Compositions and methods for carbon dioxide solidification
Compositions and methods that can be used to sequester carbon dioxide within a subterranean formation are described. The methods can include contacting carbon dioxide present in the subterranean formation with a complexing agent, resulting in precipitation of a carbonate or bicarbonate salt of the complexing agent within the subterranean formation.
1. A method for sequestering carbon dioxide within a subterranean formation, the method comprising:
contacting carbon dioxide present in the subterranean formation with an iminoguanidine complexing agent, resulting in precipitation of a carbonate or bicarbonate salt of the iminoguanidine complexing agent within the subterranean formation,
wherein the subterranean formation has a temperature below 90° C.; and
wherein the iminoguanidine complexing agent is defined by Formula I-1 or Formula I-2:
wherein
A is a ring-containing moiety or a bond, and
one or more of the hydrogen atoms in Formula I-1 or Formula I-2 may be replaced with one or more-equivalent number of methyl groups.
2. The method of claim 1 , wherein contacting comprises injecting an aqueous composition comprising the iminoguanidine complexing into the subterranean formation via a wellbore in fluid communication with the subterranean formation.
3. The method of claim 2 , wherein the iminoguanidine complexing agent is present in the aqueous composition in a concentration of from 0.1% to 10% by weight, based on the total weight of the aqueous composition.
4. The method of claim 2 , wherein the aqueous composition comprises an aqueous solution further comprising one or more of an acid, an alkali agent, a polymer, a gelling agent, a crosslinker, a biocide, a scale inhibitor, a breaker, a pH adjusting agent, a non-emulsifier agent, an iron control agent, a chelating agent, a corrosion inhibitor, a clay stabilizing agent, a wettability alteration chemical, an anti-foam agent, a sulfide scavenger, a mobility control agent, a co-solvent, a surfactant(s), a surfactant package, or any combination thereof.
5. The method of claim 4 , wherein the aqueous solution further comprises the surfactant(s) and wherein the surfactant(s) comprises an anionic surfactant, a non-ionic surfactant, a cationic surfactant, a zwitterionic surfactant, or any combination thereof.
6. The method of claim 1 , wherein the iminoguanidine complexing agent has a Ksp value of from 1×10 −4 to 1.
7. The method of claim 1 , wherein the carbonate or bicarbonate salt of the iminoguanidine complexing agent has a Ksp value of from 1×10 −8 to 1×10 −14 .
8. The method of claim 1 , wherein the iminoguanidine complexing agent and the carbonate or bicarbonate salt of the iminoguanidine complexing agent have a difference in Ksp value of from 4 to 14 orders of magnitude.
9. The method of claim 1 , wherein the iminoguanidine complexing agent is selected from:
or any combination thereof.
10. The method of claim 1 , wherein the carbonate or bicarbonate salt of the iminoguanidine complexing agent is defined by the following structures of Formula I-a or Formula I-b:
wherein
A is a ring-containing moiety or a bond; one or more of the hydrogen atoms in Formula I-a or Formula I-b may be replaced with one or more equivalent number of methyl groups;
X m˜ is a carbonate or bicarbonate anion, with m being 1 for bicarbonate and 2 for carbonate; and
n is 0.5, 1, or 2; provided that n×m=2 for Formula I-a, and n×m=1 in the case of Formula I-b.
11. The method of claim 1 , wherein the carbonate or bicarbonate salt of the iminoguanidine complexing agent is selected from:
X m˜ is a carbonate or bicarbonate anion, with m being 1 for bicarbonate and 2 for carbonate; and n is 0.5, 1, or 2 or any combination thereof.
12. The method of claim 1 , wherein the iminoguanidine complexing agent comprises a metal salt with a Ksp value of from 1×10 −4 to 1, and which reacts with CO 2 to form a carbonate or bicarbonate salt with a Ksp value of from 1×10 −8 to 1×10 −14 .
13. The method of claim 1 , wherein the subterranean formation has a temperature below 65° C.
14. The method of claim 1 , further comprising injecting CO 2 through the wellbore and into the subterranean formation.
15. A method of influencing migration of a gas or fluid within a subterranean formation, the method comprising:
injecting an aqueous composition comprising an iminoguanidine complexing agent into the subterranean formation via a wellbore in fluid communication with the subterranean formation;
displacing the iminoguanidine complexing agent to a desired location within the subterranean formation; and
contacting the iminoguanidine complexing agent with carbon dioxide, resulting in precipitation of a carbonate or bicarbonate salt of the iminoguanidine complexing agent at the desired location within the subterranean formation,
wherein the iminoguanidine complexing agent is defined by Formula I-1 or Formula I-2:
wherein
A is a ring-containing moiety or a bond, and
one or more of the hydrogen atoms in Formula I-1 or Formula I-2 may be replaced with one or more equivalent number of methyl groups; and
wherein the subterranean formation has a temperature below 90° C.
16. A method of reducing migration of a gas or fluid within a subterranean formation, the method comprising:
injecting an aqueous composition comprising an iminoguanidine complexing agent into the subterranean formation via a wellbore in fluid communication with the subterranean formation; and
displacing the iminoguanidine complexing agent to a desired location within the subterranean formation to form a barrier to gas or fluid penetration;
wherein when the iminoguanidine complexing agent contacts carbon dioxide, a precipitate comprising a carbonate or bicarbonate salt of the iminoguanidine complexing agent forms at the desired location within the subterranean formation,
wherein the iminoguanidine complexing agent is defined by Formula I-1 or Formula I-2:
wherein
A is a ring-containing moiety or a bond, and
one or more of the hydrogen atoms in Formula I-1 or Formula I-2 may be replaced with one or more equivalent number of methyl groups; and
wherein the subterranean formation has a temperature below 90° C.