RU2224823C1 - Corrosion inhibitor and a method for preparation thereof - Google Patents

Abstract

FIELD: corrosion protection. SUBSTANCE: invention relates to agents protecting equipment against corrosion and can be used in oil production industry wherein equipment is exposed to attack of hydrogen sulfide and/or oxygen, or carbon dioxide. Inhibitor includes primary C8-C25-amines or their mixtures, nonionic surfactant, and solvent, in particular methanol and higher aromatic hydrocarbons, and, in addition, monoethanolamine, weight ratio of amines to surfactant being (1- 3):1. Components are mixed successively: monoethanolamine is first added to surfactant, then solvent and primary amines. EFFECT: increased corrosion inhibition efficiency. 2 cl, 2 tbl _

Description

 The invention relates to corrosion protection equipment and can be used in the oil industry to protect oilfield equipment from hydrogen sulfide and / or oxygen and / or carbon dioxide corrosion.

 Known corrosion inhibitor, including the product of the interaction of primary aliphatic amines, technical dimethylphosphite and water in the ratio 1: (0.8-1.2): (0.8-1.2) (see RF patent 2038421, MKI C 23 F 11 / 00, 1995). However, it is effective only in hydrogen sulfide-containing environments at significant dosages.

Known corrosion inhibitor, including the product of the interaction of fatty acids with the number of carbon atoms With ₁₀ -C ₂₀ with their molar ratio 1: (0.1-1.0), respectively, nonionic surfactant and solvent (see RF patent 2061001, MKI C 23 F 11/00, 1996). However, this inhibitor is effective only in hydrogen sulfide-containing environments and at significant dosages.

The closest in technical essence to the proposed known corrosion inhibitor, comprising a fatty amine with the number of carbon atoms C ₈ -C ₂₂ or the product of the interaction of alkyl phenol with the number of hydrocarbon atoms C ₈ -C ₂₂ formaldehyde-containing product and a secondary amine R ₁ R ₂ NH with alkyl R _{1 , 2} = CH ₃ , C ₂ H ₅ , C ₂ H ₄ OH, C ₃ H ₆ OH with a molar ratio of 1: (0.8-1.2) :( 0.8-1.2), nonionic surface active substance and solvent (see RF patent 2168561, MKI C 23 F 11/14, 2001). However, the known inhibitor is effective only in hydrogen sulfide-containing oilfield environments.

 The present invention is based on the task of creating an effective corrosion inhibitor in hydrogen sulfide-containing, oxygen-containing and carbon dioxide environments.

The problem is solved in that the corrosion inhibitor, including primary amines, a nonionic surfactant (NSAID) and a solvent, additionally contains monoethanolamine, C ₈ -C ₂₅ amines as primary amines, and a Neonol mixture as a nonionic surfactant AF _9-12 and Neonol AF _9-6 when their ratio is (1-3): 1, and methanol and higher aromatic hydrocarbons are used as a solvent in the following ratio of components, wt.%:
A mixture of nonionic surfactants mentioned above - 15-25
Monoethanolamine - 5-9
Primary amines C ₈ -C ₂₅ - 1-4
Methanol - 22-25
Higher Aromatic Carbons - Else
As the primary amine, fractions of fatty amines with the number of carbon atoms C ₈ -C ₂₀ can be used: amines C ₁₀ -C ₁₄ primary (distilled) - TU 113-00203795-018-99, primary amines C ₁₇ -C ₂₀ (distilled) - TU 2413-047-00480689-95, technical tal amines - TU 2413-00203795-20-2001 or a mixture thereof.

As a nonionic surfactant, Neonol AF _9-12 and Neonol AF _{9-6 are used} — monoalkylphenols based on ethylene ethylene propylene trimers according to TU 2483-077-05766801-98.

 Monoethanolamine is taken according to TU 6-02-915-84. Methanol according to GOST 2222-78.

