Basic salts of sulphur compounds as metal corrosion inhibitors

Abstract

The present invention relates to the use of basic salts of sulphur compounds, in particular amino acids having a thiol function, such as cysteine or homocysteine, as metal corrosion inhibitors, in particular in the oil, gas and / or mining industry. The present invention also relates to anti-corrosion formulations comprising basic salts of sulphur compounds, as well as to the uses thereof in the oil, gas and / or mining industry.

Description

[0001] Description

[0002] Title of the invention: BASIC SALTS OF SULFUR COMPOUNDS AS

[0003] AS METAL CORROSION INHIBITORS

[0004] Field of invention

[0005] The present invention relates to the use of basic salts of sulfur compounds, in particular of thiol-functional amino acids, as metal corrosion inhibitors, in particular in the field of the oil, gas and / or mining industry. It also relates to anti-corrosion formulations comprising basic salts of sulfur compounds, as well as their use in the field of the oil, gas and / or mining industry. The present invention relates to certain basic salts of sulfur compounds as such.

[0006] Underground extraction of minerals or fossil compounds, such as oil and gas, typically involves the upwelling of water from the deposits. This mineral-laden water is the source of numerous problems that disrupt extraction facilities and production lines.

[0007] Indeed, it is very often responsible for metallic corrosion of installations such as platforms, pipes, conduits, tubes, valves and other metallic elements. It contains in particular dissolved carbon dioxide (CO2), and possibly dissolved hydrogen sulfide (H2S). The presence of CO2 and possibly H2S makes the aqueous environment acidic and therefore corrosive to metals (metallic corrosion is often defined as the degradation of a metal by chemical reaction with its environment).

[0008] Corrosion in oil, gas, or mineral extraction and / or production facilities is a real problem that requires extensive maintenance and repair operations. In this type of industry, the costs associated with corrosion are very high, making it essential to treat, limit, or prevent this phenomenon.

[0009] Thus, the use of formulations to treat, limit or prevent corrosion of installations in this field is widely known. Such corrosion-inhibiting formulations most often comprise one or more sulfur derivatives, in particular chosen from mercapto-alcohols and mercapto-acids. Thus, applications WO 1998 / 41673 and WO 2013 / 038100 describe corrosion-inhibiting formulations where the addition of sulfur derivatives, for example thioglycolic acid, makes it possible to increase the performance of said formulations. Application WO 2001 / 012878 describes the use of mercapto-alcohols for the same purpose of improving the performance of corrosion-inhibiting formulations. Application WO 2015 / 044576 also describes the use of 1,8-dimercapto-3,6-dioxaoctane (DMDO) as an anti-corrosion additive.

[0010] However, many of these compounds are toxic and sometimes non-biodegradable. Therefore, less toxic and more environmentally friendly compounds are sought, which can be used as anti-corrosion agents in the conditions of extraction and / or production of hydrocarbons and / or ores. Thus, application WO 00 / 75399 describes the use of sulfur compounds, such as cysteine, as corrosion inhibitors in the petroleum sector. These sulfur compounds are described in free form or in the form of acid salts.

[0011] Given the importance of the corrosion phenomenon, there is still a need for improved treatment of corrosion in industrial installations, particularly in the field of extraction and / or production of hydrocarbons and / or minerals.

[0012] An objective of the present invention is to provide an effective and environmentally friendly anti-corrosion agent, in particular non-toxic and biodegradable.

[0013] An objective of the present invention is to provide an anti-corrosion agent having improved anti-corrosion properties.

[0014] Another objective of the present invention is to provide improved anti-corrosion formulations adapted to the conditions of the oil, gas or mining industry.

[0015] Description of the invention

[0016] The present invention meets all or part of the above objectives. Thus, the present inventors have discovered that the basic salts of sulfur compounds such as according to the invention have, surprisingly, improved anti-corrosion properties and storage stability compared to the free form and / or the acidic salified form of these compounds.

[0017] Indeed, the basic salts according to the invention reduce corrosion, and in particular the corrosion rate, compared to their counterparts in free or acidic salified form. They are also more effective than certain commercial anti-corrosion agents.

[0018] In addition, the basic salts formulated according to the invention are more stable during storage than their counterparts in free or acidic salified form. For example, they are stable for at least 7 days. In particular, they release almost no H2S during storage. Their very low H2S release represents a great advantage for operators because H2S is a toxic gas, often released by sulfur compounds used as corrosion inhibitors.

[0019] These basic salts are compatible and particularly effective in combination with other known corrosion inhibitors, and more particularly nitrogen compounds commonly used in the oil, gas and / or mining industry. They thus make it possible to obtain more effective and stable anti-corrosion formulations, particularly under conditions of extraction and / or production of fossil compounds and / or ores.

