Delivery of halogens to a subterranean formation
Compositions and methods for treating kerogen in a subterranean formation by generating bromine and other halogens in situ in a subterranean formation. In some implementations, the generation of the bromine or halogen is delayed. This can occur, for example, by the decomposition of precursors, a chemical reaction, the encapsulation of precursors or reactants, or a combination of these approaches.
1. A composition for treating kerogen in a subterranean formation, comprising:
at least one of a bromate or chlorate salt, wherein the bromate or chlorate salt is encapsulated in a first polymer, and wherein the bromate or chlorate salt comprises a cation comprising a fluorine-carbon bond; and
a reducing agent, wherein the reducing agent is at least one of red phosphorus or iodine.
2. The composition of claim 1 , wherein the reducing agent is encapsulated in a second polymer.
3. The composition of claim 1 , wherein the first polymer is a polyvinyl butyral polymer, vinyl acetal polymer, butyral polymer, styrene/-maleic anhydride copolymer, or alkylated vinylpyrrolidone copolymer.
4. The composition of claim 1 , wherein the first polymer is an enteric coating, and wherein the enteric coating is methylacrylate-methacrylic acid copolymers, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, hypromellose acetate succinate, polyvinyl acetate phthalate, shellac, cellulose acetate trimellitate, sodium alginate, or zein.
5. The composition of claim 2 , wherein the second polymer is a polyvinyl butyral polymer, vinyl acetal polymer, butyral polymer, styrene/-maleic anhydride copolymer, or alkylated vinylpyrrolidone copolymer.
6. The composition of claim 2 , wherein the second polymer is an enteric coating, wherein the enteric coating is a methylacrylate-methacrylic acid copolymer, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, hypromellose acetate succinate, polyvinyl acetate phthalate, shellac, cellulose acetate trimellitate, sodium alginate, or zein.
7. The composition of claim 1 , wherein the reducing agent has a standard reduction potential between that of the bromate salt and bromine or the chlorate salt and chlorine.
8. The composition of claim 1 , wherein the cation comprises [P(CF 3 ) 4 ] + .
9. The composition of claim 1 , wherein the cation comprises [N(CF 3 ) 4 ] + .
10. The composition of claim 1 , wherein the cation comprises bis(tri(4-fluorophenyl)phosphine)iminium.
11. The composition of claim 2 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium.
12. The composition of claim 3 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium.
13. The composition of claim 4 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium.
14. The composition of claim 5 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium.
15. The composition of claim 14 , wherein the first polymer is a polyvinyl butyral polymer, vinyl acetal polymer, butyral polymer, styrene/-maleic anhydride copolymer, or alkylated vinylpyrrolidone copolymer.
16. The composition of claim 14 , wherein the first polymer is an enteric coating, and wherein the enteric coating is methylacrylate-methacrylic acid copolymers, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, hypromellose acetate succinate, polyvinyl acetate phthalate, shellac, cellulose acetate trimellitate, sodium alginate, or zein.
17. The composition of claim 6 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium.
18. The composition of claim 17 , wherein the first polymer is a polyvinyl butyral polymer, vinyl acetal polymer, butyral polymer, styrene/-maleic anhydride copolymer, or alkylated vinylpyrrolidone copolymer.
19. The composition of claim 17 , wherein the first polymer is an enteric coating, and wherein the enteric coating is methylacrylate-methacrylic acid copolymers, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, hypromellose acetate succinate, polyvinyl acetate phthalate, shellac, cellulose acetate trimellitate, sodium alginate, or zein.
20. The composition of claim 7 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium.