Investigation of Ice and Rock Drilling by Melting

Considerable experience of the Leningrad Mining Institute in deep borehole drilling by melting in Antarctica and in Arctic Ocean islands as well as successful experiments in rock drilling by melting confirm the possibility that this new method of borehole drilling provides certain important advantages. Many technological processes are followed by melting of solid bodies in contact with surface heated up to a temperature which is higher than the melting point. The melt which forms flows from the heated surface or melting sample under the action of an impressed force. This method (combined with others) is used in mining when sinking shafts, for quick ground consolidation of quicksands. The essence of this method is installing a heater into the thickness of the quick grounds to be traversed. When current passes through the electrodes of the heater, electrons come into collision with atoms of the conductor lattices and so electric energy is transformed into heat energy. The conductor (heater) is heated to a high temperature and melts the surrounding quickground. The idea of openings (holes) sunk by melting provides for 3 most important advantages:

• using of drills with hoist electrical cable, which eliminates the necessity of drill pipes and of labor-consuming and prolonged descent-hoist operations;
• supporting (when drilling) of hazardous or fissured rocks because through solidification of the hole walls by the melt which is over the penetrator, which eliminates the necessity of a casing , of expensive work on shaft lining or of plugging;
• more effective and wider application of the methods of logging and well geophysics due to the absence of the action of steel casing screening.