RU2160233C1 - Agent for suppressing growth of sulfate-reducing bacteria - Google Patents

Abstract

FIELD: petroleum industry, more particularly agents capable of suppressing of bacteria which are useful for preventing growth of sulfate-reducing bacteria in various crude media. SUBSTANCE: agent for suppressing growth of sulfate-reducing bacteria is 2-hydroxy-1-perhydro [1,3,5-dithiazin-5-yl] ethane of general formula : C₅H₁₁S₂ON. The latter compound is synthesized from formalin, monoethanol amine and hydrogen sulfide in stoichiometric ratio at room temperature. EFFECT: agent has high biocidal effectiveness, slight solubility in petroleum and corrosion of the agent. 2 ex, 1 tbl

Description

 The invention relates to the field of organic chemistry, in particular to substances with the ability to suppress the vital activity of bacteria, and can be used to prevent the growth of sulfate-reducing bacteria (SBA) in various technological environments, in particular in the oil industry.

 Known substances that inhibit the development of SVB, such as chlorophenols / 1. U.S. Patent No. 3,288,211,1966 /. Chlorophenols are added to water during waterflooding in the process of oil production. The disadvantage of this method of combating SVB is the low solubility of chlorophenols in water and high in oil, which has a negative effect on oil refining processes due to poisoning of the catalysts of these processes. In addition, chlorine-containing compounds threaten possible corrosion of equipment.

 NALCO uses biocide from ROBAN 3999, a substance called 2-methyl-5-nitroimidazole-1-ethanol, to suppress the growth of SVB. / 2. Industrial catalog of NALCO Chemical; EI, series "Technique and technology of oil production and the development of oil fields", foreign experience, 1988, N 7 /. The disadvantages of ROBAN 3999 include the feature that, over time, the effectiveness of the biocide on bacteria decreases, since the basis of the mechanism of their interaction with ROBAN 3999 is a metabolic disorder, and a decrease in the metabolic rate in bacteria leads to a decrease in the ability to absorb the biocide. As a result, the treatment of the injected water with the ROBAN 3999 biocide is carried out in several stages for several weeks, and the dosage of the reagent is calculated each time based on the varying degree of activity of anaerobic bacteria, which is very difficult in operational practice.

 Amino compounds, for example 3-tert-butyltetrahydro-1,3-oxazine / 3, have high biocidal activity. A.S. USSR N 791620, 1980 /. This substance completely inhibits the growth and development of SVB at a concentration of 0.01% (100 mg / l). However, the specified tool is not available; its synthesis is difficult and expensive, which inhibits its widespread use.

Синтез ГПДТЭ осуществляют по известной методике /4. Дж. Уокер "Формальдегид", М., ГХИ, 1957/ из формалина и моноэтаноламина и сероводорода в стехиометрических соотношениях при комнатной температуре.The authors propose a biocidal reagent - 2-hydroxy-1-perhydro- [1,3,5-dithiazin-5-yl] -ethane (hereinafter GPDTE) of the general formula C ₅ H ₁₁ S ₂ ON,

The synthesis of GPDTE is carried out according to the known method / 4. J. Walker "Formaldehyde", M., GCI, 1957 / from formalin and monoethanolamine and hydrogen sulfide in stoichiometric ratios at room temperature.

The effectiveness of using GPTTE as a reagent to suppress the growth of SSC was determined by the method. Said reagent was introduced into commercial water containing SVB under sterile anaerobic conditions and kept for 24 hours at 32 ^° C. Then, 1 ml of liquid was taken from these samples in Postgate nutrient vials and thermostated for 15 days at 32 ^° C. B As a control, similar samples were used without the addition of reagents. Evaluation of the bactericidal activity of the reagent was carried out according to the degree of suppression of SVB, determined by the amount of hydrogen sulfide formed during 15 days in experimental and control samples.

 Example 1. Synthesis of 2-hydroxy-1-perhydro [1,3,5-dithiazin-5-yl] ethane.

In a reactor equipped with a thermometer, a reflux condenser, a stirrer and a gas supply tube, thermostatically controlled at 20 ^° C, 3 M formaldehyde is added in the form of an aqueous solution and 1 M monoethanolamine (1-hydroxy-2-aminoethane) is added dropwise with stirring and sparged with hydrogen sulfide for 3 hours. The separated lower layer is separated in a separatory funnel, dried in a desiccator over calcium oxide. Anhydrous GPTE is a crystalline substance with a melting point of 46-47 ^o C. The elemental composition corresponds to the formula C ₅ H ₁₁ S ₂ ON. To test the biocidal properties of GPDTE was used in the form of a 0.5% aqueous solution.

Example 2. The formation water model was freed from oxygen, infected with a culture of sulfate-reducing bacteria isolated from oilfield formation waters, and treated with a reagent in the form of a 0.5% solution in certain dosages. The samples were held for 24 hours at 20-22 ^o C, after which part of the processed sample was introduced into a nutrient medium, placed in a thermostat and incubated for 15 days at 35 ^o C. The effectiveness of the reagent was evaluated by the appearance or absence of hydrogen sulfide in the solution. The presence of hydrogen sulfide was indicated by a solution of iron salt by the release of a black precipitate. The test results are shown in the table.

 As can be seen from the table, the inventive tool has a high efficiency of suppressing SVB, surpasses the well-known and widely used in oil production reagent "Don-52".

 The simplicity of the synthesis of GPDTE, the low cost and availability of raw materials for the production of GPDTE are obvious advantages over the reagent 3-tert-butyl tetrahydro-1,3-oxazine with the same high biocidal efficiency.

The advantages of the claimed funds are also:
- poor solubility in oil;
- manifestation of corrosion inhibiting properties;
- explosion and fire safety.

Claims (1)

Means for inhibiting the growth of sulfate reducing bacteria, characterized in that as the active active substance use 2-hydroxy-1-perhydro [1,3,5-dithiazin-5-yl] ethane of the general formula C ₅ H ₁₁ S ₂ ON.

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