ELECTROTHERMOMECHANICAL DRILLING METHOD AND APPARATUS Russian patent published in 1995 - IPC

FIELD: mining industry. SUBSTANCE: method involves effectuating simultaneously thermal unhardening of rock on face and hardening of rock by rock-destroying tool in the process of axial feeding of drilling projectile, with unhardening of rock being conducted by preliminary drying of rock at 400-450 K, dehydration at 700-750 K burning out of organic contaminants and dissociation followed by separation of gaseous phase at 750-900 K. Caking firing and melting of hardened rock in well walls are effectuated at 1800-2300 K. Drilling is performed by means of drilling machine, drill column with wave-guide for microwave channelling heater and penetrator, which is connected with drill column through reducer-crystallizer-shaper. Penetrator has part disposed adjacent to face and formed as conical rock-destoying tool. This part is connected to penetrator through reducer-thermal insulator. EFFECT: increased efficiency in drilling of wells in loose rocks. 3 cl, 4 dwg