Foam fracturing fluid with double interface layers of a phlogisticated air-liquid CO2 for shale gas production and preparation method thereof

摘要

The disclosure discloses a foam fracturing fluid with double interface layers of a phlogisticated air-liquid CO₂ for shale gas development, and a preparation method thereof. The foam fracturing fluid is prepared from a liquid CO₂ phase, a gas phase and a nano-enhancer; the liquid CO₂ phase is formed by dissolving a mixture of gas-soluble foaming agents in liquid CO₂; the gas phase is a gas mixture of phlogisticated air and saturated vapor of the liquid CO₂; the nano-enhancer is an aqueous solution of a mixture of hydrophobic silica nanoparticles, a cosolvent and a water-soluble surfactant. In the fracturing fluid prepared by the present disclosure, the phlogisticated air was encapsulated by the liquid CO₂ to form an interface layer, the liquid CO₂ was further encapsulated by the nano-enhancer to form the other interface layer, which enhanced the structural stability of the fracturing fluid while achieving high viscosity and thermal stability.