TREATING SEAWATER FOR OILFIELD OPERATIONS
A method includes mixing seawater with a two-part additive system configured to precipitate sulfate from the seawater; removing the sulfate precipitates from the seawater; and delivering the seawater into an oilfield reservoir.
1 . A method comprising:
mixing seawater with a two-part additive system configured to precipitate sulfate from the seawater;
removing the sulfate precipitates from the seawater; and
delivering the seawater into an oilfield reservoir.
2 . The method of claim 1 , wherein the two-part additive system is configured to cause formation of crystalline sulfate precipitates.
3 . The method of claim 1 , wherein the two-part additive system comprises aminoguanidine hydrochloride.
4 . The method of claim 1 , wherein the two-part additive system comprises glyoxal.
5 . The method of claim 1 , wherein the two-part additive system comprises a guanidine compound.
6 . The method of claim 1 , wherein the two-part additive system comprises a hydrazine compound.
7 . The method of claim 1 , wherein the two-part additive system comprises an aldehyde molecule.
8 . The method of claim 1 , wherein the two-part additive system comprises a dialdehyde molecule.
9 . The method of claim 1 , wherein the two-part additive system comprises.a dicarbonyl molecule.
10 . The method of claim 1 , wherein the two-part additive system comprises an additive having the following structure:
wherein each R 1 is independently be selected from H or any carbon chain and L is a direct link or any suitable molecular linkage.
11 . The method of claim 1 , wherein a concentration of sulfate in the treated seawater is less than 0.02 M.
12 . The method of claim 11 , wherein the concentration of sulfate in the treated seawater is lower than a solubility level of sulfate in the treated seawater.
13 . The method of claim 1 , wherein the seawater does not contain a scale inhibitor.
14 . The method of claim 1 , wherein removing the sulfate precipitates from the seawater comprises filtering the seawater using a filter having a pore size of at least 0.5 mm.
15 . A treated seawater composition comprising:
seawater;
aminoguanidine hydrochloride; and
glyoxal.
16 . The treated seawater composition of claim 15 , wherein the composition comprises precipitated sulfate crystals and less than 0.02 M sulfate ions in the aqueous phase.
17 . The treated seawater composition of claim 16 , wherein the composition comprises less than 0.01 M sulfate ions.
18 . The treated seawater composition of claim 17 , wherein the composition comprises less than 0.005 M sulfate ions.
19 . The treated seawater composition of claim 15 , wherein the composition contains complexes of the aminoguanidine hydrochloride, glyoxal, and chloride ions.
20 . An additive system for treating seawater comprising aminoguanidine hydrochloride and glyoxal.
21 . A composition comprising water and precipitated complexes of sulfate ions, a first additive, and a second additive.
22 . The composition of claim 21 , wherein the first additive comprises aminoguanidine hydrochloride and the second additive comprises glyoxal.
23 . The composition of claim 21 , wherein the first additive is selected from a guanidine or a hydrazine compound and the second additive is selected from an aldehyde, a dialdehyde, or a dicarbonyl.
24 . The composition of claim 21 , wherein the water is seawater.
25 . The composition of claim 21 , wherein the precipitates have an average length of at least 2 mm.
26 . The composition of claim 21 , wherein the precipitates are crystalline.