HORIZONTAL BORE CRYOGENIC DRILLING METHOD

摘要

An apparatus for drilling a horizontal bore in an earth formation includes in a first embodiment a vertical caisson installed in or near the earth formation. A horizontal casing extends radially externally and internally of the caisson. A grindable pipe extends radially externally from the horizontal casing into the earth formation. A method of forming a horizontal bore in an earth formation includes providing the vertical caisson, horizontal casing and grindable pipe of the first embodiment of the apparatus. The method includes creating a first freeze zone of frozen moisture about the grindable casing by flowing a cryogenic fluid through the grindable casing and then forming a pilot bore in the earth formation extending from the caisson through the freeze zone.