APPARATUS FOR DRILLING OUT COMPRESSED PLUG IN BOREHOLE Russian patent published in 2021 - IPC E21B37/00 

FIELD: petroleum and gas industry.

SUBSTANCE: invention relates to the petroleum and gas industry, namely to apparatuses for drilling out compressed plugs in a borehole. The apparatus is comprised of a tool for applying axial force - a pipe column, a screw non-self-braking mechanism containing a hollow cylindrical shaft and a hollow cylindrical body, and a rock cutting tool, connected in series. The pipe column is rigidly connected with the hollow cylindrical body, configured to move axially downward. The rock cutting tool configured to rotate around the axis thereof is rigidly connected to the hollow cylindrical shaft from below. The apparatus is equipped with a hollow stem inserted into the hollow cylindrical shaft from above. The upper part of the hollow stem is screwed into the hollow cylindrical body. The upper end of the hollow stem is equipped with a ball seat. The upper end of the hollow cylindrical shaft is equipped with a shutoff piece for the axial movement of the hollow cylindrical body. The hollow stem is spring-loaded upward from the shutoff piece to the inner upper end of the hollow cylindrical body. The rock-cutting tool is made in form of a sleeve with pointed blades on the bottom and flushing channels between the blades. The lower end surface of the sleeve is equipped with a babite alloy.

EFFECT: reliability of operation of the apparatus, quality of drilling out of the compressed plug, efficiency of removing the drilled cuttings from the borehole during the process of flushing are increased, the operational capabilities are expanded.

1 cl, 3 dwg