SET OF EQUIPMENT FOR CUTTING THE "WINDOW" IN A HIGH STRENGTH CASING COLUMN Russian patent published in 2021 - IPC E21B29/06 

FIELD: wells drilling.

SUBSTANCE: invention relates to the field of drilling oil and gas wells and is intended for cutting a "window" in a casing string of high strength. The device includes a whipstock with an anchoring mechanism, a milling tool in the upper part of the whipstock, including a starting mill with a support ring in the form of a sliding bearing. The support ring of the starter mill has an outer protruding part with a diameter greater than the outer diameter of the end cap of the specified mill. On the working surface of the whipstock, an abrasive layer of hard alloy chips is applied. The place of application of the abrasive layer is determined by calculation from the condition that the support ring touches the inner wall of the casing when it moves along the inclined surface of the whipstock during milling. The milling tool contains a support milling cutter-reamer, the rear part of which is made smooth, and an intermediate milling cutter-reamer. The shape and geometrical parameters of the whipstock, cutters, connecting subs and their location in the assembly are selected in such a way that the starting points of contact of the starting, intermediate and support milling cutters with the casing are at three equidistant points. Geometrical parameters of equipment elements include length, diameter, angle of inclination of working surfaces. The support ring of the starter router is made of light-alloy material.

EFFECT: cutting of a "window" in the casing during one run of running and lifting the tool into the well, ensuring the unimpeded passage of the BHA through the cut "window".

3 cl, 3 dwg, 1 tbl