CONNECTION OF SHAPED PIPES OF WELL SHUTOFF DEVICES Russian patent published in 1996 - IPC

FIELD: oil and gas producing industry; applicable in shutoff of lost circulation zones in well drilling and major repair of casing strings. SUBSTANCE: connection makes it possible to protect sealing member in assembly of shutoff device and its lowering into the well down to interval of installation and to increase its tightness. Connection of shaped pipes of well shutoff devices is made of cylindrical box 1 and nipple 2 with square thread. Made on them in places of transition to shaped part are circular shoulders, it is locked with pin 2. Shoulders 5 and 6 protect sealing member 10 from damage during running of shutoff device into well. External sealing members 10 reliably disconnect isolated zones by preventing crossflows between formations and seal the external joint of pipes. Internal sealing members 9 ensure sealing of threaded joint. EFFECT: higher efficiency. dwg