WELL BORE EXPANDER Russian patent published in 2018 - IPC E21B7/28 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of oil and gas industry, in particular to the construction of oil and gas wells and can be used to increase the diameter of the wellbore in a given interval. Expander includes a housing with a central channel and connecting threads at the ends, a hydraulic chamber with an annular piston installed inside, dies with cutting elements installed in inclined grooves, a means of turning the piston relative to the housing, side holes for supplying the working fluid to the hydraulic chamber and the fitting nozzle to create a pressure drop in the hydrochamber. Lower end of the body is provided with a tip with an additional nesting attachment installed in the side channel, made at an angle upwards. Tail part of the tip is made in the form of a cylinder with an inner annular stepwise bore, forming a hydraulic chamber with an outer wall of the housing, communicated with the central channel. To fix the position of the dies relative to the body, a tubular guide with longitudinal windows with dies installed in them with the possibility of their free passage is installed concentrically with it. Lower end of the guide on the thread is connected to the piston and fixed with a key, fixed to the piston with screws, installed in one of the spline-like grooves made along its entire perimeter. Guide is provided with stepped stops, fastened with screws, and preventing the guide and the associated piston from turning against the housing, while the upper ends of the stops are at the same time the supporting surface for the dies. Piston is provided with a return spring installed between the guide and the stepped bore of the housing.

EFFECT: simplified design, manufacturing and operation, increasing the life of the expander, the possibility of regulation in the direction of increasing or decreasing the diameter of the wellbore.

1 cl, 5 dwg