of non-ionic surfactant of the OP-10 brand are introduced and mixed until a homogeneous product is introduced.

Example 10. In the reaction flask of Example 1, 31 g of methanol was charged and 0.1 g of potassium hydroxide and 0.9 g of dimethylethanolamine were added as a catalyst, and then 39 g of paraform. The resulting suspension is stirred at a temperature of 50-55 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. The molar ratio of formaldehyde: methanol in the reaction mixture is 1.3: 1, the pH of the reaction mixture is 10.5. Then, 9 g of the bactericidal preparation Baktsid, 20 g of HOUR in the commercial form of VKS brand 80%, 1 g of nonionic surfactants of the brand Neonol AF 9-12 are introduced into the reaction mixture and mixed until a homogeneous product is obtained.

Example 11. In the reaction flask of example 1, 25 g of methanol are charged and 7 g of a mixture of methyldiethanolamine and dimethylethanolamine are added as a catalyst, and then 35 g of paraform. The resulting suspension is stirred at a temperature of 50-55 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. The molar ratio of formaldehyde: methanol in the reaction mixture is 1.5: 1 and the pH of the reaction mixture is 8.8. Then, 7 g of the bactericidal preparation Bactid, 25 g of HOUR in the marketable form of KATAPAV C.50 brand and 1 g of nonionic surfactant Sintanol ALM-10 brand are introduced into the reaction mixture and mixed until a homogeneous product is obtained.

The component composition of the biocidal reagents obtained according to examples 1-11 are shown in table 1. Here are the test results of the obtained reagents for pour point according to the standard method (GOST 20287). The resulting reagents under normal conditions are mobile liquids from colorless to yellow with a density of 0.88-1.06 g / cm ³ , a pH of 6-12 and a pour point below minus 50 ° C.

The proposed reagents are tested for the effectiveness of suppressing the growth of SVB according to the well-known method “Assessing the infestation of oilfield media and the bactericidal action of reagents with respect to sulfate reducing. Laboratory, bench and pilot tests ”RD 03-00147275-067-2001. Ufa DOOO "BashNIPIneft" LLC "ANK Bashneft". 2001. The quantitative composition of SVB is determined by the method of limiting 10-fold dilution using Postgate culture medium (OST 39-151-83).

The active accumulative culture of SVB is isolated from the commercial fluid of the Gremikhinsky oil field (Udmurt Republic). After diluting the SSC, the sample is reseeded 3 more times in fresh culture medium. For the tests, a culture of an SVB of 4-5 days old is used, giving blackening in 24 hours at a dosage of 1 cm ³ in a nutrient medium. Into a series of labeled glass penicillin vials with a deoxygenated formation water model, a 1 cm ^{3 of an} accumulative culture culture product is injected with a sterile syringe and the studied biocidal reagent is dosed in an amount that provides the required concentration in mg / L. The vials are mixed and incubated for 24 hours at 20-22 ° C, after which 1 cm ^{3 of the} treated biocidal reagent is introduced into the Postgate culture medium and thermostated at 32-35 ° C. For each concentration of biocidal reagent, 3 parallel tests are performed. As a control, use similar samples without the addition of a biocidal reagent and with the addition of a prototype reagent. Thermostatically controlled vials at 32-35 ° C are observed for 15 days, noting the appearance of a black color. The effectiveness of the bactericidal action of the reagent is evaluated by the appearance or absence of hydrogen sulfide. The presence of hydrogen sulfide is determined by the formation of a black precipitate of iron sulfides. Effective are those reagents that provide complete (100%) inhibition of the growth of SSC at low dosages. In this case, the nutrient medium containing iron sulfate remains transparent or only slightly colored. Table 2 presents comparative test results with the prototype.

To assess the effect of the storage time of the proposed reagent on its bactericidal activity, tests were carried out on the effectiveness of samples No. 4-6 of the reagents after six months of storage in a sealed container at room temperature (~ 25 ° C). The test results are also shown in table 2. Here, for comparison, the test results of the known reagent (prototype) after six months of storage are shown.

