Method of reclaiming brine solutions using an organic chelant

1. A method of reclaiming a well completion brine comprising the steps of:

a. mixing the brine containing metal impurities with an organic chelant for a time sufficient for the chelant to complex a metal and form a complexed metal precipitate; and

b. removing the complexed metal precipitate from the brine wherein the metal impurities contain iron and further wherein the complexed metal precipitate contains iron.

2. The method of claim 1 , wherein the organic chelant contains up to about 120 carbon atoms and further contains at least one functional group selected from the group consisting of —CO 2 H or —PO(OH)R 20 or a salt or ester thereof, —C(O)—, —OE, —SE, —N═C(R 2 )R 3 , EO—N═C(R 2 )R 3 , —N(R 2 )R 3 , and a —N(C(O)R 1 )R 2 group, optionally substituted with a —COOH or —PO(OH)R 20 or a salt or ester thereof or —SE or —OE group, wherein R 2 and R 3 are independently selected from E or forms, with nitrogen, phosphorous, oxygen or sulfur, a heterocyclic ring; E is R 1 or —H; R 1 is a C 1 –C 30 alkyl or aralkyl group or a derivative thereof; and R 20 is either —OH or R 1 .

3. The method of claim 2 , wherein the organic chelant is further substituted with at least one group selected from —CO 2 H or —PO(OH)R 20 or a salt or ester thereof, —C(O)—, —OE, —SE, —N═C(R 2 )R 3 , EO—N═C(R 2 )R 3 , —P(R 2 )R 3 , —POR 2 R 3 , —PO 3 , —OPO 3 , —SO 3 , —OSO 3 , —NO 2 , —N(R 2 )R 3 or —N(C(O)R 1 )R 2 .

4. The method of claim 3 , wherein the organic chelant is a dioxime having the structural formula:

R 2 C(═N—OE)(C n H 2n Y w ) x (R 6 ) y Y w (C n H 2n ) z C(═N—OE)R 3

or a derivative thereof;

wherein R 2 and R 3 are independently selected from R 1 , —(CH 2 ) s OE, —(CH 2 ) s SE or —(CH 2 ) s COOH or —CH 2 ) s PO(OH)R 20 or a salt or ester thereof, R 1 is —H or a C 1 –C 30 alkyl or aralkyl group or derivative thereof, R 6 is C n H 2n or a derivative thereof, E is R 1 or —H; Y is —O, —S, —P or —N; s is 1 to 4, n is 0 to 5, w is 0 or 1 and x, y and z are independently 0 to 5.

5. The method of claim 2 , further comprising mixing the brine with an oxidizer.

6. The method of claim 5 , wherein the oxidizer is a slow reacting oxidizer.

7. The method of claim 6 , wherein the oxidizer is calcium peroxide or magnesium peroxide.

8. The method of claim 7 , wherein the organic chelant is benzoic acid or a salt or ester thereof.

9. The method of claim 2 , wherein the functional group is —COOH or a salt or ester thereof.

10. The method of claim 9 , wherein the organic chelant is benzoic acid or a salt or ester thereof.

11. The method of claim 9 , wherein the organic chelant is further substituted with at least one group selected from —OE, —SE, —P(R 2 )R 3 , —POR 2 R 3 , —PO 3 , —OPO 3 , —SO 3 , —OSO 3 , —NO 2 , —N═C(R 2 )R 3 , EO—N═C(R 2 )R 3 , —N(R 2 )R 3 , —N(CH 2 ) 2 and —N(C(O)R 1 )R 2 optionally substituted with a —COOH or —PO(OH)R 20 group or a salt or ester thereof or with an —OE or _SE group.

12. The method of claim 11 , wherein the organic chelant further contains the functional group —NR 2 R 3 optionally substituted with a —COOH or —PO(OH)R 20 group or a salt or ester thereof or with an —OE or —SE group.

13. The method of claim 12 , wherein the organic chelant is nitrilotriacetic acid or a salt or ester thereof.

14. The method of claim 11 , wherein the organic chelant is an ethylene diamine type of the structural formula:

(F)(R 9 )A(U) k (V) t (C n H 2n )A(R 10 )(R 11 )  (I)

or a derivative thereof

wherein A is nitrogen or phosphorus; R 8 , R 9 , R 10 and R 11 are independently —(CH 2 ) x COOH or —(CH 2 ) x PO(OH)R 20 or a salt or ester thereof, —(CH 2 ) x OE or (CH 2 ) x SE or a derivative thereof; R 5 is —H or a C 1 –C 30 alkyl or aralkyl group or derivative thereof; R 14 is R 5 or R 8 ; F is —(CH 2 ) x COOH or —(CH 2 ) x PO(OH)R 20 or a salt or ester thereof, —OE, —SE, —(CH 2 ) x SE or —(CH 2 ) x OE or a derivative thereof; U is —(CH 2 CONR 14 —) x ; V is —(C n H 2n AR 8 —); n is 1 to 15; x is 1 to 4; and k, z and t are independently 0 to 2.

15. The method of claim 14 , wherein the organic chelant is selected from the group consisting of ethylene diamine tetra acetic acid; hydroxyethylenediamine triacetic; O,O′-bis(2-aminoethyl)ethyleneglycol-N,N,N′,N′-tetraacetic acid; N-(glycylglycyl)-1,2-diaminoethane-N′,N′,N″,N″-tetraacetic acid.

16. The method of claim 9 , wherein the organic chelant further contains the functional group —N(COR 1 )R 2 group optionally substituted with a —COOH or —PO(OH)R 20 group or a salt or ester thereof or with an —OE or SE group.

