reverse circulation drilling


reverse circulation drilling

[ri′vərs ‚sər·kyə¦lā·shən ‚dril·iŋ] (mining engineering) A variation of the rotary drilling method in which the cuttings are pumped up and out of the drill pipe, an advantage in certain large diameter holes. Diamond core drilling in which the water is injected through a stuffing box into the annular space around the drill rods and thus forced up special large drill rods.