DEVICE FOR FORMATION TREATMENT INSIDE WELL Russian patent published in 2006 - IPC E21B33/12 

FIELD: oil production industry, particularly bore isolation means.

SUBSTANCE: device comprises packer having through body and elastic collar, as well as isolation means having bore with radial channels and inner cylindrical recess, slide installed in bore and provided with two rows of radial channels separated one from another with transversal solid partition. The device also comprises bush installed inside the slide and having ball seat. The ball is dropped inside the device before the second formation treatment. Upper row of radial channels of the slide is in front of radial channels of the bore. Bore, slide and bush are connected with each other by differential shear members. Before the second formation treatment upper and lower rows of radial slide channels are communicated with each other by means of inner cylindrical recess formed in the bore to provide hydraulic communication between tubing string interior and packer interior. Device also has additional packer located over isolation means and spaced a distance exceeding upper formation thickness from the packer. Additional packer comprises upper rest with cylindrical narrowed part, lower rest and additional elastic collar arranged on the narrowed part. Upper rest is movably installed so that the upper rest may slide into lower rest in axial direction. The upper rest is fixed into lower rest by means of shear member. Lower rest may cooperate with additional elastic collar. Upper rest is provided with hydraulic anchors compressed inwards and cooperating with casing pipe having increased pressure created in tubing string interior.

EFFECT: elimination of additional operation for casing pipe shutoff over upper formation.

3 dwg