DEVICE TO FIX RETRACTABLE DRILL TOOLS IN CASING STRING Russian patent published in 2008 - IPC E21B7/20 E21B23/00 

FIELD: oil and gas production industry.

SUBSTANCE: invention is related to hardware used for wellbore drilling with simulations casing. Device includes shoe with inner annular and longitudinal grooves attached to the bottom of casing string, hollow bore spindle with bottom connecting thread and seal in top part located inside the shoe, annular cartridge with installed blades, thrust fans and rams for interaction with casing string shoe. The shoe is provided with rigidly connected tapered seat. Spindle is provided with tapered shoulder in midsection. The annular cartridge contains of two parts with capability of limited axial motion relative to each other, with spring-controlled rams located in bottom part with capability to interact with annular groove of the shoe and with thrust fans gimbaled in the top part provided with tapered inner and outer surfaces with tapered seat of the shoe and tapered shoulder of the spindle. The bottom part of the spindle is provided with annular groove and spring-controlled rams are provided with rigidly connected pins that can be fixed in spindle groove. Spring is installed between parts of the cartridge.

EFFECT: ensures better interface of thrust fans when couples with the shoe and also prevents seizure of central spindle with moving element when handles inside casing string till locked in the shoe.

7 dwg