No abstract

Nanoparticles have been used in conventional enhanced oil recovery to improve the oil recovery efficiency. In this review, we analyzed the roles of nanoparticles in improving enhanced oil recovery. We focused on elucidating the fundamental mechanisms that regulate nanoparticle-induced enhanced oil recovery, including surface wettability alteration, interfacial tension reduction, mobility ratio increase, emulsion stabilization, and foam stabilization. We also discussed factors that control the success of nanoparticle-induced enhanced recovery. Finally, we outlined the current challenges and future research directions with respect to the applications of nanoparticles in enhanced oil recovery.

This study investigates the effect on varying flow rates and bubble sizes on gas–liquid flow through porous media in a horizontal microchannel. A simple bubble generation system was set up to generate bubbles with controllable sizes and frequencies, which directly flowed into microfluidic channels packed with different sizes of glass beads. Bubble flow was visualized using a high-speed camera and analyzed to obtain the change in liquid holdup. Pressure data were measured for estimation of hydraulic conductivity. The bubble displacement pattern in the porous media was viscous fingering based on capillary numbers and visual observation. Larger bubbles resulted in lower normalized frequency of the bubble breakthrough by 20 to 60 percent. Increasing the flow rate increased the change in apparent liquid holdup during bubble breakthrough. Larger bubbles and lower flow rate reduced the relative permeability of each channel by 50 to 57 percent and 30 to 64 percent, respectively.