[0020] Thus, the present invention relates to the use of a basic salt of a sulfur compound, said sulfur compound being of the following general formula (I):

[0021] ZS-(CH2)n-CH(NRiR2)-X-R3(I) in which:

[0022] Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s);

[0023] X is selected from -C(=O)-, -CH2- or -CN;

[0024] R3 is:

[0025] (i) is zero when X represents -CN,

[0026] (ii) either a hydrogen atom,

[0027] (iii) either -ORa, R a being a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s);

[0028] (iv) either -NRbRc, Rb and R c , identical or different, being chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s); n is equal to 1 or 2; and

[0029] Z is a hydrogen atom, a R3-X-CH(NRiR2)-(CH2) group n -S- or a group R3-X-CH(NRiR2)-(CH2) n- , with X, n, Ri, R2 and R3 as defined below; as a metal corrosion inhibitor, preferably in the oil, gas and / or mining industry. In particular, the present invention relates to the use of a basic salt of a sulfur compound such as according to the invention, as an additive in a corrosion inhibiting formulation, preferably such as according to the invention, in order to improve both its anticorrosion effectiveness and its storage stability.

[0030] The present invention also relates to an anti-corrosion formulation comprising: a) a basic salt of a sulfur compound as according to the invention; b) a nitrogen compound chosen from amines, ethoxylated amines, amino acids and imidazolines, as well as their derivatives and their salts; and c) optionally a solvent.

[0031] The present invention relates to the use of said anti-corrosion formulation, for the treatment of corrosion of a corrodible metal in contact with a corrosive medium, preferably in the oil, gas and / or mining industry.

[0032] The present invention also relates to a method for treating the corrosion of a corrodible metal in contact with a corrosive medium comprising a step of bringing said metal into contact with a basic salt of a sulfur compound such as according to the invention, or between said metal and a formulation such as according to the invention.

[0033] The present invention also relates to basic salts as such and as defined below.

[0034] By "corrosion inhibitor" or "anti-corrosion" or "corrosion treatment" is meant in particular the reduction and / or inhibition and / or prevention of corrosion, in particular the reduction of the corrosion rate.

[0035] The basic salts and the formulation as according to the invention are thus useful in a corrosive medium. By "corrosive medium" is meant in particular an acidic medium (i.e. with a pH strictly lower than 7) and / or a medium comprising carbon dioxide (CO2) and optionally hydrogen sulfide (H2S). In particular, said medium is an aqueous medium comprising carbon dioxide (CO2) and optionally hydrogen sulfide (H2S). The CO2 and optionally the H2S are in particular dissolved in the aqueous medium. Said aqueous medium may also comprise mineral salts and in particular up to approximately 300 g / L of mineral salts. For example, the aqueous medium may be brine or seawater.

[0036] The pressure in said medium may be between 0 and 138 MPa, and more particularly between atmospheric pressure and 70 MPa.

[0037] The temperature of said medium may be between 0°C and 260°C, and more particularly between 15°C and 205°C.

[0038] The metal (i.e., the corrodible metal) is chosen in particular from iron and ferrous metals. By "ferrous metals" is meant alloys comprising iron. Among said alloys, mention may be made in particular of steels of all types (alloyed, non-alloyed and stainless). Particularly preferred are non-alloyed or low-alloy steels. Examples include API 5L grade X65 or UNS G10180. Said metal corresponds in particular to any type of metal equipment used for the extraction, production, transport and / or processing (e.g., refineries) of oil, gas and / or ore.

[0039] The anti-corrosion effect of basic salts and formulations such as according to the invention can for example be evaluated by means known to those skilled in the art and in particular using the ASTM G5-14 and G35-98 standards (American Society for Testing Materials). Sulfur compounds of general formula (I):

[0040] In particular, the sulfur compounds according to the invention are of the following general formula (I):

[0041] ZS-(CH2)n-CH(NRiR2)-X-R3(I) in which:

[0042] Z is a hydrogen atom or a R3-X-CH(NRiR2)-(CH2) group n -S- ;

[0043] Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s);

[0044] X is selected from -C(=O)-, -CH2- or -CN;

[0045] R3 is:

[0046] (i) is zero when X represents -CN,

[0047] (ii) either a hydrogen atom,

[0048] (iii) either - OR a , R a being a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s);

[0049] (iv) either -NRbRc, Rb and R c , identical or different, being chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s); and n is equal to 1 or 2.

[0050] When Z is a group R3-X-CH(NRiR2)-(CH2) n -S- or a group R3-X- CH(NRiR2)-(CH2) n- , it is understood that n and the different radicals X, Ri, R2 and R3 are respectively identical in formula (I): we obtain symmetrical disulfides or sulfides (cf. for example cystine and homocystine).

[0051] Heteroatoms include oxygen, nitrogen and sulfur.

[0052] In particular, Ri and R2 are chosen from a hydrogen atom.

[0053] In particular, n is equal to 2 and / or Z is a hydrogen atom.

[0054] Particularly preferred are compounds of general formula (I), for which X is C(O) and R3 is OR a , with R a as defined above.

[0055] As preferred compounds, mention may be made of: cysteine, of formula HS-CH2-CH(NH2)-COOH (CAS 52-90-4 for form L and CAS 921-01-7 for form D);

[0056] - cystine, of formula HOOC-CH(NH2)-CH2-SS-CH2-CH(NH2)-COOH (CAS 56-89-3 for the L form and CAS 349-46-2 for the D form); homocysteine, of formula HS-(CH2)2-CH(NH2)-COOH (CAS 6027-13-0 for the L form and CAS 6027-14-1 for the D form); and

[0057] - homocystine, of formula HOOC-CH(NH2)-(CH2)2-SS-(CH2)2-CH(NH2)-COOH (CAS 626-72-2 for form L and CAS 870-93-9 for form D).

