Imaging micro-scale multiphase flow in 3D-printed porous micromodels

In this work, we utilize an additive micro-fabrication 3D printing approach to fabricate physical micromodels (microfluidic devices) of porous reservoir rock based on their micro-CT images. The unique feature of micro-3D printing enables rapid prototyping to mimic complicated heterogeneous micro/nano-structures of rock core plugs. Moreover, surface wettability of the fabricated micromodels can be controlled by changing the combination of printing polymers. Owing to the optical transparency of micromodels, transient liquid propagation processes are captured by using a high-speed laser confocal microscopy. Three fluid pairs (oil-gas, water-gas, water-oil) are used for micromodel flooding experiments. Our results show liquid propagates differently under various surface wettability conditions. This work offers a novel methodology to study micro-scale subsurface porous flow by taking advantage of state-of-the-art micro-3D printed porous micromodel. Our new physical insights contribute to enhanced oil/gas recovery and geothermal energy production as well as geological carbon sequestration.