Composition for remediating iron sulfide in oilfield production systems

1. A method of inhibiting corrosion at a surface and removing hydrocarbonaceous deposits from the surface, the method comprising:

continuously adding an iron sulfide dissolver to a fluid which contacts a surface of a wellbore or equipment used in production, processing, transportation, storage or separation of the fluid to inhibit corrosion and/or remove hydrocarbonaceous deposits from the surface,

the iron sulfide dissolver comprising allaric acid, altaric acid, altraric acid, altronic acid, arabinaric acid, arabinonic acid, dihomocitric acid, fructuronic acid, fuconic acid, galactaric acid, galactonic acid, galacturonic acid, glucaric acid, glucoheptonic acid, gluconic acid, glucuronic acid, gulonic acid, homocitric acid, homoisocitric acid, idaric acid, idonic acid, iduronic acid, isocitric acid, mannaric acid, mannonic acid, octulosonic acid, rhamnonic acid, ribonic acid, tagaturonic acid, xylonic acid, or xyluronic acid, or a salt or derivative thereof, or a combination thereof;

the fluid comprising natural gas or a liquid hydrocarbon; and

wherein the iron sulfide dissolver inhibits iron sulfide formation on the surface during use of the wellbore or the equipment.

2. The method of claim 1 , wherein the method continuously adds the iron sulfide dissolver and the iron sulfide dissolver comprises gluconic acid, a salt thereof, or a combination thereof.

3. The method of claim 1 , wherein the method continuously adds the iron sulfide dissolver and the iron sulfide dissolver comprises sodium gluconate, ammonium gluconate, potassium gluconate, lithium gluconate, magnesium gluconate, calcium gluconate, cesium gluconate, gluconic acid, sodium glucarate, ammonium glucarate, potassium glucarate, lithium glucarate, magnesium glucarate, calcium glucarate, cesium glucarate, glucaric acid, or a combination thereof.

4. The method of claim 1 , wherein the method continuously adds the iron sulfide dissolver and the iron sulfide dissolver comprises sodium gluconate, ammonium gluconate, potassium gluconate, lithium gluconate, magnesium gluconate, calcium gluconate, cesium gluconate, gluconic acid, or a combination thereof.

5. The method of claim 1 , wherein

the iron sulfide dissolver comprises gluconic acid or a salt thereof.

6. The method of claim 1 , wherein:

the equipment comprises a pipeline, a storage vessel, downhole injection tubing, a flow line, or an injection line.

7. The method of claim 1 , wherein the iron sulfide dissolver is a component of a composition and the composition further comprises an organic solvent, and a corrosion inhibitor comprising an imidazoline compound, a quaternary ammonium compound, a pyridinium compound, or a combination thereof.

8. The method of claim 7 , wherein the organic solvent comprises an alcohol, a hydrocarbon, a ketone, an ether, an alkylene glycol, a glycol ether, an amide, a nitrile, a sulfoxide, an ester, a polyol, or a combination thereof, and the composition optionally comprises water.

9. The method of claim 7 , wherein the organic solvent comprises methanol, ethanol, propanol, isopropanol, butanol, 2-ethylhexanol, hexanol, octanol, decanol, 2-butoxyethanol, methylene glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethyleneglycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, pentane, hexane, cyclohexane, methylcyclohexane, heptane, decane, dodecane, diesel, toluene, xylene, heavy aromatic naphtha, cyclohexanone, diisobutylketone, diethyl ether, propylene carbonate, N-methylpyrrolidinone, N,N-dimethylformamide, glycerin, or a combination thereof.

10. The method of claim 9 , wherein the organic solvent comprises methanol, ethanol, ethylene glycol, glycerin, or a combination thereof.

11. The method of claim 7 , wherein the corrosion inhibitor comprises one or more of the following imidazoline compounds:

(A) an imidazoline of Formula (I):

wherein

R 10 is a C 1 -C 20 alkyl or a C 1 -C 20 alkoxyalkyl group;

R 12 and R 13 are independently hydrogen or a C 1 -C 6 alkyl group,

R 11 and R 14 are independently hydrogen, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, or C 1 -C 6 arylalkyl; and

X − is a halide, carbonate, sulfonate, phosphate, or an anion of an organic carboxylic acid;

or a tautomer thereof;

(B) an imidazolinium salt of Formula (II):

wherein

R 10 is a C 1 -C 20 alkyl or a C 1 -C 20 alkoxyalkyl group;

R 12 and R 13 are independently hydrogen or a C 1 -C 6 alkyl group,

R 11 and R 14 are independently hydrogen, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, or C 1 -C 6 arylalkyl; and

X − is a halide, carbonate, sulfonate, phosphate, or an anion of an organic carboxylic acid;

or a tautomer thereof;

(C) a bis-quaternized imidazoline compound of Formula (III):

wherein:

R 1 and R 2 are each independently unsubstituted branched, chain or ring alkyl or alkenyl having from 1 to about 29 carbon atoms; partially or fully oxygenized, sulfurized, and/or phosphorylized branched, chain, or ring alkyl or alkenyl having from 1 to about 29 carbon atoms; or a combination thereof;

R 3 and R 4 are each independently unsubstituted branched, chain or ring alkylene or alkenylene having from 1 to about 29 carbon atoms; partially or fully oxygenized, sulfurized, and/or phosphorylized branched, chain, or ring alkylene or alkenylene having from 1 to about 29 carbon atoms; or a combination thereof;

L 1 and L 2 are each independently absent, H, —COON, —SO 3 H, —PO 3 H 2 , —COOR 5 , —CONH 2 , —CONHR 5 , or —CON(R 5 ) 2 ;

R 5 is each independently a branched or unbranched alkyl, aryl, alkylaryl, alkylheteroaryl, cycloalkyl, or heteroaryl group having from 1 to about 10 carbon atoms;

n is 0 or 1, and when n is 0, L 2 is absent or H;

x is from 1 to about 10; and

y is from 1 to about 5; or

(D) a combination thereof.

