Patent ID: 7238649

Claim:
A powder composition for forming, in aqueous solution, a viscoelastic wellbore treatment fluid, the powder composition comprising: at least one oligomeric surfactant based on linked surfactant monomer subunits, each monomer subunit having the formula (R 1 -X) p Z m , where X is a charged head group, R 1 is a C 10 –C 50 organic tail group comprising a C 10 –C 25 straight chain bonded at a terminal carbon atom thereof to X, Z is a counterion, and p and m are integers which ensure that the surfactant monomer is charge neutral; and a salt of an alkali metal; wherein: the at least one oligomeric surfactant based on linked surfactant monomer subunits and the salt of the alkali metal are each in particulate form; the powder composition is stable and free flowing at ambient temperatures; and the powder composition is configured to produce a viscous surfactant solution that exhibits viscoelasticity upon mixing with an aqueous solution.