IMPULSIVE HYDRAULIC FRACTURING METHOD Russian patent published in 2018 - IPC E21B43/26 E21B28/00 

FIELD: mining.

SUBSTANCE: invention relates to mining and can be used for impulsive hydraulic fracturing. Method includes pumping of liquid into the borehole cavity, creation of pressure drop across between near-wellbore zone and borehole cavity by means of creation of pressure periodic pulses in near-wellbore area in the form of a moving wave along the cavity of the well, the movement of the mass of liquid formed during the periodic opening of the well cavity at the mouth for leakage of borehole fluid under pressure, and increase of pressure with the use of valves. First, time of movement of liquid mass movement wave from the wellhead to the bottom-hole zone and duration of formation fractures expansion and fracture healing is preliminary evaluated, in the well cavity is set an initial pressure at which formation cracks are closed, then the liquid filling valves are opened for a time, during which a liquid mass movement wave reaches the bottom-hole zone and acts on fractures of the formation. Then one closes the liquid refilling valves and opens a liquid drain valve to reduce the pressure in the well to the initial pressure value to the line connecting the wellhead and a source of liquid under pressure, two hydropneumatic accumulators are connected through two filling valves, the volume of which is determined by the flow rate of the borehole fluid during its flow into the formation. Top-up valves are opened sequentially after a period of time, providing the formation of a total pressure pulse at the bottom hole pressure, taking into account the geological and physical characteristics.

EFFECT: technical result consists in obtaining in the sump of the well high pressure pulses with a duration sufficient for deformation of cracks.

1 cl