[0058] Sulfur compounds of general formula (I) are generally in solid form and can be put into solution, especially aqueous solution. Preferably, they are in L-enantiomeric form. They can be commercially available (marketed for example by Wacker or Showa Denko).

[0059] Basic Se / s of sulfur compounds of general formula (I):

[0060] The present invention relates to any basic salt obtainable from a sulfur compound of general formula (I) as defined above. In particular, said salt is a metal salt or a quaternary ammonium salt. Preferably, said salt is selected from alkali metal salts, alkaline earth metal salts and quaternary ammonium salts.

[0061] A person skilled in the art is able to determine whether a salt is basic using conventional methods. In particular, said salt can be dissolved in water and then the pH of the resulting solution can be measured, for example using a pH meter. Thus, the term "basic salt" is understood to mean any salt whose dissolution in water forms a solution whose pH is strictly greater than 7, preferably between 8 and 14 and even more preferably between 9 and 14.

[0062] To obtain a basic salt from the free form, the free form can be solubilized in water, then the desired base (e.g. NaOH or KOH) added so as to obtain a pH strictly greater than 7. For example, in the case of homocysteine, the following preparation steps can be followed: e1) solubilization of the free form homocysteine ​​(solid) in water, preferably at a temperature between 20°C and 90°C and at atmospheric pressure; e2) addition of the base: addition of 1 molar equivalent (vs. homocysteine) of base to obtain the mono salt; or addition of 2 molar equivalents (vs. homocysteine) of base to obtain the di-salt; the pH of the solution obtained being strictly greater than 7.

[0063] Preferably, said basic salt according to the invention is of the following general formula (II): [ a Z'-(CH2) n -CH(NRiR2)-COO b ] m [ q Li ] p(II) in which: a is a charge equal to 0 or -1; b is a charge equal to -1; q is a charge between +1 and +5; preferably q is equal to +1 or +2; m is an integer, preferably between 1 and 5, more preferably equal to 1 or 2; p is an integer, preferably between 1 and 5, more preferably equal to 1 or 2; it being understood that the total number of negative charges [(a+b) xm] is equal to the total number of positive charges [qxp]; and

[0064] Z' is chosen from the group consisting of:

[0065] HS-, S-, HOOC-CH(NRiR2)-(CH2)nSS-, OOC-CH(NRiR2)-(CH2) n -SS-, HOOC-CH(NRIR2)- (CH2) n -S- and OOC-CH(NRiR2)-(CH2) n -S- ;

[0066] Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s); n is equal to 1 or 2; and - Li is chosen from the group consisting of metals and quaternary ammoniums.

[0067] More preferably, said basic salt according to the invention is of the following general formula (II):

[0068] [ a Z'-(CH2) n -CH(NRiR2)-COO b ] m fold ] p(II) in which: a is a charge equal to 0 or -1; b is a charge equal to -1; q is a charge between +1 and +5; preferably q is equal to +1 or +2; m is an integer, preferably between 1 and 5, more preferably equal to 1 or 2; p is an integer, preferably between 1 and 5, more preferably equal to 1 or 2; it being understood that the total number of negative charges [(a+b) xm] is equal to the total number of positive charges [qxp]; and - Z' is chosen from the group consisting of:

[0069] HS-, S-, HOOC-CH(NRiR2)-(CH2) n -SS- and OOC-CH(NRiR2)-(CH2) n -SS- ;

[0070] Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s); - n is equal to 1 or 2; and

[0071] Li is selected from the group consisting of metals and quaternary ammoniums. It is understood that when Z' is selected from HS-, HOOC-CH(NRiR2)-(CH2)nSS- or HOOC-CH(NRiR2)-(CH2)nS- then a is equal to 0 and when Z' is selected from S-, OOC- CH(NRiR2)-(CH2)nSS- or OOC-CH(NRiR2)-(CH2)nS-, then a is equal to -1.

[0072] When Z' is a HOOC-CH(NRiR2)-(CH2)nSS- group, _ OOC-CH(NRi R2)- (CH2)nSS-, HOOC-CH(NRiR2)-(CH2)nS- or C-CH(NRiR2)-(CH2)nS-, it is understood that n and the radicals Ri and R2 are respectively identical in formula (II): basic salts of symmetrical disulfides or sulfides are obtained.

[0073] Heteroatoms include oxygen, nitrogen and sulfur.

[0074] Preferably, Z' is HS- or S-.

[0075] In particular, n is equal to 2.

[0076] In particular, Ri and R2 are hydrogen atoms.

[0077] L1 is chosen from metals and quaternary ammoniums.

[0078] The term "metals" means, in particular, the metals in columns 1 to 5 (formerly IA to VA) of the periodic table of elements, as well as aluminum, tin and lead. In particular, L1 is chosen from the group consisting of: alkali metals, alkaline earth metals, scandium, titanium, zirconium, vanadium, niobium, aluminum, tin and lead.

