EXPANDER FOR SIMULTANEOUS DRILLING AND EXPANSION OF WELL SHAFT 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 specified interval. Expander for simultaneous drilling and expansion of well shaft comprises a housing with inclined slots and a rod in it, a piston interacting with the rod, which is made annular and arranged in chamber formed by external wall of rod and inner wall of housing. Faces fixed in inclined slots of housing and connected with tie-rods to piston are feet with teeth arranged in longitudinal rows on working surface. Lower part of the housing is equipped with a mandrel with an axial hole in the form of an internal polygon corresponding to the outer polygon of the shaft inserted with a gap into the inner polygon of the mandrel with fixation against rotation and with possibility of limited axial movement until it stops against lower end of mandrel. Upper end face of the shaft rests against the end surface of the piston in the working position of the expander. In lower part shaft is equipped with internal thread for connection with bit. In upper part shaft is equipped with radial hole and limiting nut.

EFFECT: ensuring reliability and durability of structure, guaranteed expansion of expander into working position with simultaneous drilling and expansion, and expanding the barrel of the required diameter along the entire length of the expanded interval, as well as reducing the amplitude of oscillations and the value of impact loads.

1 cl, 2 dwg