PULSED HYDRAULIC FRACTURING METHOD Russian patent published in 2020 - IPC E21B43/26 

FIELD: mining.

SUBSTANCE: present invention relates to mining and can be used for development and restoration of production well flow, which decreased as a result of colmatation of bottom-hole zone with asphalt-resin-paraffin formations and mechanical additives. Method involves generation of periodic pressure pulses in the bottomhole zone in the form of a wave moving in the well cavity formed at periodical increase of pressure in the well by connection to the first and the second sources of liquid under pressure. During hydraulic fracturing preliminary time of movement of liquid mass movement wave from wellhead to bottom-hole zone and duration of expansion and closure of formation cracks is established, initial pressure is installed in cavity of well, wherein fractures of formation are closed, then valves are opened for time, during which wave of movement of mass of liquid reaches bottom-hole zone and acts on fractures of formation. Then the valves are closed for the period of pressure reduction in the well to the value of the initial one, to the lines connecting the liquid filling valves with sources of liquid under pressure, hydropneumatic accumulators are connected. Permissible pressure created in the column head of the well, source of fluid under pressure is determined, and hydropneumatic accumulators are connected to the annular space of the well through one of gate valves of the cross piece, the gate valve is closed on the opposite side of the cross-piece. Well annular space is filled with fluid up to wellhead, plunger of pump-rocking pump is changed to position that minimizes possibility of pump damage at pressure drops, hydropneumatic accumulators are filled with liquid till pressure does not exceed permissible pressure in the column head of the well.

EFFECT: impulse-wave treatment of bottom-hole zone through annular space without extraction of submersible equipment.

1 cl