RU2248411C1 - Corrosion inhibitor in hydrogen sulfide-containing media - Google Patents

Abstract

FIELD: corrosion protection.

SUBSTANCE: invention provides inhibitor for protecting oil-field equipment against hydrogen sulfide, carbon dioxide, and oxygen corrosion, which comprises, in solvent, 1-10% of reaction product of monoethylated alkylphenol with phosphorus-containing compound and amine, 1-20% of nonionic surfactant, 5-40% of organic acid/amine reaction product, and 2-15% of interaction product of a mixture of primary and secondary aliphatic amines with low-grade dimethyl phosphite.

EFFECT: improved protection against corrosion, reduced preparation expenses, and extended resource of raw materials.

4 tbl, 11 ex

Description

The invention relates to protective equipment for oilfield equipment in environments containing dissolved hydrogen sulfide, carbon dioxide, oxygen, and can be used in the oil industry.

Known corrosion inhibitor in aqueous media, including the product of the interaction of phosphoric acid with dimethylaminomethylphenol and water (Auth. Certificate. USSR No. 1081278, 23 F 11/00, 1994).

The inhibitor is not effective enough in hydrogen sulfide and carbon dioxide environments, and also has a high pour point.

A known corrosion inhibitor, including the product of the interaction of ethoxylated monoalkylphenol with a phosphorus-containing compound when heated, followed by its interaction with an amine (RF Patent No. 2113543, MKL C 23 F 11/126). A known inhibitor is not effective enough in mixed media.

The closest in technical essence and achieved effect is known to be a corrosion inhibitor in mineralized hydrogen sulfide-containing aqueous media in the presence of carbon dioxide, including the product of the interaction of ethoxylated monoalkylphenol with a phosphorus-containing compound and an amine in a solvent, the product of the interaction of an organic acid with an amine in a solvent and a nonionic surfactant (RF Patent No. 2162116, MKL C 23 F 11/14, 2000).

The known inhibitor is not effective enough in mineralized environments containing a mixture of H ₂ S and CO ₂ .

The basis of the present invention is the task of creating a corrosion inhibitor for environments containing H ₂ S, CO ₂ and O ₂ having a high protection effect against carbon dioxide and hydrogen sulfide corrosion and cheap and available on a raw material basis.

The problem posed by the invention is solved in that a corrosion inhibitor for mineralized hydrogen sulfide-containing environments, including the product of the interaction of ethoxylated monoalkylphenol with a phosphorus-containing compound and an amine, a nonionic surfactant, the product of the interaction of an organic acid with an amine, additionally contains the product of the interaction of a mixture of primary and secondary aliphatic amines with technical dimethylphosphite and a solvent in the following ratio of components, wt.%:

Oxyethylated Interaction Product

monoalkylphenol with a phosphorus compound and 1-10

amine

Nonionic Surfactant 1-20

The product of the interaction of organic acids with amine 5-40

The product of the interaction of the mixture of primary 2-15

and secondary aliphatic amines with technical dimethylphosphite

Solvent rest

The product of the interaction of PV1 mixture of primary and secondary aliphatic amines with technical dimethylphosphite is mixed at a temperature of 50 ° C, then for 3-4 hours the mixture is heated to 60-70 ° C. A thick mass of light yellow to brown is obtained.

As aliphatic amines, for example, amines of the fraction C ₈ -C ₁₈ or C ₁₀ -C ₁₄ , or C ₁₀ -C ₁₆ , or C ₈ -C ₃₀ can be used.

Example 4 for PV1.

In a four-necked flask equipped with a stirrer, reflux condenser and dropping funnel, 92 g of technical dimethylphosphite are placed and 200 g of amines of the C ₈ -C ₁₈ fraction containing 180 g of primary and 20 g of secondary amines are metered with stirring, maintaining the reaction temperature not higher than 50 ° С . Then the mixture is heated to complete the process for 3-4 hours at a temperature of 60-70 ° C.

Examples 1-3, 5, 6 (see table. 1) carry out analogously to example 4, changing the ratio of the starting components.

