TREATMENT METHOD FOR BOTTOMHOLE ZONE OF WELL EQUIPPED WITH BOTTOM-HOLE OIL PUMP Russian patent published in 2014 - IPC E21B43/25 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to mining and can be used for development and rejuvenation of producing oil and gas wells yield, reduced as a result of mudding of a bottomhole zone with asphalt-tar-paraffin formations and mechanical additives. Treatment method for bottomhole zone includes pumping of liquid into borehole cavity, formation of differential pressure between bottomhole zone and borehole cavity by generating periodic pressure pulses in bottomhole zone. Herewith at the first stage bottomhole zone is treated by generated pressure pulses in the form of wave moving through the borehole cavity. At the second stage bottomhole zone is treated by oscillation of well fluid mass with working fluid pumped into the well due to resonant movement of its mass. At the third stage bottomhole zone is treated by oscillation of well fluid mass with periodicity providing resonant movement of its mass and circulation for backwash of the well. At that the first and second stage of treatment are made through annular space with tubing string closed at the well-head. The third stage of treatment is made in intervals between the first and second stages; for this purpose circulation is made through annular space, bottom-hole oil pump and tubing string to remove colmatants, unreacted fluid and reaction products.

EFFECT: increasing efficiency of bottomhole zone treatment without pulling and running operations and retrieving of bottom-hole oil pump.