COMPOSITIONS AND METHODS FOR FLUID FRACTURING DILUTION FOR HYDRAULIC FRACTURING Russian patent published in 2019 - IPC C09K8/68 C09K8/86 E21B43/26 E21B43/267 

FIELD: oil and gas industry.

SUBSTANCE: present invention relates to diluting compositions and methods of their use for rupture of underground formations at extraction of oil and gas. Aqueous non-emulsified diluting composition for use in a water-based treatment fluid comprises water, at least one water-soluble organic peroxide, which is tert-butyl hydroperoxide, and at least one alcohol selected from a group consisting of: propylene glycol, butyl alcohol, monosaccharide, disaccharide, a combination thereof, said peroxide and alcohol are present in an amount effective to reduce viscosity of the water-based fluid for treatment of the formation at temperature of 90–300 °F and to maintain reduced viscosity for a certain period of time after reducing temperature from 90–300 °F. Water-based fluid for treatment of a formation, containing: water, at least one gel-forming agent, at least one cross-linking agent and the above aqueous non-emulsified fluidising composition. Method for maintaining low viscosity of a water-based fluid for treating a formation, comprising combining said aqueous non-emulsified fluidising composition with a water-based fluid for treating a formation, comprising at least one gel-forming agent and at least one cross-linking agent. Method of fracturing a subterranean formation involves injecting into a subterranean formation in fracturing conditions of the above water-based fluid for treatment of a formation and said aqueous non-emulsified fluidising composition. Invention is developed in dependent items of the formula.

EFFECT: technical result is the increase in the treatment efficiency.

24 cl, 7 dwg, 7 ex