Treatment fluids comprising weakly emulsifying surfactants and associated methods
View Patent ↗Provided are acidic treatment fluids comprising a weakly emulsifying surfactant, an aqueous base fluid, and an acid. In some embodiments, the treatment fluids are capable of forming short-lived oil-in-acid emulsions due, at least in part, to the interaction of at least a portion of the weakly emulsifying surfactant with one or more oil or gas molecules within a subterranean formation.
1. A method comprising:
providing a treatment fluid that comprises a weakly emulsifying surfactant, an aqueous base fluid, and an acid; and
introducing the treatment fluid into at least a portion of a subterranean formation;
allowing at least a portion of the treatment fluid to interact with at least a portion of the subterranean formation so as to create one or more voids in the subterranean formation; and
forming one or more short-lived oil-in-acid emulsions within the subterranean formation.
2. The method of claim 1 , further comprising:
allowing at least a portion of the weakly emulsifying surfactant to interact with at least a portion of the oil, gas, or both of the subterranean formation so as to prevent the formation of acid-induced sludge;
wherein the treatment fluid contains substantially no anti-sludge agent in addition to the weakly emulsifying surfactant.
3. The method of claim 1 , further comprising:
wherein the treatment fluid contains substantially no penetrating surfactant in addition to the weakly emulsifying surfactant.
4. The method of claim 1 , wherein the weakly-emulsifying surfactant comprises a compound selected from the group consisting of: ethoxylated long-chain alcohols, polyglucosides, alkyl ammonium bromides; alkyl sulfonates; alkoxylated sulfates; hydroxysultaines; and any combination thereof.
5. The method of claim 4 , wherein the weakly-emulsifying surfactant is an alkyl ammonium bromide comprising an alkyl chain having between 1 and 50 carbon atoms.
6. The method of claim 4 , wherein the weakly-emulsifying surfactant is an alkyl sulfonate selected from the group consisting of methyl sulfonate, heptyl sulfonate, decylbenzene sulfonate, dodecylbenzene sulfonate, and any combination thereof.
7. The method of claim 4 , wherein the weakly-emulsifying surfactant is a hydroxysultaine selected from the group consisting of: cocoamidopropyl hydroxysultaine, lauramidopropyl hydroxysultaine, lauryl hydroxysultaine, and any combination thereof.
8. The method of claim 1 , wherein the weakly-emulsifying surfactant is selected from the group consisting of: cationic, anionic, zwitterionic, and non-ionic, based at least in part upon the properties of one of oil, gas, and any combination thereof found in the subterranean formation.
9. The method of claim 1 , wherein the weakly-emulsifying surfactant is one of zwitterionic, amphoteric, and any combination thereof, and further wherein the weakly-emulsifying surfactant changes to one of anionic, cationic, and non-ionic as the acid is spent in the subterranean formation.