[0079] By "alkali metals" we mean the metals corresponding to group 1 (1 ère column) of the periodic table of elements. Particular mention may be made of lithium, sodium and potassium. By "alkaline earth metals" we mean the metals corresponding to group 2 (2 ème column) of the periodic table of elements. Particular mention may be made of magnesium, calcium, strontium and barium.

[0080] By "quaternary ammoniums" is meant in particular ammoniums of the following general formula (III):

[0081] + N(R5R6R7R8) (III) in which the radicals R5, Re, R7 and Rs, which are identical or different, are chosen independently of one another from the group consisting of: the hydrogen atom, a (Ci-Cw)alkyl, a (C6-C )aryl, a (Ci-Cw)alkoxy, a polyalkylalkoxy, a (Ci-Cw)alcohol and a polyol; preferably from the hydrogen atom, a (Ci-Cw)alkyl and a (Ci-Cio)alcohol. Mention may be made in particular of the ammonium of monoethanolamine ( + NH3(CH2CH2OH)), diethanolamine, triethanolamine and methyldiethanolamine.

[0082] Preferably, L1 is selected from alkali metals, alkaline earth metals and quaternary ammoniums, more preferably from alkali metals and alkaline earth metals. More preferably, L1 is selected from sodium, potassium, magnesium, calcium, monoethanolamine ammonium, diethanolamine ammonium, triethanolamine ammonium and methyldiethanolamine ammonium. More preferably, Li is selected from sodium and potassium.

[0083] In particular, the basic salt according to the invention is of one of the following general formulas:

[0084] HS-(CH2)n-CH(NRiR2)-COO- + Li (lh);

[0085] [HS-(CH2) n -CH(NRiR2)-COO-]2 2+ Li (ll2);

[0086] -S-(CH2) n -CH(NRiR2)-COO- [ + LI]2(ll3);

[0087] -S-(CH2) n -CH(NRiR2)-COO- 2+ Li (ll4);

[0088] HOOC-CH(NRiR2)-(CH2)nSS-(CH2) n -CH(NRiR2)-COO- + Li (ll5);

[0089] [HOOC-CH(NRiR2)-(CH2)nSS-(CH2) n -CH(NRiR2)-COO-]2 2+ Li (ll6);

[0090] -OOC-CH(NRiR2)-(CH2)nSS-(CH2) n -CH(NRiR2)-COO- [ + LI]2(ll7); or

[0091] -OOC-CH(NRiR2)-(CH2)nSS-(CH2) n -CH(NRiR2)-COO- 2+ Li (II8). in which n, Ri, R2 and Li are as defined above. Formulas (IIh) and (II3) above are particularly preferred according to the invention.

[0092] The salts of formulae (II) and (1h) to (118) as defined above are basic. In particular, said basic salt is chosen from the monoalkali, dialkali, alkaline-earth or quaternary ammonium salts of homocysteine ​​or homocystine, preferably from the dialkali or alkaline-earth salts of homocysteine ​​or homocystine. Said basic salt is in particular chosen from the group consisting of: monosodium homocysteine, disodium homocysteine; monosodium cysteine, disodium cysteine, disodium cystine, disodium homocystine; monopotassium homocysteine, dipotassium homocysteine; monopotassium cysteine, dipotassium cysteine, dipotassium cystine and dipotassium homocystine. Disodium homocysteine ​​and disodium homocystine are particularly preferred.

[0093] Some of the salts described above are novel as such and therefore form part of the present invention. Thus, the present invention relates to the salts of general formula (II) as defined above, with Li being selected from lithium, potassium, rubidium, cesium, alkaline earths and quaternary ammoniums. Preferably, said salt is selected from homocysteine ​​potassium, homocysteine ​​dipotassium, homocystine dipotassium, quaternary ammoniums of homocysteine ​​and quaternary ammoniums of homocystine (in particular the ammoniums of monoethanolamine, diethanolamine, triethanolamine and methyldiethanolamine).

[0094] The sulfur compounds and their corresponding basic salts can exist in any enantiomeric form, of the L, D or racemic type. Particularly preferred is the L form, which is found in nature. The basic salts as according to the invention can be used alone (i.e. as the sole anti-corrosion agent) or in combination with one or more other anti-corrosion agents in an anti-corrosion formulation.

[0095] Anti-corrosion formulations

[0096] The present invention relates to an anti-corrosion formulation comprising a basic salt of a sulfur compound as defined above. Said basic salt may be comprised in an amount ranging from 0.5% to 30% by weight, preferably from 2% to 20% by weight, relative to the total weight of the anti-corrosion formulation.

[0097] Among the anti-corrosion agents which can be used in combination with the basic salt as according to the invention and commonly used in the field of the oil, gas and / or mining industry, mention may be made of nitrogen compounds.

[0098] Thus, preferably, said anti-corrosion formulation comprises (or consists of) a) a basic salt of a sulfur compound as defined above; b) a nitrogen compound chosen from amines, ethoxylated amines, amino acids, imidazolines, as well as their derivatives and their salts; and c) optionally a solvent.

