APPARATUS FOR DRILLING PRESSURIZED EQUIPMENT Russian patent published in 2003 - IPC

FIELD: gas and oil production industry branches, geological exploration. SUBSTANCE: apparatus includes housing, spindle with drill, feed screw, joined flange with unit for controlling pressure, pilot wheel for providing rotation and translatory motion of drill. In order to drill equipment under high pressure spindle with hexahedral cross section is mounted with possibility of reciprocation motion in housing whose inner cavity in lower portion has hexahedral cross section for transmitting rotation to spindle. Spindle has along its whole length cavity for feed screw and it has in its wall two drilled openings for passing working fluid pressure from inner cavity of drilled equipment into inner cavity of apparatus in order to equalize pressure values in inner cavity of housing and in cavity of drilled equipment. EFFECT: improved design providing release of pushing out effort from spindle. 1 dwg