Advantageous in unconsolidated formations with a high risk of caving
ODEX is an adaptation of the air-operated down-the-hole hammer. It uses a swing-out eccentric bit to ream the bottom of the casing.
Cuttings blow up through the drive sub and casing annulus to a swivel conducting them to a sample collector or onto the ground.
- Rapid removal of cuttings
- No use of drilling mud
- High penetration rate, especially in resistant rock formation (e.g. basalt)
- Easy soil and groundwater sampling during drilling
- Possible to measure yield estimate at a selected depth in the formation