[0099] Such a formulation may in particular comprise (or consist of): said basic salt a) in an amount ranging from 0.5% to 30% by weight, preferably from 2% to 20% by weight, inclusive, relative to the total weight of components a) + b) + c); said nitrogen compound b) in an amount ranging from 1% to 99.5% by weight, preferably from 5% to 50% by weight, more preferably from 10% to 35% by weight, inclusive, relative to the total weight of components a) + b) + c); and said solvent c) in an amount ranging from 0% to 90% by weight, preferably from 20% to 75% by weight, more preferably from 30% to 70% by weight, inclusive, relative to the total weight of components a) + b) + c).

[0100] Any type of nitrogen compound commonly used as an anti-corrosion agent in the oil, gas and / or mining industry may be used. Examples of such compounds include, but are not limited to: amines, ethoxylated amines, amino acids and imidazolines, as well as their derivatives and salts, preferably imidazolines. Such compounds are known to those skilled in the art.

[0101] In particular, we can cite:

[0102] - alkyl-imidazo-polyethylene-amines, for example as described in application WO 1998 / 041673, imidazoline-amine carboxylates for example as described in application WO 2010 / 031963, quaternary alkylimidazolines, alkoxylated alkylimidazolines;

[0103] - imidazolines substituted by at least one fatty chain (preferably comprising between 6 and 20 carbon atoms), alkoxylated imidazolines;

[0104] - fatty amines (preferably comprising between 6 and 20 carbon atoms), fatty amine derivatives (amino acids, amino alcohols, amido amines, ammoniums, quaternary ammoniums, pyridines and derivatives, such as, for example, pyridiniums, quinolines and derivatives, such as, for example, quinoliniums);

[0105] - ester-amines, ether-amines for example as described in application WO 2013 / 034846, or MOPA (methoxy-3-propylamine), EDIPA (N,N-di- / so-propylethylamine), diethylenetriamine, alkylamines for example as described in application WO 2013 / 038100, as well as oxy-alkylated amines (for example oxy-ethylated and / or oxy-propylated and / or oxy-butylated) such as for example Noramox®, and in particular Noramox® C11, marketed by the company CECA S. A, betaines and alkylbetaines, N-oxide derivatives of the aforementioned amines; and

[0106] - mixtures of two or more of the above compounds, such as those marketed by Arkema under the trade names Norust® 97 BX, Norust® 103, Norust® 575, Norust® 740, Norust® 900C, Prochinor® IC 32, Prochinor® IC 1950, and others.

[0107] Preferred are imidazolines substituted by at least one fatty chain (for example, having between 6 and 20 carbon atoms), optionally in admixture with an amine or an amine derivative, such as diethylenetriamine.

[0108] Said nitrogen compound may be included in the anti-corrosion formulation in an amount ranging from 1% to 99.5% by weight, preferably ranging from 5% to 50% by weight, more preferably ranging from 10% to 35% by weight, relative to the total weight of the anti-corrosion formulation. Solvent:

[0109] The corrosion inhibiting formulation according to the invention may comprise a solvent or a mixture of two or more solvents. In particular, the solvent(s) are chosen from water and water-soluble organic solvents, such as alcohols (preferably alkanols), ethers, glycols and mixtures thereof. Particularly preferred are mixtures of water with at least one water-soluble organic solvent. More particularly, the water-soluble solvents may be chosen from methanol, ethanol, glycol, monoethylene glycol (MEG), diethylene glycol (DEG), triethylene glycol (TEG), 2-butoxyethanol (or butyl glycol), and mixtures of two or more of them in any proportions.

[0110] Other possible compounds:

[0111] The anti-corrosion formulations according to the present invention may also comprise one or more other compounds carrying at least one sulfur atom and at least one, preferably at least two, carbon atom(s).

[0112] Among these compounds, we can cite in particular: alcohols and acids containing at least one sulfur atom, and more particularly mercaptoethanol, mercaptopropanol, thioglycolic acid, mercaptoacetic acid, mercaptopropionic acid, dimercapto-1,8-dioxa-3,6-octane (called DMDO and marketed by Arkema), to name only the most readily available of them.

[0113] In the case of addition of another sulfur compound as mentioned above, the corrosion inhibiting formulation may also comprise one or more hLS scavengers, and advantageously those chosen from regenerative scavengers (“regenerative H2S scavengers” in English) and non-regenerative scavengers (“non-regenerative H2S scavengers” in English). Indeed, unlike the basic salts according to the invention, the other sulfur compounds may not be stable during storage and release hhS.

[0114] At least one non-regenerative sensor can be chosen, for example chosen from triazines and their derivatives, oxidants such as chlorine dioxide, hypochlorites (for example bleach), hydrogen peroxide, transition metal salts (such as salts of iron, cobalt, nickel, chromium, copper, zinc, manganese, and others), or aldehydes, such as formaldehyde and glyoxal.

[0115] The amount of other sulfur compound(s) and / or H2S scavenger(s) in the corrosion inhibiting formulation of the present invention may vary greatly depending on the nature and amount of the other components present in said formulation.

[0116] The formulations according to the present invention may further comprise one or more other additives, fillers, and the like, which are inert with respect to the effectiveness of the corrosion inhibiting activity and well known to those skilled in the art in the field of extraction and / or production of hydrocarbons and other minerals. Among these additives, mention may be made, in a non-limiting manner, of stabilizers, preservatives, anti-UV agents, flame retardants, colorants and the like.

