COAL SEAM HYDROFRACTURING Russian patent published in 2016 - IPC E21B43/267 

FIELD: mining.

SUBSTANCE: claimed process consists in well drilling from the surface, its casing, opening of the coal seam, injecting the potassium chloride salt solution in the coal seam containing the wedging agent at the pressure sufficient for hydrofracturing at the injection rate sufficient for making of long fractures. Note here that 4% solution of potassium chloride salt solution is used while quartz sand of 40-70 mesh makes the wedging agent. Note also that the injection rate of 4.2 m³/min is maintained to sustain the quartz sand suspended.

EFFECT: higher efficiency of hydrofracturing, lower costs and harmful ecological effects.

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