RU2337181C1 - Corrosion inhibitor for hydrogen sulfide and carbon dioxide containing media - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: inhibitor contains, wt %: fatty acid - 8-20, oxyethylated alkyl- or phenol- N-methylalkylammonium methylphosphites - 7-21, nonionic surfactant - 7-16, solvent - the rest.

EFFECT: effective corrosion inhibiting composition.

1 tbl, 14 ex

Description

The invention relates to the field of protection of metals from corrosion in highly mineralized environments containing hydrogen sulfide and carbon dioxide, with the help of inhibitors and can be used in the extraction, preparation, transportation and processing of oil.

A known composition for protecting oilfield equipment from corrosion, including amines, fatty acids, surfactants and their derivatives, solvent (Guidelines for corrosion protection of oilfield equipment. Ufa. 1979).

The disadvantages of this inhibitor are the inability to prevent sulfide embrittlement, as well as poor dispersibility in highly mineralized environments.

A known inhibitor of corrosion in hydrogen sulfide-containing environments containing hydrochloride aminoparaffins (ed. Certificate No. 652315, CL EV 43/00, 1979).

However, the known inhibitor is not effective enough at a dosage of 100 mg / L.

The closest in technical essence and the achieved effect to the proposed one is a corrosion inhibitor in hydrogen sulfide-containing environments, including the product of the interaction of fatty acid with the number of carbon atoms C ₁₀ -C ₂₀ and aminoparaffin with the number of carbon atoms C ₈ -C ₂₀ with their molar ratio 1: (0 , 1 ÷ 1), respectively, in an amount of 10-50 wt.%, A nonionic surfactant is 10-30 wt.% And the solvent is the rest. (RF patent No. 2061091, C23F 11/00, 1996). The disadvantages of the known inhibitor is not high enough effect at a dosage of 50 mg / l and relatively high cost.

The basis of the present invention is the creation of an effective corrosion inhibitor in highly mineralized environments containing hydrogen sulfide and carbon dioxide with a pour point of from -20 ° C to -50 ° C.

The problem is solved in such a way that the corrosion inhibitor in highly mineralized environments containing hydrogen sulfide and carbon dioxide, containing a fatty acid, a nitrogen-containing compound, a nonionic surfactant and a solvent, contains nitrogen-containing alkylated (- or phenol) methylphosphite N-methylalkylammonium as a nitrogen-containing compound, in the following ratio of components, wt.%:

fatty acid 8-20 Nonionic surfactants 7-16 nitrogen containing compound described above 7-21 solvent rest

As a fatty acid with the number of carbon atoms C ₈ -C ₂₀ can be used, for example, ethylhexanoic acid, oleic acid according to GOST 7580-91, TU 10-04-02-62-91.

As the nonionic surfactant can be used, for example, ethoxylated monoalkylphenols: neonol AF ₉ -6, ₉ -12 neonol AF TU 3850769-300-93; or monoalkyl ether of polyethylene glycol (syntanol ALM-10) according to TU 6-14-864-88.

As a solvent, aliphatic alcohols can be used, for example: methyl, ethyl, isopropyl (IPA), butyl (BS) and / or aromatic hydrocarbons: ethylbenzene fraction according to TU 38-30225-81, Nefras Ap 120/200, Ap 150 / 330 according to TU 38101809-80; solvent or mixtures thereof.

Hydroxyethylated alkyl (or phenol) methylphosphites are hydroxyethylated isononylphenolmethylphosphites or methylphosphites of ethoxylated fatty alcohols, which are prepared in a known manner (E.E. Nifantiev. Chemistry of organophosphorus compounds. M: Moscow University, 1971, p. 71; Usp. Chemistry. 1978 1978 , 47, No. 9, p. 1565) interaction when mixing ethoxylated alkyl phenol or ethoxylated fatty alcohol with dimethylphosphite when the reaction mixture is heated to a temperature of 100-150 ° C with the removal of methanol (reaction product) by blowing nertnym gas.

The following are taken as the ethoxylated alkyl (or phenol) methylphosphite of N-methylalkylammonium: 1) hexaoxyethylated isononylphenolmethylphosphite N-methylalkylammonium, which is the product of the interaction of (PV-1) ethoxylated isononylphenolmethylphosphite of formula A, where n = 6,

and alkylamine of the formula

and get it at their molar ratio of 1: 1 for 5 hours at a temperature of 80 ° C.

The yield of the basic substance is controlled by the amine number in mg HCl / g. When a constant amine value is reached, synthesis is stopped. The product yield is 96%. The product is a homogeneous viscous liquid with a pour point of minus 1-3 ° C; 2) hexaoxyethylated N-methylammonium octylmethylphosphite, which is the product of the interaction (PV-2) of the ethoxylated octylmethylphosphite of formula B:

water and alkylamine C ₁₂ H ₂₅ NH ₂ and get them at a molar ratio of components of 1: 1.5: 1, respectively, the components being introduced sequentially, and the process is carried out with stirring for 1 hour at a temperature of 80 ° C. The process is monitored by the amine number in mg HCl / g. When a constant amine value is reached, synthesis is stopped. The yield is 100%. The product is a uniform viscous liquid with a pour point of minus 1 ° C.

