Viscosity is a measurement of a fluids resistance to flow: the greater the resistance, the higher the viscosity.
As measured by the Marsh Funnel, the viscosity of the fluid in question is influence by the density of the fluid (solids content) and gelation rate (beneficiated solids content). The viscosity of the drilling fluid in use should be based on a combination of the following parameters: Drilling rate, pump and output capacity, mud density, cuttings size, hole size and solids removal equipment.
Procedure: For seconds/quarts 1. Hold funnel in upright position with index finger over outlet. 2. Pour the test sample through the screen in top of the funnel until the mud level just reaches the underside of the screen. 3. Remove finger from outlet and measure number of seconds for a quart of sample to run out.