Drilling Methods

Flooded Reverse Circulation

Reverse circulation rotary drilling is a variant of the mud rotary method in which drilling fluid flows from the mud pit down the borehole outside the drill rods and passes upward through the bit. Cuttings are carried into the drill rods and discharged back into the mud pit.

Direct Mud Rotary

A drilling method is forcing fluid down the drill stem, out through the bit, and back up the borehole to remove the cuttings. Cuttings shake off a shaker, and fluid is recirculated in the borehole. 

Air Rotary

Drill Cuttings are removed by grinding the material finely enough so that the uphole velocity of the air is sufficient to lift them to the surface. The lifting capacity of the air can be enhanced by adding a small amount of surfactant and water solution to the air. Therefore, air drilling can be done only in semi-consolidated or consolidated materials.