[0117] The added quantity of this(these) additive(s) can vary greatly, depending on the desired effect, the regulations in force, the required conditions of solubility, compatibility, and others. As a general rule, this quantity varies from a few ppm by weight to a few percent by weight, relative to the total weight of the formulation of the invention.

[0118] In yet another aspect, the formulations of the present invention may be used alone or in combination with one or more other inhibitors, intended to inhibit other types of corrosion encountered in the field of extraction and / or production of hydrocarbons and / or minerals. For example, inhibitors intended to treat corrosion encountered during water reinjection, hydraulic fracturing, acidizing, drilling such as for example acetylenic alcohols; or intended to inhibit the formation of hydrates or their agglomeration; or to avoid or prevent the appearance of deposits; or to avoid or prevent the development of bacteria, or to promote flow, and others may be used.

[0119] The amount of this or these other inhibitor(s) added can vary greatly, depending on the desired effect, current regulations, solubility and compatibility requirements, and others.

[0120] According to one embodiment of the present invention, the corrosion inhibiting formulations contain at least one anti-mineral deposit composition, said anti-deposit composition comprising, for example and without limitation, at least one compound chosen from acidic or neutralized aminophosphonates, poly(acrylic acids), poly(alkyl acrylates), copolymers based on phosphinocarboxylic acids, tannins, lignosulfonates, polyacrylamides, naphthalenesulfonates, and others, as for example described in application WO 2013 / 034846.

[0121] The anti-corrosion formulations according to the invention can be prepared by any known means, and in general by simple mixing of the various components in any order.

[0122] The present formulation may also be presented in the form of a kit, comprising: a composition comprising a nitrogen compound as defined above; and a composition comprising a basic salt of a sulfur compound as according to the invention.

[0123] Alternatively, the kit may comprise, instead of said basic salt, a sulfur compound of formula (I) as according to the invention and a base, so as to prepare said basic salt. Thanks to the present invention, it is now possible to have corrosion inhibiting formulations comprising a basic salt of a sulfur compound which are stable on storage. In particular, they do not develop foul odors and do not release H2S. In addition, the anti-corrosion performance of the corrosion inhibiting formulations according to the invention is improved, in comparison with the corresponding formulations commonly used and known to date to those skilled in the art. The corrosion rate is notably reduced.

[0124] Said basic salts or said formulations comprising them find a very advantageous use in all fields of the oil, gas and / or mining industry; and more specifically in any type of industry of drilling, completion, stimulation and production of minerals or fossil compounds, such as gas, oil, bitumen and others. More specifically, mention may be made of drilling techniques, fracturing by fluid injection, acidification of fossil compound reservoirs, injection of fluids into underground reservoirs containing fossil compounds, as well as techniques for their production and enhanced recovery.

[0125] These basic salts or formulations can be injected using any method well known to those skilled in the art, continuously, in batch or by squeeze, preferably continuously. Injection can be carried out into wells, oil pipelines, gas pipelines, extraction lines, production water injection lines, and generally into any aqueous, organic or hydro-organic fluid used in extraction fields and / or production or transport lines. For example, these salts or formulations can also be injected via the so-called "gas-lift" system, well known to those skilled in the art.

[0126] The injected quantity of basic salt(s) or corrosion inhibiting formulation(s) according to the invention can vary within large proportions, depending on the needs, nature and composition of the extracted products. An effective quantity for treating corrosion is generally determined. As a general rule, the injected quantity is between 1 ppm and 1000 ppm, preferably between 50 ppm and 800 ppm, where "ppm" represents parts by volume of basic salt or corrosion inhibiting formulation per one million parts by volume of aqueous, organic or hydro-organic fluid to be treated.

[0127] The following non-limiting examples illustrate and provide a better understanding of the invention, without limiting its scope. EXAMPLE 1: Preparation of the monosodium and disodium salts of homocysteine

[0128] The monosodium and disodium salts are prepared from the free form of L-homocysteine ​​(L-HCY) according to the protocol below.

[0129] The free form of L-Homocysteine ​​is solubilized at 100 g / L (10%w) in water.

[0130] The pH of the aqueous solution is measured using a Mettler Toledo T5 titrator equipped with a DG111-SC electrode, with solution homogeneity ensured by constant stirring. It is understood that the pH meter has been previously calibrated with buffer solutions 4.0, 7.0 and 10.0. pH of the 10%w free L-HCY solution = 5.3.

[0131] Addition of one equivalent of NaOH to obtain the monosodium L-HCY form. pH of the L-HCY-Na solution = 9.9

[0132] Add a second equivalent of NaOH to obtain the disodium L-HCY form. pH of the L-HCY-2Na solution = 12.0.

[0133] EXAMPLE 2: Comparative efficacy of a basic salt of homocysteine ​​vs. its free or acid form

[0134] L-Homocysteine, in free and salified form, has been tested alone as a metal corrosion inhibitor.

[0135] The basic salt used is the disodium salt of L-homocysteine, whose pH in aqueous solution is 12.

[0136] The acid salt used is L-homocysteine ​​hydrochloride, whose pH in aqueous solution is 3.5.

