REAMER FOR DRILLING AND REAMING ON CASING STRING Russian patent published in 2022 - IPC E21B7/20 E21B7/28 E21B10/32 

FIELD: drilling equipment.

SUBSTANCE: invention relates to drilling equipment for the oil and gas industry, in particular to devices for increasing the diameter of a well with simultaneous drilling on a casing string in a given interval. Expander comprises a housing with a central passage channel and slots, blades equipped with shanks and rock-cutting elements fixed in housing slots with the possibility of extension upon interaction with the hollow shaft sleeve. The hollow shaft is provided with a piston located in the passage channel of the body, a thread for connection with the downhole motor and a side hole, it is fixed against rotation relative to the body by the surface of the hollow shaft and the surface of the body. The lower part of the hollow shaft in the working position is hermetically inserted into the reciprocal hole in the central flow channel of the body. The hollow shaft sleeve is made multifaceted in such a way that it brings the blades into working position when the conical surface of the hollow shaft sleeve interacts with the blade protrusion on the inner surface, formed by a radius concave surface and the inner working surface of the blades. The piston of the hollow shaft is integral with the hollow shaft. The hollow shaft is made in such a way that in the transport position its multifaceted section is inserted into the multifaceted opening of the housing, and the lower part of the hollow shaft in the transport position is hermetically inserted into the opening of the central flow channel of the housing. The upper part of the blades is equipped with a stop interacting with the upper surface of the housing grooves in the working position. The housing in the lower part is equipped with a replaceable drill head.

EFFECT: elimination of situations in which the expander would not take the working position during operation, as well as the exclusion of premature wear of the working elements of the expander and sludge in the internal cavity of the expander.

1 cl, 4 dwg