Marsh funnel measurement infers which property of drilling mud?

• A. Viscosity
• B. Density
• C. Temperature
• D. pH

Answer: (A)

Marsh funnel measurement is a quick way to gauge the apparent viscosity of drilling mud. In this test, a fixed volume of mud drains through a standardized funnel while you time the drainage. The longer the mud takes to drain, the more viscous it is; faster drainage means lower viscosity. This provides a practical, field-friendly indication of how thick or runny the mud is, which matters for suspending cuttings and keeping the wellbore stable. It doesn’t measure density, temperature, or pH, which require different tests or instruments. For precise viscosity, lab viscometers or rheometers are used, but the Marsh funnel gives a quick, useful snapshot in the field.