The interaction product of PV2 is obtained by sequential mixing of ethoxylated monoalkylphenol with a phosphorus-containing compound at a temperature of 100-150 ° C, then with an amine at a temperature of 40-70 ° C.

As amines, for example, mono-, di-, triethanolamines, as well as amines of the normal structure of the C ₁₀ -C ₁₆ fraction are used.

As a phosphorus-containing compound, dimethyl phosphite according to TU 6-36-5763445-6-88 or monomethyl phosphite or phosphorus trichloride is used.

As the ethoxylated alkyl phenol, neonols AF _9-4 , _{10, 12} with C ₉ alkyl or OP-4, 7, 10 are used.

Example 1 for PV-2.

54 g of technical dimethylphosphite are added to 198 g of neonol AF _9-4 , the reaction mixture is heated with stirring to 120-150 ° C for 3 hours. To the resulting reaction mixture was added 75 g of triethanolamine and stirred until a homogeneous mass.

Examples 2-11 (see table 2) are carried out analogously to example 1, changing the original components and their quantities.

The product of the interaction of an organic acid with an amine PVZ is obtained by mixing at a temperature of 40-50 ° C for 2-3 hours.

As amines, ethanolamine of the general formula H _3-n N (C ₂ H ₂ OH) _n , where _n = 1, 2, 3; secondary amines R ₁ R ₂ NH with alkyl R ₁ , R ₂ = CH ₃ , C ₂ H ₅ , C ₂ H ₄ OH, C ₃ H ₆ OH; isoalkylamine fraction C ₁₂ -C ₁₈ or an ethoxylated fatty amine with the number of carbon atoms C ₈ -C ₂₀ .

As an organic acid, the reaction product contains, for example, oleic acid according to GOST 7580-91, 2-ethylhexanoic acid according to TU 2431-03-53-505-711-01 or fatty acids from natural coconut oils of fraction C ₅ -C ₁₆ .

Example 1 for PV3.

To 280 g of organic acid from coconut oils add 73.5 g of monoethanolamine. The reaction mixture is heated with stirring to 60-70 ° C for 3 hours until a homogeneous mass is obtained.

Examples 2-9 (see table 3) are carried out analogously to example 1, changing the quantitative ratio.

As nonionic surfactants in the composition of the claimed product use neonols AF _{9-4, 6, 10} according to TU 2483-077-05766801-98, or ethoxylated alkyl phenols based on polymer-distillate OP-7, 10 according to GOST 8433-81, or monoalkyl ether polyethylene glycol based on higher fatty alcohols - syntanol ALM-10.

As a hydrocarbon solvent can be used, for example, aliphatic alcohol (methyl, ethyl, propyl, isopropyl, butyl, etc.); Nefras AR 120/200 (TU 138-101809-80), AR 130/150 (GOST 10214-78), AR 150/330 (TU 38.1011049-87E); ethylbenzene fraction (EBF) (TU 6-01-1037-78); butylbenzene fraction (BBP) (TU 38-10297-78); mixtures thereof in various combinations.

The inventive corrosion inhibitor is obtained by sequential mixing of the components. The product of interaction of PVZ is cooled to 20 ° C. The product of interaction of PV1 is introduced, it is stirred for 0.5 hours. PV2, a nonionic surfactant and a solvent are introduced into the resulting mixture, the mixture is stirred for 0.5 hours until a homogeneous mass is obtained. The resulting inhibitor is a homogeneous brown liquid with a pour point of minus 30-50 ° C.

Example 1 to obtain the claimed product.

400 g of PV3 are placed in a four-necked flask equipped with a reflux condenser and a stirrer, and 20 g of the reaction product PV1, 50 g of the reaction product PV2, 10 g of neonol AF _9-6 and 520 g of methanol are added with stirring.

Examples 2-7 are carried out analogously to example 1. Quantitative ratios are shown in table 4.

