METHOD FOR PROPPANT HYDRAULIC FRACTURING OF OIL FORMATION Russian patent published in 2020 - IPC E21B43/26 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry and can be used in process of proppant hydraulic fracturing of oil formation with variable size of granules of proppant. Method includes drilling or selection of an already drilled vertical or directional well, well shutdown, hydraulic fracturing in the well (HFW), determination of the zone of distribution of fractures of hydraulic fracturing, fixation of hydraulic fracturing with proppant, successive reduction of the size of the fraction of the injected proppant, development of the well, extraction of products from the well. Total volume of injected proppant is determined from the volume of actual fractures of hydraulic fracturing, which are fixed during fracturing, hydraulic fracturing is fixed with proppant in several stages, wherein in each subsequent step, portions of the proppant are pumped both at a smaller size of the fraction and in a smaller volume: the first portion is used to inject proppant with particle diameter D and total volume of portion V, the second portion injecting proppant, respectively, with particle diameter D/6 and in volume (0.2...0.1)·V, further, if necessary, third – D/12 and (0.03...0.05)·V, fourth – D/24 and (0.02...0.03)·V, if necessary, pumping only two or three portions of different fractions of the proppant, between each stage, a process exposure of not more than 2 hours, wherein the pressure at the wellhead during the process of holding is maintained at the level of not less than 50 % of the maximum at which the proppant is pumped.

EFFECT: technical result consists in improvement of efficiency of hydraulic fracturing of oil formation and increase in accumulated oil production of well.

1 cl