EXTENDING REAMER Russian patent published in 2014 - IPC E21B7/28 

FIELD: oil-and-gas industry.

SUBSTANCE: extending reamer comprises body, piston, spring, pusher and articulated working tool. Rock destruction tool is composed of all-symmetric blade, a bit wider in central section and gradually converging at ends, to run in vertical plane on horizontal pivot penetrating through the body and blade mid part. Said body has two diametrical openings shaped to lengthwise cavities in width equal to that of the blade. One opening is arranged above the other to allow the blade one half to penetrate inside the body via lower opening and blade second half to pass via upper opening to transport position. Blade completely extended to working position via said openings, it is located perpendicular to body lengthwise axis. Note here that blade top part lower surface is placed on upper opening lower surface while blade bottom part upper surface thrusts against bottom opening upper surface to lock the blade in operating position. Body top part has thread for connection with string while cylindrical stepped channels is made under said thread and shifted relative to body lengthwise axis. Wide part of the body accommodates piston closed from above by piston cover with bore and made integral with pusher that passes through channel narrow part and has recess at free end in contact with blade top surface. Recess bottom is shaped to an arc. Cylindrical bore shifted relative to body lengthwise axis is arranged nearby said stepped channel to feed flushing fluid to processing zone. Blade return spring is arranged between the blade and body to force the blade to transfer position.

EFFECT: higher efficiency and reliability, decreased sizes.

4 dwg