UNIT FOR DRILL OPENING OF CASING PIPE IN WELL Russian patent published in 2010 - IPC E21B43/119 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil and gas industry, particularly to devices for secondary drill opening of a bed (perforation) by drilling. The unit comprises a rejecting device with a curved channel lowered in a casing pipe on pipes wherein on a pipe string there is lowered an engine with an output shaft connected by a flexible shaft with a cutting tool provided with a stop block. The rejecting device is supplied with an anchor unit fixing it in relation to the casing pipe at the required interval. The pipes above the rejecting device are supplied with internal stoppers, while the engine is provided with external limiters interacting with the coupled stoppers with fixing the engine in relation of the pipes from rotation and descent downwards. Between the output and flexible shafts, there is mounted a loaded shaft connected to the output shaft to perform limited axial motion.

EFFECT: design of the offered device allows using both hydraulic, and electric engines, it is reliable and efficient due to controlled arrangement of the engine in relation to the rejecting unit which is fixed by the anchor unit in relation to the well walls.

4 cl, 1 dwg