SU833558A1 - Method of preventing sulfate-reducing bacteria formation in stratum water - Google Patents

Description

(54) METHOD FOR THE PREVENTION OF THE FORMATION OF SULFAT ROSTERS OF WELDING BACTERIA IN PLASTIC WATER

This invention relates to methods for inhibiting the development of sulfate reducing bacteria and preventing formation and odor formation and fouling in reservoir and wastewaters as a result of the formation of sulfate reducing bacteria.

These bacteria are anaerobic, i.e. they can develop without free oxygen; when metabolized, they reduce water sulphates and hydrogen sulfide.

Sulfate-reducing bacteria can develop and release hydrogen sulfide in the reservoir waters of oil fields. The product of vital activity, hydrogen sulfide, causes corrosion of drilling equipment. The products of hydrogen sulfide corrosion of steel and, in particular, iron sulfide, cause blockage of the pore channels of the formation, which significantly reduces oil recovery. The presence of hydrogen sulfide and bacterial viability products in the extracted products significantly deteriorates the quality of oil and gas, which complicates their processing.

Sulfate-reducing bacteria may develop at the bottom of tanks.

or in the sections of pipelines for the slow-motion of stationery factories, forming black spots, which can seriously reduce the quality of products. At metallurgical plants, stopping the apparatus at the end of the shift causes the growth of sulphate-reducing bacteria in the boilers for cooling oils, causing

0 the formation of foul odors of hydrogen sulfide, and the loss of time when changing oils and cleaning the boiler.

One way to combat sulfate reduction bacteria is to introduce a bactericide, which should not only effectively inhibit the development of bacteria, but should also be used in low concentrations for economy. He should not also

0 clogging filters used, for example, to remove secondary oil from contaminated fluid.

Since sulphate-reducing bacteria are resistant or become resistant to large amounts of bacteriostatic or bactericidal agents and multiply very rapidly, especially in humid conditions or in a contaminated environment, the concentration of bactericides, such as chlorine. necessary for their destruction, so great that it causes corrosion of non-emanating equipment. The known method of injection into the reservoir of a solution of formalin and highly mineralized waste water of calcium chloride | GO type 1. However, in the known method sul (bacteria that reduce bacteria are able to adapt to high minergshizatsii, forming halophilic (salt tolerant) forms. The closest in technical essence to the proposed method is suppression the development of sulfate-reducing bacteria by injection of one formalite into oil-bearing formations by 2. The known method has the following disadvantages; during repair work on wells and in the process water injection into the reservoir formalin vapors enter the air and cause severe irritation of the mucous membranes of the eyes of workers; to suppress the growth of bacteria, a large dose of reagent 100 mg of formalin per liter of water is required. However, taking into account that the reservoir will be diluted with the reservoir water , the dosage of formaxim is increased up to 400 mg / l of the injected water. Therefore, its use is very expensive. The aim of the invention is to increase the efficiency of preventing the growth of bacteria, improve working conditions and reduce the doses of bactericide and required for the treatment of reservoir. The goal is achieved by the fact that in the reservoir water before injection into the quality of the bactericide 1-CHLORETOXI-2, 2.2 trichloro. Ethyl-N-methylcaprammate is introduced. This substance has a structural formula. Szez CH-OCONH-CMi, ocH-cHice and is a viscous liquid with beats. 1.4085, bp 147-148 C / 4 m In water it does not dissolve, dissolves in alcohol, ai-tone and benzope. p-chloroethoxy-2, 2, 2-trichlorostil-N-methylcarbamate is dissolved before use in one of the solvents (alcohol, acetone, benzene), preferably in alcohol at the rate of 10% solution and used in the amount of 0.4- 0.45 mg / l. The proposed method is carried out as follows. Before injection into the reservoir, a solution of | L-chloroethoxy-2, 2,2-trichloroethyl-I-methylcarboylmat in an amount of 0.4-0.45 mg n liter of water is injected into the reservoir. The carbamate concentration of 0.1 mg / l completely suppresses the viability of sulphate-reducing bacteria, however, taking into account the fact that in the reservoirs the injected water will be diluted with the already available water, the bactericide concentration is increased to 0.4-0.45 mg / l. The water thus treated is fed to high-pressure pumping stations, where it is pumped into oil-bearing formations. The bactericidal activity of the drug is illustrated by the following examples. Example 1. Van-Delden sterile medium, elective (selective) for sulphate-reducing bacteria, is infected with a cumulative bacteria culture and carbamate is added to it at the rate of 0.025 mg / l; parallel to the same experiments with formalin. Experimental vessels are poured to the top and covered with ground stoppers, which allows creating an oxygen deficiency. The vessels are incubated for 10 days. After 10 days in vessels with carbamate and formalin, they detect a heavy precipitate of iron sulfide and release of hydrogen sulfide. Example 2. Van-Delden sterile medium is infected with sulfate-reducing bacteria and carbamate is introduced into it from paschet 0.05 mg / l. After 10 days, thermostating was not observed when there was a visual change in the medium: no hydrogen sulfide was released, no black iron sulfide precipitate occurred. However, microscopy reveals that the bacteria are alive, but they do not multiply. If 1 ml from an experimental vessel is transferred to a fresh nutrient medium without carbamate, then sulphate-reducing bacteria produce abundant growth, precipitate of iron sulfide and hydrogen sulfide. Consequently, a concentration of 0.05 mg / l inhibits the growth and reproduction of bacteria, but they remain viable. Other vessels with medium contaminated with bacteria are introduced with a formalin concentration of 0.05 mg / l. After 10 days, an abundant growth of sulfate-reducing bacteria is found. Example Z. In the nutrient medium of Van Delden, infected with sulfate reducing bacteria, carbamate is introduced at the rate of 0.1 mg per liter. In parallel, formalin of the same concentration is introduced into the medium inoculated with bacteria to obtain comparative data. After 10 days there is no thermostating in the vessels with carbamate living cells in the medium; black precipitate and hydrogen sulfide are absent. Consequently, a concentration of 0.1 mg / l of carbamate is bactericidal for sulphate-reducing bacteria. In vessels with formalin, abundant bacterial growth, the release of hydrogen sulfide, and iron sulfide precipitate are observed. Only

Formalin concentration of 100 mg / l of medium completely inhibits the growth of bacteria.

The obtained comparative results are shown in the table.

Claims (2)

Claim . 1. A method of preventing the formation of sulfate-reducing bacteria in formation water, including treating the water with a bactericide, which is based on the fact that, in order to reduce the dose of the reagent and increase the effectiveness of prevention, | E- is used as a bactericide chloroethoxy-2, '2,2-trichloroethyl-M-methylcarbamate. 2. The method according to claim 1, characterized in that the bactericide is used in the form of a 10% alcohol solution in the amount of 0.40.45 mg / l of treated water.