FR2762016A1 - USE OF THIOLS CONTAINING AMINO GROUPS AS CORROSION INHIBITORS IN THE OIL INDUSTRY - Google Patents

Abstract

The present invention relates to the use of a compound (la) or (Ib) or of an addition product of at least one compound (IV) (CF DRAWING IN BOPI) chosen from aliphatic amines (V) ; amidoamines (VI) and imidazolines (VII), as an inhibitor of carbonic and / or hydrogen sulfide corrosion of carbon steels in the petroleum industries. (CF DRAWING IN BOPI) R1, R2, R3, R4 - H, C1 -C10 alkyl or aromatic residue: R5 = C8 -C30 alkyl or alkenyl; R6 = C1-C30 alkyl or C2-C30 alkenyl, or group - (CR1 R2 -CR3 R4 -S) n -H: m, n = integer from 1 to 10; R'5 = C7 -C29 alkyl or alkenyl: A represents a group (II) linked to R'5 by -CO-, or a group (III) linked to R'5 by carbon: (CF DRAWING IN BOPI) x, y = 0 or integer from 1 to 10, with 1 <= x + y <= 10; q, r, o, p = an average number of sequences -CR1 R2 -CR3 R4 -S-, this number being able to be zero, the “r” being able to be different if x> 1 and the “p” being able to be different if y> 1, and “q + SIGMA r + o + SIGMA p” when A is (II) or “q + SIGMA r” when A is (III) being greater than 0 and up to 30; R "6 = H or alkyl or alkenyl; R7 and R8 each have the same meaning as R'5; z = 0 or an integer from 1 to 10.

Description

USE OF THIOLS CONTAINING AMINO GROUPS LIKE

CORROSION INHIBITORS IN THE OIL INDUSTRY

The present invention relates to the protection against corrosion of petroleum production, transport, storage and refining installations, which

are usually made of carbon steel.

At present, such protection is mainly provided by the use of corrosion inhibitors based on organo-nitrogen compounds, such as amines, quaternary ammonium derivatives, amidoamines and

imidazolines, or based on phosphoric esters.

It is also known that the addition of elemental sulfur can improve the inhibitory efficiency of

corrosion of organo-nitrogen compounds (DE-A-3 437 936).

Also, mixtures of organosulfur compounds and organonitrogen compounds have been cited as effective corrosion inhibitors (US-A-5,368,774; US-A-4,295,979; US-A-4,446,056). Likewise, compounds containing both sulfur and nitrogen in their molecule have been proposed as corrosion inhibitors: US Pat. No. 4,633,019 thus describes, as corrosion inhibitors, the compounds of formula:

R1 R3

\ I

N-CH-SR5

H o R1 is a C1-C18 alkyl, cycloalkyl or hydroxyalkyl group; R3 is a C1-C4 alkyl group; and R5 is C1-C18 alkyl; and Movsum-Zadz, M.M .; Mamedov

F.N .; Sultanova, N.R .; Dzhafarova N.V., in Korroz.

Zashch. Neftegazov. Prom-sti. (1980), (10), 8-10, describe the compounds: Ph-S-CH2H2O-CH2CH2O-CH2CH2ÉC

CH3 r-

ICC C

Ph-SCH2CHO-CH2CH20 - CH2CH2É (Bu-SCH2CH20-CH2CH20-CH2CH2CH2 CH3 C7HlsSCH2HOCH2-O-CH20-O-CH2CH2

as corrosion inhibitors.

A new family of compounds has now been discovered which possess an even more effective petroleum corrosion inhibiting efficiency than the compounds known hitherto. A subject of the present invention is therefore first of all the use of a mono- or polythiol chosen from those of formula (Ia): (CR1R2-CR3R4-S) mH R5-N (Ia) R6 in which: R1, R2 , R3 and R4 each independently represent a hydrogen atom, a C1-C10 alkyl group or an aromatic residue, the residues R1 and R3 (or R2 and R4) being able to be linked together to form a hydrocarbon ring with the two atoms of carbon that carry them; - R5 represents an alkyl or alkenyl group, linear or branched, C8-C30; and - R6 represents a linear or branched alkyl group, C1-C30, or an alkenyl group, linear or branched, C2-C30, or a group - (CR1R2-CR3R4-S) n-H; - m and n, identical or different, each represent an integer ranging from 1 to 10, the total number m + n of sequences - CR1R2-CR3R4-S-, identical or different, possibly ranging up to 20, preferably up to 10; and those of formula (Ib): R'5-A- (CH2CH2N) x- (CRlR2-CR3R4-S) qH (Ib) (CR1R2-CR3R4_S) rH in which: - R1, R2, R3 and R4 are such that defined above; - R'5 represents an alkyl or alkenyl residue, linear or branched, C7-C29, in particular C7-C19; - A represents a group (II): -C-N- (CH2CH2N) y- (CR1CR2-CR3R4-S) o-H (II) 0l1I1 2_C 3R4_S (CR R2-CR3R4 -S) p-H linked to R'5 by -CO-; or a group (III):

ND (III)

