TOOL FOR REMOVING CEMENT Russian patent published in 2021 - IPC E21B10/00 E21B37/00 

FIELD: petroleum industry.

SUBSTANCE: invention relates to the petroleum and gas industry and can be used for performing technological works in an underwater borehole. The tool for removing cement from the intertube space of an underwater column head system comprises a housing in the form of a rotating body with a central hole, inserted whereto is a core with a central hole and holes in the core wall for supplying flushing liquid. The housing is made in the form of a core drill, the housing has holes configured to communicate the flushing liquid from the holes in the core wall to the cleaned processing area. Grooves are made at the end of the cylindrical part of the body placed in the intertube space. A ring is installed on the housing, with protrusions arranged along the circumference and protruding above the outer surface of the housing so as to be able to centre the tool when lowering into the intertube space and prevent damage to the matching surface in the intertube space. A possible is provided of removing the flushing liquid and sludge from the cleaning area through the space between the protrusions.

EFFECT: ensured cleaning of the intertube space, reliable subsequent sealing thereof, prevented damage to the surfaces of underwater column heads during cleaning of the intertube space.

6 cl, 6 dwg