HYDROMECHANICAL SLOT-TYPE PERFORATOR (VERSIONS) Russian patent published in 2012 - IPC E21B43/112 

FIELD: mining.

SUBSTANCE: perforator includes casing, piston-pusher located in it and cutting unit located below the piston that includes extending cutting tools with extending mechanism in a form of balancing lever on the shoulders of which there are cutting tools. The balancing lever is mounted capable of turning round the centre line at piston-pusher movement downwards and making simultaneously as minimum two slots in production string by cutting tools. The perforator is equipped with additional piston located in the casing of lower cutting unit capable of creating additional effort against the lower shoulder of balancing lever that carries the lower cutting tool, when the lower piston moves upwards. The movement of lower piston upwards is provided by the effect of fluid that is supplied to it under pressure, for example, through one or several hydraulic channels made in perforator casing or through hydraulic system made in perforator in a different manner. Invention versions are proposed with different structures of cutting tools extension mechanism.

EFFECT: even opening of production string simultaneously in minimum two projections with guaranteed formation of slots of equal high quality.

12 cl, 6 dwg