PULSE HYDRAULIC FRACTURING METHOD Russian patent published in 2011 - IPC E21B43/25 

FIELD: mining.

SUBSTANCE: pulse hydraulic fracturing method involves pumping of liquid to the borehole cavity, formation of pressure drops between bottom-hole zone and borehole cavity by creating periodic pressure pulses in bottom-hole zone in the form of liquid mass wave moved via the borehole cavity. Wave is formed at periodic opening of borehole cavity on the mouth for discharged well liquid under pressure and pressure increase by using liquid drain and filling valves. Liquid drain valve connects the borehole cavity to the drain capacity. Liquid filling valve connects the borehole cavity to source of liquid under pressure. Both valves are opened and pressure is applied which is enough for circulation of liquid through annular space and cavity of tubing string. After the flow reaches the specified velocity speed, circulated liquid supply pressure is abruptly increased. Increased pressure is maintained during the time enough for the blast wave to reach the bottom-hole zone and to act on the bed cracks.

EFFECT: increasing oil production of the bed by hydraulic fracturing performed due to mass and inertia of the well liquid without using any pump high-pressure units.