WELL REAMER Russian patent published in 2025 - IPC E21B7/28 

FIELD: earth or rock drilling.

SUBSTANCE: invention relates to drilling, namely to rock cutting tool for well expansion. Reamer of wells comprises a housing with a central through channel and slots, blades equipped with shanks and rock-destroying elements, fixed in slots of housing with possibility of extension at interaction with bushing of hollow shaft, made multifaceted. Hollow shaft is equipped with a piston arranged in a through channel of the housing, and at the top it is equipped with a thread for connection with downhole equipment, a side hole and is installed with fixation against turning relative to the housing. Besides, the lower part of the hollow shaft in the working position is tightly inserted into the mating hole in the central through channel of the housing. Spring is installed on the shaft between the piston and the end surface of the housing. Hollow shaft is made integral with the bushing and is equipped with a nozzle in the central channel, and the piston of the hollow shaft is equipped with a collar. To obtain the required alignment, a cage is screwed onto the housing. Dural centralizer with diameter 0.5-5 % larger than reamer diameter and equipped with inter-blade planes guiding flushing fluid flow to reamer blade cutters is installed on the housing in the lower part on thread and fixed against the turnout. Centralizer is reinforced with hard-alloy pellets on the outer surface of the blades and is equipped with a replaceable sleeve with nozzles; the number of centralizer blades is a multiple of the number of expander blades.

EFFECT: proposed device is reliable and durable design, allows to lower it to specified interval of well, by creation of pressure it is guaranteed to extend into working position of cutting elements, to expand the well to the required diameter at minimum flow rate of flushing fluid and to be guaranteed to be folded into the transport position for unobstructed extraction due to coaxiality of the hollow shaft with the piston and the housing with the cage.

1 cl, 3 dwg