WO2015119528A1

WO2015119528A1 - Inhibitor of metal corrosion and scaling

Info

Publication number: WO2015119528A1
Application number: PCT/RU2014/000367
Authority: WO
Inventors: Нелли Евгеньевна РОМАНОВА; Денис Сергеевич ПЕТРОВ; Сергей Васильевич ПЕТРОВ; Tatiana Petrovna GOLUB (ГОЛУБ, Татьяна Петровна)
Original assignee: Нелли Евгеньевна РОМАНОВА; Денис Сергеевич ПЕТРОВ; Сергей Васильевич ПЕТРОВ
Priority date: 2014-02-06
Filing date: 2014-05-22
Publication date: 2015-08-13
Also published as: RU2016106814A3; RU2016106814A

Abstract

The invention relates to the field of organic chemistry, and specifically to reagents for inhibiting metal corrosion, corrosion inhibitor scaling and mineral salt deposition in equipment of the gas and oil industry, and also for increasing well production through the washing-off of scaling and the decolmatation of productive formations. The invention can also be used as an inhibitor, in hot water supply systems, and in water circulation cooling systems of industrial enterprises and thermal power stations, for washing-off scaling on industrial facilities. Proposed is an inhibitor, comprising: phosphonic acid, in the role of which the composition contains at least one acid from a group including phosphonobutane tricarboxylic acid, nitrilo trimethylene phosphonic acid and oxyethylene diphosphonic acid; glycol, in the role of which the composition contains at least one substance from a group including polyethylene glycol, polyglycol and ethylene glycol; a stabilizer, in the role of which the composition contains at least one substance from a group including hydrolyzed polymaleic anhydride, polyacrylic acid, and polyepoxysuccinic acid, with the following ratio of ingredients (mass%): phosphonic acid, 20-40%; glycol, 1-50%; stabilizer, the remainder. The produced results have shown that inhibitors having the claimed composition allow for simultaneously solving the problems of protecting equipment and materials against corrosion and scaling, while also exhibiting biocidal properties which exceed the efficacy of known analogues.

Description

METAL CORROSION INHIBITOR AND SCALING

The technical field The invention relates to the field of organic chemistry, and in particular to reagents for inhibiting corrosion of metals and scaling, corrosion inhibitors and deposition of mineral salts in gas-oilfield equipment, as well as to increase the flow rate of wells by washing out scaling and decolmatization of productive formations . The invention can also be used as an inhibitor in centralized hot water supply systems of open and closed type, in water recycling cooling systems of industrial enterprises (chemical, petrochemical, metallurgical, etc.) and thermal power plants, for washing salting at various industrial facilities.

State of the art

Issues of protecting equipment from corrosion of metals and scaling are among the most significant both in the oil fields, and in industrial enterprises and in the housing and communal services.

Thus, wells and ground equipment operating in conditions of flooding of produced products are subject to corrosion and scaling processes, which, in particular, is accompanied by the deposition of solid sediments of inorganic substances that accumulate in the bottom-hole zone of the reservoir of production wells, on the walls of the production casing and lift pipes , in pumping equipment and land communications systems for the collection and treatment of oil, when the concentration of salt or ions in the creation exceeds the equilibrium [RU 23240055, 2008]. A similar situation develops under conditions of heating fluid in power plants, when cooling products of metallurgical and engineering enterprises, etc. cases.

In recent years, methods of intensive stimulation of the formation have been widely used in oil fields in Western Siberia in combination with the use of modern high-performance electric centrifugal pump (ESP) plants. Intensive oil production inevitably leads to an increase in production of associated produced water, which is the main source of salt formation in the form of a solid phase, as well as equipment corrosion. An increase in the number of wells subject to salt deposition, a decrease in the time between failures of downhole equipment, necessitated the development and implementation of effective methods to combat salt deposition and to predict their occurrence in specific oil production conditions.

