How is drilling fluid density adjusted?

Drilling fluid density is primarily adjusted by adding weighted materials such as barite. Barite, which is a high-density mineral, increases the overall density of the drilling fluid, allowing it to effectively counterbalance the pressures encountered in the borehole. This is essential, as maintaining the appropriate density is crucial for stabilizing the wellbore and preventing issues like blowouts or fluid influx.

Using weighted materials like barite provides a controlled and effective means of modifying density according to the specific requirements of the drilling operation. It also ensures that the fluid can return to the surface carrying cuttings and other debris efficiently, maintaining optimal drilling conditions.

The other methods mentioned do not provide a reliable or effective means of density adjustment for drilling fluids. For instance, adding air would reduce density rather than increase it, while reducing fluid temperature typically has minimal effect on density and is not commonly used for this purpose. Filtering out impurities is aimed at improving the quality of the drilling fluid but does not directly affect its density.