N linked to R'5 by carbon; - x and y, identical or different, each represent 0 or an integer from 1 to 10, with the condition that 1 <x + y <10; - q, r, o and p each represent an average number of sequences -CR1R2-CR3R4-S-, said average number may be zero and said sequences may be identical or different, the "r" may be different if x is greater to 1 and the "p" may be different if y is greater than 1, and "q + E r + o + E p" in the case where A is a group (II) or "q + E r" in the case o A is a group (III) being greater than 0 and being able to range up to 30, being in particular between 0.5 and 10; or an addition product of at least one compound of formula (IV):

R1 R2 R3 R4

\ 1 I /

C C (IV)

\ /

S

in which R1, R2, R3 R4 are as defined above, on at least one compound having at least one -NH2 or \ NH group, chosen from: / (a) aliphatic amines of formula (V):

R5 - N - H (V)

R "6

in which: - R5 is as defined above; and - R "6 represents a hydrogen atom or an alkyl group, linear or branched, C1-C30, or an alkenyl group, linear or branched, C2-C30; (b) amidoamines of formula (VI): (CH2CH2NH) xH /

R7-C-N (VI)

Il \ O (CH2CH2NH) y-H in which: - R7 has the same meaning as R'5; - x and y are as defined above; and (c) imidazolines of formula (VII):

8N (II)

N (CH2CnNH - H (VII) in which: - R8 has the same meaning as R'5; and - z is 0 or is an integer from 1 to 10; as an inhibitor of carbonic and / or hydrogen sulfide corrosion of steels carbon in the petroleum industries. In particular, R1, R2, R3 and R4 each independently represent a hydrogen atom, a C1-C6 alkyl group or a phenyl group, R1 and R3 (or R2 and R4) which can be linked between them to form an alkylene chain. In formula (Ia), R5 may in particular represent the residue of a primary complex fatty amine, such as a coconut chain or an oleic chain, R6 then representing a group - (CR1R2-CR3R4 -S) nH, the resulting dithiol then being in the form of a mixture; R5 and R6 can also simultaneously represent residues of a secondary complex fatty amine (each being for example a coconut chain), the resulting monothiol is

then presenting in the form of a mixture.

In formula (Ib), R ′ 5 may in particular represent the residue of a complex fatty acid amide, the resulting mono- or polythiol then appearing under the

form of a mixture.

As adduct, mention may in particular be made of the adduct of at least one compound of formula (IV) on a mixture of compound (VI) and of compound (VII) consisting of a product of the condensation reaction by dehydration of a fatty acid with a polyamine with formation of amidoamine and partial cyclization of this

last in imidazoline.

The compound of formula (IV) is chosen in particular from ethylene sulfide, propylene sulfide, 1,2-dimethyl thiirane, 2,2-dimethyl thiirane, n-octyl thiirane, cyclohexene sulfide, sulphide

styrene and 1,2-diphenyl thiirane.

The amines of formula (V) are chosen for example from decyl amine, undecyl amine, lauryl amine, myristyl amine, cetyl amine, stearyl amine, primary amines derived from a fatty acid obtained from coconut oil, primary amines derived from oleic acid, primary amines derived from a fatty acid obtained from soybean oil, didecyl amine, diundecyl amine, dilauryl amine, dimyristyl amine, dicetyl amine, distearyl amine, secondary amines derived from a fatty acid obtained from coconut oil, secondary amines derived from oleic acid, and secondary amines derived from a fatty acid obtained from

soybean oil.

The amidoamines of formula (VI) are chosen in particular from: - lauric acid monoamide with ethylene diamine; - lauric acid amide with diethylene triamine; - lauric acid amide with triethylene tetramine; - lauric acid amide with tetraethylene pentamine; and analogous amides with stearic acid, oleic acid, fatty acid derived from coconut oil and acid

fat derived from soybean oil.

The imidazolines of formula (VII) are chosen in particular from: 2undecyl imidazoline; * 1- (2-aminoethyl) -2-undecyl imidazoline; * 1- [N- (2-aminoethyl) -2-aminoethyl] -2-undecyl imidazoline; * 2heptadecyl imidazoline; * 1- (2-aminoethyl) -2-heptadecyl imidazoline; * 1- [N- (2-aminoethyl) -2-aminoethyl] -2-heptadecyl imidazoline; * imidazolines obtained by dehydration and cyclization of: lauric acid amide with tetraethylene pentamine; * stearic acid amide with tetraethylene pentamine; * oleic acid monoamide with ethylene diamine; * oleic acid amide with diethylene triamine; * oleic acid amide with triethylene tetramine; * oleic acid amide with tetraethylene pentamine; * fatty acid amide derived from coconut oil with triethylene tetramine; * fatty acid amide derived from coconut oil with tetraethylene pentamine; * fatty acid monoamide derived from soybean oil with ethylene diamine; * fatty acid amide derived from soybean oil with diethylene triamine; * fatty acid amide derived from soybean oil with triethylene tetramine; the fatty acid amide derived from soybean oil with the

tetraethylene pentamine.

In the adducts of the invention, the compound of formula (IV) was added in particular in an amount of 1 to moles on average per 1 mole of (a); and from 0.5 to

moles per 1 mole of (b) or (c).

The addition reaction leading to the products of the invention is generally carried out in an organic solvent which is inert under the reaction conditions,

the use of a solvent can however be omitted.

