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 pumping fluid into the well cavity, generating periodic pressure pulses in the bottomhole zone in the form of a wave moving in the well cavity, which is formed at periodical pressure increase in the well, using valves. During hydraulic fracturing preliminary time of movement of liquid mass movement wave from wellhead to bottom-hole zone is estimated and duration of expansion and closure of formation cracks, initial pressure is set in well cavity, at which cracks of formation are closed, then first valve is opened for a time, during which the liquid mass flow wave reaches the bottomhole zone and acts on the formation fractures. Then, the first valve is closed and the second valve is opened to reduce pressure in the well to the value of the initial one, to the line connecting the first valve and the source of liquid under pressure, the hydropneumatic accumulator is connected, estimating duration of time intervals between periods of increase and decrease of pressure, as well as rate of pressure reduction, opening of the second valve is performed through a period of time and at a rate providing creation in combination with periodic pressure increase due to opening of the first valve creation of pressure drops required for removal of bridging agents and mechanical destruction of the formation skeleton.

EFFECT: technical result is obtaining in bore-hole zone of the well alternating multidirectional pressure pulses, having amplitude and duration, sufficient for development of network of cracks and cleaning from mud deposits.

1 cl