At present, various inhibitors, usually of a single-functional effect, are used both to prevent salt deposits and to protect against corrosion. The specificity of anticorrosion protection in the oil and gas industry is that corrosion control measures often need to be taken when the field

1 _t

already equipped and the main equipment and communications are in operation. The use of other, even very effective protective measures (for example, coatings) requires, as a rule, the replacement of existing equipment with new ones, which is associated with large capital costs. Therefore, the use of inhibitor protection is predominantly nym [Tonic A.A. Corrosion of oilfield equipment and measures to prevent it. M .: Nedra, 1976, p.192].

Each of the inhibitors acts in its intended area. The corrosion inhibitor does not protect against the formation of salts, and the salt inhibitor does not protect against corrosion, but only does not cause it. Thus, a composition is known containing, wt%: polyaminomethylphosphonic acid OD-OD 25, sodium salt of polyacrylic acid 0.375-0.9, the rest is water [RU2230766, 2004]. The action of the composition is aimed at preventing salt deposits and is completely ineffective in relation to corrosion.

Currently, a large number of various additives and compositions are known that are used both to prevent corrosion and to prevent scaling, which differ in composition and field of application. In particular, various mixtures of organic and mineral substances are used as corrosion inhibitors (IR) [SU 1610871, 1995; V. Kuznetsov, L. Verzhbitskaya. Protection of metal against corrosion in fresh water. Permian. PKI, 1980. S.64-65; A.G. Dorofeev. Corrosion and protection in the oil and gas industry. 1980, issue, p.17; B.L. Reyzin. Protection of hot water systems against corrosion. M .: Stroyizdat, 1986, p. 79-83]. In particular, corrosion inhibitors are known, which represent 73.0-77.5% of the reaction product of phosphoric acid with dimethylaminomethylphenol and 22.5-27.5% water (SU 1801278, 1994), a mixture of sodium hexametate-phosphate, zinc sulfate, potassium dichromate and hydroxyethylidene diphosphonic acid [SU 1834915, 1993].

It is known to use a composition containing hydroxyethylidene diphospho- as a corrosion inhibitor in water recycling systems new acid, sodium tripolyphosphate, nonionic surfactant PEG-300, zinc sulfate [RU 2128628, 1999]. It is proposed to use this inhibitor by introducing individual components in solid form into the water circulation systems, which complicates the mode of selecting an effective inhibition mode and does not provide a quick uniform distribution of reagents in the system. The disadvantage of this inhibitor is the possibility of its effective use only in low-mineralized aqueous media (total salinity of 600-850 mg / DM ³ ). The disadvantage of such additives is, as a rule, the limited scope and conditions of use, as well as the inability to use these compositions to prevent scaling.

A known method of inhibiting salt deposits in industrial water supply systems, heating using the IOMS reagent [Comparative evaluation of the effectiveness of domestic and imported scale inhibitors / BN Driker, A. L. Vankov // “Energy saving and water treatment”, Nel, 2000- 55-59]. However, this method is ineffective for inhibiting corrosion of structural steels, as well as when using simultaneously with oxidizing biocides, such as sodium hypochlorite, in the presence of which there is a partial destruction of the organophosphonates that make up IOMS, and, as a result, the loss of effect tivnosti.

Known acid-containing composition to prevent scaling during oil production, including nitrilotrimethylene phosphonic acid (NTP), hydrochloric acid and water [RU2087677, 1997]. However, this the composition is used mainly in the treatment of productive formations with carbonate rock.

Compositions exhibiting inhibitory properties both against corrosion and against salt formation are more promising for practical use. Thus, a known composition [RU 2256727, 2005], consisting of a corrosion inhibitor, including a phosphate inhibitor, phosphonate inhibitor, anhydrous hygroscopic salt of alkali or alkaline earth metals of inorganic acids (sulfates and carbonates of sodium, potassium, calcium, orthophosphates of alkali metals) and ingi - a scaling inhibitor based on water-soluble acrylates with a molecular weight of 3000–20000, nonionic surfactants selected from a number of polyoxyethylated esters of fatty acids, alcohols, amines, and alkyl phenols. This composition of corrosion inhibitor and scaling is proposed to be produced in tabulated form. The disadvantage of this composition is the need to dose it into the water circulation system in tablet solid form, which does not ensure timely and uniform distribution of the inhibitor in the system. In this case, a high concentration of phosphates is formed in the reagent dissolution zone, which can lead to the precipitation of phosphate sludge in a mineralized aqueous medium. In addition, the inhibitor contains substances that increase the mineralization of recycled water and the possibility of scale formation, in particular sulfates and carbonates. Sulphates can form soluble iron sulphates, acidifying water, stimulating local corrosion, and under anaerobic conditions sulphates are easily processed by sulphyreducing bacteria into sulphides, which can cause biocorrosion and biofouling of technological equipment.

