Patent ID: 7216709

Claim:
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.