As concrete examples of organic solvents which can be used, mention may be made of aromatic compounds, such as benzene, toluene and xylene; ether type compounds, such as diethyl ether, ethyl isobutyl ether, tetrahydrofuran and dioxane; alcohol-type compounds, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butanol, heptanol, 2-ethylhexanol and cyclohexanol; nitrile-type compounds, such as acetonitrile and benzonitrile; amide-type compounds, such as N, N-dimethyl formamide

and N-methylpyrrolidone, and dimethyl sulfoxide.

The reaction temperature, although not particularly defined, is generally in the range 10-200 ° C, preferably 50 ° C.

at 120'C.

Particularly preferred adducts for the application of the invention are: the adduct of 2 moles of ethylene sulfide on one mole of lauryl amine; and - the adduct of about 2 to 3 moles of sulphide

ethylene on 2-aminoethyl dodecanamide.

A subject of the present invention is also a composition for protecting carbon steels against carbonic and / or hydrogen sulphide corrosion in the petroleum industries, characterized in that it consists of or that it comprises a solution in at least one organic solvent. of at least one mono- or polythiol and / or at least one adduct as defined above, when it is intended for use in a corrosive medium consisting of an oily phase, said composition further comprising at least one surfactant when it is intended for use in a corrosive medium consisting of an aqueous phase or of an aqueous phase and an oily phase. Such a composition, intended for use in a corrosive medium consisting of an oily phase, may consist of or comprise, per 100 parts by weight: (A) 20 to 50 parts by weight of at least one mono- or polythiol and / or at least one adduct as defined above; and (B) 50 to 80 parts by weight of at least one organic solvent chosen in particular from alcohols such as those mentioned above, mono- or di-ethers of glycols such as di- or tri-ethylene glycol and propylene glycol, cuts oil like white

spirit, fuels, kerosene and naphtha.

Such a composition, intended for use in a corrosive medium consisting of an aqueous phase or of an aqueous phase and an oily phase, may consist of or comprise, per 100 parts by weight of (A) + (B) + (C) : (A) 20 to 40 parts by weight of at least one mono- or polythiol and / or at least one adduct as defined above; (B) 40 to 20 parts by weight of at least one organic solvent chosen in particular from glycol ethers, in particular butyl glycol; and

(C) 20 to 40 parts by weight of at least one surfactant

active agent, chosen in particular from fatty chain amino acids and oxyethylenated derivatives (2 to 20 units)

fatty amines (tallow or copra).

The present invention also relates to a process for protecting carbon steels against carbonic and / or hydrogen sulphide corrosion in the petroleum industries, characterized in that said steels are treated with a composition as defined above, at a temperature between room temperature and

'C, preferably about 120 ° C.

The following Examples illustrate the present invention without, however, limiting its scope. They are preceded by the Reference Examples A to T which describe the preparation of the compounds or products of the invention respectively A to T, and in which the following abbreviations have been used: ES: ethylene sulfide DMF: N, N- dimethylformamide AEDAM: 2-aminoethyl dodecanamide

AEOAM: 2-aminoethyl octadecanamide.

The average number of moles of ES added per mole of amine (a) (Examples A-H and ST) or amidoamine (b) (Examples IL) or mixture of amidoamine (b) and imidazoline ( c) (Examples M to R) was calculated on the basis

1 H NMR analysis.

>. *

** Reference Examples A to H describe the preparation of compounds of formula: (CH2CH2S) mH R5-N (CH2CH2S) nH obtained by adding m + n moles of ES to one mole of amine

primary (a) of formula R5NH2.

Reference Example A: R5 = n-C12H25 and mean value of m + n = 2 In a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a bromine funnel, 30.0 g (162 mmol) of lauryl amine and 49.5 g of dioxane were placed, heated to 107 ° C and brought to reflux. To the resulting reaction mixture, maintained at this temperature, 19.5 g (324 mmol) of ES was added dropwise over 4 hours. After the dropwise addition was completed, the compounds were allowed to react at the same temperature for 4 hours. After the completion of the reaction, the resulting reaction solution was distilled to remove the solvent by evaporation, to obtain 48.2 g of a transparent liquid.

colorless (yield: 97%).

Reference Example B: R5 = C12H25 and mean value of m + n = 5 In a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a bromine funnel, 30.0 g ( 92 mmoles) of the adduct of ES on lauryl amine (average number of moles of ES added: 2.3), obtained substantially by the same procedure as in Reference Example A, 25.0 g of acetonitrile and 5.0 g of dioxane were placed and heated to 78 ° C. To the resulting reaction mixture maintained at this temperature, 16.6 g (276 mmol) of ES was added dropwise over a period of 40 minutes. After the dropwise addition was completed, the combined compounds were reacted at the same temperature for 3.5 hours. After this reaction was completed, the resulting reaction solution was brought to normal room temperature and filtered to remove 4.8 g of white solids insoluble in the solvent. The filtrate was distilled to remove the solvent, to obtain 40.5 g of a yellow waxy product.

clear (yield: 87%).

Reference Example C: R5 = n-C18H37 and mean value of m + n = 2.3 44.0 g (yield: 78%) of a white waxy product were obtained by following the procedure of Example of Reference A, while using 30.8 g (111 mmol) of stearyl amine and 25.4 g (423 mmol) of ES as reagents and

44.7 g of dioxane as solvent.

