DEFLECTING DEVICE TO CUT PORT IN WELL CASING Russian patent published in 2018 - IPC E21B7/08 E21B29/06 

FIELD: oil and gas industry.

SUBSTANCE: device comprises a hollow mill-reamer fixed on the drill pipe string. A deflecting wedge is suspended from mill-reamer on a shear element provided with a hydraulic attachment unit with spacer element and at least one ram having teeth on the outer surface. Fluid supply channel is made in the form of a pipeline connecting the inner cavity of the mill-reamer and the hydraulic attachment unit comprising a fishing sleeve with inner collar and circulation holes and a nozzle jet with central channel and a seat directed against the flow for drawdown ball. The nozzle jet is placed inside the fishing sleeve. The hydraulic attachment unit comprises a cylinder sleeve, a hollow rod secured to the spacer element of the deflecting wedge, a hollow rod inside the cylinder sleeve, a threaded cap fixed to the lower part of cylinder sleeve, an annular piston, a supporting bushing in the bore of the lower part of the cylinder sleeve, an elastic rod fastened to the annular piston and a ram. The hollow rod is in communication with the pipeline connecting the inner cavity of the mill-reamer and the hydraulic attachment unit. The fishing sleeve is provided with its own channel for fluid located inside its side wall and inner collar, the inlet of the channel inside the side wall is located on the end of the fishing sleeve directed against the fluid flow, the outlet of the channel in the inner collar of the fishing sleeve is located on the end directed towards the hydraulic attachment unit. The pipeline for supplying fluid to the hydraulic attachment unit is connected to the outlet of the channel on end of the fishing sleeve through a flushing hole. The pipeline at point of connection to the fishing sleeve is equipped with a union comprising an annular groove with reduced cross-section of the union wall, capable of tearing the pipeline from the pipe union with tension of the drill string.

EFFECT: improved reliability of deflecting device fastening, reduced risk of accident, level of vibration, increased cutting ability of the mill-reamer, provided pure milling with smooth edges, increased accuracy when cutting a port per one running-pulling operation.

3 cl, 10 dwg