DRILLABLE SHOE WITH POWER DRIVE FOR CASING STRING BOTTOM EQUIPMENT Russian patent published in 2020 - IPC E21B17/14 E21B33/14 

FIELD: drilling equipment.

SUBSTANCE: invention relates to the field of drilling equipment, namely to the equipment for the bottom of the casing string in order to protect the elements included in the assembly of the string, from damages during descent, its direction along the well bore with possibility of development of problematic sections of the shaft and further drilling of the rock-destructing tool after cementing. Drillable shoe with power drive is made of easy-drilled parts, which makes it possible to use standard rock-destructing tool for drilling of subsequent columns, is equipped with cutting structure and mechanisms for well cementing and fixation of internal parts against rotation during drilling, as well as system of autocomplete of internal cavity of casing string with flushing fluid. Cutting structure is equipped with PDC cutters and spindle, core profile of which is made with inner cone repeating the profile of PDC bits, and by its departure does not exceed height of blades of spindle tip. Well cementing mechanism is located in the upper part of the device and comprises a reducer with a cementing breaking diaphragm. Mechanism for fixation of inner parts against rotation is located in lower part of device. Wide variability of technical characteristics makes it possible to use the device with any required standard sizes of casing strings.

EFFECT: simplified lowering of the casing string, higher quality of performed operations, reduced time of well construction.

1 cl, 1 dwg