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:
a fracturing fluid; and
at least one N-halosuccinimide selected from a group consisting of N-bromosuccinimide, N-chlorosuccinimde, and N-iodosuccinimide,
wherein the N-halosuccinimide is dissolved in the fracturing fluid, and wherein the N-halosuccinimide is present in the fracturing fluid at a concentration of 0.001M to 0.10M.
2 . The composition of claim 1 , wherein the fracturing fluid is an aqueous-based fracturing fluid.
3 . The composition of claim 1 , wherein the fracturing fluid is a carbon-dioxide based fluid.
4 . A composition for treating kerogen in a subterranean formation, comprising:
a polymer;
at least one N-halosuccinimide selected from a group consisting of N-bromosuccinimide, N-chlorosuccinimide, and N-iodosuccinimide, wherein the N-halosuccinimide is encapsulated in the polymer; and
carbon dioxide-based fluid.
5 . The composition of claim 4 , wherein the polymer is a polymer matrix selected from a group consisting of polyvinyl butyral polymer, vinyl acetal polymer, butyral polymer, styrene/-maleic anhydride copolymer, and alkylated vinylpyrrolidone copolymer.
6 . The composition of claim 4 , wherein the polymer is an enteric coating selected from a group consisting of 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, and zein.
7 . The composition of claim 4 , wherein the encapsulated N-halosuccinimide is dissolved in the carbon dioxide-based fluid at a concentration of 5 to 100 pounds of encapsulated N-halosuccinimide per 1000 gallons of carbon dioxide-based fluid.
8 . A method for treating kerogen in a subterranean formation, comprising
dissolving at least one N-halosuccinimide selected from a group consisting of N-bromosuccinimide, N-chlorosuccinimide, and N-iodosuccinimide in a fracturing fluid to create an N-halosuccinimide solution; and
flowing the N-halosuccinimide solution into a subterranean formation at which kerogen is present.
9 . The method of claim 8 , wherein the dissolving at least one N-halosuccinimide in a fracturing fluid comprises dissolving at least one N-halosuccinimide in the fracturing fluid at a concentration of 0.001M to 0.10M.
10 . The method of claim 8 , wherein the fracturing fluid is an aqueous-based fracturing fluid.
11 . The method of claim 8 , wherein the fracturing fluid is a carbon dioxide-based fracturing fluid.
12 . The method of claim 11 , further comprising encapsulating at least one N-halosuccinimide before dissolving the N-halosuccinimide in the fracturing fluid, wherein the encapsulated N-halosuccinimide is dissolved in the fracturing fluid at a concentration of 1 to 100 pounds of encapsulated N-halosuccinimide per 10000 gallons of fracturing fluid.
13 . The method of claim 12 , wherein encapsulating the N-halosuccinimide further comprises encapsulating the N-halosuccinimide in a polymer matrix selected from a group consisting of polyvinyl butyral, vinyl acetal polymer, butyral, styrene/-maleic anhydride copolymer, and alkylated vinylprrolidone copolymer.
14 . The method of claim 12 , wherein encapsulating the N-halosuccinimide further comprises encapsulating the N-halosuccinimide in an enteric coating selected from a group consisting of 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, and zein.