The proposed inhibitor is evaluated by the value of the protective effect at certain dosages according to GOST 9.506-87 by the electrochemical method. As an aggressive environment, a reservoir water model with a density of 1.12 g / dm ^{3 was used} at a concentration of: a) hydrogen sulfide 100 mg / l; b) hydrogen sulfide 100 mg / l and dissolved carbon dioxide 400 mg / l; c) oxygen 1 mg / l, hydrogen sulfide 20 mg / l, dissolved carbon dioxide 200 mg / l.

The test results are shown in table 4. Analysis of the data presented in the tables shows that the proposed corrosion inhibitor is more effective compared to the prototype.

Table 1
Initial data for the interaction product PV1 No. Molar ratio Number Ratio p / p amine: technical dimethylphosphite in the product of the interaction of PV1 hydrocarbon atoms in alkylamine first and sec. amines, wt.% 1 1: 1 C ₈ -C ₁₈ 98: 2 2 1: 1 C ₁₀ -C ₁₄ 90:10 3 1: 1 C ₁₀ -C ₁₆ 80:20 4 1: 1 C ₈ -C ₃₀ 70:30 5 1: 0.8 C ₈ -C ₁₈ 98: 2 6 1.2: 0.8 C ₈ -C ₃₀ 50:50

table 2 No. Initial data for the product of the interaction of PV2 (molar ratios) p / p Oxyethylated
alkyl phenol Phosphorus compound Amine 1 Neonol AF _9-4 Dimethylphosphite technical Triethanolamine 1 1 1 2 Neonol AF _9-6 Dimethyl phosphite Isoalkylamines 1 1 1 3 Neonol AF _9-6 Dimethylphosphite technical Monoethanolamine 1 1 1 4 Neonol AF _9-6 Monomethylphosphite Monoethanolamine 1 1 1 5 Neonol AF _9-6 PCl ₃ Monoethanolamine 1 1,2 1 6 Neonol AF _9-12 Dimethylphosphite technical Monoethanolamine 1 1 1 7 Neonol AF _9-10 Dimethylphosphite technical Diethanolamine 1 1 1 8 Neonol AF9-12 Dimethylphosphite technical Normal Fatty Amines 1 1 1 nine OP-4 Dimethylphosphite technical Monoethanolamine 1 0.8 0.8 10 OP-7 Monomethylphosphite Monoethanolamine 1 1 1 eleven OP-10 Dimethylphosphite technical Isoalkylamines 1 1 1

Table 3 No. The initial components taken to obtain the product of the interaction of PV3 The molar ratio of org. acid: amine p / p organic acid amine 1 Coconut Oil Organic Acid Monoethanolamine 1: 1,2 2 Coconut Oil Organic Acid Isoalkylamine 1: (0.5-1.5) 3 Coconut Oil Organic Acid Diethanolamine 1: 1,2 4 Oleic acid Monoethanolamine 1: (1-1.5) 5 Oleic acid Triethanolamine 1: (1-1.5) 6 Oleic acid Oxyethylated Fatty Amine 1: 1,2 7 Synthetic fatty acid (2-ethylhexanoic) Monoethanolamine 1: (1-1.2) 8 Synthetic fatty acid (2-ethylhexanoic) Diethanolamine 1: (1-1.2) nine Synthetic fatty acid (2-ethylhexanoic) Oxyethylated Fatty Amine 1: (0.5-1.5)

Claims (1)

Corrosion inhibitor in mineralized media containing a mixture of dissolved gases H ₂ S, CO ₂ , O ₂ , including the product of the interaction of ethoxylated monoalkylphenol with a phosphorus-containing compound and an amine, a nonionic surfactant, the product of the interaction of an organic acid with an amine, characterized in that it additionally contains the product of the interaction of a mixture of primary and secondary aliphatic amines with technical dimethylphosphite and a solvent in the following ratio of components, wt.%: product of the interaction of ethoxylated monoalkylphenol with a phosphorus-containing compound and amine 1-10 nonionic surfactant 1-20 the product of the interaction of organic acids with amine 5-40 product of the interaction of a mixture of primary and secondary aliphatic amines with technical dimethylphosphite 2-15 solvent rest.