HYDRAULIC PERCUSSION MEANS FOR SAND PLUG REMOVAL FROM WELL Russian patent published in 2007 - IPC E21B37/00 E21B21/00 

FIELD: oil and gas industry, particularly well cleaning devices.

SUBSTANCE: device comprises hollow body connected to sub and provided with circulation orifices, seat, end valve, annular piston fixedly connected to hollow spring-loaded shaft and arranged in axial channel of hollow body, crown with end teeth, throttle and hydraulic monitor head. Seat is arranged between the body and the sub. Hollow shaft sliding in axial sub channel and axial seat channel is spring-loaded with respect to the sub. Crown is directly connected with annular piston, which defines end valve along with the seat. Piston is installed to close circulation orifices of the body. Annular space between the rod and the sub is permanently fluidly communicated with axial channel made in the shaft and the seat.

EFFECT: increased efficiency of sand plugs breakage.

2 dwg