Patent ID: RE41585

Claim:
A method for controlling the rheology of treating an underground formation with a viscoelastic fluid in generated from an aqueous system , said method comprising: adding at least one gelling agent to said aqueous system in an amount effective to form said viscoelastic fluid, wherein said gelling agent comprises: a) providing one or more gelling agents selected from the group consisting of i) an one or more amidoamine oxide oxides of the general formula wherein R 1 is a saturated or unsaturated, straight or branched chain aliphatic group of from about 7 to about 30 carbon atoms, R 2 is a divalent alkaline alkylene group of from 2 to about 6 carbon atoms, R 3 and R 4 are the same or different and are alkyl or hydroxy alkyl of from 1 to about 4 carbon atoms, or R 3 and R 4 together with the nitrogen atom to which they are bonded form a heterocyclic ring of up to 6 members , and ; ii) a quaternary one or more ammonium salt salts obtained from the reaction of a monoamine or diamine possessing at least one secondary or tertiary amine group with the amine nitrogen directly bonded to a saturated or unsaturated, straight or branched chain aliphatic group of from about 12 to about 30 carbon atoms and an aromatic dicarboxylic acid; or iii) mixtures of i) and ii) b) adding said gelling agent to an aqueous fluid in an amount sufficient to form a viscoelastic fluid ; and c) injecting said viscoelastic fluid into an said underground formation in order to treat said underground formation .