REAMER FOR GUIDED DRILLING AND CASING EXPANSION Russian patent published in 2021 - IPC E21B7/28 E21B7/20 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 in a given interval. The expander contains a housing with a central passage channel and grooves, blades equipped with shanks and rock-breaking elements, fixed in the grooves of the housing with the possibility of extension when interacting with the hollow shaft sleeve, the hollow shaft is equipped with a piston placed in the housing passage channel, and at the top it is provided with a thread for connection with downhole equipment, side hole and is installed with fixation against rotation relative to the housing. The blades of the expander, when lowering into the well, are fixed in working position by shear elements connecting the housing and the hollow shaft with the possibility of their disconnection after the destruction of the shear elements when the hollow shaft is pulled relative to the blades. The end surface of the tapered sleeve of the hollow shaft, interacting with the shanks of the blades, translates the blades into the transport position. The lower part of the hollow shaft in the working position is hermetically inserted into the mating hole in the central bore of the housing. The connecting thread of the hollow shaft is made with a locking thread for connection with the downhole motor. Below the tooling thread, there are grooves for screwing a downhole expander with a downhole motor. The diameter of the circumscribed circle of the expander in the working position is 40-60% larger than the diameter of its circumscribed circle in the transport position. The length of the expander to the connecting thread is 2-2.5 diameters of the expander in the working position.

EFFECT: invention improves device reliability.

1 cl, 2 dwg