Mud balance

Drilling Fluids & Logging

A mud balance constitutes the simplest yet most critical instrument on the rig. It is a beam balance scale used to verify the density (mud weight) of the drilling fluid, typically measured in pounds per gallon (ppg).

The mud engineer or derrickman fills the cup with mud and balances the beam. Accurate density is the primary control against formation pressure. If the mud weight is too low, the well flows (kick); if too high, the formation fractures (lost returns).