1.
n. [Drilling Fluids]
A
parameter of the
Bingham plastic model. PV is the slope of the
shear stress/
shear rate line above the
yield point. PV represents the
viscosity of a
mud when extrapolated to infinite shear rate on the basis of the mathematics of the Bingham model. (Yield point, YP, is the other parameter of that model.) A low PV indicates that the mud is capable of drilling rapidly because of the low viscosity of mud exiting at the
bit. High PV is caused by a viscous base fluid and by excess
colloidal solids. To lower PV, a reduction in solids content can be achieved by
dilution of the mud.