DEVICE FOR ADJUSTING BOTTOM-HOLE PRESSURE IN PROCESS OF DRILLING Russian patent published in 1998 - IPC

FIELD: oil production industry; bore-hole drilling technology. SUBSTANCE: device has body with packing member, and installed inside this member is pipe which is hydraulically connected with above- and under-packing annular space. Packing member is made in the form of collar with reinforced ring. Internal space of it through non-return valve with calibrated hole is connected with internal space of drilling string. Device ensures local dynamic disconnection of annular space of drilling tool in adjusting bottom-hole pressure in process of drilling bore-hole at maintaining round circulation of liquid through drilling tool. EFFECT: higher efficiency. 3 dwg