METHOD OF DEPOSIT HYDRAULIC FRACTURING IN WELL Russian patent published in 2015 - IPC E21B43/267 F04F5/02 

FIELD: oil and gas industry.

SUBSTANCE: method includes perforation of the well walls in the deposit interval by channels with depth at least equal to length of zone of stresses concentration in rocks from the well hole, run of the string with packer such that the bottom end of the string will be at level of the deposit top, packer seating above the perforated deposit top, determination of total volume of gel fracturing liquid prior to the deposit hydraulic fracturing, the gel fracturing liquid injection in the underpacker zone, creation in the under packer zone of the deposit hydraulic fracturing pressure, and the cracks creation in the deposit with further their casing in the deposit by injection of the carrying liquid with proppant, well holding for the pressure bleeding-off, packer releasing and removal with the string from the well. At the wellhead the pipes string above the packer at distance 10 m outside is equipped with jet pump, then string is run in the well, and packer is seated above the perforated deposit top. Then in the string the flexible tubes string is rum such that bottom end of the flexible tubes string will be below the pipes string end and at the middle of the deposit, at the wellhead the space between the pipes string and the flexible tubes string is sealed, total volume of the gel fracturing liquid is determined, this volume is divided to two equal parts. The first part is the fracturing liquid, the second part is carrying liquid. Via the flexible tubes string the first part, i.e. fracturing liquid is injected in the under packer zone, and in the under packer zone the pressure of the deposit hydraulic fracturing is created with the cracks creation in the deposit. Then the cracks in the deposit are cased by the injection of the second part, i.e. carrying liquid with the proppant. At that the proppant of lower and larger fractions is used as the proppant. The carrying liquids with smaller fraction proppant 20/40 mesh and larger fraction proppant 16/40 mesh are injected simultaneously in ratio 4:1. At that via the flexible tubes string the carrying liquid with the larger fraction proppant is injected, and via the pipes string the carrying liquid with the smaller fraction proppant is injected with gradual increasing of concentration of smaller and larger fractions of proppant in the carrying liquid. The well is held for pressure bleeding-off, at the wellhead the space between the pipes string and flexible tubes string is unsealed. At the wellhead between the pipes string and flexible tubes string a sealing ring insert is installed and press through the pipes string under overpressure to the hydraulic connection of the pipes string and jet pump. The deposit completion is performed via the jet pump. Upon the deposit completion the flexible tubes string is removed from the pipes casing, the packer is released and removed with the pipes string from the well.

EFFECT: increased efficiency of the deposit hydraulic fracturing.

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