17. The method of claim 16 , wherein the organic chelant contains from ten to one hundred twenty carbon atoms.

18. The method of claim 17 , wherein the organic chelant contains a counter ion selected from the group consisting of ionic forms of sodium, potassium, cesium, ammonium, monoethanolamine, diethanolamine, triethanolamine, N-propylamine, isopropylamine, 2-amino-2-methyl-1,3-propane diol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propane diol, tris(hydroxymethyl)aminomethane, group II metals, and a Group 3–7 transition metal.

19. The method of claim 9 , wherein the organic chelant is substituted with at least one —OE, —SE, —POR 2 R 3 , —PO 3 , —OPO 3 , —SO 3 , or —OSO 3 group.

20. The method of claim 19 , wherein the organic chelant is substituted with an —OE group.

21. The method of claim 20 , wherein the organic chelant is zinc di-(12-hydroxy-9-octadecenoate).

22. The method of claim 9 , wherein the organic chelant is substituted with a —P(R 2 )R 3 or —POR 2 R 3 group.

23. The method of claim 22 , wherein the organic chelant is of the formula (HOOCCH 2 ) 2 PCH 2 CH 2 P(CH 2 COOH) 2 or a salt or ester thereof.

24. The method of claim 8 , wherein the organic chelant is selected from the group consisting of benzoic acid; benzene-1,2-dicarboxylic acid; benzene-1,3,5-tricarboxylic acid; nonyl-1,3-dicarboxylic acid; and 1-hydroxy-2-napthoic acid and salts thereof.

25. The method of claim 2 , wherein the organic chelant contains at least one —N(R 2 )R 3 , —N═C(R 2 )R 3 , EO—N═C(R 2 )R 3 or a —N(C(O)R 1 )R 2 group wherein R 2 and R 3 independently may be substituted with a —COOH, —PO(OH)R 20 , —SE or —OE group or a salt or ester thereof.

26. The method of claim 25 , wherein the organic chelant is N,N′-dimethyl-N,N′-dilauroylethylenediamine or a salt thereof.

27. The method of claim 25 , wherein the organic chelant is 1,2-diaminobenzene or a salt thereof.

28. The method of claim 25 , wherein the organic chelant is iminobis (methylenephosphonic acid) or a salt or ester thereof.

29. The method of claim 25 , wherein the organic chelant is further substituted with at least one group selected from —OE, —SE, —PO 3 , —OPO 3 , —SO 3 , —OSO 3 , or —NO 2 .

30. The method of claim 29 , wherein the organic chelant is substituted with an —OE group.

31. The method of claim 30 , wherein the organic chelant is 8-hydroxy quinoline or a salt thereof.

32. The method of claim 30 , wherein the organic chelant is substituted with a —SO 3 or a —OSO 3 group.

33. The method of claim 25 , wherein the organic chelant is substituted with a —SO 3 or a —OSO 3 group.

34. The method of claim 33 , wherein the organic chelant is 1-aminobenzene-2-sulfonic acid or a salt thereof.

35. The method of claim 25 , wherein the organic chelant is a nitrogen, phosphorous, oxygen or sulfur containing heterocyclic ring.

36. The method of claim 35 , wherein the organic chelant is porphine or derivatives thereof or salts thereof.

37. The method of claim 25 , wherein the organic chelant is selected from the group consisting of ethylenediaminetetraacetic acid, 1,2-dimethylethylenedinitrilotetraacetic acid; DL-1-alkylethylenedinitrilotetraacetic acid N,N′-diamide; 1,2-dimethylethylenedinitrilotetraacetic acid N,N′-diamide; 1,2-phenylenedinitrilotetraacetic acid; N,N-dimethyl-2-aminophenol; and 4-phenyl-8-mercaptoquinoline and salts thereof.

38. The method of claim 2 , wherein the functional group is —OE or —SE.

39. The method of claim 38 , wherein the organic chelant is N-hydroxy-N-nitrosobenzenamine or a salt thereof.

40. The method of claim 38 , wherein the organic chelant further contains at least one group selected from —PO 3 , —OPO 3 , —SO 3 , —OSO 3 , or —NO 2 .

41. The method of claim 40 , wherein the organic chelant contains a —SO 3 or —OSO 3 group.

42. The method of claim 41 , wherein the organic chelant is 1-hydroxybenzene-2-sulfonic acid or a salt thereof.

43. The method of claim 38 , wherein the organic chelant contains a —PO 3 or —OPO 3 group.

44. The method of claim 40 , wherein the organic chelant is 4-nitro-1,2-dihydroxy benzene or a salt thereof.

45. The method of claim 2 , wherein the organic chelant is a diketone having the structural formula:

R 12 C(O)(C n H 2n Y w ) x (R 6 ) y Y w (C n H 2n ) z C(O)R 13

or derivative thereof

wherein R 12 and R 13 are independently —H or a C 1 –C 30 alkyl or aralkyl group optionally substituted with a —COOH or —PO(OH)R 20 or a salt or ester thereof, —N(R 2 )R 3 , —SE or —OE group; R 6 is C n H 2n or a derivative thereof; Y is —O, —S, —P or —N; n is 1 to 30, w is 0 or 1, and x, y and z are independently 0 to 5.

46. The method of claim 45 , wherein the organic chelant is pentane-2,4-dione or octadecane-2,4-dione.

47. The method of claim 4 , wherein the organic chelant is 2,3-butanedionedioxime.

48. The method of claim 1 , further comprising mixing the brine with an oxidizer.

49. The method of claim 48 , wherein the oxidizer is a slow reacting oxidizer.

50. The method of claim 1 , further comprising adding to the brine an absorbent or defoamer.

51. The method of claim 50 , wherein the absorbent is activated carbon.

52. The method of claim 48 , further comprising adding to the brine an absorbent or defoamer.