Method of using biosurfactants as acid corrosion inhibitors in well treatment operations
Corrosive effects arising during well treatment applications are inhibited and/or prevented by introducing into the well composition containing a corrosion inhibitor of a biosurfactant selected from glycolipids (other than sophorolipids and mannosylerythritol lipids), phospholipids; polyol lipids; lipoproteins, lipopeptides, ornithine lipids, carbohydrate-lipids, neutral lipids, aminoacid lipids, exolipids, liposan; siderolipids, protein polyamines diglycosyl diglycerides, fimbriae, saponified triglycerides and fatty acids. The composition may also contain a corrosion inhibitor intensifier.
1. A method of inhibiting corrosion during a well treatment operation which comprises introducing into a well a composition comprising a corrosive inhibiting effective amount of a biosurfactant selected from the group consisting of rhamnolipids, cellobiose lipids, trehalose, lipopolysaccharides, emulsans, alasans and protease enzymes.
2. The method of claim 1 , wherein the biosurfactant is a mono-rhamnolipid of formula (I A) or a di-rhamnolipid of formula (I B):
3. The method of claim 1 , wherein the biosurfactant is a cellobiose lipid of the formula (II):
where R is —H or —OH and n is 2 to 4.
4. The method of claim 1 , wherein the biosurfactant is a trehalose of the formula (III):
where RCO is mycoloyl.
5. The method of claim 1 , wherein the biosurfactant is an emulsan of formula (IV):
having an approximate molecular weight of 1,000 kDa.
6. The method of claim 1 , wherein the biosurfactant is a protease enzyme.
7. The method of claim 1 , wherein the composition further comprises a corrosion inhibitor intensifier selected from the group consisting of formic acid, sodium formate, potassium formate, methylformate, ethylformate, sodium iodide, potassium iodide, copper iodide, molecular iodide, metal oxides, and combinations thereof.
8. The method of claim 7 , wherein the corrosion inhibitor intensifier is potassium iodide.
9. The method of claim 1 , wherein the biosurfactant is a rhamnolipid containing one or two rhamnose units linked glycosidically to a 3-hydroxy acid.
10. The method of claim 1 , wherein the biosurfactant is a cellobiose lipid comprising a disaccharide cellobiose linked O-glycosidically to a ω-hydroxyl group of 15,16-dihydroxyhexadecanoic acid or 2,15,16-trihydroxyhexadecanoic acid.
11. The method of claim 10 , wherein the disaccharide cellobiose further has hydroxyl groups esterified either to an acetate or a 3-hydroxy fatty acid.
12. The method of claim 1 , wherein the biosurfactant is a trehalose comprising a non-reducing disaccharide having two glucose units linked in an α,α-1,1-glycosidic linkage.
13. The method of claim 1 , wherein the biosurfactant is an emulsan consisting of a disaccharide backbone of D-galactosamine, D-galactosaminouronic acid and a deoxyaminohexose to which C 10-22 fatty acid groups are linked via ester and amide bonds.
14. The method of claim 1 , wherein the biosurfactant is a protease enzyme selected from the group consisting of subtilisin, diglycosyl diglycerides and fimbriae.
15. A method of treating an alloy surface during a well treatment operation comprising the step of contacting the alloy surface with a treatment fluid comprising an aqueous acidic fluid and a corrosion inhibitor selected from the group consisting of rhamnolipids, cellobiose lipids, trehalose, lipopolysaccharides, emulsans, alasans and protease enzymes, wherein reduction in corrosion of the alloy surface is greater than when the alloy surface is only contacted with the aqueous acidic fluid.
16. The method of claim 15 , wherein the composition further comprises a corrosion inhibitor intensifier selected from the group consisting of formic acid, sodium formate, potassium formate, methylformate, ethylformate, sodium iodide, potassium iodide, copper iodide, molecular iodide, metal oxides, and combinations thereof.
17. The method of claim 16 , wherein the corrosion inhibitor intensifier is potassium iodide.
18. A method of inhibiting corrosion of a steel surface in contact with an acidic fluid during a well treatment operation comprising the steps of:
(a) contacting the acidic fluid with a corrosion inhibitor selected from the group consisting of rhamnolipids, cellobiose lipids, trehalose, lipopolysaccharides, emulsans, alasans and protease enzymes; and
(b) contacting the steel surface with the acidic fluid and the corrosion inhibitor.
19. The method of claim 18 , wherein the step of contacting the steel surface with the acidic fluid and the corrosion inhibitor comprises pickling a tubular, cleaning a wellbore, matrix acid stimulation, acid fracturing, acid tunneling, scale treatment, coiled tubing application, or damage removal.
20. A composition for use in the acid treatment of wells, comprising:
(a) a corrosion inhibitor comprising a biosurfactant selected from the group consisting of rhamnolipids, cellobiose lipids, trehalose, lipopolysaccharides, emulsans, alasans and protease enzymes; and
(b) corrosion inhibitor intensifier in an acidic solution.