It is an inert, heavy mineral that has a theoretical specific gravity of 4.5, and its main use is in oil well drilling. In practice, the material used in drilling fluids is between 4.10 and 4.25 specific gravity.

In the process of drilling for oil and gas, drilling fluids serve a variety of vital purposes in the economic achievement of reaching the desired depth.

The functions of a drilling fluid are:

• Clean cuttings from the bottom of the well.
• Clean cuttings from the surface.
• Cool and lubricate the drill bit.
• Deposit a layer of "filter cake" on the borehole wall to prevent loss of circulating fluid.
• Prevent formation fluids from entering the wellbore and mixing with circulating fluids.
• Support the wellbore walls without damaging the formation.
• Control pressures below the surface.

The reason for the use of barite over other materials is its neutrality: chemical, physical and magnetic.

Most barite is environmentally acceptable from the standpoint of disposal as part of the drilling fluid. It is much less abrasive than other materials.