Method of reclaiming brine solutions using an organic chelant
View Patent ↗A method of reclaiming a well completion brine solution by using an organic chelant that is capable of discriminating between (i) iron and non-zinc heavy metals; and (ii) calcium and zinc. The chelant contains a functional group selected from the group —CO 2 H or —PO(R 21 )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 —N(C(O)R 1 )R 2 group optionally substituted with a —COOH or —PO(R 21 )R 20 or a salt or ester thereof, —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 and R 21 are independently selected from —OH, —OR 1 and R 1 .
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, 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.
2. The method of claim 1 , wherein the chelant is of the formula:
(R 5 CO)(R 4 )AR 6 A(R 8 )(R 9 ).
3. The method of claim 1 , wherein the chelant is of the formula:
(R 5 CO)(R 27 )A(R 28 ).
4. The method of claim 1 , further comprising mixing the brine with an oxidizer.
5. The method of claim 4 , wherein the oxidizer is a slow reacting oxidizer.
6. The method of claim 1 , wherein the organic chelant is N-acyl ethylenediaminetriacetic acid or a salt or ester thereof
7. The method of claim 6 , wherein the organic chelant is N-lauroyl ethylenediaminetriacetic acid or a salt or ester thereof.
8. The method of claim 1 , wherein the organic chelant contains a counter ion selected from the group consisting of ionic forms of lithium, 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) amino methane, zinc, group II metals, and a Group 3-7 transition metal.
9. The method of claim 1 , wherein the organic chelant is selected from the group consisting of acyl glutamic acid; N-lauroyl glutamic acid; acyl sarcosinic acid; and N-lauroyl sarcosinic acid and salts or esters thereof.
10. The method of claim 1 , further comprising adding to the brine an absorbent or defoamer.
11. The method of claim 10 , wherein the absorbent or adsorbent is activated carbon.
12. The method of claim 1 , wherein R 5 is C 6 -C 30 alkyl or aralkyl group or derivative thereof.
13. The method of claim 12 , wherein R 5 is C 12 -C 30 alkyl or aralkyl group or derivative thereof.
14. The method of claim 12 , wherein the organic chelant is the reaction product formed between a diamine and acyl glutamic acid, N-lauroyl glutamic acid, acyl sarcosinic acid, or N-lauroyl sarcosinic acid, or salts or esters thereof.