It is also proposed to use a mixture of alcohols with polyacrylic and carboxylic acids to inhibit corrosion and salt formation [RF patent application N294042402, 1994], a mixture of polynuclear zinc nitrolotrimethylene phosphonates [SU1465427, 1987], or a mixture of alkyl dimethyl amine oxide, alkyl dimethyl benzyl ammonium ammonium oxide [RU 2254399, 2004]. A drawback of these compositions is their lack of effectiveness, especially when operating at elevated temperatures over a wide pH range. ' ''

In recent years, compositions based on phosphonic acids have been widely used. Thus, it is known to use for this purpose a mixture of hydroxyethylidene diphosphonic acid and iminodiacetic acid dimethyl ester hydrochloride, which can significantly (up to 50%) reduce salt deposition at temperatures up to 150 ° C and slightly reduce the corrosion of ferrous metals [SU1636348, 1989]. The disadvantage of such compositions is insufficient corrosion protection.

Complexonates, complex preparations based on complexes of zinc and phosphonic acids, have found wide industrial application for use in highly mineralized water at a temperature of about 90 ° C [A.P. Kovalchuk. Heat Supply News, 2001, M l, pp. 32-35]. The essence of the action of complexons is their sorption on the active centers of the formed scale crystals, which prevents the growth of crystals and blocks their agglomeration, ensuring the maintenance of hardness salts (Ca ⁺⁺ , Mg ^) in suspension. At the same time, their use is simultaneous. It significantly reduces the corrosion activity of water by an average of 8–9 times due to their adsorption on metal surfaces and the formation of a protective layer of complex compounds of zinc and iron with HEDP, as well as Zn (OH) ₂ . That is, during their use, phosphonium acid binds Ca * and Mg ^ ions, and the zinc-containing component acts as an inhibitor of metal corrosion.

In particular, complexonates containing a mixture of 25-30% zinc salts, 40-50% phosphonic acid derivatives and 25-30% insoluble divalent tin salts are known [RU1524537, 1987]; soluble zinc salt and 1-hydroxyethane-1, J-diphosphonic acid [RU2235808, 2002] and a mixture of zinc chloride, ammonium arylsulfonate and hydroxyethylidene diphosphonic (HEDP) acid [SU1813797, 1990]. Known [RU2307798, 2007], a composition for inhibiting scaling contains hydroxyethylene diphosphonic acid (HEDP), sodium hydroxide, zinc oxide, ethylene glycol (EG), sodium lignosulfonate and water in the following ratio, wt.%: HEDP 16, 0-18.03, sodium hydroxide 5.83-7.0, zinc oxide 5.42-7.12, EG 25.0-40.0, sodium lignosulfonate 4.17-5.0, water - the rest. In another embodiment, the composition for inhibiting scaling contains hydroxyethylenediphosphonic acid (HEDP), sodium hydroxide, zinc oxide, ethylene glycol (EG), sodium lignosulfonate, nitrilotrimethylphosphonic acid (NTP) and water in the following ratio, wt.%: OEDP 5 , 0-8.0, sodium hydroxide 5.83-7.0, zinc oxide 5.42-7.12, EG 25.0-40.0, sodium lignosulfonate 4.17-5.0, NTF 6.67 -9.0, water - the rest. These complexonates provide protection against corrosion of ferrous metals up to 98%, however, their protective functions significantly depend on temperature and pH of the medium. In addition, insufficiently high efficacy was detected in relation to the inhibition of salt formation; most complexons are characterized by the absence of effective biocidal properties, which does not allow solving the problems of biocorrosion.

