FORMATION HYDRAULIC FRACTURING METHOD (OPTIONS) AND COUPLING FOR ITS IMPLEMENTATION Russian patent published in 2022 - IPC E21B43/26 E21B34/10 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to the oil and gas industry, namely to methods for hydraulic fracturing of a productive formation (fracking) in boreholes. The method includes the descent in the casing of at least one hydraulic fracturing coupling consisting of a cylindrical body with radial holes in which plugs with bursting membranes and covers are installed, into a given interval of the borehole, cementing of the backwater space. Before assembling the coupling, the membranes are manufactured with the ability to withstand a pressure no less than 7% greater than the pressure of the casing crimping. Each lid is equipped with a central hole, which excludes the leakage of viscous liquid pumped into the cavity of the plug when descending into the well. The viscosity of the liquid in reservoir conditions, the thickness and diameter of the hole in the lid are selected so that after the rupture of the membrane, this liquid flows out through the hole, and the lid does not collapse at a pressure lower than the pressure of the hydraulic fracturing after cementing. The opening of the formation is carried out in two stages, at the first of which pressure is created to destroy the membrane, but less than the pressure of hydraulic fracturing, and at the second stage the pressure of hydraulic fracturing, including acid, with the destruction of the cover of the cement stone and hydraulic fracturing. Hydraulic fracturing is created by means of a double packer with spaced cuffs and a perforated branch pipe between them, the cuffs of which ensure the creation of a sealed cavity in the area of the corresponding hydraulic fracturing coupling, which is lowered into the well to the installation site of the hydraulic fracturing coupling on the pipe column.

EFFECT: scope of application is expanding, including at high reservoir pressure and/or low permeability, reliability increases due to rupture of at least 95% of membranes, high-quality cementing of the casing string is provided.

4 cl, 5 dwg