RU2263726C1 - Inhibitor of metal corrosion in hydrogen sulfide media - Google Patents

Abstract

FIELD: corrosion protection.

SUBSTANCE: invention relates to means of protecting oil-field equipment against corrosion and provides inhibitor containing, wt %: alkylbenzyldimethylammonium chloride fraction C₁₀-C₁₈ 2.5-10, oxyethylated C₈-C₁₈-alkylamine 3-10, ethanolamine 1-5, mixture of polymer-polyols of oxyethylated polypropylene glycol 2.5-7.5, and solvent the balance.

EFFECT: increased metal corrosion inhibitory efficiency for acid and neutral hydrogen sulfide-containing oil-field media at low specific consumptions.

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Description

The invention relates to the protection of oilfield equipment from corrosion and can be used in the oil industry.

A known inhibitor of hydrogen sulfide corrosion, including a chlorine-containing Quaternary ammonium salt of the General formula

[R _C5-C15 N ⁺ (CH ₃ ) ₂ R ₁ ] Cl ^- , where R ₁ = CH ₂ —CHCl— or —CH ₂ —CCl = CH ₂ , or a mixture of these chlorine radicals, a tertiary amine salt of the formula [R _{C5 -C15} N ⁺ (CH ₃ ) ₂ R ₁ ] Cl ^- and water [RF patent No. 2064021, IPC 6 C 23 F 11/14, publ. 25.08.92]. The disadvantage of this inhibitor is that these compounds are organochlorine, since the chlorine atoms in these radicals form a covalent bond with carbon atoms, the ingress of such compounds into oil has a negative effect on oil refining processes due to poisoning of the catalysts of these processes. Ionic bonds in quaternary salts do not give such an effect.

The known inhibitor of hydrogen sulfide corrosion is dimethyldialkylammonium chloride (Thematic scientific and technical reviews "Corrosion inhibitors for the oil industry", a series of "Corrosion and protection in the oil and gas industry." M .: VNIIOENG, 1974, p.20-27, 32-33, 40-41) . The disadvantage of this corrosion inhibitor is the high pour point (at a temperature of 10-12 ° C it turns into a thick paste-like mass), so its use in commercial conditions is difficult.

Known corrosion inhibitor catapine A, which is a mixture of alkylpolybenzylpyridinium chlorides (AS USSR No. 1121927, IPC 5 C 07 C 217/08, Thematic scientific and technical reviews "Corrosion inhibitors for the oil industry", series "Corrosion and protection in the oil and gas industry" M.: VNIIOENG, 1974, p.20-27, 32-33, 40-41). The disadvantages of this corrosion inhibitor are:

- the need to use large doses of the reagent to achieve a high protective effect;

- lack of effectiveness in neutral hydrogen sulfide-containing environments.

The closest to the proposed is a corrosion inhibitor for oil-water emulsions, which is a Quaternary ammonium salt of the formula [R ₁ N ⁺ R ₂ R ₃ R ₄ ] X ^- , where R ₁ , R ₂ , R ₃ , R ₄ are organic radicals (aliphatic, cyclic , heterocyclic or aromatic) containing from 1 to 22 carbon atoms, and X ^{- -} a halogen atom (for example, lauryldimethylbenzylammonium chloride) - UK Pat. No. 798620, IPC C 10 g, F 061, publ. 23.07.58).

The disadvantage of this inhibitor is that being effective in acidic hydrogen sulfide-containing oilfield environments, it exhibits low efficiency in neutral environments.

The objective of the invention is to develop a highly effective corrosion inhibitor of complex action, working both in acidic and neutral hydrogen sulfide-containing oilfield environments at low specific costs.

The problem is solved by the development of a metal corrosion inhibitor in hydrogen sulfide-containing media, including, along with a quaternary ammonium salt and a solvent, ethoxylated alkyl amines of the C ₈ -C ₁₈ fraction, ethanolamine selected from the group of mono-, di- and triethanolamine, a mixture of hydroxyethylated polypropylene glycol polymer polyols, and as ammonium salt - alkylbenzyldimethylammonium chloride, where alkyl is an unbranched hydrocarbon radical containing 10-18 carbon atoms, in the following ratio of initial nents, wt.%:

Alkylbenzyldimethylammonium chloride fraction C ₁₀ -C ₁₈ 2,5-10 Oxyethylated alkyl amines of fraction C ₈ -C ₁₈ 3-10 Ethanolamine 1-5 A mixture of oxyethylated polymer polyols polypropylene glycol 2.5-7.5 Solvent rest

As a solvent, the inhibitor may contain aromatic hydrocarbons, aliphatic alcohols, or mixtures thereof.