Closest to the claimed invention in terms of composition and achieved effect is the composition developed earlier by the authors [RU232765051, 2008], which combines inhibitory activity against metal corrosion and scaling, which contains aminotrimethylene phosphonic acid - 35-45% by weight, hydrolyzed polymaleic anhydride, containing 70-120 links in a chain, in an amount of 18-22% of the mass, and water - the rest. The tests showed that in this concentration range it inhibits scale formation at 150-180 C in a wide pH range, excludes biofouling of heating systems, and prevents the development of corrosion processes of various origins. This composition, as shown by production tests, was more effective than additives such as IOMS, OEDP, OEDP-Фη, reagents NALCO, VK Giulini and others.

However, further studies in this area have shown that the performance of this additive can be improved, in particular, by increasing the anticorrosion activity, as well as by lowering the crystallization temperature, which is especially important when using the composition in regions of the far north .

The technical problem solved by the authors was the creation of a composition combining enhanced inhibitory properties in relation to formation and corrosion of metals with extended applications in temperature conditions and pH ranges.

SUMMARY OF THE INVENTION

The technical result was achieved by creating a composition consisting of:

- from phosphonic acid, for which the composition contains at least one acid from the group consisting of phosphonobutantricarboxylic acid (PBTC), nitrilotrimethylene phosphonic acid (NFC) and hydroxyethylene diphosphonic acid (OEDP),

- glycol, in which the composition contains at least one substance from the group consisting of polyethylene glycol (PEG), polyglycol (PG) and ethylene glycol (EG),

- a stabilizer, in which the composition contains at least one substance from the group consisting of hydrolyzed polymaleic anhydride (GPMA), polyacrylic acid (PAA) and polyepoxy succinic acid (PEC)

in the following ratio of ingredients (% wt.)

phosphonic acid -20-40%;

glycol -1-50%;

the stabilizer is the rest.

The use of phosphonic acid in a concentration of less than 20% of the mass does not allow achieving the necessary technological efficiency, in a concentration of more than 40% it does not provide a significant improvement in properties and is not economically efficient. The use of glycol in a concentration of less than 1% of the mass does not allow to reduce the freezing point of the product, in concentrations of more than 50% of the composition lose their storage stability. Low amounts of the stabilizer or its absence make the suspension unstable during storage, unnecessarily high concentrations of the stabilizer do not allow to reduce the freezing point of the product and negatively affect its effectiveness.

Inhibitors are prepared by mixing predetermined amounts of ingredients (so-called compounding). Inhibitors are used in the form of liquid concentrated formulations at an active principle concentration of 30%. The working concentration of inhibitors is 2-20 mg / l, depending on the intended use and the characteristics of the water.

The resulting inhibitors are a clear liquid from colorless to yellow with a density of 1, 1-1, 4 g / cm ³ , they are stable during storage and allow you to work in the range of pH 6-10.

The specific formulation of the inhibitor is selected based on the characteristics of the object and the problems posed to the testers.

Industrial applicability

Example 1. By mixing predetermined amounts of phosphonic acids, a stabilizer and glycols, inhibitors were prepared, which were then tested for inhibitory activity with respect to scaling, and their crystallization onset temperature was determined.

The method of determining the efficiency of salt inhibition was used, based on the preparation of supersaturated solutions based on calcium sulfate and a comparison of titration data from two experiments: without an inhibitory additive and with the addition of the test composition. Sulfa Solution calcium with a mass concentration of 10 g / dm ^{3 was} prepared by mixing two solutions containing: solution Ν-> 1 - 250 cm ^{3 of the} solution contains 4.08 g of dehydrated calcium chloride; solution Ν ° 2 - 250 cm ^{3 of the} solution contains 5.22 g of sodium sulfate.

