纳米氧化石墨烯改性CO2泡沫压裂液稳定机理研究OA

Carbon dioxide(CO2)foam fracturing fluid features the advantages of low water consumption,weak reservoir damage,and excellent stimulation performance,making it particularly suitable for the extraction of water-sensitive unconventional shale oil and gas as well as coalbed methane.To address the poor stability of traditional CO2 foam fracturing fluids,flake-structured nano-graphene oxide(GO)was used to modify the CO2 foam fracturing fluid.The CO2 foam fracturing fluid was prepared in a sealed reactor,and the variation of foam half-life with surfactant type was investigated by visual observation to optimize the formulas.Subsequently,the effects of surfactant type,concentration,and temperature on the stability of the CO2 foam fracturing fluid were studied.The results show that the addition of GO to the octadecyltrimethylammonium chloride(OTAC)system leads to a large amount of flocculent material and fails to stabilize the foam.In contrast,the α-olefin sulfonate(AOS)system exhibits good compatibility with GO.The formula of 0.50%AOS+1.00%NaCl+0.25%GO presents high foam quality,and the introduction of GO significantly improves the temperature resistance of the foam system.A foam liquid film model was constructed using Materials Studio,and molecular dynamics simulations were performed to reveal the synergistic foam-stabilizing mechanism and failure mechanism of GO at the molecular level.This study provides a theoretical basis and technical support for the development of oil and gas reservoirs.