Hydraulic fracturing using non-ionic surfactant gelling agent
View Patent ↗The present invention generally relates to a method for treating a subterranean formation with an aqueous viscoelastic treating fluid that an aqueous base fluid and one or more non-ionic amido amine oxide surfactant gelling agents. The treatment method comprises injecting the aqueous viscoelastic surfactant treating fluid through a wellbore and into the subterranean formation under conditions effective to control fluid loss, and breaking the gel of the aqueous viscoelastic treating fluid subsequent to treating said formation.
1. A method for controlling fluid loss in a subterranean formation comprising:
providing an aqueous viscoelastic treating fluid having:
an aqueous base fluid; and
one or more non-ionic amido amine oxide surfactant gelling agents having the formula:
where R is an alkylamido group averaging from about 8 to 27 carbon atoms and R′ are independently hydrogen or alkyl groups averaging from about 1 to 3 carbon atoms as the only gelling agents employed; where the viscoelastic treating fluid further comprises a salt or easily removed solid or mixtures thereof;
wherein said treatment comprises
injecting the aqueous viscoelastic surfactant treating fluid through a wellbore and into the subterranean formation under conditions effective to form a gel thereby controlling fluid loss, and
breaking the gel of the aqueous viscoelastic treating fluid subsequent to treating said formation.
2. The method of claim 1 where the non-ionic amido amine oxide surfactant gelling agent is employed is present in the aqueous base fluid in a proportion from about 0.5 to about 25 vol. %.
3. The method of claim 1 where the non-ionic amido amine oxide surfactant gelling agent is tallow amido propylamine oxide (TAPAO).
4. The method of claim 1 where the aqueous base fluid is brine.
5. The method of claim 1 wherein the breaking of the gel of the aqueous viscoelastic treating fluid is accomplished by a mechanism selected from the group consisting of contact with a hydrocarbon, contact with alkoxylated alcohol solvents, dilution, and contact with at least one reactive agent.
6. A method for controlling the fluid loss in a subterranean formation which comprises treating said formation with a viscoelastic treating fluid which comprises:
an aqueous base fluid; and
a gelling agent that comprises a non-ionic amido amine oxide, wherein said amido amine oxide is tallow amido propylamine oxide (TAPAO);
wherein said viscoelastic treating fluid further comprises a salt or solid, or and mixtures thereof;
wherein said treatment comprises
injecting the aqueous viscoelastic surfactant treating fluid through a wellbore and into the subterranean formation under conditions effective to form a gel thereby controlling fluid loss, and
breaking the gel of the aqueous viscoelastic treating fluid subsequent to treating said formation.
7. The method of claim 6 where the non-ionic amido amine oxide surfactant gelling agent is employed is present in the aqueous base fluid in a proportion from about 0.5 to about 25 vol. %.
8. The method of claim 6 where the aqueous base fluid is brine.
9. The method of claim 6 wherein the breaking of the gel of the aqueous viscoelastic treating fluid is accomplished by a mechanism selected from the group consisting of contact with a hydrocarbon, contact with alkoxylated alcohol solvents, dilution, and contact with at least one reactive agent.