Patent ID: 7884057

Claim:
A viscoelastic composition comprising water, at least one polycationic quaternary ammonium compound to control the viscoelasticity of the composition, wherein the at least one polycationic quaternary ammonium compound comprises a bis-quaternary compound of the following general formula: wherein R 2 , R 3 , R 4 , and R 5 are members independently selected from the group consisting of: (a) hydrocarbyl groups having from about 1 to about 4 carbon atoms; and (b) substituted hydrocarbyl groups having from about 1 to about 4 carbon atoms; or alternatively wherein R 2 and R 3 are members of a heterocyclic ring, and R 4 and R 5 are members of a different heterocyclic ring or are independently selected from group (a) as defined above or group (b) as defined above; wherein R 7 is a substituted hydrocarbyl group having from about 3 to about 8 carbon atoms; wherein R 1 and R 6 are independently selected from (c) substituted hydrocarbyl groups having from about 13 to about 40 carbon atoms; and wherein A 1 − and A 2 − are independently selected from the group consisting of: (i) negatively charged inorganic ions; (ii) organic molecules with one or more negatively charged functional groups; and (iii) negatively charged functional groups which are part of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , or R 7 ; the composition further comprising at least one additive selected from the group consisting of inorganic salts, organic acids, salts of organic acids, poly acids, salts of poly acids, diacids, salts of diacids, anionic surfactants, anionic hydrotropes, poly-anionic polymers, and combinations thereof; wherein the viscoelastic composition is a viscoelastic solution and wherein the combination of the at least one polycationic quaternary ammonium compound and the at least one additive is effective to obtain a viscosity of at least about 100 cP measured at a temperature of 90° C. and at a shear rate of 100 sec −1 .