Air-Lift Concentric casing system / PiloTec

The PiloTec Air-Lift type stable concentric casing system consists of a pilot bit, segments and locking system. The segments expand and retract concentrically so a straighter hole can be drilled. The segments are closed by rotating the system in reverse direction to allow withdrawal of the PiloTec system and dth drill string after reaching the required depth.

The PiloTec AIR-LIFT type Stable Concentric Casing System consists of a pilot bit, segments and locking system. The segments expand and retract concentrically and so a straighter hole can be drilled. The segments are closed by rotating the system in reverse direction to allow withdrawal of the PiloTec casing system and dth drill string after reaching the required depth. The segments can be replaced separately and economically when they are worn out.

Having the two stages of air-lift hole specialist design, the PiloTec Air-Lift type stable concentric casing system can minimize disturbance to the surrounding sub-structure outside the casing.

Cross-section diagram indicates the two stages of air-lift hole system

• i. Compressed air travels back between the casing and inner drill string. There are two stages of air-lift hole creating vacuum pressure to ensure all cuttings and return air to suck back inside the casing. The second stage of air-lift hole system is to make sure and increase the suction effect efficiency and accelerate the cuttings inside the casing.
  Hence, the disturbance to the surrounding soil is minimized significantly.
• ii. Live air goes through passages in the body and is then returned inside the casing, whereby creating vacuum suction to suck cuttings away from the bottom and accelerate them inside the casing bore. There is almost negligible of live air passing into the system travels in contact with the ground.
• iii. The casing shoe forms a seal around the end of the casing, preventing air and cuttings from going outside of the casing.