Wireline Core Drilling Systems
Rod strings, core barrels, overshots and bits where the inner tube is winched out on a cable without pulling the rods. The standard method for medium to very deep exploration holes.
Features
- Retrieving only the inner tube keeps the rod string in the hole, so tripping time stops growing with depth the way it does in conventional drilling.
- The rod acts as the outer tube, which means rod wall thickness and internal finish are part of the core recovery system.
- Overshot and latch condition decides whether a run is recovered first time; a worn latch costs more than the part does.
- Triple-tube assemblies with a split inner liner preserve broken and friable core for geotechnical logging.
- Rod string life is tracked by drilled metres, and inspection is on a schedule rather than after a failure.
Specifications
| Figure | Typical range | Unit | Why it matters |
|---|---|---|---|
| Size designation | BQ / NQ / HQ / PQ | Fixes rod, barrel, bit and casing sizes together. | |
| Core diameter | 36,5 / 47,6 / 63,5 / 85,0 | mm | Sets the sample available for assay and testing. |
| Barrel configuration | double tube / triple tube | Triple tube preserves broken core for geotechnical work. | |
| Core barrel length | 1,5 / 3,0 / 6,0 | m | Trades retrieval time against core loss risk per run. |