CASING PACKER Russian patent published in 2006 - IPC E21B33/12 

FIELD: mining, particularly casing pipe cementing inside well bore.

SUBSTANCE: packer comprises cylindrical body with central axial and inlet channels. Figured bush is fixedly fastened to one end of the body. The bush is provided with inner annular turning. Inlet channel from inner cylindrical body side is closed with shear plug installed in the channel and with check valve. Longitudinally corrugated shell composed of separate end and central sections is installed outside the body. The sections are connected with each other by means of reducing bushes. One end section of the shell is fixedly fastened to outer body surface. Reducing bushes are concentrically arranged along body length from outer body side and may perform axial movement relatively the body. Inner surface of reducing bush sections of the shell and outer body surface create hydraulic chamber communicated with central axial channel of the body through inlet valve. Sealing member with sealed inner cavity is arranged outside central shell section. The inner cavity is filled with plastic substance, for instance with raw rubber, sealant or mixture including hardening tar with liquid hardening agent contained in breakable capsules.

EFFECT: increased reliability of casing annulus packing due to elimination of cross-feed during cementing operation.

3 cl, 3 dwg