MILLING CUTTER FOR CUTTING WINDOW IN CASING WHEN DRILLING SIDETRACK Russian patent published in 2023 - IPC E21B29/06 

FIELD: drilling.

SUBSTANCE: drilling and major repairs of oil and gas wells for milling the casing string during drilling a sidetrack. The device includes a body with a conical and cylindrical part, a coupling with a connecting thread, body blades made entirely milled and coated with a wear-resistant cutting-abrasion coating, an end part made in the form of a crown, a central channel and flushing holes in the body. The crown is made in steps, protruding from the periphery to the center and is equipped with grooves in which carbide plates are installed. The flushing holes of the crown are made between the incisors of each row. The working ends of the blades of the conical part are equipped with carbide inserts with a cutting-abrasion coating on top. The helical blades of the cylindrical part are made with the lower part of the blade shifted forward in the direction of rotation relative to the upper part of the blade and are additionally reinforced with carbide inserts.

EFFECT: reliability and durability of the structure is ensured with the ability to drill a pocket direction through the rock after cutting out the window, the passage of the bit for drilling a sidetrack is ensured, the speed of window milling is increased, and the wear of the cutting elements is reduced.

1 cl, 2 dwg