DEVICE FOR CUTOUT OF WINDOW IN WELL CASING STRING Russian patent published in 2013 - IPC E21B29/06 

FIELD: oil and gas industry.

SUBSTANCE: device includes a cylindrical housing from dielectric material with an axial longitudinal channel for supply of electrolyte with density exceeding the density of borehole fluid and a side transverse channel, the axes of which intersect in its central part. In the body of cylindrical housing there radially made is an inclined channel in the form of a sector of an annular ring, which is hydraulically connected to the axial longitudinal channel. The inclined channel angle to the plane of cross section of the cylindrical housing is 20-40°, and height of the incline channel is within 10 to 30 mm. On side surface of the housing there made diametrically opposite to the inclined channel is a longitudinal cavity for an elastic membrane so that a cavity hydraulically connected to the side transverse channel is formed. A removable electrode, on the surface of which dielectric elements are arranged, is installed under the inclined channel. The removable electrode is a cathode and connected through an electrically insulated cable to a negative pole of the current source, and the casing pipe is an anode and connected to the positive pole of the current source.

EFFECT: improving quality and cutout efficiency of a window in the well casing string.

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