A solution of N ° l was loaded into a thermostatic crystallizer, a calculated amount of the test inhibitory composition was added, and a solution of См 2 was added. The mixture was kept under stirring at a temperature of 38–42 ° C for two hours. Then, the contents of the crystallizer were filtered and the filtrate was titrated with Trilon B solution in the presence of a calcium solution. To calculate the effectiveness of inhibition of scaling, a blank experiment was performed without an inhibitory additive.

The efficiency of inhibition of scaling (E) in percent was calculated by the formula: e = C - V _k ) / (V ₀ - V _k )] x 100

J where V ₀ is the volume of Trilon B spent on titration of the mixture of salt solutions at the initial moment, cm ³ ; V _k is the volume of Trilon B spent on titration of the solution without an inhibitory additive at the end of the test, cm ³ ; V \ is the volume of Trilon B used for titration of the solution with the addition of an inhibitor at the end of the test, cm ³ . The results of the studies are shown in table 1. Table 1 Some production characteristics of aqueous solutions of the obtained inhibitors.

Composition Stability- Efficiency- Temp.

(no less than

30 days) saline crystallization, ° C

%

30% PBTK + 70% BAP is stable 90 0

30% PBTK + 10% NTF + 69% POF stable 98 -15

+ 1% PEG

20% PBTK + 69% BAP + 1% PEG stable 96 -15

40% NTF + 60% GPA stable 93 0

40% NTF + 35% GPA + 15% EG + 10% PEG stable 98 -32

20% NTF + 80% PAA stable 96 0

20% NTF + 70% PAK + 10% EG is stable 98 -25

20% NTF + 30% PAA + 50% EG is stable 95 -32

40% NTF + 60% GHG non-95-28

beating

40% NTF + 60% PEG Little sta-95 -28

beating

35% NTF + 3% GPA + 2% PAA + 60% PEG stable 98 -32

30% OEDFK + 70% GPA stable 90 0

30% OEDFK + 50% GPA + 20% GHG stable 99 -28 W

13

As follows from the table, the optimal results are achieved in the presence of a three-component composition. The absence of one of the components reduces both the inhibitory ability of the mixture and leads to a deterioration in performance — it decreases the stability of the composition or increases its crystallization temperature.

Example 2. Laboratory tests of the comparative effectiveness of the reagents were carried out on the basis of and in accordance with the “Methodological Recommendations for the Use of Anti-Scum and Corrosion Inhibitors OEDPK, AFON 200-60A, AFON 230-23 A, PAF-13A, IOMS-1 and their analogues tested and certified by RAO "UES of Russia" at energy enterprises "(СО 34.37.536-2004) and" Methodological guidelines for determining the brand and optimal concentration of anti-scale for the treatment of makeup and network water of heating systems " СО 34.37.533-2001 (RD 153-34.0-37.533-2001)

Tests on anti-scale efficiency were evaluated by direct measurement of water hardness. Water in autoclaves of simplified design with temperature measurement. The autoclave was heated to a certain temperature in an oven.

In addition, the inhibitor content in the samples was monitored before and after heating.

The effectiveness of the antiscale action of the inhibitor (E) was determined by the equation:

E = (L _n . ₀ ./J _ref ) · 100%, where L _ref and F _n . ₀ - total water hardness before the experiment and after the experiment, respectively. So, as, for waters with low hardness, for example, 2 mEq / dm, with an analytical accuracy of its determination of 0.1 mEq / dm ³ , the effectiveness of anti-scale action will be estimated with an accuracy of ± 5%, which is an obstacle for reliable comparison of the effectiveness of different inhibitors, it seemed appropriate to increase the hardness of the tested water for a more correct assessment of the action of inhibitors. In addition, the concentration of sulfates was increased, because, firstly, the prevention of sulfate scale formation for heat supply systems is a rather urgent problem. Secondly, preventing the formation of a precipitate of calcium sulfate is a more difficult task than preventing the formation of a precipitate of calcium carbonate. This is due to the greater (10,000 times, based on the values of solubility products) necessary degree of supersaturation of the solution and, accordingly, a large number of crystallization centers formed.

