EXPANDER FOR SIMULTANEOUS DRILLING AND EXPANSION ON CASING STRING Russian patent published in 2020 - IPC E21B7/28 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling equipment of oil and gas industry, in particular to devices for increasing diameter of well in given interval. Expander for simultaneous drilling and expansion on a casing string consists of a body with through slots, in which on axes there are blades reinforced with hard alloy, spring-loaded piston with central rod and expanding cone at end interacting with blades made with ledge and installed with possibility of its contact with expander cone surface. Housing is made integral with coupling lower thread and is equipped with flushing holes, in which nozzles are installed, aimed at hard-alloy blade cutters in working position. Piston is made integral with expanding cone and is installed so that it under pressure drops moves downwards relative to housing. On external surface of piston there is a locking ring interacting with internal groove of housing in working position. Blades have cutting profile allowing uniform distribution of load on cutters, and in upper inner part are equipped with shanks, which interact with upper end surface of expanding cone and retaining blades in transport position.

EFFECT: ensuring reliability and durability of the structure.

1 cl, 3 dwg