DEVICE TO APPLY REPEATED HYDROIMPULSIVE ACTION TO BOTTOMHOLE FORMATION ZONE Russian patent published in 2007 - IPC E21B28/00 E21B43/26 E21B34/06 

FIELD: oil production industry, particularly means to increase bottomhole formation zone permeability.

SUBSTANCE: deice comprises implosion chamber fastened to lower flow string part and piston installed in the chamber. The implosion chamber comprises windows made in upper widened part thereof. Connected to implosion chamber is cup with windows and with spring-loaded valve installed in the cup. The spring-loaded valve closes area of implosion chamber connection to cup. Device also has guide means to provide vortex-free liquid movement. The guide means is made as a part of the valve. Valve and guide means may slide downwards under the liquid flow action.

EFFECT: possibility of repeated action application to bottomhole formation zone, provision of vortex-free flow of liquid creating hydraulic hammer and decreased load applied to tubing string carrying the disclosed device.

5 cl, 3 dwg