Patent ID: 7678281

Claim:
A method of reclaiming a well completion brine comprising the steps of: (a.) mixing the brine containing metal impurities with an oxidizer and at 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 ) u (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 from the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups; Z is —H, a balanced organic counterion or a balanced counterion of an alkali or alkaline earth metal, Zn or NH 4 + or a mixture thereof; 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.