RU2546697C1 - Composition for preparation of acid structure with varying changing viscosity for productive formation treatment and acid composition with varying viscosity for productive formation treatment - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: acid composition with varying viscosity for the productive formation treatment contains an surface-active agent SAA1 of amide amine oxide with the generalised formula:

where R1 - an non-branched or branched chain of saturated or non-saturated aliphatic group with a number of carbon atoms from about 7 to about 30; R2 - an non-branched or branched chain of saturated or non-saturated bivalent alkylengroup with a number of carbon atoms from 2 to 6; R3 and R4 - identical or different value, they represent alkyl or hydroxyalkyl with a number of carbon atoms from 1 to about 4, or R3 and R4, together with the nitrogen atom to which they are linked, they form heterocycle containing up to six terms; R5 - hydrogen, either alkyl, or hydroxyalkyl group with a number of carbon atoms from 1 to 4, and SSA2 - an amine oxide with the generalised formula:

where R3 and R4 - identical or different, represent alkyl or hydroxyalkylite with the number of carbon atoms from 1 to about 4, or R3 and R4, together with nitrogen atom to which they are linked, they form the heterocycle containing to six terms; R6 - cocoalkyl-fraction of residues of fatty acids (C10-C16), meanwhile SAA2 use in composition with PAV1 at a mass ratio (in terms of active ingredient for both SAA) as 1: (3.3-20) respectively, at the contents in acid composition of the named ratio from SAA2 and SAA1 1-2 wt % and solution of hydrochloric acid (in terms of HCl) 6-14 wt % to the total weight of the composition.

EFFECT: achieving of minimum initial viscosity of the acid composition at the minimum effect on rheological behaviour of the acid composition at acid depletion.

3 cl, 1 tbl, 1 ex, 4 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the oil and gas industry, namely to chemical reagent acid compositions and compositions for their preparation, designed to restore the filtration characteristics in the bottomhole zone of the wells of the reservoir and to intensify oil production.

BACKGROUND OF THE INVENTION

The main reason leading to a sharp decrease in the filtration characteristics of the reservoir in the near-wellbore zone of the wells is its contamination with clogging particles. Colmatants (contaminants) can be both technogenic and natural in nature, and are formed as a result of the impact during construction and repair of wells on the rock and formation fluids of the used drilling fluids and other process fluids, as well as due to physicochemical processes caused by the technology and operation mode wells.

It is known to use viscous compositions during acid treatment of wells in conjunction with hydrochloric acid, for example: sulphite-alcohol stillage (ed. Certificate of the USSR No. 287867); lignosulfonate reagent (RF patent application No. 94026721; RF patent No. 1577420); thickened oil and petroleum products (RF Patent No. 2082880). The acid treatment technology in this case consists in the initial injection of a viscous composition, and then acid. This technology provides blocking of highly permeable water-saturated layers in the bottomhole zone before hydrochloric acid treatment, protecting them from excessive (unnecessary) destruction. The bulk of the acid, therefore, is directed to the treatment of the oil-saturated, low-permeability part of the reservoir. However, this known acidic effect is characterized by insufficient efficiency, since a pack of viscous composition penetrates not only the water-saturated part of the reservoir, but also enters its oil-saturated part, colmatizing and reducing the permeability of the latter. Which leads to a sharp decrease in the effectiveness of acid treatment.

Also, several compositions are known in the art for preparing an acid composition with a varying viscosity based on various surfactants, which together with an acid form acid compositions with a varying viscosity. These compositions are capable of thickening the acid as it is depleted, and are used for these purposes in acid formulations for the acid treatment of oil and gas condensate wells: for example, cationic surfactants (US Patent No. 5,259,137), zwitterionic surfactants (US Patent No. 7,418,184). These types of surfactants provide an effective increase in the viscosity of the acid composition when it interacts with calcium carbonate in the oil reservoir, preventing excessive stimulation of highly drained and washed areas of the reservoir and the formation of caverns.

