1. n. [Drilling Fluids]

A fluid described by the two-parameter rheological model of a pseudoplastic fluid, or a fluid whose viscosity decreases as shear rate increases. Water-base polymer muds, especially those made with XC polymer, fit the power-law mathematical equation better than the Bingham plastic or any other two-parameter model. Power-law fluids can be described mathematically as follows:

See related terms: Bingham plastic model,  centipoise,  direct-indicating viscometer,  Herschel–Bulkley fluid,  Newtonian fluid,  non-Newtonian fluid,  plastic fluid,  pseudoplastic,  rheological property,  rheology,  shear rate,  shear stress,  viscosity,  XC polymer