In order to avoid this, it is necessary to check the axis of the well during drilling, it is good to refuel the bite, to pass a dangerous place several times, with a backfill of the well each time with sand or pebbles in places of curvature.
When meeting with a large boulder, especially if it lies on soft rocks, explosive work is used – torpedoing, with which a large boulder is crushed into small parts, which are then extracted with a bastard. Torpedoing is as follows: the well is cleaned of the dirt and a small hole is poured out in the boulder; casing pipes rise 2-3 m above the slaughter, after which an explosive charge is lowered into the well.
The charge is made elongated in order to freely pass in the well to the place of the explosion. The charge is lowered into the well in browned cardboard and is tightly pressed to the boulder. The volume of the charge is determined in accordance with the diameter of the well within 1-2 kg of dynamite or ammonal. If it turns out that the boulder after the explosion remained intact or the fragmented is not enough, then it is possible to move it using a loader.
To protect against emissions from the well during the explosion of the well, the well should be closed with a shield. In the explosion, all workers must be removed from the drilling tower. Explosive work should be carried out by experienced drilling masters who have a formal right.
With drilling not very solid rocks, simple tickling chisels are used; for more solid breeds – bite and zeta; For hard fissured, the cross -bit are consumed, and if passable hard rocks are intended to be overlap with pipes, the diameter of the couplings of which is more than the length of the loan blade, then the drilling is made with an extensor, which is turned on, as already indicated, between the chisel and the shock bar.