Multiphase flow in subsurface formations is ubiquitous in both oil production and CO2 storage. The non-linear nature of the flow leads to complex fluid displacement mechanisms that operate across various scales, from pore-level to Darcy scale. Accurate flow models, necessary in the design and optimization of injection processes, require detailed description of pore scale multiphase flow. Traditionally, flow behavior at different temperature and pressure conditions is evaluated on laboratory-scale experiments using core-flooding systems, PVT cells and other equipment. The experiments are expensive, require long measurement times and large volumes of fluids. In this context, microfluidics emerges as a valuable technique. Improvement on the fabrication of microfluidic devices and flow control have led to growth in the use of microfluidics to gain fundamental understanding of pore-scale multiphase flow, enabling the correlation between pore scale events and macroscopic flow characteristics, and phase behavior. Recent developments allow microfluidic experiments to be run at high pressure and high temperature conditions, allowing the determination of minimum miscibility pressure between CO2 and crude oil in approximately 30 minutes and using only 0.1 mL of oil sample for each data point. 

Here, we report various multiphase flow analyses using porous media microfluidic devices to examine oil displacement by water, emulsions, and foam, as well as CO2 storage in saline aquifers. By visualizing pore-scale phenomena, we can correlate these events with macroscopic flow characteristics, which may be leveraged to optimize subsurface processes.