RU2082825C1 - Corrosion inhibitor for mineralized aqueous media - Google Patents

Abstract

FIELD: anticorrosion agents. SUBSTANCE: corrosion inhibitor has product of interaction of hydroxyethylated saturated alcohol or hydroxyethylated alkylphenol, phosphorous acid and ethanolamine of the general formula H_3-nN-(C₂H₄OH)_n, where: n = 1, 2, 3 taken at mole ratio = 1:(0.8-1.2): (0.8-1.2), respectively. Preferably, corrosion inhibitor has interaction product indicated above and solvent at the following ratio of components, wt.-%: interaction product 20-80, and solvent - the rest. Corrosion inhibitor can be used in petroleum production industry. EFFECT: enhanced effectiveness of inhibitor. 2 cl, 2 tbl

Description

 The invention relates to means for protecting oilfield equipment from corrosion in mineralized aqueous media and can be used in the oil industry.

 Known hydrogen sulfide corrosion inhibitor ANP-2, which is an aminoparaffin hydrochloride [1] Its disadvantages are: low inhibitory activity in hydrogen sulfide-containing mineralized aqueous media at a high dosage of over 100 mg / l.

 A known corrosion inhibitor, including salts of mono- and diphosphate esters with the number of carbon atoms 10 20 and water [2] However, the known inhibitor is effective only in neutral aqueous media at a high dosage and is ineffective in hydrogen sulfide-containing mineralized aqueous media.

The closest in technical essence and the achieved result is a corrosion inhibitor, which is an alkyl phosphate of primary fatty alcohols of the C ₇ -C ₁₃ fraction, which is the product of the interaction of the fatty alcohol of the C ₇ -C ₁₃ fraction, an amine and a phosphorus-containing acid derivative (phosphorus pentoxide or phosphorus oxychloride) [ 3] The disadvantage of this inhibitor is the low protective effect of oxygen and hydrogen sulfide corrosion.

 The basis of the invention is the creation of a corrosion inhibitor for mineralized aqueous media, having both a high protective effect against hydrogen sulfide and oxygen corrosion.

The problem is solved in that the corrosion inhibitor for mineralized aqueous media containing the product of the interaction of fatty compounds, a derivative of phosphorus-containing acid and an amine, as a compound of a fatty series contains ethoxylated fatty alcohol or ethoxylated alkylphenol, phosphorous acid as a derivative of phosphorus-containing acid, ethanolamine as an amine general formula H _3-n N (C ₂ H ₄ OH) _n , where n 1, 2, 3, taken in a molar ratio of 1 (0.8 1.2) (0.8 - 1.2), respectively.

The following are used as the ethoxylated fatty alcohol: L-2 oxanol; ethoxylated fatty alcohol of the fraction C ₁₀ -C ₁₂ with the number of hydroxyethyl groups equal to 2; or KD-6 oxanol, ethoxylated fatty alcohol of fraction C ₈ -C ₁₀ with the number of hydroxyethyl groups equal to 6; or syntanol DT-7, ethoxylated fatty alcohol FR ₁₀ -C ₁₃ with the number of hydroxyethyl groups equal to 7; or syntanol DS-10, ethoxylated fatty alcohol fr C ₁₀ -C ₁₈ with the number of hydroxyethyl groups 8 10 (Surfactants. Handbook / Ed. by A.A. Abramzon and G.M. Gayev, L. Chemistry, 1979, p. . 302 303).

The following are used as ethoxylated alkyl phenol: monoalkyl phenols based on propylene trimers, ethoxylated neonols AF9-4, AF9-6, AF9-10, AF9-12 with alkyl and the number of hydroxyethyl groups equal to 4, 6, 10, 12, respectively (Specifications 38.507- 63-171-91), or ethoxylated alkyl phenols based on polymeric distillate OP-4, OP-7, OP-10 with C ₈ -C ₁₀ alkyl and the number of hydroxyethyl groups equal to 3 4, 6 7, 10 12, respectively. (Surface active substances. Handbook / Edited by A.A. Abramzon and G.M. Gayevoy, L. Chemistry, 1979, p. 305).

 Phosphorous acid is a by-product of dimethyl phosphite production.

