EXPANDER FOR SIMULTANEOUS DRILLING AND EXPANSION OF WELLS Russian patent published in 2020 - IPC E21B7/28 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry, in particular to devices for increasing diameter of well in given interval. Expander for simultaneous drilling and expansion of wells comprises a housing equipped with upper and lower limiters and a rod arranged therein to form a chamber, an annular piston with a pusher arranged in the chamber, legs with cutters equipped with chamfers from below and configured to interact with corresponding inclined surfaces of housing and pusher of annular piston and limited radial movement outward. Feet are made in the form of dies with inclined surfaces on the upper and lower ends. In upper part of housing there is a spring-loaded down annular pusher, having inclined surface interacting with inclined surfaces located on upper end of slips. Pusher of the ring piston is movable and spring-loaded upward relative to the annular piston and is equipped with an inclined surface interacting with inclined surfaces of the dies on the lower end face and holding the die in the transport position. Water jet nozzles are installed in the flushing openings of the housing below the lower limiter. Plugs are equipped with carbide inserts behind row of cutters. Upper limit stop is connected with housing by left-hand thread.

EFFECT: ensuring reliability and durability of the structure.

1 cl, 2 dwg