| 摘要 |
FIELD: drilling without earth removal, for instance, with self-propelled burrowing devices. ^ SUBSTANCE: device comprises drill rod, displacing head removably connected to drill rod and displacing part formed on drill rod. The displacing part is widened with respect to adjacent drill rod part. Displacing part adapted for well wall smoothening is cylindrical and form lower drill rod end provided with removable displacing head. ^ EFFECT: increased stability of ready well wall. ^ 14 cl, 1 dwg |
