Polymers dissolved in solvents are employed widely as
adhesives and coatings. And, with added surfactants,
polymer solutions provide the basis for paints, cosmetics,
detergents, and other recovery fluids. Both steady and
dynamic rheological tests can be used to evaluate these
materials. High polymer solutions are used to enhance oil
recovery, but they lose effectiveness after extended use.
This happens because of a permanent viscosity reduction
due to shear degradation of the polymer, under the high
shear rates generated by the rotating bit in the well bore.
The combination of a high molecular weight polymer and
a surfactant can develop high viscosities by formation of
complexes insensitive to shear degradation.