We give specific examples of the preparation of the claimed inhibitor and methods for testing its effectiveness.

Example 1 (prototype). 30 g of solvent and 30 g of methyl alcohol are successively added to 12 g of fatty acids of the C ₅ -C ₉ fraction, and 21 g (PV-1) are added with stirring. Self-heating of the reaction mass occurs with the formation of an interaction product. Then, 7 g of neonol AF9-6 is added to the mixture and mixed until a homogeneous mass is obtained.

Example 2 (as claimed). 20 g of isopropyl alcohol are added to 40 g of the solvent, and 20 g of FFA of the C ₅ -C ₉ fraction, 12 g of neonol AF ₉ -12 and 8 g (PV-2) are successively added with stirring. The mixture is stirred until a homogeneous mass.

Examples 3-14 are carried out analogously to example 2, changing the components and their number.

The resulting corrosion inhibitor is a clear liquid from yellow to brown in color with a pour point of from -20 ° C to -50 ° C.

The protective effect is determined by the gravimetric method in the circulation cells in an inhibited (with the addition of a reagent) standard hydrogen sulfide-containing solution according to GOST 9506-87, as well as by the electrochemical method in a solution containing hydrogen sulfide and carbon dioxide. As an aggressive medium, the gravimetric test method uses a formation water model with a density of 1.12 g / l at a hydrogen sulfide concentration of 100 mg / l, and the electrochemical test method uses a formation water model with a density of 1.12 g / l saturated with CO ₂ up to 1000 mg / l, as well as a model of produced water with a density of 1.12 g / l, saturated with CO ₂ up to 1000 mg / l, and a hydrogen sulfide content of 50 mg / l. Test duration 6 hours

The data in examples 1-14 and the protective effect are shown in the table.

From the presented data it follows that the proposed corrosion inhibitor is highly effective, technologically advanced and can be used at low temperatures at a dosage of 30 mg / l.

Table The components of the corrosion inhibitor, wt.% Protective effect,% at a dosage of 30 mg / l N / N n / a fatty acid fractions Nonionic surfactants ethoxylated
N- methylalkylammonium alkyl (or phenol) methylphosphite Solvent alcohol aromatic hydrocarbon MPV + CO ₂ MPV + CO ₂ + H ₂ S MPV + H ₂ S one 2 3 four 5 6 7 8 9 one SJK S5-S9
12 neonol AF ₉ -6
7 (PV-1) 21 methanol 30 solvent 30 94 94 93 2 SJK S5-S9
twenty neonol AF ₉ -12
12 (PV-2) 8 IPS 20 solvent 40 90 90 91 3 SJK S10-S16
8 Neonol AF ₉ -6 10 (PV-1) 12 methanol 60 solvent 10 91 92 92 four SJK S10-S16
fourteen neonol AF ₉ -12
12 (PV-2) 9 methanol 35 Nefras Ar120 / 200
thirty 91 92 92 5 Olein. set (C18) 10 neonol AF ₉ -12
16 (PV-1) 14 methanol 40 solvent 20 92 93 92 6 Olein K-ta (C18) 15 Neonol AF ₉ -6 15 (PV-2) 10 methanol 10 solvent 50 90 90 91 7 SZhKS10-S16
17 neon AF ₉ -6 11 (PV-1) 7 ethanol 15 solvent 50 90 91 90 8 Olein K-ta (C18) 12 Neonol AF ₉ -6 12 (PV-2) 16 methanol 40 Nefras Ar150 / 330
twenty 91 93 92 9 Olein K-ta (C18) 14 neonol AF ₉ -12
8 (PV-1) 18 methanol 60 solvent 94 93 93 10 Olein K-ta (C18) 14 Sintanol ALM-10 12 (PV-2) 12 methanol 35 solvent 25 90 91 90 eleven SJK S5-S9
fourteen Neonol AF ₉ -6 12 (PV-1) 9 BS 20 solvent 35 93 92 92 12 SJK S10-C16 19 neonol AF ₉ -12
eleven (PV-2) 20 methanol 25 solvent 25 92 91 91 13 SJK S10-S16
twenty neonol AF ₉ -12
16 (PV-1) 21 methanol 20 Nefras Ar120 / 200
23 94 93 95 fourteen Olein to-that (C18) 8 Neonol AF ₉ -6 7 (PV-2) 7 IPS 40 Nefras Ar150 / 330
38 90 90 90

Claims (1)

Corrosion inhibitor in highly mineralized environments containing hydrogen sulfide and carbon dioxide, including fatty acid, a nitrogen-containing compound, a nonionic surfactant and a solvent, characterized in that it contains ethoxylated alkyl or phenolmethylphosphites of N-methylalkylammonium components as a nitrogen-containing compound in the following ratio wt.%: fatty acid 8-20 hydroxyethylated alkyl or phenol methyl phosphites N-methylalkylammonium 7-21 nonionic surfactant 7-16 solvent rest