All tests were carried out at a temperature of 170 ° C and a concentration of inhibitors of 5 mg / dm.

The first series of experiments was conducted on water that corresponded to the water characteristics of the city drinking water supply system in Omsk with a total hardness value of 2.1 mEq / dm ³ , alkalinity of 1.65-2.2 mEq / dm, carbonate index 2.6 3.5 (mEq / dm). The pH value of water 9.0 * 9.7 was achieved by alkalization. Table 1 shows the data on the obtained efficacy of inhibitors. Table 2: Test Results at

mEq / dm ³ a) experiment 1

Time Efficiency,%

And _k = 2.6

endurance- Without in- 40% NTF ATM IOM 40% NTF + (mg-, min of inhibitor + 35% GPA 35% GPA + equiv / dm ³ ) ² ;

+ 25% EG 25% EG pH = 9.01;

Щ = 0.15 / 1.6

30 79 99 89 86 99 5 mg

45 71 98 89 86 96 equiv / dm ²

60 61 92 80 82 89 experience Ne 2

And _k = 3.5 Time Efficiency,

(mg- aged- Without in- 40% NTF 40% NTF + ATMMP RVTS eq / dm); Ki, min of bitter + 35% GPA 35% GPA +

pH = 9.63; + 25% EG 25% EG

U = 0,

5 / 2.2 mg - 40 61 99 99 98 99 equiv / dm ² 55 49 97 95 94 95

70 45 88 85 81 70

And _k = 3.1 Time Efficiency,%

(mg- aged- Without in- 40% NTF 40% NTF + ATMMP RVTS eq / dm); ki, min gibit- + 35% GPA 35% GPA +

pH = 9.5; RA + 25% EG 25% EG

N = 0, 5 / 2.0

mEq / dm; 30 85 99 99 97 98 S0 ₄ ² '45 68 99 96 95 95

= 250mg / dm ³ 60 58 93 90 86 88

From the results obtained, the following conclusions can be drawn:

- when the hardness of tap water is up to 3 mEq / dm ^{3, the} effectiveness of the claimed inhibitors was significantly higher than that of the other tested inhibitors;

Example 3. Tests of the anticorrosion properties of inhibitors were carried out at a temperature of 70 ° C, under conditions of free aeration of the solution, which ensures the maintenance of oxygen concentration at the level of 4 mg / dm ³ . When using an autoclave, oxygen and carbon dioxide in the test water should be completely consumed at the beginning of the experiment and be absent until its end. Therefore, according to the experience of previous studies, the effectiveness of corrosion inhibitors in the conditions of free aeration of a solution, i.e. under tightened conditions, significantly lower than their efficiency obtained using an autoclave.

Corrosion tests were carried out in flasks with reverse refrigerators and magnetic stirring of the water. The ratio of the volume of the water sample and the surface area of the samples is taken from GOST 9.502.82.

Samples for anticorrosion testing were made of steel 3. The size of the samples is 40x13x1 mm. Each experiment was carried out on 2 samples. The experiment was repeated twice. Corrosion losses were averaged from 4 samples. The concentration of inhibitors was 20 mg / dm. Samples were ground, degreased with acetone and weighed to an accuracy of 0.1 mg. At the end of the experiment, the corrosion products were removed. In water samples without an inhibitor (“blank” samples), the corrosion products were iron-carbonate deposits tightly adhered to the surface of the sample and not mechanically removed. Corrosion products on samples placed in inhibited water, in contrast, were easily removable. At the end of the experiments, all samples, including test subjects with inhibitors, were washed with water, placed in a 5% hydrochloric acid inhibited by urotropine for 1 minute, then washed again with water and passivated with a soda solution. After drying, the samples were weighed to determine the corrosion loss.

The protective ability of the corrosion inhibitor (Z,%) was calculated by the formula-.Ζ = (ΔΡ - ΔΡι) / ΔΡ · 100,%, where ΔΡ are the corrosion losses of the sample in a corrosive medium without the addition of an inhibitor, Γ; ΔΡ] are the corrosion losses sample in a corrosive environment with the addition of an inhibitor,

The results of experiments and calculations are shown in table 3.

