Long-chained polymer compounds are useful to viscosify aqueous brine fluids so that they can function as drilling fluids, completion/workover fluids, fracturing fluids, agricultural products, cleaning compounds, etc. These polymers may be hydrated with a microemulsion or lactescent emulsion prior to being added to the target fluid. The rate and completeness of hydration by this method are controlled and improved. In one non-limiting embodiment the microemulsion includes a polar hydrocarbon component, a nonpolar hydrocarbon oil, a small amount of water, a surfactant and optionally a co-surfactant.