Experimental study of the flow characteristics of surfactant-assisted aerosols in low permeability porous media

Gas channeling in formations is a primary factor affecting the effectiveness of gas flooding and CO₂ geo-storage. Current dominant methods for controlling gas channeling include water-alternating-gas injection and foam flooding, among others. This study proposes an innovative approach using an aerosol system to manage gas channeling in low-permeability reservoirs. Through ANSYS simulation, an effervescent aerosol generator was selected and optimized. Two surfactants, sodium dodecyl sulfate and polyoxyethylene (20) cetyl ether, were employed to assist aerosol generation. Core flooding experiments were conducted to investigate the flow characteristics of aerosols in porous media and revealed that the liquid phase content significantly influenced flow pressure. For instance, in a water aerosol system with a total mass flow rate of 5.5 mg/s, increasing the liquid–gas flow ratio from 0.2 to 0.8 resulted in an approximately 53% rise in balance pressure and an 185% increase in the resistance factor. Nuclear magnetic resonance scanning was used to examine aerosol distribution patterns with and without surfactants. In water aerosol injections, aerosols preferentially occupied pores with radii of 0.16–0.83 μm, whereas surfactant-assisted aerosols predominantly entered pores with radii of 0.04–0.21 μm, indicating that the addition of surfactants enhances injectability and blocking capacity.