A common drawback of these known compositions based on these surfactants is the preservation of the high viscosity of the spent acid composition (i.e., with maximum acid depletion) generated during acid stimulation. This complicates the effective operation of the well after treatment, especially in the initial stages, because the residual high viscosity of the acid composition prepared using the indicated composition makes it difficult to move the oil fluid through the pores and cracks of the reservoir, sometimes completely blocking the oil. The evidence of this fact is the curve in Fig. 1, which shows the data on the change in viscosity, depending on the depletion of the acid of the acid composition, which includes the doctyl-N, N dodecyl-N, N cationic surfactant of the Ethoquad E12 / 75 brand on the total composition weight (active ingredient). bis (2hydroxyethyl) -N-methylammonium chloride and 20% inhibited hydrochloric acid (in terms of HCl).

The closest in technical essence to the proposed composition is a composition for the preparation of an acid composition with a changing viscosity (RF Patent No. 2311439), consisting of 0.5-10% wt. (in terms of the active substance) of a surfactant-1-amidoamine oxide of a certain formula in a solvent - glycol. The disadvantage of this known composition is that when it is used to prepare the hydrochloric acid composition, the minimum initial viscosity is not provided when the content, based on the total weight of the composition, is 6-14% hydrochloric acid solution (in terms of HCl), and at the same time, the minimal effect on the rheological the behavior of the acid composition during the depletion of acid in it.

The prior art (RF Patent No. 2230186) known thickened acid composition with a viscosity of 200 MPa · s, which consists of hydrochloric acid, a surfactant - lignosulfonate, hydrocarbon component and activated carbon, in the following ratio, wt.%: Hydrochloric acid 30- 40, activated carbon 30-40, surfactant - lignosulfonate 8-10, hydrocarbon component - the rest. It is used in powder form by drying in an oven at a temperature of 19 ° C, in order to obtain an inactive acid. When this powder is delivered to the well, it dissolves under the influence of water and produces an acid effect on the formation. And although, due to a sharp decrease in the reaction rate of hydrochloric acid with the carbonate rock of the reservoir, the depth of treatment of the bottom-hole formation zone (PZP) increases, this approach does not eliminate the main drawback - the decrease in the efficiency of acid treatment due to the ingress of viscous, clogging components into the oil-saturated part of the reservoir.

The closest in technical essence to the proposed invention are thickened acidic compounds (RF Patent No. 2311439), consisting of 0.5-10% wt. (in terms of the active substance) of a surfactant-1-amidoamine oxide of a certain formula in a solvent - glycol, and from a solution of hydrochloric acid. Moreover, these known thickened compositions are free from the drawbacks of the previous analogue, namely, with a high content of hydrochloric acid in the composition (approximately 20% in terms of HCl), the viscosity of this composition changes best when acid is depleted: it is minimal in the initial period, which guarantees easy injection of acid composition into the well. Further, as a result of the interaction of the acid with the calcium carbonate of the formation, as the depletion of the acid reaches 40 to 70%, the viscosity of the known acid composition reaches maximum values. This prevents the formation of caverns and the acid is directed (self-rejected) to the untreated sections of the reservoir, which leads to the formation of deep dominant wormholes, and acid stimulation becomes most effective. And at high degrees of conversion (degree of depletion) of the acid, the viscosity again becomes minimal, which is important to ensure the flow of oil through the formed dominant wormholes.

To illustrate, Fig. 2 shows data on the dependence of changes in dynamic viscosity on the degree of acid depletion of the thickened acid composition, known by the prototype and including the total weight of the composition of 2% (active ingredient) surfactant-amidoamine oxide, manufactured by Akzo-Nobel (according to RF patent No. 2311439, the commercial form of the Aromox APA-TW surfactant was used, consisting of the active substance PAS1 50% and propylene glycol 50%), and 20% inhibited hydrochloric acid (in terms of HCl), in which as a corrosion inhibitor Soling m. L was used according to TU 2499-043-53501222-2004, at a concentration of 0.3%.

However, the use in the acid composition of hydrochloric acid with a high concentration (about 20%) is not always technologically feasible and possible, due to a number of complicating factors. Among them:

- this is the formation of polluting secondary precipitation with high salinity associated with a high concentration of acid,

- excessively high corrosivity

- and a high reaction rate with calcium carbonate, especially at elevated temperatures in the well.