The tables show the following data: table 1 - physico-chemical parameters of ethoxylated alkyl amines fraction C ₈ -C ₁₈ ; table 2 - compositions and protective effect of the claimed corrosion inhibitor; table 3 - the bactericidal effect of the claimed corrosion inhibitor with respect to sulfate reducing bacteria (SBA).

The ethoxylated alkyl amines of the C ₈ -C ₁₈ fraction are obtained by reacting primary fatty amines with ethylene oxide in a molar ratio of 1: (10-16) in the presence of a technical caustic soda catalyst at a pressure of not more than 4 kgf / cm ² (P.V. Zimakov, O. N. Dyment et al. “Ethylene Oxide”, M., 1979; N. Shepfeld. Surfactants based on ethylene oxide, M., Chemistry, 1982). The characteristics of the ethoxylated alkyl amines of the C ₈ -C ₁₈ fraction are shown in Table 1. As the primary fatty amines for hydroxyethylation, tall distilled amines according to TU 2413-00203795-019-2001 or coconut oil fatty amines are used (Akzo Nobel quality data sheet and safety data sheet) . Ethylene oxide complies with GOST 7568-88.

As ethanolamine, monoethanolamine according to TU 6-02-915-84 or diethanolamine according to TU 6-09-2652-91, or triethanolamine according to TU 6-02-916-79 are used.

Alkylbenzyldimethylammonium chloride fraction C ₁₀ -C _{18 is} used in the form of an alcohol solution according to TU 2482-003-04706205-01.

As a mixture of oxyethylated polypropylene glycol polymer polyols, a simple polyester 4202-2B-30 according to TU 2226-039-05766801-2000, or its water-methanol solution - Reapon-4V according to TU 6-55-54-91 with changes 1-5 are used.

The solvent used is an aromatic solvent, for example, a heavy oil solvent (nefras-A-120/220) according to TU 38.101809-90, or diethylbutylbenzene fraction of isopropylenebenzene production according to TU 38.102144-90, or ethylbenzene fraction of isopropylbenzene production during alkylation of benzene with 6-propylene -01-010-37-78, or an aliphatic solvent, for example: aliphatic alcohols - methyl (GOST 2222-78), or ethyl (GOST 18300-84), or isopropyl (GOST 9805-84), or still bottoms rectification of butyl alcohols according to TU-2421-086-95766575-99, or mixtures thereof .

An analysis of the known technical solutions selected during the search showed that there is no object in science and technology that is similar to the claimed combination of essential features and has high inhibitory properties in these environments, which allows us to conclude that the claimed object meets the criteria of “novelty” and “inventive step”.

The proposed corrosion inhibitor of oilfield equipment is obtained by simple mixing of the starting components. To 19 g (19%) of a 50% alcohol solution of alkylbenzyldimethylammonium chloride of the C ₁₀ -C ₁₈ fraction, 3 g (3%) of the reaction product of ethylene oxide with amines of coconut oil fatty acids are added, 5 g (5%) of monoethanolamine, 7.5 g (7.5%) of polyether simple - 4202-2B-30, and 65.5 g (65.5%) of solvent. The mixture is thoroughly mixed until a homogeneous mass. Other examples of obtaining with different ratios of the starting components in accordance with the claims were carried out similarly as described above (see table 2).

In table 2, example 1 is a prototype, 2-9 are samples of the compositions of corrosion inhibitors in the absence of one of the components, 10-67 are samples of the compositions of the claimed corrosion inhibitor.

The resulting inhibitor is a liquid from light yellow to brown in color with a pour point of no higher than -50 ° C.

The protective effect of the proposed corrosion inhibitor of oilfield equipment is determined in aqueous and aqueous-acidic and neutral environments. Standard aqueous solutions for corrosion tests containing 100 mg / dm ^{3 of} hydrogen sulfide at pH 6.5 (neutral medium) and at pH 3.5-4 (acidic medium) according to OST 39-009-79 “Corrosion inhibitors. A method for assessing the protective effect of corrosion inhibitors in oilfield wastewater. " Tests of corrosion inhibitors in a two-phase system were carried out on water-oil emulsions (acidic and neutral) according to GOST 9.506-87 "Inhibitors of metal corrosion in water-oil environments."

As can be seen from table 2, the claimed corrosion inhibitor compared with the prototype is a more effective reagent for the protection of oilfield equipment in both acidic and neutral hydrogen sulfide-containing oilfield environments. The absence of at least one component in the composition of the corrosion inhibitor leads to a decrease in the protective effect.

The claimed corrosion inhibitor, along with a good protective effect, has bactericidal activity against SVB (see table 3).

