Definition - What does Mud Balance mean?
The mud balance or mud scale is a device used to measure the density of drilling mud (drilling fluid) and cement slurries. It is a simple and practical way to determine fluid density as it can be easily carried for field use. It is also one of the most sensitive and accurate field instruments to determine the density or specific gravity of drilling fluids.
Determining mud density is important as mud has many important functions including transporting cuttings, serving as a medium for formation logging, transmitting power to bit nozzles, cooling and lubrication of drill bit, and reducing formation damage.
Trenchlesspedia explains Mud Balance
The mud balance device consists of a graduated beam, with a mud cup of fixed volume with a lid on one end, a bubble level and weight slider along its length, and a counterweight. The cup holds a fixed volume of fluid so that it can be weighed, and the weight slider can be moved along the beam. The bubble level indicates when the beam is level.
The mud balance is designed in such a way that a mud cup at one end of the beam is balanced by the fixed counterweight at the other end. The weight slider is moved along the beam and the density is read at the point where the weight slider sits on the beam at level. The mud balance can be calibrated with water or any liquid of known density by adjusting the counterweight. Mud weight accuracy should be within ±0.01 g/cm3 or ±0.1 lbm/gal.