Annular velocity is the speed of the drilling fluid's movement in a column called an annulus in oil wells.
For this article, annular velocity is described, as used in drilling fluid applications in the oil exploration industry.
Or Where: The annular velocity is one of two major variables in the process of cleaning solids (drill cuttings) from the wellbore.
Viscosity (sometimes thought of as its thickness) is a very basic measurement of the fluids resistance to change in movement or flow.
Rheology is the study of viscosity and requires more precise and complicated procedures and equipment for its determination.