METHOD OF PERFORMING PULSED HYDRAULIC FRACTURING Russian patent published in 2025 - IPC E21B43/26 E21B43/24 

FIELD: mining.

SUBSTANCE: invention relates to mining and can be used for development and recovery of flow rate of production wells, which 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 fluid wave moving along the well cavity, which is formed during periodic pressure increase in the well using valves, the first of which connects the well cavity with a source of liquid under pressure, the second one connects the well cavity with a drain tank. When carrying out hydraulic fracturing, the time of movement of the fluid wave moving through the well cavity from the wellhead to the bottomhole zone and the duration of expansion and closure of the formation cracks are preliminarily estimated, the initial pressure in the well cavity is established, at which the formation cracks are closed, then the first valve is opened for the time during which the fluid wave moving along the well cavity reaches the bottomhole zone, duration of time intervals between periods of pressure increase and decrease, as well as the pressure decrease rate, is then closed, then the first valve is closed. After a period of time and at a rate which provide for removal of colmatants, the second valve is opened to reduce the pressure in the well to the initial value. Hydropneumatic accumulator is connected to the line connecting the first valve and the source of fluid under pressure, volume of the accumulator is determined by the flow rate of the well fluid as it flows into the formation. Fluid used is preheated portion of well fluid, which is pumped into annular space and circulation through annular space, pump valves and tubing are moved to the lower end of the tubing, then the tubing is shut off at the wellhead, and with the help of hydraulic shocks safe for pumping equipment, heated fluid is pushed to perforation of the well and counter-parallel hydraulic impacts are performed for washing out and cleaning of bottom-hole zone.

EFFECT: creation of pulsed counter-parallel movement of heated liquid through the wellbore zone of the formation in order to develop cracks and washout thereof from viscous fractions with increase in permeability of the formation section adjacent to the well perforation.

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