WORKING BOTTOM Russian patent published in 2021 - IPC E21B37/00 

FIELD: well construction.

SUBSTANCE: invention relates to the field of well construction, in particular to devices designed for working boreholes during casing of oil and gas wells, installed in the guide part of the column or shank. The device includes a housing with cylindrical part and connecting thread on top for connection to the casing, equipped with side flushing holes and blades in the lower part. The housing is hollow with a bottom part in shape of cone-shaped tip and is equipped with a central flushing hole. The central and side flushing holes are directed downwards, the cone-shaped tip is equipped with at least three blades made straight or helical and having a flat shape. The blades are uniformly equipped with flat carbide teeth placed on the same level with surface of the blade over the entire surface, the blade length is 0.3-0.5 of the length of cylindrical part of the body. The bottom is made of easily drilled material and its diameter along the blades does not exceed the effective diameter of the borehole.

EFFECT: reliability of the descent and installation of casing string in complicated borehole increases, reliable passage of narrowed sections of the trunk with study without jamming and planting is ensured.

1 cl, 6 dwg