Therefore, most often in commercial conditions, hydrochloric acid based compositions with an HCl content of about 10% are used (in fact from 6 to 14%). However, with such a content of hydrochloric acid used to prepare the indicated thickened acid compositions known for the prototype, the initial (initial) viscosity of the latter increases significantly, which greatly complicates the injection of the acid composition into the well, especially when using coiled tubing (flexible metal pipes) during acid stimulation . Also, the penetration of the acid composition into low-permeable oil-saturated areas of the reservoir is seriously hindered, which generally leads to a decrease in the efficiency of acid treatment.

To illustrate this statement, Fig. 3 shows the data on the initial viscosity and the dependence of the change in dynamic viscosity on the degree of depletion of the acid of the thickened acid composition, known by the prototype and including the total weight of the composition of 2% (active ingredient) surfactant-amidoamine oxide, manufactured by Akzo -Nobel (according to the patent of the Russian Federation No. 2311439, the commercial form of the surfactant Aromox APA-TW was used, consisting of 50% of the active substance SAW1 (according to the active substance) and 50% of a solvent of propylene glycol), and 10% inhibition hydrochloric acid (in terms of HCl).

SUMMARY OF THE INVENTION

A single technical result achieved by the proposed group of inventions is to eliminate this drawback, namely, to give the proposed acid composition prepared using the inventive composition, the minimum initial viscosity when calculated on the total weight of the composition of 6-14% hydrochloric acid solution (in terms of on HCl), while minimally affecting the rheological behavior of the composition during acid depletion.

To achieve a uniform technical result, a composition is proposed for preparing an acid composition with a varying viscosity for treating a productive formation, including a surfactant PAV1 - amidoamine oxide of the general formula:

,

,

Where

R1 is a straight or branched chain saturated or unsaturated aliphatic group with the number of carbon atoms from about 7 to about 30;

R2 is a straight or branched chain saturated or unsaturated divalent alkylene group with the number of carbon atoms from 2 to 6;

R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or

R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;

R5 is hydrogen, or an alkyl or hydroxyalkyl group with the number of carbon atoms from 1 to 4,

while new is that it additionally contains a surfactant PAS2 - amine oxide of the General formula:

,

,

Where

R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or

R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;

R6 is the cocoalkyl fraction of fatty acid residues (C ₁₀ -C ₁₆ ),

while surfactant2 is used in composition with surfactant1 at a mass ratio (in terms of the active substance for both surfactants) as 1: (3.3-20), respectively.

The technical result is also achieved by the proposed acid composition with varying viscosity for processing the reservoir, containing the composition in the form of a surfactant PAV1 - amidoamine oxide of the General formula:

,

,

Where

R1 is a straight or branched chain saturated or unsaturated aliphatic group with the number of carbon atoms from about 7 to about 30;

R2 is a straight or branched chain saturated or unsaturated divalent alkylene group with the number of carbon atoms from 2 to 6;

R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or

R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;

R5 is hydrogen, or an alkyl or hydroxyalkyl group with the number of carbon atoms from 1 to 4,

and a solution of hydrochloric acid, while new is that the composition additionally contains a surfactant PAS2 - amine oxide of the General formula:

,

,

Where

R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or

R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;

R6 is the cocoalkyl fraction of fatty acid residues (C ₁₀ -C ₁₆ ),

in this case, surfactant2 is used in the composition with surfactant1 at a mass ratio (in terms of the active substance for both surfactants) as 1: (3.3-20), respectively, when the content of the specified composition from surfactant2 and surfactant1 is 1-2 wt.% and a solution of hydrochloric acid (in terms of HCl) 6-14 wt.% on the total weight of the composition.

As a hydrochloric acid solution, an inhibited solution containing a corrosion inhibitor Soling M.L. or VNPP-2 V.

The achievement of the specified technical result is achieved due to the synergistic effect with a certain selection of components (qualitative and quantitative) in the claimed acid composition.

