The Flooded Reverse Circulation method is normally employed in drilling large diameter wells in unconsolidated formations.

As the drill bit rotates, a suction type pump is used to pull the cuttings loosened by the bit, through the hollow drill stem to the surface. Water from a supply pit near the rig circulates through a trench to the open drilled hole. This water serves to raise the water level in the drill hole to pit level so that hydrostatic pressure is applied against the wall of the open hole to prevent caving.

Flooded Reverse Circulation Strengths:

  • Deep large diameter boreholes possible
  • Can drill most geological formations
  • Less expensive than conventional rotary
  • Reduces borehole wall cake
  • Geophysical logging easily completed
  • Underbalanced drilling method leads to less well development and more efficient wells