TROUBLESOME WELL ZONE ISOLATION DEVICE Russian patent published in 2006 - IPC E21B33/13 E21B33/12 

FIELD: oil and gas industry, particularly well cementing means, for instance secondary well cementing under pressure for well repair, for separation bridge installation in well in predetermined intervals and for other well isolation works performing.

SUBSTANCE: device comprises hollow shaft with hydraulic cylinder fastened in upper device part, radial orifices in lower part thereof and shoe located under the orifices. Sealing unit with support members and cones located on outer shaft surface is also provided. Device comprises lower jaw for device fastening on well wall, hydraulic drive to bring lower jaw in working position, which is combined with isolation solution supply unit adapted to inject isolation solution in well. The unit is made as lower and upper seats arranged inside shoe or shaft below radial orifices. The seat is adapted for free fall elastic member receiving and is located in annular gap between the shoe and outer surface of annular piston shaft. Working space of the piston is connected to shaft interior through radial orifices. Sealing unit deformation assembly is connected with mechanical drive, which brings upper jaw in working position to provide additional device fastening to well wall. The mechanical drive is made as installation unit having clutch in upper unit part. One clutch end is adapted to be connected to pipes for device lowering in well. Another clutch end is fixedly fastened to connection pipe and to nipple made as hollow piston. The nipple and hollow piston define annular gap for hydraulic cylinder installation. Connection pipe is installed outside of hydraulic cylinder and is connected with it by shear members to provide deformation force transmission from pipes to sealing unit for device lowering in well in working device position. Nipple-piston is located in hydraulic cylinder and has length, which differs from connection pipe length for not more than 20%.

EFFECT: increased operational reliability and simplified device structure.

6 cl, 1 dwg