Due to the fact that the composition for preparing the acid composition with varying viscosity for treating the reservoir in addition to surfactant 1 contains surfactant 2 and is used in a mixture with surfactant 1 at a mass ratio of surfactant 2: surfactant 1 (in terms of the active substance for both surfactants) as 1: (3.3 -20), respectively, provides the composition with a low initial viscosity with a hydrochloric acid content of 6-14% wt. (in terms of HCl), with a slight effect on subsequent rheology, while maintaining the general nature of the change in dynamic viscosity with acid depletion. To illustrate this conclusion, Fig. 4 shows the data on the initial viscosity and on the dependence of the change in dynamic viscosity on the degree of acid depletion of the proposed acid composition containing, based on the total weight of the composition, a 2% mixture of surfactants: surfactant-1-amido amine oxide produced by Akzo-Nobel ( according to patent No. 2311439 or synthesized) and surfactant 2-amine oxide (reagent: Kama-03 according to TU 2482-038-53501222-2004 or synthesized), (surfactant 2: surfactant 1 (for active substances) as 1:20) and from 10% (for HC1) inhibited hydrochloric acid solution (the rest new in the acid composition are solvents from commodity forms of surfactants, corrosion inhibitors and water).

The graph in Fig. 4 shows that the initial viscosity of the proposed acid composition prepared using the inventive composition containing 10% (in HCl) hydrochloric acid is 1.9 times lower than that of the prototype (Fig. 3), while the maximum viscosity with acid depletion within 60%, it shows close values to the maximum viscosity of the composition of the prototype (with only one surfactant1) (Fig. 3).

This result, apparently, is due to the following reasons. It is known that increasing the viscosity of an acid composition containing micelle-forming surfactants is due to the transformation (transformation) of spherical micelles into rod-shaped micelles, which penetrate the entire volume of the acid phase and intertwine (meshing) with each other, leading to a sharp increase in viscosity. With the reverse transformation of micelles, from rod-shaped to spherical, the viscosity reversibly decreases. The ratio of spherical and rod-shaped micelles of surfactants in the composition (and hence the viscosity of the acid composition) mainly depends on two key parameters: the acidity of the medium and its general mineralization. In the general case, these dependencies are nonlinear (complex) in nature. The resulting form of the curves of viscosity versus acidity and degree of acid depletion is shown in Figs. 1-3.

With the additional introduction into the proposed composition for surfactant 1 of the declared amounts of surfactant 2 having a similar chemical structure, but with a significantly lower molecular weight and higher values of the critical micelle concentration, the preferred formation of spherical micelles and a sharp decrease in viscosity with a low HCl content (6-14%) but in the absence of mineral salts (CaCl ₂ and CaCO ₃ ). As acid depletion as a result of interaction with the carbonate reservoir and an increase in general mineralization, surfactant 2 in the inventive acid composition is likely to easily integrate into rod-shaped micelles forming surfactant 1, and therefore the further rheological behavior of the acid composition is very similar. In fact, the proposed composition of surfactant 1 and surfactant 2 acts as an additive for the acid composition with varying viscosity.

DETAILED DESCRIPTION OF THE INVENTION

To obtain the proposed composition and the claimed acid composition with varying viscosity in the laboratory, the following substances were used:

- an aqueous solution of hydrochloric acid of 20-22% concentration, according to TU 2122-066-53501222-2007;

- corrosion inhibitors: Soling m.L according to TU 2499-043-53501222-2004; VNPP-2 V in accordance with TU 2122-131-05807960-97;

- surfactant 1 - having the structural formula:

was used:

- either a AkzoNobel product according to RF patent No. 2311439, trade name Aromox APA-TW: where R1 are the residues of tall oil fatty acids of the saturated and unsaturated alkyl groups C ₁₄ -C ₂₂ ; R3 and R4 were CH ₃ groups; R5 is hydrogen; R2 is C ₃ H ₆ .

