Abstract: To further evaluate the adaptability of fracturing fluid and proppant to the dense sandstone reservoir in the Denglouku Formation of CL block, the commonly used fracturing fluid and proppant in the target formation were selected for core permeability testing experiments, flowback experiments, CT reconstruction experiments and reservoir conductivity experiments to comprehensively evaluate the effects of different types of fracturing fluid and proppant on the permeability of rock samples. The study shows that there is still some damage to the core after fracturing fluid flowback, and the damage rate of guar gum fracturing fluid is larger than that of slickwater fracturing fluid, mainly manifested as water-sensitivity damage, water-locking damage and residue damage, and the mechanism is that the pore structure of rock samples treated with guar gum fracturing fluid changes significantly, and the percentage of micropores with pore throat radius of 7-22 μm increases; the permeability of dense sandstone reservoir is affected by proppant embedding, and the conductivity is negatively correlated with the particle size and closure pressure. The research results can provide theoretical guidance for the preferential selection of fracturing fluid system for dense sandstone gas reservoirs in Denglouku Formation of CL block.

Key words: fracturing fluid, proppant, conductivity, tight sandstone, gas reservoir