Total Hardness and Chloride Content in Water Based Mud

“Total Hardness” or “Water Hardness” is a measurement of calcium (Ca2+) and magnesium (Mg 2+) ions in water base mud. The total of both soluble ions of calcium (Ca2+) and magnesium (Mg 2+) is given by titration with standard Vesenate solution.


What will be happening if you have a lot of total hardness in your drilling mud?

  • Bad mud cake (thick and mushy)
  • High fluid loss
  • Flocculation of clay content
  • Less polymer effectiveness
  • Ineffective chemical treatment

For most of the water base mud, the acceptable value of total hardness must be below 300 mg/L. If the lime drilling mud is used, it is acceptable to have a higher valu,e but is should be kept below 400 mg/L. Continue reading