I would like to start with a hope that you and your families are staying safe. This month and next month, we will discuss the many descriptions and definitions of viscosity as it applies to drilling fluids. Key topics include:
Viscosity, the word, is derived from the Latin viscum, a word for both mistletoe and a viscous glue made from mistletoe berries. To confuse the issue even more, we often hear these terms to describe a drilling fluid: plastic viscosity (PV), apparent viscosity (AV), yield point (YP), shear thinning, Newtonian, and non-Newtonian. How do we put this all together so it makes sense?