Triple tube wireline core barrels have all the benefits of the standard wireline system with the additional advantage that difficult formations can be cored and the core can be inspected in an almost undisturbed condition. It is especially useful for coring in coal, clay-bearing or highly crushed and fractured formations.
The triple tube system is made up by adding a third tube to the standard wireline core barrel. This third tube is made of stainless steel, split lengthwise and nested inside the inner tube.
Coring with the W/L3 core barrel proceeds in the same way as the standard wireline type. However, after the inner tube is retrieved with the overshot, the corelifter case is removed and the split tube is hydraulically pumped out from the inner tube. The upper half of the split tube is carefully lifted off, revealing the core in a virtually undisturbed condition for transfer to the core box.
These core barrels are available in hole sizes B, N, H and P. All parts are fully interchangeable with Longyear "Q-3" series and Boyles "O-3" series wireline core barrels.
Features of the W/L wireline system include:
| Triple Tube W/L3 Core Barrel | ||
| Size Designation |
Hole Diameter (mm) |
Core Diameter (mm) |
| B W/L3 | 59.9 | 33.5 |
| N W/L3 | 75.7 | 45.1 |
| H W/L3 | 96.1 | 61.1 |
| P W/L3 | 122.6 | 83.0 |
| Core Bit and Diamond Reaming Shell to be purchased separately. | ||