RCD Air-lift Drilling Pipe
Reverse Circulation Drilling (RCD) is an effective drilling technique for a wide range of hole diameters including very large & deep holes, and holes drilled into hard-rock.
RCD involves the supply of air down through the drill-string to decrease the ‘effective density’ of the water in the center of the drill-string. Operating much like an ‘air-lift’, the drilling spoils are carried out of the hole through this rising column lower-density air/water mixture. RCD requires that the outer annular area of the casing be kept full of water in order to provide the hydraulic head required to effectively ‘push’ the central column of air/water/spoils up and out of the hole through the central pipe of the drill-string.
The flanged drilling pipe is a part of drill string to transmit torque from the rotator of pile-top drilling rig to drilling bit.