[0137] Anti-corrosion effectiveness is assessed by a bubble test in synthetic water, the composition of which is given in the table below. To prepare this synthetic water, the salts are dissolved in demineralized water.

[0138] [Table 1]

[0139] A non-alloyed steel metal coupon is immersed in the resulting aqueous solution, under continuous bubbling of CO2. The assembly is protected from air.

[0140] The conditions of the bubble test are as follows:

[0141] Solution: 700 mL synthetic water with 100 ppm anti-corrosion agent

[0142] Technique: LPR “Linear Polarization Resistance” Potentiostat GAM RY

[0143] Electrodes: API 5L Grade X65 unalloyed steel - Cylinder diameter 3.4 cm 2 Platinum counter electrode

[0144] Saturated calomel reference electrode

[0145] Reactor: Double-jacketed reactor with a capacity of 1 L (diameter 19 cm)

[0146] Temperature: 90°C

[0147] Gas: Saturation with CO2 (1 bar) Agitation: Magnetic stirring 400 RPM (turn / min)

[0148] [Table 2]

[0149] The results show that the basic salt of L-homocysteine ​​decreases the corrosion rate and has a higher effectiveness than the acid or free form of L-homocysteine.

[0150] Furthermore, the basic salt alone is much more effective against corrosion than compounds commercially used in anti-corrosion formulations in combination with fatty amines such as thioglycolic acid and sodium thiocyanate. EXAMPLE 3: Basic salt of homocysteine ​​in anti-corrosion formulation

[0151] Different anti-corrosion formulations were prepared from a commercial product.

[0152] The commercial product used is Arkema's Norust® 900C: it is an imidazoline Tall Oil (unsaturated C18) mixed with DETA (diethylenetriamine). This commercial formulation was tested as a corrosion inhibitor with or without L-Homocysteine ​​in salified form. Butyl glycol was used as a solvent.

[0153] The formulations prepared and tested are as follows (percentages are given relative to the total weight of the formulation): [Table 3]

[0154] Anti-corrosion effectiveness is assessed by a bubble test in synthetic water, the composition of which is given in the table below. To prepare this synthetic water, the salts are dissolved in demineralized water.

[0155] [Table 4]

[0156] The non-alloyed steel metal coupon is immersed in the resulting aqueous solution, under continuous bubbling of CO2. The assembly is protected from air.

[0157] The conditions of the bubble test are as follows:

[0158] Solution: Synthetic water 700 mL

[0159] Technique: LPR “Linear Polarization Resistance” Potentiostat GAM RY

[0160] Electrodes: API 5L Grade X65 unalloyed steel - Cylinder diameter 3.4 cm 2

[0161] Platinum counter electrode

[0162] Saturated calomel reference electrode

[0163] Reactor: Double-jacketed reactor with a capacity of 1 L (diameter 19 cm)

[0164] Temperature: 90°C

[0165] Gas: Saturation with CO2 (1 bar)

[0166] Agitation: Magnetic stirring 400 RPM

[0167] Dosage Formulas: 100 ppmv (relative to the volume of synthetic water) The initial corrected speed before adding the formulation is of the order of 3.70 mm / year for the

[0168] 2 formulations below (Cl 1 and Cl 2).

[0169] [Table 5]

[0170] The addition of homocysteine ​​in disodium form allows an anticorrosion efficiency of 98.1% to be achieved after 24 hours. The basic form of homocysteine ​​allows a corrosion rate of less than 0.1 mm / year to be achieved.

[0171] EXAMPLE 4: Storage stability

[0172] Experimental protocol:

[0173] The samples are prepared from an anti-corrosion formulation as according to the invention comprising (relative to the total weight of the formulation):

[0174] 10% by weight of the sulfur compound or its basic salt,

[0175] 30% by weight of Imidazoline Tall Oil / DETA (commercial product Norust® 900C), and 60% by weight of butyl glycol.

[0176] The sky of the 10 mL bottles is first flushed with nitrogen for 2 minutes and then the previously prepared formulation is introduced into the bottle in a ratio of 2 / 3 in the formulation and 1 / 3 in the sky of the bottle.

[0177] Aging is carried out on the formulations described above at 80°C without stirring in an oven for a period of one week (accelerated aging conditions).

[0178] Three independent preparations were carried out for each sample (for each product and each aging time).

[0179] Measurements of hLS concentrations in the headspace of the vials (ppmv) were carried out by GC / MS using a standard range.

[0180] The GC / MS analysis parameters were as follows: [Table 6]

[0181] The headspace parameters were as follows: [Table 7]

[0182] Results :

[0183] [Table 8] These results show that the basic salt of L-Homocysteine ​​is very stable in anti-corrosion formulations. It does not release H2S under the conditions of the study (< detection limit (DL) ~ 2.5 ppmv), in comparison with the free form of homocysteine ​​and with products used commercially in anti-corrosion formulations or their corresponding basic salts. These results are confirmed by i) the use of lead acetate paper (uncolored) and ii) the absence of characteristic odor of H2S.

[0184] In addition, argentometric potentiometry measurements confirmed that the absence of H2S release with the basic salt of L-homocysteine ​​is indeed linked to an increase in the intrinsic stability of the product and not the formation of sodium hydrosulfur (NaSH) in the sample.

