DEVICE FOR SHUTOFF OF TROUBLESOME DRILLING ZONES IN BOREHOLE Russian patent published in 2011 - IPC E21B29/10 

FIELD: oil and gas production.

SUBSTANCE: device consists of shutter out of sections of profile tubes with cylinder portions on ends, lower one of which is equipped with shoe with back valve, while upper one is equipped with main opener with anchor unit for pressure tight connection with upper end of shutter. On top each lower section of profile tubes is equipped with an intermediate opener with the anchor unit for connection with the upper end of the section; while beneath each upper section is equipped with a connecting shoe. All shoes are threaded for connection with a corresponding section of the profile tubes, and with a fishing tool on top. From beneath each opener has a fishing head for the fishing tool of a corresponding shoe ensuring mutual fixation at interaction, while intermediate openers on top have a connecting unit telescopic connected with the connecting shoe located higher to facilitate limited lengthwise motion and to transfer torque. Length of the connecting unit is conditioned with a borehole.

EFFECT: expanded process functionality, reduced material expenditures.

3 dwg