METHOD OF PERFORMING PULSED HYDRAULIC FRACTURING Russian patent published in 2022 - IPC E21B43/26 

FIELD: mining.

SUBSTANCE: proposed invention relates to mining and can be used for development and recovery of flow rate of production wells, decreased due to mudding of bottomhole zone with asphalt-resin-paraffin formations and mechanical impurities. Method for implementation of pulsed hydraulic fracturing includes pumping into well cavity of liquid, formation of periodic pressure pulses in the bottomhole zone in the form of a wave moving along the well cavity, which is formed at periodic pressure increase in the well, using valves. During hydraulic fracturing, time of movement of fluid mass movement wave from wellhead to bottomhole zone and duration of expansion and closure of formation fractures are preliminary estimated, setting initial pressure in well cavity, at which formation fractures are closed, then the first valve is opened for the time during which the wave of movement of the fluid mass reaches the bottomhole zone and acts on the formation fractures, then the first valve is closed and the second valve is opened to reduce the pressure in the well to the initial value. Opening of the second valve is carried out after a period of time and at a rate that provides for the removal of colmatants, a hydraulic-pneumatic accumulator is connected to the line connecting the first valve and the source of pressurized fluid, volume of which is determined by flow rate of well fluid when it flows into the formation. In order to generate a pressure pulse in the bottomhole zone, the first valve is closed when the speed of movement into the well is reduced after opening the first valve, to form fluid flows in the bottomhole zone, the first valve is closed at the highest rate of fluid flow into the well after the first valve is opened.

EFFECT: task of the invention is to alternate pressure pulses for creation and development of a network of cracks in the bottomhole zone, as well as counter-parallel flows of liquid for washing out and removal of colmatage deposits from the formation thickness into the well cavity.

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