Reverse Circulation Drilling Tools
Dual-wall drill pipe, reverse circulation hammers, bits, swivels and cyclones that return cuttings up an inner tube. Fast, clean chip sampling for grade control and resource drilling.
Features
- Cuttings return up an inner tube rather than the annulus, so the sample is not contaminated by the hole wall as it rises.
- A reverse circulation hammer is a down-the-hole hammer with an inner tube running through its centre.
- Sample recovery and contamination are the deliverables, so seal condition in the dual-wall string is part of sample quality.
- Penetration rates are much higher than core drilling, which is why it is used for grade control and infill rather than for structural logging.
- Cyclone, splitter and sample bagging arrangements are part of the tooling decision, not an afterthought.
Specifications
| Figure | Typical range | Unit | Why it matters |
|---|---|---|---|
| Hole diameter | 100 - 165 | mm | Sets sample mass per metre and the pipe size required. |
| Working air pressure | 17 - 35 | bar | Sets both penetration rate and sample lift. |