Properties of multi-phase foam and its flow behavior in porous media

Abstract

Aqueous foams were produced with partially hydrophobic SiO 2 nanoparticles and sodium dodecyl sulfate (SDS) dispersions. The injection behavior of SiO 2 stabilized foam (SiO 2 /SDS foam) was analyzed and compared with SDS stabilized foam (SDS foam). The experimental results showed that the SiO 2 nanoparticles and SDS surfactants had a synergistic effect on foam stability at proper SDS concentration. And the effect was although with a slight decrease of foam volume. The adsorption of nanoparticle on the bubble surface was confirmed by laser-induced confocal fluorescence microscopy. And the effect of absorbed nanoparticles on bubble surface viscoelasticity was also verified by the interfacial dilational rheological measurement. The dilational viscoelasticity increased with increasing SiO 2 concentration, corresponding with foam stability. The plugging flow experiment demonstrated that the maximum differential pressure in SiO 2 /SDS foam flooding was 1.9 MPa, much higher than that in SDS foam flooding. The SiO 2 /SDS foam had better diversion property and resistance to water flushing than SDS foam. In the oil displacement experiments, SiO 2 /SDS foam could reduce the residual oil saturation noticeably. The enhanced oil recovery and the final oil recovery could reach to 41.2% and 75.7%, respectively. It was deduced that the enhanced foam stability and dilational viscoelasticity were the main reasons for the effective performance in porous media. magnitude greater than that of either gas or liquid, so the foam fluids can inhibit viscous fingering and thus increase the oil recovery. Especially in heterogeneous formation, which contains layers of different permeabilities, foam can block the high-permeability layer first, and then divert subsequent fluid into the low-permeability layer.Bubble is unstable thermodynamically in nature, especially in porous media under formation condition. Thus, how to increase foam stability is the prerequisite for better application in oil field. Foam stabilized by nanoparticles has attracted special attentions recently in food-making process, 14 flotation, 15 and water borne coatings. 16 Like surfactant molecules, nanoparticles with proper surface amphiphilicity could adsorb at air/liquid interface and enhance the foam stability. The adsorption of nanoparticles is usually irreversible and its adsorption energy determines the foam stability. 17 Furthermore, the adsorbed nanoparticles at air/water interface resist the water flow on liquid film and separate the dispersed phase, and thus slow down the liquid film thinning and bubble shrinkage. [18][19][20][21] Previous studies indicated that the dilational viscoelasticity of particle-coated bubble surface was another key parameter of foam stabilization. 22 The dilational property is usually used to characterize the physical process in the dispersion surface layer and provides useful information about the adsorption of nanoparticles at the air/water interface. The enhanced viscoelasticity gave the resistance ability of bubble film to dilationa...

Study on three phase foam for Enhanced Oil Recovery in extra-low permeability reservoirs

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Experimental investigation on foam formation through deformable porous media

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Enhanced stability and high temperature-tolerance of CO2 foam based on a long-chain viscoelastic surfactant for CO2 foam flooding

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