METHOD FOR PREPARING HYDRAULIC FRACTURING FLUID USING SOLID CARBON DIOXIDE Russian patent published in 2023 - IPC C09K8/66 E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: method for preparing hydraulic fracturing fluid where a gelling agent is first added to water while stirring, and the gelling agent is hydrated. Then a demulsifier and a destructor are introduced into the resulting gel, then a crosslinker is added. A crosslink stabilizer is introduced together with the crosslinker or after adding the crosslinker. Immediately before injection into the formation, carbon dioxide in the solid state - “dry ice” - is added to the resulting gel in an amount of 0.15 to 0.45 wt.%, mixed, and the resulting mixture is pumped into a vertical well to a minimum depth of 800 m with a minimum bottom hole temperature 31°C, at which carbon dioxide goes into a supercritical state.

EFFECT: reduced concentration of supercritical carbon dioxide in the hydraulic fracturing fluid while maintaining high efficiency in expanding the pores of the shale formation to displace methane molecules from them.

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