DEVICE FOR THERMAL-MECHANICAL DRILL OF HARD FORMATIONS Russian patent published in 2009 - IPC E21B7/15 B28D1/14 

FIELD: mining engineering.

SUBSTANCE: invention relates to field of drilling, rocks extraction and stones-working. Device contains plug bit, plasmatron, feed system of plasma-forming gas, cooling system of plasmatron, casing, nozzle and is outfitted by core barrel, connected in top part with boring bar, on which there are installed plough for supplying of electricity to plasmatron and swivel for feeding of compressed air for cleaning of well bottom, cooling of plasmatron and crown bit. Bottom part of core barrel is connected to cylindrical removable crown bit, on which there are installed cutters, implemented from heat-resistant materials. On external surface of core barrel there are installed feed system of air-water mixture and feed system of electricity and plasma-forming mixture of gas and water into plasmatron and are connected in bottom part to cylindrical crown bit. In top part they are connected to two tanks of plasma-forming mixture of gas and water, the first from them is rigidly fixed to boring bar, and the second tank is connected to the first tank by means of bearings with the device, providing its pressurisation. Feeding of gas and water into the first tank is implemented through connecting pipes and communicating openings on side walls of the first tank.

EFFECT: it provides effectiveness increase of hard formation drilling with removing of weakened streak of formation from well bottom.

3 cl, 3 dwg