Evaluation of bactericidal activity was carried out in accordance with the methodological recommendations of VNIISPTneft: "Methodology for controlling the microbiological contamination of oilfield waters and the evaluation of the protective and bactericidal action of reagents" (RD 39-3-973-83, 1984).

The studies were carried out using accumulative cultures of SBB isolated from oilfield waters of the oil fields of the Urals, Volga Region, and Western Siberia.

Table 1
Physico-chemical characteristics of ethoxylated alkyl amines fraction C ₈ -C ₁₈ Name of indicator The product of the interaction of ethylene oxide with amines of coconut oil fatty acids The product of the interaction of ethylene oxide with distilled tall amines Appearance at 20 ° C Light to dark brown oily liquid Mass fraction of polyethylene glycol derivatives in terms of nitrogen,% 1.47-1.72 1.65-1.96 Mass fraction of water,%, no more 0.5 Pour point, ° C, not higher 10

table 2
Compositions and protective effect of the claimed corrosion inhibitor. Sample The composition of the active base of the corrosion inhibitor Protective effect, Z,% Oxyethylated alkyl amines of fraction C ₈ -C ₁₈ Alcohol solution of alkylbenzyl dimethylammonium chloride fraction C ₁₀ -C ₁₈ Ethanolamine A mixture of polymerpolyols of oxyethylated polypropyl angicol Test environment The product of the interaction of oxyethylene with amines of coconut oil fatty acids The product of the interaction of ethylene oxide with tall distilled amines Mono-Ethanol-Amine Di-ethanol-amine Tri-ethanol amine Standard solution for corrosion tests (OST 39-099-79) Water-oil emulsion (GOST 9.506-87) Acidic environment Neutral environment Acidic environment Neutral environment 1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen The dosage of corrosion inhibitor, mg / DM ³ 10 thirty 10 thirty 10 thirty 10 thirty 1 Prototype (25% solution of lauryl dimethylbenzylammonium chloride in isopropyl alcohol) * 80 84 68 76 79 84 67 76 2 - - twenty - - 5 7.5 80 82 72 79 80 85 70 78 3 - 10 - - 3 - 7.5 76 79 79 84 73 78 75 82 4 - 7.5 twenty - 5 - - 81 85 81 83 77 82 79 82 5 10 - 10 - - - 7 80 83 81 84 80 85 79 84 6 - 10 5 - - - 10 80 84 80 84 78 83 78 82 7 10 - - - - 5 2,5 77 80 75 79 73 77 75 78 8 - 8 - 5 - - - 76 79 76 81 73 76 74 74 nine 3 twenty - 3 - 5 81 84 77 82 76 83 78 82 10 3 - 19 5 - - 7.5 87 93 85 91 86 94 87 95 eleven 5 - 10 - 5 - 5 86 96 87 94 89 95 85 94

1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen 12 5 - fifteen - - 5 2,5 87 95 88 94 89 94 87 93 thirteen 5 - twenty 5 - - 2,5 88 95 86 95 90 95 87 95 14 5 - 10 - 5 - 5 87 94 87 95 87 95 87 95 fifteen 5 - fifteen - 5 - 2,5 88 94 88 96 90 95 86 95 16 5 - twenty - - 5 2,5 89 95 89 95 91 96 88 94 17 5 - 10 - - 5 6 87 90 90 96 90 96 87 95 eighteen 5 - twenty - - 5 6 85 95 90 94 89 95 88 94 19 7.5 - 5 3 - - 5 88 94 89 95 91 95 89 91 twenty 7.5 - 10 - 3 - 5 89 93 90 91 92 91 86 89 21 7.5 - 10 - 5 - 7.5 88 94 89 96 91 95 89 93 22 7.5 - 10 5 - - 7.5 89 95 89 95 93 94 90 92 23 7.5 - fifteen - - 3 5 90 94 88 91 90 92 87 90 24 7.5 - twenty - - 3 5 89 93 89 90 91 96 89 96 25 7.5 - twenty 3 - - 5 91 96 87 94 91 93 89 91 26 7.5 - twenty - - 3 5 89 96 89 91 90 95 88 90 27 10 - 10 3 - - 3 86 95 88 92 90 94 89 91 28 10 - twenty - 3 - 3 88 94 89 90 91 94 89 91 29th 10 - 5 3 - - 3 86 90 90 92 90 93 90 95 thirty 10 - 5 - - 3 3 88 89 88 93 89 90 89 92