The proposed reagent is tested for the effectiveness of its protective action against corrosion in accordance with the "Methodology for assessing the corrosiveness of oilfield environments and the protective effect of corrosion inhibitors using corrosion meters" RD 39-3-611-81. Ufa VNIISPTneft. 1982. The protective effect of the reagent is determined in the inhibited (with the addition of the test reagent) standard and hydrogen sulfide-containing solution according to GOST 9.506-87. As an aggressive environment, a reservoir water model with a density of 1.12 g / cm ³ and a hydrogen sulfide concentration of 100 mg / l is used. Table 3 presents comparative results of the corrosion test with the prototype.

From the data presented in tables 1 and 2, it can be seen that the proposed reagent, in comparison with the known one, has a higher effect of suppressing the growth of SVB and stability of the bactericidal action during storage, and also has a low pour point (minus 50 ° C and below), therefore, it is suitable for storage and all-weather use in commercial conditions in regions with severe climatic conditions. Analysis of the data in tables 1-3 shows that the proposed biocidal composition based on hemiformals and QAS has higher effects of suppressing the growth of SVB and inhibiting hydrogen sulfide corrosion, and also has a low pour point, therefore, can be used as a corrosion inhibitor. In addition, the reagent will expand the range of currently used bactericides, which is necessary to exclude the adaptation of microorganisms to them.

Table 1 Sample Number Component composition, wt.% Pour point, ° C Hemiformal HOUR in commodity form Bactid Nonionic surfactants one Hemiformal methanol - 50 KATAPAV S.50 - 50 - - Below minus 50 2 Ethanol Hemoformal - 95 KATAPAV S.80 - 5 - - Below minus 50 3 Hemiformal methanol - 55 KATAPAV S.50 - 45 - - Below minus 50 four Hemiformal methanol - 90 KATAPAV S.80 - 10 - - Below minus 50 5 Hemiformal methanol - 50 KATAPAV S.50 - 50 - - Below minus 50 6 Hemiformal methanol - 80 ALKAPAV S.50 - 20 - - Below minus 50 7 Hemiformal methanol - 85 SEPTAPAV XC.70 - 15 - - Below minus 50 8 Hemiformal methanol - 80 KATAMIN AB - 15 5 - Below minus 50 9 Ethanol Hemoformal - 70 XINAL - 16 12 OP-10 - 2 Below minus 50 10 Hemiformal methanol - 70 VKS 80% - 20 9 Neonol -1 Below minus 50 eleven Hemiformal methanol - 67 KATAPAV S.50 - 25 7 Sintanol - 1 Below minus 50 12 Prototype Minus 34 13 Catamine AB Minus 1

table 2 Sample Number Bactericidal effect against SVB at a dosage of reagent, mg / l 200 one hundred fifty 25 Freshly prepared reagent one complete suppression complete suppression complete suppression complete suppression 2 also also also incomplete suppression 3 also also also complete suppression four also also also also 5 also also also also 6 also also also also 7 also also also also 8 also also also also 9 also also also also 10 also also also also eleven also also also also 12 (prototype) also also incomplete suppression incomplete suppression 13 also also incomplete suppression incomplete suppression Reagent after six months of storage four complete suppression complete suppression complete suppression complete suppression 5 also also also also 6 also also also also 12 (prototype) also incomplete suppression incomplete suppression incomplete suppression

Table 3 Sample Number Reagent concentration, mg / l The degree of protection against corrosion,% 3 fifty 86 four fifty 92 5 fifty 98 6 fifty 95 12 (prototype) fifty 78 13 fifty 82

Claims (2)

1. A reagent for inhibiting the growth of sulfate-reducing bacteria, including the product of the interaction of formaldehyde, characterized in that the product of the interaction it contains hemiformals of C ₁ -C ₆ oliphatic alcohols, mainly methanol and / or ethanol, and additionally contains a quaternary ammonium chloride salt in a commodity form in the following ratio of components, wt.%:
Quaternary ammonium chloride salt 5-50 Hemiformy of methanol and / or ethanol Rest 2. The reagent according to claim 1, characterized in that it further comprises a bactericidal preparation of bacteriostatic action, preferably of the Bactic brand and, optionally, a nonionic surfactant, mainly hydroxyalkylated alkyl phenols or higher alcohols, in the following ratio, wt.%:
Quaternary Chloride Salt 5-45 Bactericidal drug 5-20 Oxyalkylated alkyl phenols or higher alcohols 0-10 Hemiformy of methanol and / or ethanol Rest