1. n. [Drilling Fluids]
A property of fluids and slurries that indicates their resistance to flow, defined as the ratio of shear stress to shear rate. Viscosity can be expressed mathematically as follows:
See: bentonite, Bingham plastic model, breaker, Brookfield viscometer, capillary tube viscometer, carboxymethylcellulose, centipoise, derrickman, direct-indicating viscometer, funnel viscosity, gel strength, gyp mud, Herschel-Bulkley fluid, high-pressure, high-temperature viscometer, Marsh funnel, mud additive, Newtonian fluid, non-Newtonian fluid, pill, plastic fluid, power-law fluid, pseudoplastic, PVT, rheological property, rheology, shear rate, shear stress, VG meter, yield