Reference Example D: R5 = n-C18H37 and average value of m + n = 4.85 By operating as in Reference Example C with more ES, we obtained a product D with an average value

m + n of 4.85.

Reference Example E: R5 = copra chain and average value of m + n = 2 38.9 g (yield: 73%) of a slightly whitish cloudy liquid were obtained by following the procedure of Reference Example A , while using 25.0 g (124 mmol) of an aliphatic primary amine derived from coconut oil (total amine content of 4.98 meq / g determined by non-aqueous titration) and 28.4 g (472 mmoles) of ES as

reagents and 53.4 g of dioxane as solvent.

Reference Example F: R5 = copra chain and average value of m + n = 4.6 This product was obtained by operating as in

The previous example using more I / O.

Reference Example G: R5 = oleic chain and mean value of m + n = 1.9 36.3 g (yield: 94%) of a reddish brown liquid were obtained by following the procedure of the Reference Example A, while using 25.0 g (92 mmol) of an aliphatic primary amine derived from oleic acid (total amine content of 3.69 meq / g, determined by non-aqueous titration) and 13.8 g ( 230 mmoles) of ES as reagents and

38.8 g of dioxane as solvent.

Reference Example H: R5 = oleic chain and average value of m + n = 4.8 This product was obtained by operating as in

The previous example using more I / O.

*

* * Reference Examples I to L describe the preparation of adducts of p moles of ES to an amidoamine (b):

CH2CH2NH2

R7-C-N

Il \ O H Reference Example I: R7 = n-C11H23; mean value of p = 2.7 In a four-neck flask having an internal volume of 500 ml and equipped with a stirrer, thermometer and Dimroth condenser, 60.0 g of AEDAM and 180 g of dioxane were placed and heated to 101 ° C while being maintained in a nitrogen atmosphere. To the solution maintained at this temperature, 44.6 g of ES placed in a dropping funnel (AEDAM / ES = 1 / 3.0 in molar ratio) was added dropwise over 7 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 1.5 hours. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove a small amount of insoluble material (0.3 g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 98.8 g of a yellow waxy product.

clear (yield: 95%).

Reference Example J: R7 = n-CllH23; mean value of p = 5.6 In a four-necked flask having an internal volume of 200 ml and equipped with a stirrer, a thermometer and a Dimroth condenser, 38.0 g of the product obtained in Example Reference I, 57 g of DMF and 57 g of dioxane were placed and heated to 101 ° C while being kept in a nitrogen atmosphere. To the solution kept at this temperature, 16.9 g of ES placed in a dropping funnel was added dropwise over 2.5 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 0.5 hour. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove an extremely small amount of insoluble material. The filtrate was subjected to vacuum distillation to remove the solvent by evaporation and obtain

54.6 g of a light yellow waxy product (yield: 99%).

Reference example K: R7 = n-C17H35 and mean value of p = 2.7 In a four-neck flask having an internal volume of 500 ml and equipped with a stirrer, a thermometer and a Dimroth condenser, 80.0 g of AEOAM and 240 g of dioxane were placed and heated to 103 ° C, while being kept in a nitrogen atmosphere. To the solution maintained at this temperature, 36.8 g of ES placed in a dropping funnel (AEOAM / ES = 1 / 2.5 in molar ratio) was added dropwise over 4 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 7 hours. After the completion of the reaction, the reaction solution was subjected to vacuum distillation to remove the solvent by evaporation, then concentrated to half the original volume to cause precipitation of insoluble matters, which were removed (21 , 5 g) by filtration. The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 94.0 g of a yellow waxy product.

clear (yield: 80%).

Reference example L: R7 = n-C17H35 and mean value of p = 5.5 In a four-neck flask having an internal volume of 200 ml and equipped with a stirrer, a thermometer and a Dimroth condenser, 40.0 g of the product obtained in Reference Example K, 60 g of DMF and 60 g of dioxane were placed and heated to 105 ° C, while being kept in a nitrogen atmosphere. To the solution kept at this temperature, 14.7 g of ES placed in a dropping funnel was added dropwise over 2 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 0.5 hour. After the completion of the reaction, the reaction solution was subjected to vacuum distillation to remove the solvent by evaporation to obtain 54.6 g of a yellow waxy product.

clear (yield: 99%).

* * * Reference Examples M to R describe the preparation of ES adducts on a product (d) obtained by condensation and dehydration of a fatty acid with a polyamine, as defined in Table 1 below. after.

