Patent ID: 7681672
Filing Date: 2010-03-23
Classification: E21B

Abstract:
1. A cryogenic rapid boring system for rapidly boring a hole in a material comprising: a) a borehead having at least one pulsejet with a proximal end and a distal end located adjacent to said material intended to be bored; b) a cryogen supply unit for providing a cryogenic liquid to fill the pulsejet; c) a pulsejet having an expansion section located adjacent to the distal end; d) a tube having a freeze section located just proximal to the expansion section; e) at least one thermal unit capable of freezing cryogenic liquid into a plug and capable of melting the frozen plug located adjacent to the freeze section; f) at least one thermal unit capable of vaporizing the cryogenic liquid into a gas, and capable of cooling the expansion section; g) a controller coupled to the cryogen supply unit, the thermal units, and operating to activate: