Method of reclaiming a well completion 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 a least one organic chelant for a time sufficient for the chelant to complex a metal and form a complexed metal precipitate, the organic chelant being a neutral compound or a corresponding salt of the formula:

wherein:

D is F—A(Y 3 ) n (Y 4 ) v ;

R is independently selected from C p or C p C(O);

C p is a C 1 –C 36 hydrocarbyl group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups;

each A is independently selected from —N and —P;

Y 1 is independently selected from J, —[(F)—A(J)] w Y 6 and R;

J, R 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 are independently selected from the group consisting of —H, R, —(F) n CO 2 Z and —(CH 2 ) n PO(OZ) 2 ;

each F is independently selected from a C 1 –C 12 hydrocarbyl group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups;

Z is —H or a balanced counterion of an alkali or alkaline earth metal or NH 4 + ;

m is 0 to 7;

n is 1 to 7;

r+s+t is 1 or 2;

u+v is 1 or 2; and

w is 0 to 7

provided when m is 0, no more than one of R 1 , Y 1 , Y 2 and Y 5 can be —H; 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 s and t are 0 and m is 1 to 7.

3. The method of claim 2 , wherein the at least one organic chelant is a compound or a corresponding salt of the formula:

wherein D represents random repeating blocks of F—A (Y 3 ) u (Y 4 ) v .

4. The method of claim 3 , wherein the at least one organic chelant is a compound of the formula:

wherein R 1 is —H, —(CH 2 ) n PO(OZ) 2 or —(F) n CO 2 Z; and Y 3 and Y 5 are independently selected from —(F) n CO 2 Z, —(CH 2 ) n PO(OZ) 2 and —H; and k is from 1 to 6.

5. The method of claim 4 , wherein k is 3.

6. The method of claim 5 , wherein at least one organic chelant is selected from the group consisting of:

(a.) R—N(CH 2 COOZ)—(CH 2 ) k —NH(CH 2 COOZ);

(b.) R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ;

(c.) R—NH—(CH 2 ) k —N(CH 2 COOZ) 2 ;

wherein R is C p or C p C(O).

7. The method of claim 6 , wherein the C p group is selected from C 8 to C 36 .

8. The method of claim 7 , wherein the C p group is selected from C 12 to C 36 .

9. The method of claim 8 , wherein the C p group is selected from C 12 to C 22 .

10. The method of claim 6 , wherein k is 3, Z is —H and R is a C 14 –C 22 hydrocarbyl group.

11. The method of claim 4 , wherein the at least one organic chelant is selected from the group consisting of:

(a.) R—N(CH 2 COOZ)—(CH 2 ) k —NH 2 ;

(b.) R—N(CH 2 COOZ)—(CH 2 ) k —NH(CH 2 COOZ)

(c.) R—NH—(CH 2 ) k —NH(CH 2 COOZ)

(d.) R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ;

(e.) R—NH—(CH 2 ) k —N(CH 2 COOZ) 2 ;

wherein R is C p or C p C(O).

12. The method of claim 11 , wherein k is 3.

13. The method of claim 11 , wherein k is 3, R is a C 14 –C 22 hydrocarbyl group and Z is —H.

14. The method of claim 3 , wherein at least one R 1 , Y 3 or Y 5 is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 .

15. The method of claim 2 , wherein the at least one organic chelant is a compound of the formula:

wherein Y 3 is —H, C p or C p C(O), —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 ; and R 1 and Y 5 are independently selected from —(CH 2 ) n PO(OZ) 2 , —(F) n CO 2 Z and —H; and k is from 1 to 6.

16. The method of claim 15 , wherein k is 3.

17. The method of claim 15 , wherein the at least one organic chelant is selected from the group consisting of:

(a.) R—N (R 1 )—(CH 2 ) k —NH(CH 2 COOZ);

(b.) R—N (R 1 )—(CH 2 ) k —N(CH 2 COOZ) 2 ;

(c.) R—NH—(CH 2 ) k —NY 5 (CH 2 COOZ);

(d.) R—N(CH 2 COOZ)—(CH 2 ) k —NHY 5 ;

(e.) R—N(CH 2 COOZ)—(CH 2 ) k —NY 5 (CH 2 COOZ).

18. The method of claim 17 , wherein the at least one organic chelant is selected from the group consisting of R—NR 1 —(CH 2 ) k —N(CH 2 COOZ) 2 ; R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ; and R—N(CH 2 COOZ)—(CH 2 ) k —NY 5 (CH 2 COOZ).

19. The method of claim 17 , wherein each Z is —H.

20. The method of claim 17 , wherein R 1 is —(F) n CO 2 Z or —H.

21. The method of claim 2 , wherein the at least one organic chelant is a compound of the formula:

wherein Y 3 is —H, C p or C p C(O), —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 ; and R 1 and Y 5 are independently selected from —(F) n CO 2 Z, —(CH 2 ) n PO(OZ) 2 and —H; k is from 1 to 6; and at least one R 1 , Y 3 or Y 5 is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 .

22. The method of claim 1 , wherein s, t and m are 0.

23. The method of claim 22 , wherein the at least one organic chelant is a compound of the formula:

wherein R 1 is —H, —(CH 2 ) n PO(OZ) 2 or —(F) n CO 2 Z; and Y 5 is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 .

24. The method of claim 23 , wherein the at least one organic chelant is a compound of the formula:

R—NH(CH 2 COOZ) or R—N(CH 2 COOZ) 2 .

25. The method of claim 1 , wherein the at least one organic chelant is a salt and further wherein s is 0.

26. The method of claim 25 , wherein the salt is a compound of the formula:

wherein R 1 is —H, C p , —(CH 2 ) n PO(OZ) 2 or —(CH 2 ) n CO 2 Z; each of Y 4 and Y 5 are independently selected from —H, —(CH 2 ) n PO(OZ) 2 or —(CH 2 ) n CO 2 Z; X is an anion; and k and n are independently selected from 1 to 6.

27. The method of claim 1 , further comprising adding to the brine an absorbent, adsorbent or defoamer in an amount sufficient to reduce foaming.

28. The method of claim 1 wherein at least one J, R 1 , Y 2 , Y 3 , Y 4 , Y 5 or Y 6 is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 .

29. 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, wherein the organic chelant is at least one member selected from the group consisting of R—N (R 1 )—(CH 2 ) k —N(CH 2 COOZ) 2 ; R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ; and R—N(CH 2 COOZ)—(CH 2 ) k —NY 5 (CH 2 COOZ)

wherein

R is independently selected from C p or C p C(O);

C p is a C 12 –C 36 hydrocarbyl group, optionally substituted with one or more substituents selected from the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups;

R 1 and Y 5 are independently selected from —H, R, —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 ;

each F is independently selected from a C 1 –C 12 hydrocarbon group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups;

Z is —H or a balanced counterion of an alkali or alkaline earth metal or NH 4 + ;

n is 1 to 7; and

k is from 1 to 6; 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.