Patent ID: 7172703

Claim:
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 Fâ€”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 â€“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 â€”(CH 2 ) n PO(OZ) 2 groups; each A is independently selected from â€”N and â€”P; Y 1 is independently selected from J, â€”[(F)â€”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 â€”H, R, â€”(F) n CO 2 Z and â€”(CH 2 ) n PO(OZ) 2 ; each F is independently selected from a C 1 â€“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 â€”(CH 2 ) n PO(OZ) 2 groups; Z is â€”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 â€”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.