CARBONATE FORMATION HYDRAULIC FRACTURING METHOD Russian patent published in 2014 - IPC E21B43/267 E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: in a carbonate formation hydraulic fracturing method involving perforation of well walls at the required interval of the well with channels with depth of not less than length of a stress concentration zone in rocks from the well shaft, lowering to the well of the tubing string with a packer, sealing of the tubular annulus with the packer above the perforation interval, performance of hydraulic formation fracturing by stage pumping to the well of gel-like fracturing liquid and acid, hydraulic fracturing of carbonate formation is performed in series at several stages; with that, at the fist stage, gel-like fracturing liquid is pumped in the volume of at least 6 m³; at the second stage, gel-like fracturing liquid mixed with a propping agent is pumped. As the propping agent, metallic spheres with particle size of 12/18, or 16/20, or 20/40 mesh, which are made from magnesium metal, are used. The propping agent is pumped in portions with subsequent increase in its concentration mixed with gel-like fracturing liquid; at the third stage, forcing-through liquid - service water is pumped in the volume equal to inner volume of the tubing string lowered to the well; at the fourth stage, chlorhydric acid is pumped in the volume of at least 0.6-0.7 of total volume of gel-like fracturing liquid; at the fifth stage, forcing-through liquid - service water is pumped in the volume equal to the volume of the tubing string lowered to the well plus 0.2 m³.

EFFECT: improving efficiency of a method in carbonate formations containing hardly soluble asphaltene-resin deposits; simplifying the method and protecting a production string.

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