Experimental investigation of acoustically enhanced colloid transport in water-saturated packed columns

Changes in permeability caused by transient stresses: Field observations, experiments, and mechanisms

“…Much of this work has focused on using ultrasonic stimulation to reduce particle clogging near well bores [e.g., Poesio et al , 2004], but ultrasonic stimulation has limited relevance to earthquakes because such high‐frequency waves are rapidly attenuated in natural porous media. Experiments with lower‐frequency stimulation, from 26 to 150 Hz, have shown (1) enhanced transport of polystyrene microspheres through glass beads [ Thomas and Chrysikopoulos , 2007], (2) mobilization of fines from Fontainebleau sandstone [ Roberts and Abdel‐Fattah , 2009], and (3) mobilization of polystyrene microspheres previously deposited on glass beads [ Beckham et al , 2010]. Permeability changes were not observed during mobilization of fines from sandstone, but were indicated by transient pressure drops during mobilization of microspheres from glass beads.…”

Colloid particle size‐dependent dispersivity

“…The breakthrough data were fitted with the nonlinear least squares regression program ColloidFit, which employs the analytical colloid transport model derived by Sim and Chrysikopoulos [1995] and extended by Thomas and Chrysikopoulos [2007]. The model accounts for colloid transport in one-dimensional, homogeneous, water-saturated porous media with first-order attachment (or filtration) and inactivation.…”

“…Condition (9) establishes that there is no initial colloid concentration within the one-dimensional porous medium. The third or flux-type boundary condition (10) describes the influent flux, as an ''instantaneous'' pulse concentration [Thomas and Chrysikopoulos, 2007]. The downstream boundary condition (11) preserves concentration continuity for a semiinfinite system [Chrysikopoulos et al, 1990].…”

“…The analytical solution to equations (6) and (8) subject to conditions (9)- (11) has been derived by Thomas and Chrysikopoulos [2007]:…”

Maximization of wave motion within a hydrocarbon reservoir for wave-based enhanced oil recovery

“…However, since waves at such high frequencies attenuate rapidly with distance, techniques relying on ultrasound waves are not viable for mobilizing oil droplets at the reservoir scale (Roberts and Abdel-Fattah (2009);Roberts et al (2001)). On the other hand, a number of laboratory tests have demonstrated dislodging of oil droplets by using elastic or acoustic wave sources at low frequency ranges: Beckham et al (2010), Roberts and Abdel-Fattah (2009), and Roberts et al (2001 showed that dynamic stress, exerted on a solid rock matrix of a sandstone core at low frequencies (10Hz -100Hz), can release trapped oil droplets; Vogler and Chrysikopoulos (2004), Thomas and Chrysikopoulos (2007) also showed that acoustic waves of frequencies up to 300Hz can remove the non-aqueous phase liquid (NAPL) from porous permeable core samples; Spanos et al (2003) conducted experiments demonstrating that fluid-pressure pulsing at frequencies ranging from 30Hz to 60Hz can increase the oil recovery rate from confined sand packs;…”