Table 1

Example Product d Fatty acid Polyamine Amine Amine Amine Imidazoline ** of primary secondary tertiary (% by weight) Reference (meq / g) (meq / g) (meq / g) M dl Fatty acid Diethylene 1.634 1.697 3.034 76 Copra triamine N d2 Fatty acid Triethylene 3.812 3.085 2.462 68 of tetramine coconut oil O d3 Fatty acid Tetraethylene 5.908 2.467 3.239 45 of coconut pentamine oil P d4 Diethylene acid 1.871 2.193 1.945 64 Oleic triamine Q d5 Triethylene acid 2.961 1.579 2.796 72 oleic tetramine R d6 Tetraethylene acid 4.359 3.121 2.313 66 oleic pentamine Quantities found by non-aqueous titration ** Percentage found by H NMR o Reference Example M In a four neck flask having an internal volume of 500 ml and equipped with a stirrer , a thermometer and a Dimroth condenser, 68.3 g (339.1 meq of active amine per equivalent weight of hydrogen) of product (dl) and 273.3 g of dioxane were placed and heated to 102 ° C, while being maintained in a nitrogen atmosphere. To the solution maintained at this temperature, 21.3 g of ES placed in a dropping funnel was added dropwise over a period of 5 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 1.5 hours. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove insolubles (12.1 g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 77.5 g of a.

light yellow waxy product (yield: 86%).

1H NMR analysis showed that the average number of moles of ES added per mole of (dl) was 0.7 and that the imidazoline content of the product obtained was 74% by weight. Reference Example N In a four neck flask having an internal volume of 500 ml and equipped with a stirrer, thermometer and Dimroth condenser, 70.6 g (756.1 meq of active amine by weight hydrogen equivalent) of product (d2) and 280 g of dioxane were placed and heated to 104 ° C, while being maintained in a nitrogen atmosphere. To the solution maintained at this temperature, 45.4 g of ES placed in a dropping funnel was added dropwise over a period of 6 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for one hour. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove insolubles (32.3 g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 83.2 g of a.

yellow waxy product (yield: 72%).

1H NMR analysis showed that the average number of moles of ES added per mole of (d2) was 1.8 and that the imidazoline content of the product obtained was 61% in

weight.

Reference Example O In a four neck flask having an internal volume of 500 ml and equipped with a stirrer, thermometer and Dimroth condenser, 65.0 g (929.0 meq of active amine by weight hydrogen equivalent) of product (d3) and 267.5 g of dioxane were placed and heated to 102 ° C, while being maintained in a nitrogen atmosphere. To the solution maintained at this temperature, 55.9 g of ES placed in a dropping funnel was added dropwise over a period of 6 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 0.5 hour. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove insolubles (28.6g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 92.1 g of a.

yellow cloudy liquid product (yield: 76%).

1 H NMR analysis showed that the average number of moles of ES added per mole of (d3) was 2.5 and that the imidazoline content of the product obtained was 26% by weight. Reference Example P In a four-neck flask having an internal volume of 500 ml and equipped with a stirrer, thermometer and Dimroth condenser, 75.75 g (929.0 meq of active amine by weight hydrogen equivalent) of product (d4) and 303.9 g of dioxane were placed and heated to 102 ° C, while being maintained in a nitrogen atmosphere. To the solution maintained at this temperature, 48.6 g of ES placed in a dropping funnel was added dropwise over a period of 5 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for 0.5 hour. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove insolubles (36.4 g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 87.7 g of a.

yellow cloudy liquid product (yield: 71%).

NMR analysis showed that the average number of moles of ES added per mole of (d4) was 1.3 and that the imidazoline content of the product obtained was 64% by weight. Reference Example 0 In a four neck flask having an internal volume of 500 ml and equipped with a stirrer, thermometer and Dimroth condenser, 71.6 g (537.1 meq of active amine per equivalent weight of hydrogen) of product (d5) and 286.4 g of dioxane were placed and heated to 104 ° C, while being kept in a nitrogen atmosphere. To the solution maintained at this temperature, 48.4 g of ES placed in a dropping funnel was added dropwise over a period of 7 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for one hour. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove insolubles (39 g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 79.8 g of a.

yellow cloudy liquid product (yield: 67%).

NMR analysis showed that the average number of moles of ES added per mole of (d5) was 1.2 and that the imidazoline content of the product obtained was 68% in

weight.

Reference Example R In a four neck flask having an internal volume of 500 ml and equipped with a stirrer, thermometer and Dimroth condenser, 73.1 g (862.5 meq of active amine by weight hydrogen equivalent) of product (d6) and 291.4 g of dioxane were placed and heated to 103 ° C while being maintained in a nitrogen atmosphere. To the solution maintained at this temperature, 52.0 g of ES placed in a dropping funnel was added dropwise over a period of 5 hours. After the dropwise addition was completed, the reaction was allowed to proceed at the same temperature for two hours. After the completion of the reaction, the reaction solution was allowed to cool to room temperature and was filtered to remove insolubles (40.5 g). The filtrate was subjected to vacuum distillation to remove the solvent by evaporation to obtain 84.1 g of a.

yellow cloudy liquid product (yield: 67%).

NMR analysis showed that the average number of moles of ES added per mole of (d6) was 1.8 and that the imidazoline content of the product obtained was 74% by weight. s * Reference Examples S and T describe the preparation of compounds of formula: Copra chain N- (CH2CH2S) mH Copra chain obtained by adding m moles of ES to an amine

secondary (a) of formula R5R "6H with R5 = R" 6 = coconut chain.

Reference Example S: mean value of m = 1.7 31.8 g of an off-white cloudy liquid (yield: 84%) was obtained by following the procedure of Reference Example A, while using 30, 0 g (65 mmol) of an ES adduct (average number of moles of ES added = 0.75) of an aliphatic secondary amine derived from coconut oil, obtained in substantially the same manner as in Reference Example A and 7.8 g (130 mmol) of ES as reagents and 18.9 g of dioxane and 18.9 g of DMF as solvents. Reference Example T: mean value of m = 1 This product was obtained by operating as in

Example S using less I / O.