Table 3

The results of anticorrosion tests of the claimed corrosion inhibitors (indicators of the initial water: W ₀ = 2, 1 mEq / dm; AH _{f / f} = 0, O5 ^ -0.3 mEq / dm ³ ;

Inhibitor ΔΡ, g ΔΡς _ρ , g Protective ability,

Without inhibitor 0.0146 0.0160

0.0144

0.0184

0.0165

40% NTF + 35% GPA + 25% EG 0.0074 0.0076 0.0059

0.0085

20% NTP + 30% PAA + 50% EG 0.0085 0.0085 50

0.0080

0.0076

0.0092

30% HEDPA + 50% GPA + 0.0090 0.0090 48

20% GHG

0.0092

0.0088

0.0086

30% PBTK + 69% BAP 0.0070 0.0073 53

+ 1% PEG

0.0069

0.0072

0.0080

ATMP 0.0110 0.0112 30

0.0110

0.0152

0.01 17

IOMS 0.0140 0.0126 21

0.0125

0.0120

0.0118

RVTS 0.01 15 0.0122 25

0.0118

0.0134

0,0208

Thus, the effectiveness of the claimed inhibitors in relation to the prevention of corrosion is significantly higher than that of other inhibitors.

Example 4. The possibility of implementing a method of protection of water-circulation systems was modeled on a laboratory installation simulating a revolution system, in which, to assess the corrosion rate, lindric samples from Art.10 (d = 8 mm, 1 = 60 mm), sanded and degreased with ethanol. The biocidal effect was checked by estimating the number of bacteria per unit volume of water using the TTC test. The duration of each test was 350 hours. For testing, Neva tap water was used with an initial salt content of 60 mg / L and a Ca ^{4 "1"} ion content of 8 mg / L. As the model water circulation system worked, water evaporated, which was compensated by the addition of fresh tap water .. In the absence of water treatment by the inhibitor, the corrosion rate of the sample was 0.22 mm / year, the salt deposition was 216 g / m, the bacterial count was 150 tank / cm .

When the inhibitor was introduced into water, 20% NTP + 70% PAA + 10% EG at a concentration of 10 mg / dm ^3, the corrosion rate was 0.012 mm / year, the salt deposition was 1 g / m, the number of bacteria was 56 tank / cm. 5% NTF + 5% GPA + 60% PEG in the inhibitor water at a concentration of 10 mg / d ^3, the corrosion rate was 0.006 mm / year, scaling was 8 g / m ² , the amount of bacteria was 73 tank / cm ³ . When an inhibitor was introduced into water, 30% HEDPA + 50% GPA + 20% GH at a concentration of 10 mg / dm ^3, the corrosion rate was 0.01 mm / year, scaling 2 g / m, and the number of bacteria 44 tank / cm

The results showed that the inhibitors of the claimed composition can simultaneously solve the issues of protecting equipment and materials from corrosion and scaling, and also exhibit biocidal properties. Tests have shown that the combination of the inhibitory effect of the claimed compositions exceeds similar characteristics of known analogues.

Claims

CLAIM

1. A corrosion and scale inhibitor containing phosphonic acid and a stabilizer, characterized in that it additionally contains glycol in the following ratio of ingredients (% wt.) Phosphonic acid -20-40%;

glycol -1-50%;

the stabilizer is the rest.

2. The inhibitor according to claim 1, characterized in that as the phosphonic acid it contains at least one acid from the group consisting of phosphonobutanetricarboxylic acid, nitrilotrimethylene phosphonic acid and hydroxyethylene diphosphonic acid.

3. The inhibitor according to claim 1, characterized in that it contains at least one substance from the group consisting of polyethylene glycol, polyglycol and ethylene glycol as glycol.

4. The inhibitor according to claim 1, characterized in that it contains at least one substance from the group consisting of hydrolyzed polymaleic anhydride, polyacrylic acid and polyepoxy succinic acid as a stabilizer.