- either the surfactant reagent SA1 was synthesized independently by oxidation of the corresponding amidoamine according to the procedure described in RF patent No. 2311439, in which case R1 was represented by either a stearic acid residue C ₁₇ H ₃₅ or a oleic acid residue C ₁₇ H ₃₃ . We used mixed compositions of surfactants from the options presented above;

- SAW2 - having the structural formula:

was used:

- either Kama-03 reagent according to TU 2482-038-53501222-2004;

- either synthesized independently by oxidation of the corresponding tertiary amine according to the procedure described in the book: A.A. Abromson, L.P. Zaichenko, S.I. Feingold. Surfactants. Synthesis, analysis, properties, application. Leningrad "Chemistry" 1988, in both cases R3 and R4 are similar to these radicals in SAS1, and R6 was a cocalkyl fraction of fatty acid residues (C ₁₀ -C ₁₆ );

- fresh water for the preparation of a solution of hydrochloric acid of the desired concentration.

Example. The proposed acid composition with varying viscosity was prepared as follows. The inventive composition of surfactant 1 and surfactant 2 was prepared, for this, 2 g of the AkzoNobel manufactured surfactant form 1 (Aromox APA-TW) with an active concentration of 50 wt% for surfactant 1 was taken and 0.33 g of surfactant form 2 (Kama-03) with the active concentration was added by surfactant2 30 wt.%. Separately, a hydrochloric acid solution was prepared. To do this, 49 g of inhibited hydrochloric acid of 20.45% concentration was taken, 48.67 g of fresh water was diluted, then the claimed composition of surfactants was added to it. Then it was stirred on a magnetic stirrer for 30 minutes at a temperature of 25-30 ° C. As a result, an acid composition was obtained containing, on a total weight of the composition, 1.1 wt.% Of the composition of the indicated surfactants (surfactant: surfactant ratio 1 (calculated on the active substance) as 1:10) and 10 wt.% (Calculated on HCl) a solution of inhibited hydrochloric acid. The remaining amount of 88.9 wt.% In the resulting composition was the content of solvents from commodity forms of a surfactant, water and a corrosion inhibitor from a solution of hydrochloric acid.

The proposed acid compositions with a different content of the claimed composition was prepared in a similar manner.

During laboratory tests, the following properties of the acid composition prepared using the specified composition were determined:

- dynamic viscosity, (MPa · s) using the Visco Star + device;

- the concentration of surfactants was determined by calculation (prepared by adding the required amount of reagent to the proposed composition);

- the concentration of hydrochloric acid was determined by calculation (prepared by adding the calculated amount of fresh water to a 20-22% solution of inhibited hydrochloric acid and was controlled analytically by titration).

Data on the content of components in the proposed and known acid compositions and their properties are shown in the table.

The data shown in the table show that the proposed acid composition containing 6-14% wt. hydrochloric acid (in terms of dry HCl), has an initial dynamic viscosity of 18.0-45 MPa · s, which is 1.7-4.9 times lower than the initial viscosity of the known composition according to the prototype, also prepared with a content of 6-14% hydrochloric acid (in terms of HCl), but without the claimed composition. This ensures ease of injection of the acid composition and deep penetration of the composition, including into low-permeability sections of the formation.

Along with the specified, the inventive composition prepared using the proposed composition provides an effective change in dynamic viscosity depending on acid depletion - with an acid conversion of about 60%, the viscosity of the composition reaches 150 mPa · s. Moreover, its final viscosity is a fairly low value (less than 10 MPa · s), which will allow in field conditions to easily remove the specified composition from the well after completion of acid treatment.

INDUSTRIAL APPLICABILITY

Thus, when using the proposed group of inventions in commercial conditions, the maximum efficiency of acid treatment of the carbonate reservoir will be ensured.