1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen 31 10 - twenty 1 - - 6 87 94 89 94 87 93 91 94 32 10 - twenty - 1 - 6 86 93 89 94 88 94 92 96 33 10 - twenty - - 1 6 87 96 88 95 89 91 92 95 34 10 - 10 - - 1 7.5 86 89 89 94 88 90 93 93 35 10 - 10 - 1 - 7.5 87 89 87 94 89 91 92 92 36 10 - 10 1 - - 7.5 87 89 90 93 91 92 93 92 37 10 - 10 - - 1 7.5 88 89 89 91 89 90 91 92 38 10 - 10 5 - - 6 89 91 90 91 88 90 91 93 39 10 - 10 - - 5 6 89 90 89 92 89 93 90 92 40 - 5 fifteen 5 - - 7.5 90 92 90 91 87 90 92 91 41 - 5 10 - 5 - 7.5 87 90 90 91 90 92 92 90 42 - 5 fifteen - - 5 7.5 89 91 91 90 89 92 91 92 43 - 5 twenty - 5 - 2,5 89 92 90 92 89 91 91 95 44 5 10 - - 3 7.5 88 89 88 90 89 90 90 91 45 - 5 fifteen 3 - - 7.5 90 93 89 91 88 90 92 92 46 5 10 - - 5 5 87 90 90 93 90 93 91 96 47 - 5 10 5 - - 2,5 90 92 91 94 88 93 92 95 48 - 5 twenty 5 - - 2,5 89 92 90 92 90 91 89 95 49 - 7.5 5 3 - - 5 87 90 92 95 89 93 90 92

1 2 3 4 5 6 7 8 nine 10 eleven 12 thirteen fifty - 7.5 10 - 3 - 5 88 90 89 92 88 91 89 90 51 - 7.5 10 - 5 - 7.5 89 91 89 90 86 92 90 92 52 - 7.5 10 5 - - 7.5 87 90 89 91 87 91 91 93 53 - 7.5 fifteen - - 3 5 90 93 90 91 89 92 89 91 54 - 7.5 fifteen - 3 - 2,5 90 92 91 90 89 91 87 90 55 - 7.5 twenty - 3 5 93 95 92 94 91 92 90 93 56 7.5 twenty 3 - - 5 93 95 92 94 91 92 91 94 57 - 7.5 twenty - 3 - 5 93 94 91 94 90 92 90 92 58 - 10 10 3 - - 5 87 90 91 92 88 91 89 91 59 - 10 twenty - 3 - 5 94 96 90 94 90 91 89 91 60 - 10 twenty 3 - - 5 93 96 91 95 90 92 90 92 61 - 10 5 - 3 - 3 89 91 90 92 86 89 90 94 62 - 10 5 - - 1 3 88 90 90 92 87 90 91 92 63 - 10 twenty 1 - - 6 94 96 93 96 92 93 90 91 64 - 10 twenty - 1 - 6 93 95 92 94 92 94 91 92 65 - 10 twenty - 1 6 94 97 91 93 92 94 90 93 66 - 10 10 - - 1 6 91 92 91 92 90 92 91 92 67 - 10 10 1 - - 7.5 91 92 90 93 90 92 90 93 * - the prototype was tested under the same conditions as the claimed corrosion inhibitor

Table 3
The bactericidal effect of the claimed corrosion inhibitor relative to SSC. Reagent Bactericidal effect against SVB Reagent dosage, mg / l fifty 100 150 200 Visual inspection Protective action,% Visual inspection Protective action,% Visual inspection Protective action,% Visual inspection Protective action,% 25% solution of lauryl dimethyltylbenzylammonium chloride in isopropyl alcohol Incomplete suppression 55 Incomplete suppression 87 Incomplete suppression 90 Complete suppression 100 The claimed corrosion inhibitor. (at a solvent content of 75%) Incomplete suppression 60 Complete suppression 98 Complete suppression 100 Complete suppression 100

Claims (1)

Inhibitor of metal corrosion in hydrogen sulfide-containing media, including a quaternary ammonium salt, a solvent, characterized in that it further comprises ethoxylated alkyl amines of the C ₈ -C ₁₈ fraction, which use the reaction product of ethylene oxide and primary fatty amines of the C ₈ -C ₁₈ fraction, ethanolamine, selected from the group of mono-, di- and triethanolamine, and a mixture of polypolyols of ethoxylated polypropylene glycol, and alkylbenzyldimethylammonium chloride is used as a quaternary ammonium salt, where erazvetvlenny hydrocarbon radical containing 10-18 carbon atoms, with the following ratio of the starting components, wt.%: Alkylbenzyldimethylammonium chloride fraction C ₁₀ -C ₁₈ 2,5-10 Oxyethylated alkyl amines of fraction C ₈ -C ₁₈ 3-10 Ethanolamine 1-5 A mixture of oxyethylated polymer polyols polypropylene glycol 2.5-7.5 Solvent Rest