Ethanolamines of the general formula H _3-n N (C ₂ H ₄ ON) _n , where n 1, 2, 3, are mono-, di- or triethanolamine.

An advantageous embodiment of the invention is a corrosion inhibitor comprising a reaction product of an ethoxylated fatty alcohol or ethoxylated alkyl phenol, phosphorous acid and ethanolamine of the general formula H _3-n N (C ₂ H ₄ ON) _n , where n 1, 2, 3 in a molar ratio of 1 ( 0.8 1.2) (0.8 1.2) and additionally a solvent in the following ratio of components, wt.

The product of the interaction specified above 20 80
Solvent Else
As a solvent, the proposed inhibitor contains an aliphatic alcohol (methyl, ethyl, isopropyl or butyl), or a mixture of alcohols, for example, a mixture of methyl and ethyl in a ratio of 1 1, or a mixture of aliphatic alcohol with water in a ratio of 1 (0.2 4), respectively.

 The interaction product specified above is obtained in a known manner in 2 stages: 1) by the interaction of ethoxylated fatty alcohol with phosphorous acid (Nifantiev E.E. Chemistry of organophosphorus compounds, published by Moscow University, 1971, p. 71); 2) subsequent neutralization of the obtained monoalkylphosphorous acid with ethanolamines.

Example 1 (sample 1, table. 1). 250 g of KD-6 oxanol are mixed with 65 g of phosphorous acid at room temperature. Then the mixture is heated to 125-145 ^° C., water is distilled off and nitrogen is purged, after which the mixture is cooled to 60 ^° C. 73 g of monoethanolamine are added to the obtained reaction mixture and stirred until a homogeneous product is obtained.

 Examples 2 to 15 are performed analogously to example 1.

Example 16 (sample 16, table. 1) prototype (the product of the interaction of fatty alcohol C ₁₀ -C ₁₃ , monoethanolamine and phosphorus pentoxide - alkyl phosphate primary fatty alcohols fraction C ₁₀ -C ₁₃ .

 We give examples of the preparation of an inhibitor in a solvent.

 Example 1 (sample 1, table. 2). To 20 g of the reaction product (PV1) add 80 g of methanol and mix until a homogeneous product is obtained.

 Examples 2 to 6 perform analogously to example 1.

 Example 7. To 40 g of the product of the interaction of PV1 add 50 g of methanol and 10 g of water. The mixture is stirred until smooth.

Examples 8 to 22 perform analogously to example 7. The resulting product is a clear yellow liquid with a pour point of from -10 to -60 ^o C.

The proposed interaction product and its marketable form in a solvent are tested in mineralized aqueous media as an inhibitor of hydrogen sulfide and oxygen corrosion, the protective effect is determined by the gravimetric method in circulation cells in an inhibited (with the addition of a reagent) standard mineralized solution (GOST 9.506-87). A model of produced water with a density of 1.12 g / cm ³ at a concentration of hydrogen sulfide of 20 to 100 mg / l and oxygen up to 4 mg / l is used as an aggressive medium. Test duration 6 hours

 The test results of the protective effect of the proposed inhibitor and prototype are given in table. 1, and its commodity form in table. 2.

 Data analysis table. 1 and 2 shows that the proposed corrosion inhibitor has a higher protective effect against hydrogen sulfide and oxygen corrosion. In addition, the proposed inhibitor is technologically advanced for a wide temperature range and can be used in winter conditions and the Far North.

Claims (2)

1. A corrosion inhibitor for mineralized aqueous media containing a product of the interaction of a fatty compound, a derivative of a phosphoric acid and an amine, characterized in that the interaction product as a fatty compound contains an ethoxylated fatty alcohol or ethoxylated alkylphenol, as a derivative of a phosphoric acid, phosphorous acid, in as an amine, ethanolamine of the general formula
H _{3 - n} N (C ₂ H ₄ OH) _n ,
where n 1, 2, 3,
taken in a molar ratio, respectively, 1 0.8 1.2 0.8 1.2.  2. The corrosion inhibitor according to claim 1, characterized in that it further comprises a solvent in the following ratio of components, wt. The specified product of the interaction of ethoxylated fatty alcohol or ethoxylated alkyl phenol, phosphorous acid and ethanolamine 20 80
Solvent Else,

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