PULSE HYDRAULIC FRACTURING METHOD Russian patent published in 2016 - IPC E21B43/26 

FIELD: mining.

SUBSTANCE: invention can be used for development and recovery of production wells' yield, which decreased as a result of mudding of bottom-hole zone by asphalt-resin-paraffin formations and mechanical additives. Method includes pumping of liquid into the well cavity, formation of pressure drops between the bottom hole zone and the well cavity by creating periodic pressure pulses in the bottom hole zone in the shape of a travelling within the well cavity wave of liquid mass movement formed during periodic opening of the well cavity at the mouth for well fluid outflow, and increase of pressure by use of valves. During hydraulic fracturing, one previously estimates time of a liquid mass movement wave from the mouth to the bottom-hole zone and duration of expansion and closing of formation cracks. One sets in the well cavity an initial pressure at which formation cracks are closed. Then a liquid refilling valve is opened for the time during which the fluid mass movement wave reaches the bottom hole zone and acts on the formation cracks. Then one closes the liquid refilling valve and opens a liquid drain valve to reduce pressure in the well to the initial pressure value. To a line connecting the liquid refilling valve and a source of liquid under pressure, one connects a hydro-pressure-compensator, the volume of which is determined by formula V≥(3÷4)q, where q is the well fluid flow rate during its overflow to the formation under the pressure defined by the source of fluid under pressure.

EFFECT: obtaining in the well dibhole of pressure pulses with duration sufficient for deformation of cracks.

1 cl