Patent ID: 8524642

Claim:
A viscoelastic fluid, comprising: one or more cationic surfactants; one or more anionic surfactants having alkyl chains of about 6 to about 18 carbon atoms with at least one negatively charged moiety; one or more zwitterionic surfactants and/or one or more amphoteric surfactants; and water; wherein the one or more cationic surfactants is polyoxyethylene(2-15)cocoalkylamines wherein the one or more zwitterionic surfactants has the following structural formula: wherein R 1 is a hydrophobic moiety of alkyl, alkylarylalkyl, alkoxyalkyl, alkylaminoalkyl or alkylamidoalkyl, wherein R 1 has from about 18 to about 30 carbon atoms and may be branched or straight-chained and saturated or unsaturated; R 2 and R 3 are, independently, selected from the group consisting of an aliphatic moiety having from 1 to about 30 carbon atoms and an aromatic moiety having from 7 to about 30 carbon atoms; the aliphatic moiety being branched or straight-chained and saturated or unsaturated; R 4 is a hydrocarbyl radical with a chain length 1 to 4; and wherein the one or more amphoteric surfactants has the following structural formula: wherein R 1 , R 2 , and R 4 are as described above.