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

FIELD: mining.

SUBSTANCE: invention relates to mining and can be used for development and recovery of flow rate of production wells, which decreased as a result of colmatation of bottomhole zone by asphaltene-resin-paraffin formations and mechanical additives. Method includes injecting liquid into the well cavity, formation of pressure drops between the bottomhole zone and the well cavity by creating periodic pressure pulses in the bottomhole zone in the form of a liquid mass wave movement in the cavity of the well, formed by periodic opening of the well cavity to increase pressure using the valve, pressure in well is increased by connection of wellhead with source of liquid under pressure. During hydraulic fracturing preliminary duration of expansion and closing of formation cracks is estimated, initial pressure is set in well cavity, at which cracks of formation are closed, then valve is opened for a time, during which movement of the liquid mass acts on fractures of the formation, then closing the valve and reducing pressure in the well to the value of the initial one. Based on geological and technical conditions, valve opening rate is set, it is installed in lower part of tubing string and arranged in perforation zone, annular space is disconnected and perforation zone by means of packering, liquid pressure in the tubing is increased until the valve is opened, then liquid pressure in the tubing string is reduced to close the valve through a time interval sufficient for formation and opening of cracks.

EFFECT: technical result is creation of a network of cracks of a given configuration in the borehole zone of the formation.

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