1.
n. [Drilling Fluids]
The instantaneous volume (spurt) of liquid that passes through a
filter medium prior to deposition of a
competent and controlling filter
cake. In static
filtration, the spurt volume can be a disproportionately large percentage of the total 30-minute filtrate in an
API-type test. This indicates that
filter cake is slow in being deposited compared to a similar
mud with lower spurt loss. To avoid uncertainties of spurt-loss volume, relative filtrate volume is used in static tests.