Barite

Barite or Barium Sulphate (BaSO4) is an inert mineral named after the Greek word ‘barus’ meaning heavy. It is usually colorless or milky white, but can be almost any colour depending on the impurities trapped in the crystals during their formation.

Pure barite has a specific gravity of 4.50 and its principal use is in the manufacture of oil well drilling fluids. In practice the material used in drilling fluids runs between 4.10 and 4.25 specific gravity. Currently, over 75% of barite consumption in the U.S. is for this drilling application. However, the consumption in drilling "mud" fluctuates from year to year depending on the amount of oil and gas exploration.

The functions of a drilling fluid are;

  • - To clean cuttings from the well bottom.
  • - Flush those cuttings to the surface.
  • - Cool and lubricate the drill bit.
  • - Deposit a “ filter cake’ layer on the wellbore wall to prevent loss of the circulating fluid.
  • - Prevent formation fluids entering the borehole and mixing with circulating fluids.
  • - Support the walls of the well bore without damaging the formation.
  • - Control pressures under the surface.

Reasons for barite’s use over other materials:

  • - Neutrality - chemically, physically and magnetically neutral
  • - environmentally acceptable from the standpoint of its disposal as part of the drilling fluid.
  • - Far less abrasive than other materials and does little damage to drilling equipment.
  • - Low cost