EXAMPLE 1

The carbonic corrosion inhibiting efficiencies of compounds A to T were evaluated by measuring the instantaneous corrosion rate of a carbon steel specimen by the Tafel straight method "Structural effect of quaternary ammonium group on inhibition on steel ", D. Bernard, M. Haim and TE Pou.30 Proceeding of the 6th European Symposium on Corrosion

Inhibitors (6SEIC) Ann. Univ. Ferrara, N.S., Sez. V, Suppl.

N.8, P. 1497, 1985)).

The operation is carried out in a 600 ml Pyrex cell comprising, in addition to an inlet and an outlet for the gases, three electrodes secured to the cell by lapping, namely: - a carbon steel working electrode whose contact surface with the corrosive solution is 1 cm2; - a saturated calomel reference electrode; and - a platinum counter-electrode having a very large

contact surface with the solution.

In the cell, 500 ml of the corrosive solution are placed.

The corrosive medium consists of a 50 g / l solution of NaCl plus 0.25 g / l of acetic acid. The counter electrode and the reference electrode are then introduced. The solution is deaerated by bubbling nitrogen through for 1 hour and the solution is saturated by bubbling for an additional 1 hour with either CO2 or H2S, depending on the type of corrosion to be investigated. We worked at the

ambient temperature.

Compounds A to T were used in the solubilized state or dispersed in isopropyl alcohol before

to be added in the corrosive environment.

For each test, a solution or dispersion of the test compound is introduced in order to have a given concentration of the latter in the corrosive medium. We dive

then the measuring electrode in said corrosive medium.

The corrosion potential is inspected. When this is stable, the experiment is started according to the following parameters: starting potential = -1000 millivolts compared to the potential of the reference electrode final potential = 100 millivolts compared to the corrosion potential scanning speed

of potential = 1 millivolt per second.

The corrosion current (icorr) is determined by intersection of the anodic and cathodic Tafel lines (see bibliographical reference cited above). The percentage of protection (% P), which expresses the corrosion inhibiting efficiency of a compound, is given by:% P = (i 0corr icorr / i0corr) x 100 o - i0corr = corrosion current without corr inhibitor - icorr = corrosion current in the presence of a dose of inhibitor The percentages of protection (% P) obtained with the various compounds at concentrations varying from 1 to ppm are given in Table 2. Examination of the results shows that the compounds A, E and I are the most efficient.

Table 2

Concentration of% P compound (ppm) _ _ Compound 1 2 5 10 20 50 100 200

A 69 92 97 98 97 98 98 98

B 14 36 76 95 97 98 98 98

C 04 10 07 29 66 86 90 89

D 00 16 19 36 57 59 68 77

E 39 66 95 95 96 97 97 99

F 23 23 64 83 91 97 97 98

G 28 13 31 53 81 86 96 96

H 06 46 65 56 73 94 99 98

I 26 33 93 96 97 97 97 97

J 21 40 61 83 96 96 96 97

K 03 03 00 16 32 45 57 63

L 00 00 05 15 35 55 70 80

M 00 26 68 81 92 94 96 97

N 36 58 78 83 89 95 97 97

O 53 63 81 85 89 93 96 96

P 05 45 67 80 90 94 96 97

Q 47 63 78 83 88 93 94 94

R 47 66 76 81 89 91 93 95

S 00 07 10 24 35 57 71 81

T 00Q 1913 1 9 1333 56 75 92

EXAMPLE 2

The procedure is as in Example 1, replacing C02

by H2S.

The percentages of protection (% P) obtained with the various compounds at concentrations varying from 1 to 200 ppm are given in Table 2. Examination of the results shows that compounds A, H and I are the most effective.

Table 3

Concentration of% P compound (ppm) __ Compound (ppm) 1 2 5 10 20 50 100 200

A 91 97 97 97 97 97 97 96

B 63 75 89 90 91 93 95 96

C 14 17 56 70 81 85 91 96

D 07 08 23 30 53 88 96 98

E 32 82 88 88 88 92 92 95

F 47 58 76 90 93 93 90 97

G 42 41 71 88 90 86

H 20 90 96 96 98 98 98 98

I 77 82 90 91 91 93 95 96

J 69 82 85 90 94 94 97 99

K 54 72 85 85 85 83 89 89

L 38 38 70 85 84 93 94 97

M 54 64 65 71 84 92 97 97

N 54 58 68 80 80 96 98 99

O 44 45 55 66 81 93 98 98

P 51 52 71 80 89 91 96 98

Q 00 14 28 37 57 82 90 94

R 14 20 48 74 80 81 96 96

EXAMPLE 3 Preparation of a composition for protecting carbon steels A composition formulated as follows was prepared: Parts by weight Compound I ..................... 20 N- cocoaminepropionic acid (surfactant) ................. 20 Polyoxyethylenated cocoamine (11 EO units) (co-surfactant) ............. .20 Butyl glycol .................. 40 This composition, soluble in oil and dispersible in water, can be injected continuously into corrosive fluids, at 'Using a metering pump, at a rate of 10 to 20 ppm of formulation relative to the total volume of fluid. It can also be used to form a film

protective at a dose of 100 to 1000 ppm for 2 hours.

