SU1747681A1 - Reagent for suppressing activity of sulfate-reducing bacteria in flooded oil formation - Google Patents

Abstract

The essence of the invention: the use as a reagent for suppressing the life activity of SRB in a waxy oil reservoir of hydroxypropylated polyacrylic acid of the structural formula

Description

The invention relates to the oil industry, in particular to combating the growth of sulfate reducing bacteria (SRB), which contribute to the formation of hydrogen sulfide in wadded oil reservoirs.

It is known to use a variety of polymers and copolymers to inhibit the growth of SSC.

The disadvantages of the known methods of combating SSC are the relatively high concentration of reagents and chlorine content, which can have a negative effect on the refining processes due to the poisoning of catalysts.

The closest to the intended reagent by technical essence and the achieved effect is a method of suppressing the growth of sulfate reducing bacteria by introducing a reagent-bacterium into the treated medium; cidz, which is used as a copolymer of butyl acrylate, acrylonitrile and

methacrylic acid, modified monoethanolamine.

However, this reagent has a relatively high concentration (1000–5000 mg / l) to completely suppress the growth of SRB, which leads to a large consumption of reagent.

The purpose of the invention is to suppress the growth of UHV in the waxy oil reservoir.

This goal is achieved by using xypropylated polyacrylic acid (copolymer of acrylic acid with hydroxypropylacrylate) to suppress the viability of SSC in the oil-bearing reservoir.

The synthesis of the proposed reagent is carried out as follows. Hydroxypropyl polyacrylic acid (copolymer of acrylic acid with hydroxypropyl acrylate) is synthesized by radical polymerization of acrylic acid in water: with

cl

in the presence of propylene oxide under the influence of a water-soluble initiator, ammonium persulfate at 40 - 60 ° C. Another important feature of the preparation of the proposed polymer is the introduction into the reaction system as a molecular weight regulator 5% by volume (of acrylic acid) isopropyl alcohol; The process chemistry is described by the combination of the following steps.

Ammonium persulphate is taken in an amount of 0.5% by weight of acrylic acid to reduce the molecular weight of the final product at elevated temperatures (40-60 ° C) decomposed into free radicals (R):

H4NON ABOUT ONH,

Before

The resulting free radicals initiate the homopolymerization of acrylic acid-25 (the initial concentration of acrylic acid is 0.192 mol / l):

psyche y + cn-sn} -n

he

,about

he

At the end of the process of homopolymerization of acrylic acid, the reaction of hydroxypropylation proceeds (the concentration of propylene acid is 0.192 mol / l) with the formation of hydroxypropylated polyacrylic acid (copolymer of acrylic acid with hydroxypropylacrylate) with laughter

+ sn2-snsng-i: n-sn1

Сff V

he + sn2-sn -) - p - (-fy

1-0 ru

ct i 3 chon

0 (СН2СНО) тН ОН

Gder 64-81%, p I9-36%, t 1- -4, p 1300 1445. 55 Conversion of propylene oxide is 50-70%. The final product dissolves well in fresh, sea, and stratal waters without forming a precipitate.

0

five

0

five

0

five

Here are some physico-chemical indicators of the reagent:

Color Colorless liquid

Concentration

reagent in water

solution of 2.0-2.1 wt.%

Density

at 20 ° С-1,005 - 1,010 g / cm3

Kinematic

viscosity

at 25 ° С1.8-2.0 сСг

Acidic

number 450-570mg KOH / g

Molecule

mass135000-150000

Surface

tension 0.05 wt.%

boundary solution

kerosene - water

at 20 ° С20 - 22 days / cm

The effectiveness of inhibiting the growth of SIS is determined by a known method. In the industrial water containing SSC 102 cells in 1 ml, under sterile conditions, the reagent is introduced in appropriate concentrations and incubated for 24 hours at 32 ° C. Then, 1 ml of liquid is taken from these samples and injected into bottles with Postgate nutrient medium. Bottles thermostatic at 32 ° C for 15 days.

At the same time, control samples without reagent were set up.

The degree of inhibition of sulfate reducing bacteria (8) is determined by the formula

with Ct - C2

0

Ci

100%

0

five

0

five

where Ci and C2 are the hydrogen sulfide content in the control and test samples, mg / l.

The experiment is carried out in triplicate.

Table 1 gives comparative data on the bactericidal activity of the proposed reagent, hydroxypropylated polyacrylic acid (copolymer of acrylic acid with hydroxypropyl acrylate) and copolymer of butyl acrylate, acrylonitrile and methacrylic acid, modified with monoethanolamine,

The technology of application of the proposed reagent may be different: the delivery of the loading dose, for a constant pumping of the reagent. The choice of technology occurs depending on the infection of the processed object. A shock dose of 200 mg / l, exceeding the laboratory dose by a factor of 10, was used for one-time treatment of well No. 1685 (Oil Stones deposit) with an intake capacity of 250 m3 / day and infection with an SVB network 102 cells / ml and 45.5 mg / l. At the indicated dosage, the consumption of the reagent was 50 kg.

The results of a pilot test of hydroxypropylated polyacrylic acid as a bactericide in the PLD system of the injection well N ° 1685 (Yllla horizon) at the Oil Stones birthplace are presented in Table. 2

As can be seen, the proposed reagent completely suppresses the viability of SCB and eliminates the contamination of HaS. As a result of the test, an increase in the injectivity of the well by 20% was observed, as well as the inhibitory effect of the reagent (the inhibitory capacity of the reagent was evaluated by a gravimetric method using the weight gain of steel samples installed at the wellhead).

The economic effect of the use of bactericides is achieved by increasing the injectivity of injection wells, increasing oil production by washing

the bottomhole zone of bacterial bodies and corrosion products, as well as an increase in the overhaul period, an increase in the life of the Oilfield Equipment Service.

Claims (1)

Claims of the invention: Use of hydroxypropylated polyacrylic acid of structural formula: (-sn7-sn )P CH 0 (CH2CHO) tN he where q is 64-81%; p 19-36% t 1-4, as a reagent for suppressing the viability of sulfate-reducing bacteria in a waxy oil reservoir. Table 1 table 2