As the highest aromatic hydrocarbons take:
1) Nefras Ar 150/330 - a mixture of aromatic hydrocarbons according to TU 38101809-80;
2) super heavy oil solvent (nefras ST, TU 381014149-98);
3) the average ethylbenzene fraction (TU 38401-58-196-97).

 The closest in technical essence and the achieved effect to the claimed object of claim 2 of the claims is also a method of producing an inhibitor according to the patent of the Russian Federation 2168561 C1, including mixing the starting components.

The task of claim 2 of the claims is solved by the fact that in the method for producing a corrosion inhibitor according to claim 1, comprising mixing the components into a mixture of nonionic surfactants Neonol AF _9-12 and Neonol AF _9-6 , taken in the ratio (1- 3): 1, monoethanolamine is added sequentially with stirring, then the solvent and primary amines or a mixture of primary amines.

Obtained by the claimed method, the claimed inhibitor compositions are a clear yellow liquid with a viscosity of not more than 7 mm ² / s, pour point not higher than minus 50 ^o C.

 We give specific examples of the preparation of the claimed inhibitor.

Example 1. To a mixture of 15 g of Neonol AF _9-12 and 5 g of Neonol AF _9-6 (1: 1), 6 g of monoethanolamine are added with stirring. Then, 47 g of Nefras Ap 150/330 and 23 g of methanol are added with stirring. To the resulting mixture, 4 g of technical tal amines are added with stirring.

 Examples 2-14. Carried out analogously to example 1, changing the qualitative and quantitative composition of the inhibitor.

 Obtained in examples 1-14, the inhibitors are tested for anticorrosive effectiveness. The inhibitor compositions are shown in table 1.

The protective effect of hydrogen sulfide, oxygen, carbon dioxide or mixed corrosion is determined by the gravimetric method in the circulation cells in the inhibited (using the claimed inhibitor) standard hydrogen sulfide solution according to GOST 9.506.87 "Inhibitors of metal corrosion in oil-water environments." The test medium is a standard water solution simulating oilfield formation water with a density of 1.12 g / cm ³ containing hydrogen sulfide (10-100 mg / l) and / or carbon dioxide in an amount of 25-100 mg / l and / or oxygen (1.8-3 mg / l). The total mineralization of the media is 188 g / DM ³ . The test duration is 6 hours. Before the experiment, metal samples are degreased and weighed with an accuracy of 0.0005 g. The test duration is 6 hours.

The protective effect Z (%) is calculated by the formula:
Z = (P ₁ -P ₂ ) / P1 • 100,
where P ₁ - weight loss of the sample in an uninhibited medium,
P ₂ - weight loss of the sample in an inhibited medium.

 The protective effect of a corrosion inhibitor is calculated as the arithmetic mean of the results of at least three parallel determinations.

 The test results of the proposed inhibitor are presented in table 2.

 From the data presented in the tables it can be seen that the claimed corrosion inhibitor obtained by the claimed method has a high corrosion inhibition effect in hydrogen sulfide, carbon dioxide and oxygen containing media.

Claims (2)

1. A corrosion inhibitor, including primary amines, nonionic surfactant (nonionic surfactant) and a solvent, characterized in that it additionally contains monoethanolamine, as primary amines - amines C ₈ -C ₂₅ or their mixture, as nonionic surfactants - a mixture of Neonol AF _9-12 and Neonol AF _9-6 when their ratio is (1-3): 1, and methanol and higher aromatic hydrocarbons are used as a solvent in the following ratio of components, wt.%: Primary amines C ₈ -C ₂₅ or a mixture thereof 1-4 A mixture of nonionic surfactants 15-25 Monoethanolamine 5-9 Methanol 22-25 Higher aromatic hydrocarbons Else 2. A method of obtaining a corrosion inhibitor, comprising mixing the components, characterized in that the corrosion inhibitor according to claim 1 is prepared, and the components are mixed sequentially: monoethanolamine is introduced into the nonionic surfactant mixture, then the solvent and primary amines or a mixture thereof.

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