EXPANDING HYDRAULIC PACKER Russian patent published in 2000 - IPC

FIELD: oil and gas producing industry; applicable in isolation of wellbore. SUBSTANCE: packer has body with sealing member secured thereto in form of elasto-expanding hose, hollow barrel coaxially installed in body, and main piston. They form pressure hydraulic chamber. Installed between body and barrel above main piston is external piston. The latter forms additional cavity together with main piston. Additional cavity is communicated with intrapipe space through radial holes in barrel. Barrel is installed for axial motion relative to body and sealing member. Barrel has bead for thrusting the main piston. Installed concentrically on barrel is spring thrusting the body. Pressure chamber is filled with pure pressure fluid during packer assembly. Additional cavity is filled with well working mixture. EFFECT: extended functional potentialities due to multiple change over of packer from transportation to working positions and vice versa in running it into well without its withdrawal. 2 cl, 1 dwg