12. The method of claim 7 , wherein the corrosion inhibitor comprises a pyridinium compound of Formula (V):

wherein

R 9 is an alkyl group, an aryl group, or an arylalkyl group, wherein said alkyl groups have from 1 to about 18 carbon atoms; and

X − is a halide.

13. The method of claim 12 , wherein the corrosion inhibitor comprises the pyridinium compound of Formula (V), R 9 is benzyl, and X − is chloride.

14. The method of claim 7 , wherein the quaternary ammonium compound comprises either:

the quaternary ammonium salt, and the quaternary ammonium salt comprises a tetramethyl ammonium salt, a tetraethyl ammonium salt, a tetrapropyl ammonium salt, a tetrabutyl ammonium salt, a tetrahexyl ammonium salt, a tetraoctyl ammonium salt, a benzyltrimethyl ammonium salt, a benzyltriethyl ammonium salt, a phenyltrimethyl ammonium salt, a phenyltriethyl ammonium salt, a cetyl benzyldimethyl ammonium salt, a hexadecyl trimethyl ammonium salt, a dimethyl alkyl benzyl quaternary ammonium salt, a monomethyl dialkyl benzyl quaternary ammonium salt, a trimethyl benzyl quaternary ammonium salt, or a trialkyl benzyl quaternary ammonium salt, wherein the alkyl group has about 6 to about 24 carbon atoms; or

a quaternary ammonium compound of Formula (IV):

wherein

R 1 , R 2 , and R 3 are independently C 1 to C 20 alkyl, R 4 is methyl or benzyl, and X − is a halide or methosulfate.

15. The method of claim 7 , wherein the corrosion inhibitor further comprises an alkoxylated amine, a phosphate ester, or a monomeric or oligomeric fatty acid.

16. The method of claim 7 , wherein the composition comprises from about 5 wt. % to about 95 wt. % of the iron sulfide dissolver, from about 5 to about 95 wt. % of the organic solvent, and from about 5 to about 95 wt. % of the corrosion inhibitor.

17. The method of claim 7 , wherein the composition comprises from about 10 wt. % to about 60 wt. % of the iron sulfide dissolver, from about 10 to about 60 wt. % of the organic solvent, and from about 10 to about 60 wt. % of the corrosion inhibitor.

18. The method of claim 7 , wherein the composition comprises from about 15 wt. % to about 30 wt. % of the iron sulfide dissolver, from about 20 to about 40 wt. % of the organic solvent, and from about 15 to about 30 wt. % of the corrosion inhibitor.

19. The method of claim 7 , wherein the composition further comprises either: a sulfur-containing compound of HS—(CH 2 ) n OH, wherein n is 2-6; or a sulfur-containing compound comprised of thioglycolic acid, 3,3′-dithiodipropionic acid, thiourea, 2-mercaptoethanol, L-cysteine, tert-butyl mercaptan, sodium thiosulfate, ammonium thiosulfate, sodium thiocyanate, ammonium thiocyanate, sodium metabisulfite, or a combination thereof.

20. The method of claim 7 , wherein the composition further comprises at least one of an asphaltene inhibitor, a paraffin inhibitor, a scale inhibitor, an emulsifier, a water clarifier, a dispersant, an emulsion breaker, a hydrogen sulfide scavenger, a gas hydrate inhibitor, a biocide, a pH modifier, and a surfactant.

21. A method of inhibiting corrosion at a surface and removing hydrocarbonaceous deposits from the surface, the method comprising:

continuously adding an iron sulfide dissolver to a fluid which contacts a surface of a wellbore or equipment used in production, processing, transportation, storage or separation of the fluid to inhibit corrosion and/or remove hydrocarbonaceous deposits from the surface,

the iron sulfide dissolver comprising allaric acid, altaric acid, altraric acid, altronic acid, arabinaric acid, arabinonic acid, dihomocitric acid, fructuronic acid, fuconic acid, galactaric acid, galactonic acid, galacturonic acid, glucaric acid, glucoheptonic acid, gluconic acid, glucuronic acid, gulonic acid, homocitric acid, homoisocitric acid, idaric acid, idonic acid, iduronic acid, isocitric acid, mannaric acid, mannonic acid, octulosonic acid, rhamnonic acid, ribonic acid, tagaturonic acid, xylonic acid, or xyluronic acid, or a salt or derivative thereof, or a combination thereof;

the fluid comprising natural gas or a liquid hydrocarbon; and

wherein the iron sulfide dissolver dissolves iron sulfide present on the surface.