Functions of Rheology

Success of a drilling, workover or completion fluid can be directly attributed to its viscosity at the shear rate of interest. In practice, fluids are subjected to a wide range of shear rates; therefore, a thorough understanding of fluid rheology and the impact of shear is necessary to optimize fluid design. Ideally, high viscosity is desirable only under low shear rate conditions, and should decrease as flow rate increases. Among the viscosifiers used, biopolymers exhibit unique rheological properties including increased low shear rate viscosity and an extended power law region. These differences stress the importance of understanding the rheological behavior of fluids in order to maximize performance and evaluate the relative merits of each fluid.