| 摘要 |
FIELD: mining.SUBSTANCE: head comprises external and internal pipes, a centraliser installed between them with axial channels and a slurry-receiving cone arranged above the crown and comprising washing channels in the form of slit-shaped slots. The upper part of the slurry-receiving cone and the contacting lower end of the internal pipe are made with inclined slots matched with slit-shaped slots of the slurry-receiving cone. The centraliser is equipped with hydraulic monitor attachments, the inlet part of which is connected to a descending washing channel, and the output part is directed to the well head.EFFECT: higher speed of drilling, reduced probability of core material jamming, reduced injury rate.2 cl, 2 dwg |
