Abstract: A permeability-enhancing flooding system for tight oil reservoirs and preparation and use thereof are disclosed. The permeability-enhancing flooding system is present in a state of oil-in-water droplet and composed of a surfactant, an oil-soluble substance and water, and has an outer phase that is an aqueous solution containing the surfactant, and an inner phase that is the oil-soluble substance; and the surfactant comprises one of nonionic gemini surfactants and anionic gemini surfactants, or a combination of two or more thereof. The preparation process for the permeability-enhancing flooding system is simple to operate, suitable for industrialized production, and low in overall cost, and has obvious application prospects in the field of tight oil reservoirs for an enhanced oil recovery.

Abstract: A permeability-enhancing flooding system for tight oil reservoirs and preparation and use thereof are disclosed. The permeability-enhancing flooding system is present in a state of oil-in-water droplet and composed of a surfactant, an oil-soluble substance and water, and has an outer phase that is an aqueous solution containing the surfactant, and an inner phase that is the oil-soluble substance; and the surfactant comprises one of nonionic gemini surfactants and anionic gemini surfactants, or a combination of two or more thereof. The preparation process for the permeability-enhancing flooding system is simple to operate, suitable for industrialized production, and low in overall cost, and has obvious application prospects in the field of tight oil reservoirs for an enhanced oil recovery.

Abstract: A CO2-sensitive fracturing and displacement fluid contains a surfactant, an auxiliary agent, water, and CO2, wherein CO2 is liquid and/or supercritical CO2. The CO2-sensitive fracturing and displacement fluid provided by the invention does not flow back after completion of fracturing construction, and the gel breaking fluid displacement is carried out after soak for a period of time to improve the tight oil recovery ratio. The CO2-sensitive fracturing and displacement fluid exerts the “one-agent multi-purpose” function of sand carrying, CO2 energization and oil displacement, surfactant imbibition and oil discharge of a fracturing-displacement system in different development and production stages, and achieves the dual goals of expanding the utilization degree of tight oil and improving the displacement efficiency of the tight oil, which can effectively reduce costs and achieve the goal of unified, highly efficient and green development of oil and gas fields.

Abstract: A CO2-sensitive fracturing and displacement fluid contains a surfactant, an auxiliary agent, water, and CO2, wherein CO2 is liquid and/or supercritical CO2. The CO2-sensitive fracturing and displacement fluid provided by the invention does not flow back after completion of fracturing construction, and the gel breaking fluid displacement is carried out after soak for a period of time to improve the tight oil recovery ratio. The CO2-sensitive fracturing and displacement fluid exerts the “one-agent multi-purpose” function of sand carrying, CO2 energization and oil displacement, surfactant imbibition and oil discharge of a fracturing-displacement system in different development and production stages, and achieves the dual goals of expanding the utilization degree of tight oil and improving the displacement efficiency of the tight oil, which can effectively reduce costs and achieve the goal of unified, highly efficient and green development of oil and gas fields.

Abstract: A performance testing device for acid fracturing fluid includes: two semiterete rock core holders, the flat face sides of the two semiterete rock core holders being arranged opposite to each other; the two semicircle sides of the two semiterete rock core holders being provided with a rotation member which is opened with a first groove; the two semiterete rock core holders being able to rotate about a first rotation axis formed corporately by the two rotation members; a pressure applying shell having a recessed portion that matches with the curved face side, the recessed portion being able to cooperate with the curved face side, the pressure applying shell being able to apply a pressure to the two rock core holders to bring the two flat face sides thereof together.

Abstract: The present invention relates to viscoelastic fracturing fluids comprising one or more zwitterionic surfactants having multiple hydrophobic and hydrophilic groups. The viscoelastic fracturing fluids can be used to stimulate reservoir and increase oil and gas production.

Abstract: A performance testing device for acid fracturing fluid includes: two semiterete rock core holders, the flat face sides of the two semiterete rock core holders being arranged opposite to each other; the two semicircle sides of the two semiterete rock core holders being provided with a rotation member which is opened with a first groove; the two semiterete rock core holders being able to rotate about a first rotation axis formed corporately by the two rotation members; a pressure applying shell having a recessed portion that matches with the curved face side, the recessed portion being able to cooperate with the curved face side, the pressure applying shell being able to apply a pressure to the two rock core holders to bring the two flat face sides thereof together.

Abstract: The present invention relates to viscoelastic fracturing fluids comprising one or more zwitterionic surfactants having multiple hydrophobic and hydrophilic groups. The viscoelastic fracturing fluids can be used to stimulate reservoir and increase oil and gas production.