Marsh Funnel Viscosity

•Funnel viscosity is an indication of the overall viscosity of a drilling mud.
•It is affected by the concentration, type, size, and size distribution of the solids present, and the electrochemical nature of the drilling mud’s solid and liquid phase
•Consequently, funnel viscosity should only be used to provide an indication of change or consistency of viscosity from time to time. •Since Gel Strength can have a great effect on the magnitude of the funnel viscosity, the measurement should be taken quickly as possible Test Procedure
•With the funnel in an upright position, cover the orifice with a finger and rapidly pour a freshly collected mud sample through the screen, and into the funnel until the mud just touches the base of the screen (1500 ml).
•Immediately remove the finger from the orifice and measure the time required for the mud to fill the viscosity cup to the one (1) litrelevel for sec/l and (1) quart level for sec/q
•Report the result to the nearest second as the marsh funnel viscosity, at the temperature of measurement in degrees Celsius..