摘要 |
<p>Fluids viscosified with viscoeiastic surfactants (VESs) may have their viscosities affected (increased or reduced) by the indirect or direct action of a composition that contains at least one fatty acid that has been affected, modified or reacted with an alkali metal halide salt, an alkaline earth metal haiide salt, and/or an ammonium salt and a water soluble base. The composition containing the resulting saponification product is believed to either act as a co-surfactant with the VES itself to increase viscosity and/or possibly by disaggregating or otherwise affecting the micellar structure of the VES-gelled fluid. In a non-limiting instance, a brine fluid gelled with an amine oxide surfactant has its viscosity broken with a composition containing naturally-occurring fatty acids in canola oil reacted with a water soluble base such as NaOH, KOH, NH4OH, and the like with an alkali halide salt such as CaCI2, MgCI2, NaCI, NH4CI and the like.</p> |