Reverse Circulation Drilling RC
Reverse Circulation (RC) drilling requires the usage of rods with inner and outer tubes. The drill cuttings are returned to the surface inside the drill rod. This is achieved by blowing air down the annulus of the rod and into the RC hammer. A shroud on the hammer ensures that the cuttings return through the rod. The drill cuttings then reach a deflector box at the top of the drill string and travel through the sample hose into a cyclone, where drill cuttings are caught into sample bags.