Annular velocity

Annular velocity is the speed of a fluid's movement in a column called an annulus in wells being drilled with circulating drilling fluid. It is commonly measured in feet per minute (ft/min) or meters per minute (m/min). Annular velocity is often abbreviated as AV, though this is not exclusively so, as AV also refers to apparent viscosity which is calculated from rheometer readings from tests that the mud engineer performs. Annular velocity is the speed of a fluid's movement in a column called an annulus in wells being drilled with circulating drilling fluid. It is commonly measured in feet per minute (ft/min) or meters per minute (m/min). Annular velocity is often abbreviated as AV, though this is not exclusively so, as AV also refers to apparent viscosity which is calculated from rheometer readings from tests that the mud engineer performs. For this article, annular velocity is described, as used in drilling fluid applications in the oil exploration industry. There may be other applications in other fields of study such as fluid mechanics (the study of the movement of fluid) or fluid dynamics (the study of the flow of fluid). The annular velocity can be calculated using one of the following formulas.