This film can then be maintained with a very

low (of the order of 5 ppm).

For a treatment by forced injection under pressure, the dose of composition to be injected can range from 2 to 20% relative to the fluid injected into the well in the form of

cap.

Claims (16)

1 - Use of a mono- or polythiol chosen from those of formula (Ia): (CR1R2-CR3R4-S) m-H _ / R5-N (Ia) \ R6 in which: - R1, R2, R3 and R4 each independently represent a hydrogen atom, a C1-C10 alkyl group or an aromatic residue, the residues R1 and R3 (or R2 and R4 ) which can be linked together to form a hydrocarbon ring with the two carbon atoms which carry them; - R5 represents an alkyl or alkenyl group, linear or branched, C8-C30; and - R6 represents a linear or branched alkyl group, C1-C30, or an alkenyl group, linear or branched, C2-C30, or a group - (CR1R2-CR3R4-S) n-H; - m and n, identical or different, each represent an integer ranging from 1 to 10, the total number m + n of -CR1R2-CR3R4-S- sequences, identical or different, possibly ranging up to 20; and those of formula (Ib): R'5-A- (CH2CH2N) x- (CRlR2- CR3R4-S) qH (Ib) (CR1R2-CR3R4_S) rH in which: - R1, R2, R3 and R4 are such that defined above; - R'5 represents an alkyl or alkenyl residue, linear or branched, C7-C29; A represents a group (II): -C-N- (CH2CH2N) y- (CR1CR2-CR3R4-S) o-H (II) i (CR R2-CR3R4 -S) p-H linked to R'5 by -CO-; or a group (III): N I linked to R'5 by carbon; rx and y, identical or different, each represent 0 or an integer from 1 to 10, with the proviso that 1 <x + y <10; - q, r, o and p each represent an average number of sequences -CR1R2-CR3R4-S-, said average number may be zero and said sequences may be identical or different, the "r" may be different if x is greater to 1 and the "p" may be different if y is greater than 1, and "q + E r + o + E p" in the case where A is a group (II) or "q + E r" in the case o A is a group (III) being greater than 0 and being able to range up to 30; or an addition product of at least one compound of formula (IV): R1 R2 R3 R4 \ 1 I / c -c (IV) \ / S in which R1, R2, R3, R4 are as defined above, on at least one compound having at least one -NH2 or NH group, chosen from NH, chosen from: (a) aliphatic amines of formula (V) : R5 - N - H (V) R "6 in which: - R5 is as defined above; and - R" 6 represents a hydrogen atom or an alkyl group, linear or branched, C1-C30, or an alkenyl group, linear or branched, in C2-C30; (b) amidoamines of formula (VI): (CH2CH2NH) X-H R7-C-N (VI) Il \ O (CH2CH2NH) y-H in which: - R7 has the same meaning as R'5; - x and y are as defined above; and (c) imidazolines of formula (VII): 2O R R q N \ D N (VII) \ (CH2CH2NH> zH in which: - R8 has the same meaning as R'5; and - z is 0 or is an integer from 1 to 10; as an inhibitor of carbonic and / or hydrogen sulfide corrosion of carbon steels in petroleum industries. 2 - Use according to claim 1, characterized in that, in formula (Ia), the total m + n does not exceed 10. 3 - Use according to claim 1, characterized in that, in formula (Ib) "q + E r + o + E p" in the case o A is a group (II) or "q + E r" in the case where A is a group (III) is between 0.5 and 10. 4 - Use according to one of claims 1 to 3, characterized in that R1, R2, R3 and R4 each independently represent a hydrogen atom, a C1-C8 alkyl group or a phenyl group, R1 and R3 (or R2 and R4) which can be linked together to form a alkylene linkage. - Use according to one of claims 1, 2 and 4, characterized in that, in formula (Ia), R5 represents the residue of a primary complex fatty amine, such as a coconut chain or an oleic chain, R6 then representing a group - (CR1R2-CR3R4 -S) nH, the resulting dithiol then being in the form of a mixture, or that R5 and R6 simultaneously represent residues of a secondary complex fatty amine, monothiol resulting in the form of a mixture. 6 - Use according to one of claims 1 to 4, characterized in that, in formula (Ib), R'5 represents the residue of a complex fatty acid amide, the resulting mono- or polythiol then appearing under the form of a mixture. 7 - Use according to claim 1, characterized in that the adduct is that of at least one compound of formula (IV) on a mixture of compound (VI) and of compound (VII) consisting of a product of the condensation reaction by dehydration of a fatty acid with a polyamine with the formation of amidoamine and partial cyclization of the latter to imidazoline. 8 - Use according to claim 1, characterized in that the compound of formula (IV) is chosen from ethylene sulfide, propylene sulfide, 1,2-dimethyl thiirane, 2,2-dimethyl thiirane, n-octyl thiirane, cyclohexene sulfide, styrene and 1,2-diphenyl thiirane. 