CO₂-sensitive fracturing and displacement fluid and method of making the same and method for fracturing and displacement of tight oil reservoir

摘要

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.