A polymer composition has been developed that provides low viscosity oil-in-water polymer emulsions that release the polymer in the emulsion at a faster rate and without an additional surfactant when the emulsion is added to a hydrocarbon stream. Use of a temperature-sensitive emulsifying surfactant facilitates inversion of the oil-in-water polymer emulsion when applied to a hydrocarbon composition at a temperature sufficiently high to destabilize the emulsion. These compositions are particularly useful as drag reducers for delivery to a subsea flowline via an umbilical line.