WELL EXPANDER Russian patent published in 2023 - IPC E21B7/28 

FIELD: well drilling.

SUBSTANCE: rock cutting tool for expanding wells. Well expander consists of a body with a central passage channel and grooves, blades equipped with liners and rock-cutting elements, fixed in the body grooves with the possibility of extension upon interaction with a hollow shaft sleeve made with a conical surface and multifaceted. The hollow shaft is equipped with a piston located in the passage channel of the body, and at the top is provided with a thread for connection with downhole equipment, a side hole and is fixed against rotation relative to the body. The lower part of the hollow shaft in the working position is hermetically inserted into the reciprocal hole in the central passage channel of the housing, equipped with a replaceable drill head. A spring is installed on the lower part of the hollow shaft between the piston and the end surface of the housing with a force that allows holding the hollow shaft and expander rams in the transport position when it is lowered in the inclined wellbore to the expansion interval. The conical surface and the faces of the sleeve interacting with the blades are provided with a wear-resistant coating, the hollow shaft is provided with a centralizer with a diameter of 6-9% more than the diameter of the expander in the transport position.

EFFECT: unhindered descent of the expander into the specified interval of the well, guaranteed extension of the rock-breaking elements to the working position, expansion of the well to the required diameter while maintaining the expansion diameter, guaranteed return of the expander to the transport position.

2 cl, 3 dwg