DEVICE FOR TROUBLESOME ZONE ISOLATION IN WELL Russian patent published in 2007 - IPC E21B29/10 

FIELD: oil and gas well drilling and repair, particularly means to isolate troublesome well zones and casing pipe leaking zones.

SUBSTANCE: device comprises shutter including sections made as profiles pipes with cylindrical end parts. The sections are connected with each other by threaded connection. Device also has reamer with mandrelling or rolling head arranged over profiled pipe and provided with drilling pipe connection unit. Shoe with check valve is arranged in lower shutter end. Inner thread formed in cylindrical profiled pipe sections is provided with inner annular grooves. Outer pipe created therein has inner annular extension corresponding to inner annular grooves. Outer thread of cylindrical profiled pipe part has inner annular grooves, inner thread therein has inner annular extension corresponding to annular grooves. Outer and inner annular extensions have annular inner and outer beads correspondingly. The beads correspond to outer and inner annular groves.

EFFECT: increased connection seal reliability.

3 dwg