9 - Use according to claim 1, characterized in that the amines of formula (V) are chosen from decyl amine, undecyl amine, lauryl amine, myristyl amine, cetyl amine, stearyl amine, amines primary amines derived from a fatty acid obtained from coconut oil, primary amines derived from oleic acid, primary amines derived from a fatty acid obtained from soybean oil, didecyl amine, diundecyl amine , dilauryl amine, dimyristyl amine, diketyl amine, distearyl amine, secondary amines derived from a fatty acid obtained from coconut oil, secondary amines derived from oleic acid, and secondary amines derived from 'a fatty acid obtained from soybean oil. - Use according to Claim 1, characterized in that the amidoamines of formula (VI) are chosen from: - lauric acid monoamide with ethylene diamine; - lauric acid amide with diethylene triamine; - lauric acid amide with triethylene tetramine; - lauric acid amide with tetraethylene pentamine; and analogous amides with stearic acid, oleic acid, fatty acid derived from coconut oil and fatty acid derived from soybean oil. 11 - Use according to claim 1, characterized in that the imidazolines of formula (VII) are chosen from: * 2-undecyl imidazoline; * 1- (2-aminoethyl) -2-undecyl imidazoline; * 1- [N- (2-aminoethyl) -2-aminoethyl] -2-undecyl imidazoline; * 2-heptadecyl imidazoline; 1- (2-aminoethyl) -2-heptadecyl imidazoline; * 1- [N- (2-aminoethyl) -2-aminoethyl] -2-heptadecyl imidazoline; imidazolines obtained by dehydration and cyclization of: lauric acid amide with tetraethylene pentamine; * stearic acid amide with tetraethylene pentamine; * oleic acid monoamide with ethylene diamine; * the amide of oleic acid with diethylene triamine; * the amide of oleic acid with triethylene tetramine; the amide of oleic acid with tetraethylene pentamine; * fatty acid amide derived from coconut oil with triethylene tetramine; * fatty acid amide derived from coconut oil with tetraethylene pentamine; * fatty acid monoamide derived from soybean oil with ethylene diamine; * fatty acid amide derived from soybean oil with diethylene triamine; * fatty acid amide derived from soybean oil with triethylene tetramine; * fatty acid amide derived from soybean oil with the tetraethylene pentamine. 12 - Use according to claim 1, characterized in that, in the adduct, the compound of formula (IV) has been added in an amount of 1 to 20 moles on average per 1 mole of (a); and from 0.5 to 30 moles for 1 mole of (b) or (c). 13 - Use according to claim 1, characterized in that the adduct is the adduct of 2 moles of ethylene sulfide on a mole of lauryl amine. 14 - Use according to claim 1, characterized in that the adduct is the adduct of approximately 2 to 3 moles of ethylene sulfide on 2-aminoethyl dodecanamide. 15 - Composition for protecting carbon steels against carbonic and / or hydrogen sulfide corrosion in the petroleum industries, characterized in that it consists of or that it comprises a solution in at least one organic solvent of at least one mono - or polythiol and / or at least one addition product as defined in one of claims 1 to 14, when it is intended to be used in a corrosive medium consisting of an oily phase, said composition further comprising at least one surfactant when it is intended for use in a corrosive medium consisting of an aqueous phase or with an aqueous phase and an oily phase. 16 - Composition according to claim 15, intended for use in a corrosive medium consisting of an oily phase, characterized in that it consists of or that it comprises, per 100 parts by weight: (A) 20 to 50 parts by weight of at least one mono- or polythiol and / or at least one adduct such as defined in one of claims 1 to 14; and (B) 50 to 80 parts by weight of at least one organic solvent chosen in particular from alcohols such as those mentioned above, mono- or di-ethers of glycols such as di- or tri-ethyleneglycol and propylene glycol, petroleum fractions like white spirit, fuels, kerosene and naphtha. 17 - Composition according to claim 14, intended for use in a corrosive medium consisting of an aqueous phase or of an aqueous phase and an oily phase, characterized in that it consists of or that it comprises, per 100 parts of weight of (A) + (B) + (C): (A) 20 to 40 parts by weight of at least one mono- or polythiol and / or at least one adduct such as defined in one of claims 1 to 14; (B) 40 to 20 parts by weight of at least one organic solvent chosen in particular from glycol ethers, in particular butyl glycol; and (C) 20 to 40 parts by weight of at least one surfactant active, chosen in particular from chain amino acids fatty and oxyethylenated derivatives of fatty amines. 18 - Process for protecting carbon steels against carbonic and / or hydrogen sulphide corrosion in the petroleum industries, characterized in that said steels are treated with a composition as defined in one of claims 15 to 17, at a temperature between Room temperature. and 180'C, preferably about 'C. 19 - Process according to claim 18, characterized in that the composition is injected continuously into the corrosive fluids, using a metering pump, at a rate of 10 to 20 ppm of formulation relative to to the total volume of fluid. - Method according to claim 18, characterized in that the composition is used to form a protective film at a dose of 100 to 1000 ppm for 2 hours, this film then being able to be maintained with a very low dose, of the order of 5 ppm. 21 - Process according to claim 18, characterized in that one carries out a treatment by forced injection under pressure, according to which the dose of composition to be injected can range from 2 to 20% relative to the fluid injected into the well in the form of a plug.