Claims

CLAIMS 1. Use of a basic salt of a sulfur compound, said sulfur compound being of the following general formula (I): ZS-(CH2)n-CH(NRiR2)-X-R3(I) in which: Z is a hydrogen atom, a R3-X-CH(NRiR2)-(CH2) group n -S- or a group R3-X-CH(NRiR2)-(CH2) n - ; Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s); X is selected from -C(=O)-, -CH2- or -CN; R3 is: (i) is zero when X represents -CN, (ii) either a hydrogen atom, (iii) either - OR a , R abeing a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s); (iv) either -NRbRc, Rb and R c , identical or different, being chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s); and n is equal to 1 or 2; as a metal corrosion inhibitor, preferably in the oil, gas and / or mining industry.

2. Use according to claim 1, in which said basic salt is of the following general formula (II): [ a Z'-(CH2) n -CH(NRiR2)-COO b ] m [ q Li ] p(II) in which: a is a charge equal to 0 or -1; b is a charge equal to -1; q is a charge between +1 and +5; m is an integer, preferably between 1 and 5; p is an integer, preferably between 1 and 5; it being understood that the total number of negative charges [(a+b) xm] is equal to the total number of positive charges [qxp]; Z' is chosen from the group consisting of: HS-, S-, HOOC-CH(NRiR2)-(CH2)nSS-, OOC-CH(NRiR2)-(CH2) n -SS-, HOOC- CH(NRiR2)-(CH2) n -S- and OOC-CH(NRiR2)-(CH2) n -S- ; Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s); n is equal to 1 or 2; Li is selected from the group consisting of metals and quaternary ammoniums.

3. Use according to any one of the preceding claims, in which said basic salt is chosen from alkali metal salts, alkaline earth metal salts and quaternary ammonium salts.

4. Use according to any one of the preceding claims, wherein said basic salt is the disodium salt of homocysteine or homocystine, preferably the disodium salt of homocysteine.

5. Use according to any one of the preceding claims, wherein said basic salt is in combination with another anti-corrosion agent chosen from amines and their derivatives.

6. Use according to any one of the preceding claims, wherein said metallic corrosion occurs in an acidic medium comprising carbon dioxide and optionally H2S.

7. Anti-corrosion formulation comprising: a) a basic salt of a sulfur compound, said sulfur compound being of general formula (I) following: ZS-(CH2) n -CH(NRiR2)-X-R3(I) in which: - Z is a hydrogen atom, an R3-X-CH(NRiR2)-(CH2)nS- group or an R3-X-CH(NRiR2)-(CH2)n- group; Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s); - X is chosen from -C(=O)-, -CH2- or -CN; R3 is: (i) is zero when X represents -CN, (ii) either a hydrogen atom, (iii) either - OR a , R abeing a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and possibly comprising one or more heteroatom(s); (iv) either -NR b Rc, Rb and R c , identical or different, being chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s); n is equal to 1 or 2; and b) a nitrogen compound chosen from amines, ethoxylated amines, amino acids, imidazolines, as well as their derivatives and their salts; and c) optionally a solvent.

8. Anti-corrosion formulation according to claim 7, comprising: said basic salt a) in an amount ranging from 0.5% to 30% by weight, preferably from 2% to 20% by weight, inclusive, relative to the total weight of components a) + b) + c); said nitrogen compound b) in an amount ranging from 1% to 99.5% by weight, preferably from 5% to 50% by weight, more preferably from 10% to 35% by weight, inclusive, relative to the total weight of components a) + b) + c); and said solvent c) in an amount ranging from 0% to 90% by weight, preferably from 20% to 75% by weight, more preferably from 30% to 70% by weight, inclusive, relative to the total weight of components a) + b) + c).

9. Use of a formulation according to one of claims 7 or 8, for the treatment of corrosion of a corrodible metal in contact with a corrosive medium, preferably in the oil, gas and / or mining industry.

10. Basic salt of the following general formula (II): [ a Z'-(CH2)n-CH(NRiR2)-COO b ] m [ q Li ] p (II) in which: a is a charge equal to 0 or -1; b is a charge equal to -1; q is a charge between +1 and +5; preferably q is equal to +1 or +2; m is an integer, preferably between 1 and 5, more preferably equal to 1 or 2; p is an integer, preferably between 1 and 5, more preferably equal to 1 or 2; it being understood that the total number of negative charges (a+b) xm is equal to the total number of positive charges qxp; Z' is chosen from the group consisting of: HS-, S-, HOOC-CH(NRiR2)-(CH2) n -SS-, OOC-CH(NRiR2)-(CH2) n -SS-, HOOC- CH(NRiR2)-(CH2) n -S- and OOC-CH(NRiR2)-(CH2) n -S- ; Ri and R2, identical or different, are chosen from: a hydrogen atom or a hydrocarbon chain, saturated or unsaturated, linear, branched or cyclic, aromatic or not, of 1 to 20 carbon atom(s) and which may comprise one or more heteroatom(s); n is equal to 1 or 2; Li being chosen from lithium, potassium, rubidium, cesium, alkaline earths and quaternary ammoniums.

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