DEVICE FOR FORCED FLUSHING AND OILING OF DRILL BIT BEARING ASSEMBLY Russian patent published in 2004 - IPC

FIELD: well drilling equipment, particularly for well drilling with the use of roller bit and for bottomhole washing with water-and-air mixture.

SUBSTANCE: device comprises sub with nipple and bushing cavities separated one from another by partition arranged in central part thereof, axial orifice formed in central sub part, spring-loaded piston installed in axial orifice and having rod extending in bushing cavity, peripheral orifices connecting with sub chambers, radial orifice with plunger communicating with axial orifice and with nipple chamber by peripheral longitudinal channel. Radial orifice also communicates with outer space through horizontal orifice. Device has roller bit connected to sub bushing and having channels in sub legs and central flushing nozzle provided with check valve and spacing tube which extends into bushing cavity during well flushing over a distance equal to valve stroke. Rod remains in initial position during flushing process due to establishing communication between nipple cavity and rod cavity through longitudinal channel. When forced bit drilling assembly flushing and oiling plunger is manually moved to sub center for closing channel and opening horizontal channel for communicating rod cavity orifice with ambient space. Rod is moved downwards to prevent valve opening and the whole flushing flow is directed to bit bearing assembly for flushing and oiling thereof before new well drilling.

EFFECT: simplified structure, improved production technology.

1 dwg