METHOD OF OPERATION OF PRODUCTION AND WATER-BEARING FORMATIONS SEPARATED BY IMPERMEABLE INTERLAYER, WELL WITH HORIZONTAL SHAFTS AND CRACKS OF FORMATION HYDRAULIC FRACTURING Russian patent published in 2017 - IPC E21B43/14 E21B43/26 E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: according to method, well is drilled with orientation of horizontal shafts in direction perpendicular to the direction of maximum stress. A multi-stage hydraulic fracturing of the formation is performed in the horizontal shaft of the production well. A vertical well is drilled in the production formation. The first horizontal shaft is drilled from the bottom of the vertical well in direction perpendicular to the direction of the maximum stress. The first horizontal shaft is cased and perforated. The multi-stage hydraulic fracturing is carried out to form cracks with their subsequent fixing by proppant of fraction corresponding to permeability of production formation. A carrier fluid with 20/40 mesh proppant is pumped to fix the crack into the production formation with permeability of 0.01 to 50 mD. A carrier fluid with proppant of 12/18 mesh is pumped into the production formation with permeability of 50 to 500 mD. The horizontal shaft at the entrance is temporarily cut off. The second horizontal shaft is drilled from the bottom of the vertical well in the direction perpendicular to the direction of the maximum stress and opposite to the direction of the first horizontal shaft. The second horizontal shaft is cased and perforated. Hydraulic fracturing is perfoemed in horizontal shaft in perforation interval to form a crack penetrating through impermeable interlayer into underlying aquifer. A fracturing fluid with lightweight proppant of 40/70 mesh fraction is pumped by the first portion to form the crack. The second portion is pumped with the fracturing fluid with weighted proppant of 16/20 mesh fraction. The horizontal shaft at the inlet and before hydraulic fractuning interval is cut off. A downhole pump is lowered into the vertical well and the well is put into operation.

EFFECT: improving the efficiency of the process by eliminating additional energy costs for pumping water into the injection wells.

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