SU578448A1 - Method of fighting bacteria in water-filled oil bed - Google Patents

Description

one

The invention relates to the field of the oil industry, in particular, to methods of developing oil fields with the use of waterflooding, and is intended to prevent the formation of hydrogen sulfide in oil by shedavat the life of sulphate-reducing bacteria in the oil reservoir.

There is a known method for suppressing the growth of bacteria in an oil reservoir by treating water injected into it with bactericides, such as nthroparaffin 1.

The disadvantage of this method is the necessity of producing bactericides, storing and delivering them to the place of use.

Known method of struggle with sulfate and restore them to bacteria ;; in the oil reservoir, which means that the water injected into the reservoir is treated with bactericides 2J before it is fed into the well.

The disadvantage of using used bactericides is their low efficiency, high cost, and toxicity. In addition, bactericides cause equipment corrosion.

The aim of the invention is to increase the effectiveness of the fight against bacteria in the reservoir and the corrosion protection of downhole equipment.

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This is achieved by the fact that bactericides are produced in the well by electrolysis of the injected water, the i and anode of the electrolysis unit is dispersed below the cathode, and the flow rate of water is set to within the limits of the rate of accumulation of hydrogen bubbles and the diffusion rate of chlorine in water.

The following is one of the variants of the proposed method.

In the upper part of the perforation and the perforation of the infected sulphate using a two-core cable, strain the electrodes by passing a constant current with a density of 16 A / dm and simultaneously pumping the oil field waste water containing Hieil 95 g / l of ionic chlorine.

The anode of the electrolytic device is made of graphite and is located in the water flow of the perforation zone of the reservoir, and the cathode is made of steel X181I10T and is located at 0.6 m of the anode in order to eliminate the combination of the evaporating gases through electrolysis. In this way, the flow rate of the injected water is maintained within 1.1 -1.3 m / s, which does not prevent the bubbling of hydrogen bubbles released at the cathode in the water flow. Chlorine is released in the anode, which dissolves in the injected

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water n, falling into the reservoir, affects the colonies of bacteria. The diffusion rate of chlorine in water is 1.0 m / s.

As research has shown, to completely suppress the viability of the bacteria in the reservoir, it is necessary to concentrate chlorine in the injected water to maintain a 5 g / m of treated water and inject water for 48 days once a year. since the incubation perpod (the time from the moment when the culture of bacteria was introduced into the reservoir to the reduction of sulfates in quantities exceeding the allowable coprecitation of hydrogen sulfide in the production of the reservoir) is approximately equal to this period.

The magnitude of the current in the circuit and the time of electrolysis are calculated from the conditions of the minimum energy consumption and obtaining the required amount of chlorine, which is determined in a particular case by the design of the electrodes, by the flow rate of the injected water and by coprecipitation in the chlorides.

Obtaining bactericide i; introducing it into the injected water directly into the area of the processed nlast reduces its loss of oxidation, prevents equipment corrosion, improves safety conditions and eliminates the costs of storage, transportation and dosing.

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In addition, as a result of the interaction of x; iopa and oxygen with hydrogen sulfide, the concept of the latter in the formation production decreases, i.e. the quality of production (isfti and ip) of this gas increases.

Formally li ;; about b and those

A method for combating bacteria in a flooded oil reservoir, which involves injecting water into the reservoir and applying bactericides, characterized in that, in order to increase the efficiency of the method and to prevent corrosion of the well equipment, bactericides are obtained in electrolytic injected water by injection electrolytic equipment the catheter catheter, and the flow rate of water is set to within the limits limited by the rate of rise of hydrogen bubbles and the diffusion rate of chlorine in water.

Sources and and forms of the CPU and, taken into account in the examination

1. Pateit USA No. 3054748, cl. 252-8.55, publ. 1962.

2. Kuznetsova, V.A., et al. Experience in the inhibition of the development of reducing sulfate bacteria in the oil reservoir of the Kalinovsky deposit. - “Microbiologists, t. 26, vy. 3, 1957, p. 330--336.