Experimental study on rheological properties of GRF-CO₂ fracturing fluid

Based on the principle of tube rheometer, the experimental study on the rheological properties of GRF-CO₂ system is carried out by means of the large-scale high-temperature high-pressure foam fracturing fluid test system. The varying laws of the rheological parameters of the GRF-CO₂ system with test temperature, foam quality, shear rate and test pressure are discussed in detail, and the correlation formulas to calculate the rheological parameters of the fracturing fluid are obtained. The average error of the rheological index and the rheological coefficient of the GRF-CO₂ fracturing fluid system calculated using the correlation formulas is less than 10%, which can meet the need of the practical engineering.