Table №№ The content of components according to the active substance,% wt., Based on the total weight of the composition The mass ratio in the composition of surfactant to surfactant 1 (active substance) Variable Viscosity Acid Properties The proposed composition of surfactant 2 and surfactant 1 Hcl The dynamic viscosity of the composition to exhaustion (initial), MPa · s The dynamic viscosity of the composition at 60% depletion of acid, MPa · s The dynamic viscosity of the composition at 100% depletion of acid, MPa · s The proposed acid composition prepared using the claimed composition one 1.05 9 1:20 45 150 5 2 1,1 10 1:10 43 146 4,5 3 1,2 7 1: 5 eighteen 110 7 four 2 fourteen 1: 3.3 28 84.5 4.0 5 1,02 10 1:50 75 one hundred 5.5 6 1.4 7 1: 2.5 thirty 35 fifteen 7 1,1 5 1:10 85 120 8 8 1,1 17 1:10 7.9 80 8.8 Acid composition of the prototype 9 one 7 - 88 105 6 10 one 10 - 75.3 108.7 5.2 eleven 1,5 fourteen - 76 250 78 Note: 1. In experiments 3 and 11, VNPP-2V was used as an inhibitor in the HCl solution; in the remaining experiments, Soling M.L. 2. In experiments 9-11 used only surfactant 1 3. In experiments 2, 4, 6, 8, 9, and 11, Aromox APA-TW reagent was used as a surfactant; in experiments 1, 5, 7 and 10 - synthesized with R1 - the remainder of stearic acid C ₁₇ H ₃₅ ; R3 and R4 are CH ₃ ; R5 is hydrogen; R2 is C ₃ H ₆ ; in experiment 3 — synthesized with R1 — oleic acid residue C ₁₇ H ₃₃ ; R3 and R4 are CH ₃ ; R5 is hydrogen; R2 - C ₃ H ₆ 4. In experiments 1, 3, 5, and 8, Kama-03 reagent was used as a surfactant; in experiments 2, 4, 6, 7 — the cocoalkyl fraction of C ₁₀ C ₁₆ synthesized with R1 - residue; R3 and R4 - CH ₃ 5. The remaining amount of components (up to 100 wt.%) In the obtained proposed acid composition (in addition to the active base of active substances PAV1, PAV2 and HCl) was the content of solvents from commodity forms of surfactant, water and a corrosion inhibitor from a solution of hydrochloric acid

Claims (3)

1. A composition for preparing an acid composition with a varying viscosity for treating a reservoir, including a surfactant PAS1 - amidoamine oxide of the general formula:

,
where R1 is a straight or branched chain saturated or unsaturated aliphatic group with the number of carbon atoms from about 7 to about 30;
R2 is a straight or branched chain saturated or unsaturated divalent alkylene group with the number of carbon atoms from 2 to 6;
R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or
R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;
R5 is hydrogen, or an alkyl or hydroxyalkyl group with the number of carbon atoms from 1 to 4,
characterized in that it further comprises a surfactant PAV2 - amine oxide of the General formula:

,
where R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or
R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;
R6 is the cocoalkyl fraction of fatty acid residues (C ₁₀ -C ₁₆ ),
while surfactant2 is used in composition with surfactant1 at a mass ratio (in terms of the active substance for both surfactants) as 1: (3.3-20), respectively. 2. An acid composition with varying viscosity for treating a reservoir containing a composition in the form of a surfactant PAS1 - amidoamine oxide of the general formula:

,
where R1 is a straight or branched chain saturated or unsaturated aliphatic group with the number of carbon atoms from about 7 to about 30;
R2 is a straight or branched chain saturated or unsaturated divalent alkylene group with the number of carbon atoms from 2 to 6;
R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or
R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;
R5 is hydrogen, or an alkyl or hydroxyalkyl group with the number of carbon atoms from 1 to 4,
and a hydrochloric acid solution, characterized in that the composition further comprises a surfactant PAS2 - an amine oxide of the general formula:

,
where R3 and R4 are the same or different, are alkyl or hydroxyalkyl with carbon numbers from 1 to about 4, or
R3 and R4, together with the nitrogen atom to which they are attached, form a heterocycle containing up to six members;
R6 is the cocoalkyl fraction of fatty acid residues (C ₁₀ -C ₁₆ ),
in this case, surfactant2 is used in the composition with surfactant1 at a mass ratio (in terms of the active substance for both surfactants) as 1: (3.3-20), respectively, when the content of the specified composition from surfactant2 and surfactant1 is 1-2 wt.% and a solution of hydrochloric acid (in terms of HCl) 6-14 wt.% on the total weight of the composition. 3. The composition according to claim 2, characterized in that, as a solution of hydrochloric acid, its inhibited solution containing a corrosion inhibitor Soling M. L. is used. or VNPP-2V.

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