Patent ID: 7674384

Claim:
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, the chelant being of the formula (R 5 CO)(R 4 )AR 6 A(R 8 )(R 9 ); or (R 5 CO)(R 27 )A(R 28 ) or derivatives thereof, wherein each A is independently selected from nitrogen or phosphorus; R 4 , R 8 and R 9 are independently R 28 , —(CH 2 ) x COOH or —(CH 2 ) x PO(R 21 )(R 20 ) or a salt or ester thereof, —H, —(CH 2 ) x OH or R 5 C(O)— or a derivative thereof; R 5 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; R 20 and R 21 are independently —OH, —R 1 or —OR 1 ; R 1 is a C 1 -C 30 alkyl or aralkyl group or derivative thereof; R 27 is —H, —R 1 , —R 4 , R 28 or a derivative thereof; R 28 is —(CHR 30 ) y (CH 2 ) Z COOH or —(CH 2 ) x PO(R 21 )R 20 or a salt or ester thereof; R 30 is —H, —COOH or R 28 ; x is 1 to 4; y is 0 to 2; z is 0 to 6; and n is 1 to 15; 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.